Ecological land classification for Nova Scotia, PD Neily, E Quigley, L Benjamin, B Stewart, T Duke

Tags: Nova Scotia, ecoregion, white pine, ecodistrict, red pine, Cape Breton, red spruce, area, coastal forest, coastal forests, black spruce, Cape Breton Highlands, Annapolis Valley Ecodistrict, total area, Chedabucto Bay, classification, South Shore, Cape Breton Hills Ecodistrict, Eastern Shore Ecodistrict, Cobequid Bay, South Mountain, white spruce, Cape Breton Coastal Ecodistrict Extending, Atlantic Coastal Ecoregion, Cape Breton Highlands Ecodistrict, Cape Breton Coastal Ecodistrict, Western Barrens Ecodistrict, Inverness Lowlands Ecodistrict, Cumberland Marshes Ecodistrict, Victoria Lowlands Ecodistrict, Pictou Antigonish Highlands Ecodistrict, Ecological Land Classification, Central Lowlands Ecodistrict, Northumberland Lowlands Ecodistrict, Parrsboro Shore Ecodistrict, Minas Lowlands Ecodistrict, Cumberland Hills Ecodistrict, Valley Slope Ecodistrict, Sable Island Ecodistrict, North Mountain Ecodistrict, Chignecto Ridges Ecodistrict, Mulgrave Plateau Ecodistrict, Central Uplands Ecodistrict, Department of Natural Resources
Content: ECOLOGICAL LAND CLASSIFICATION for Nova Scotia
Revised Edition 2005 Peter D. Neily, Eugene Quigley, Lawrence Benjamin, Bruce Stewart, Tony Duke Nova Scotia Department of natural resources Renewable Resources Branch April 2005 Report DNR 2005 -
TABLE of CONTENTS
ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Mapping ELC Units
3
A Hierarchical Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
METHODOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 GIS Aggregation of the BIOSYS Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Ecozone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Ecoregions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Ecodistricts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Ecosections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Ecosites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
OTHER CLASSIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
FUTURE DEVELOPMENT of the ELC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
DESCRIPTION of the ECOLOGICAL LEVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
ACADIAN FOREST ECOZONE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 100 Cape Breton Taiga Ecoregion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 200 CAPE BRETON HIGHLANDS ECOREGION . . . . . . . . . . . . . . . . . . . 18 210 Cape Breton Highlands Ecodistrict . . . . . . . . . . . . . . . . . . . . 20 220 Victoria Lowlands Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . 21
i
300 NOVA SCOTIA UPLANDS ECOREGION . . . . . . . . . . . . . . . . . . . . . . 22 310 Cape Breton Hills Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 23 320 Inverness Lowlands Ecodistrict . . . . . . . . . . . . . . . . . . . . . . 24 330 Pictou Antigonish Highlands Ecodistrict . . . . . . . . . . . . . . . 25 340 Cobequid Hills Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . 26 350 Cobequid Slopes Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 27 360 Mulgrave Plateau Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 28 370 St. Mary's River Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 29 380 Central Uplands Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 29 400 EASTERN ECOREGION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 410 Rawdon/Wittenburg Hills Ecodistrict . . . . . . . . . . . . . . . . . . 31 420 Eastern Drumlins Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 32 430 Eastern Granite Uplands Ecodistrict . . . . . . . . . . . . . . . . . . . 33 440 Eastern Interior Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . 33 450 Governor Lake Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . 34 500 NORTHUMBERLAND BRAS D'OR LOWLANDS ECOREGION . . . 35 510 Bras d'Or Lowlands Ecodistrict . . . . . . . . . . . . . . . . . . . . . . 37 520 St. George's Bay Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 38 530 Northumberland Lowlands Ecodistrict . . . . . . . . . . . . . . . . . 39 540 Cumberland Hills Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 40 550 Cumberland Marshes Ecodistrict . . . . . . . . . . . . . . . . . . . . . 41 560 Chignecto Ridges Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 42 600 VALLEY & CENTRAL LOWLANDS . . . . . . . . . . . . . . . . . . . . . . . . . . 43 610 Annapolis Valley Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 44 620 Minas Lowlands Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 45 630 Central Lowlands Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 46 700 WESTERN ECOREGION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 710 Valley Slope Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 720 South Mountain Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 50 730 Clare Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 740 LaHave Drumlins Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . 52 750 Rossignol Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 760 Sable Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 770 Western Barrens Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 55 780 St. Margaret's Bay Ecodistrict. . . . . . . . . . . . . . . . . . . . . . . 56 800 ATLANTIC COASTAL ECOREGION . . . . . . . . . . . . . . . . . . . . . . . . . 57 810 Cape Breton Coastal Ecodistrict . . . . . . . . . . . . . . . . . . . . . . 59 820 Eastern Shore Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 ii
830 South Shore Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 840 Tusket Islands Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 850 Sable Island Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 900 FUNDY SHORE ECOREGION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 910 Parrsboro Shore Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 64 920 North Mountain Ecodistrict . . . . . . . . . . . . . . . . . . . . . . . . . 66 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 WEB SITES OF INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 APPENDIX I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 iii
ACKNOWLEDGEMENTS The development and guidance for this classification has been provided by the Ecological Technical Committee of the Renewable Resources Branch of the Nova Scotia Department of natural resources and has included the following individuals: Lawrence Benjamin, Dr. Sherman Boates, Tony Duke, John Leduc, Art Lynds, David MacKinnon, Peter MacQuarrie, Nancy McInnis-Leek, Peter Neily, Eugene Quigley, and Bruce Stewart. The following organizations and individuals gave assistance in numerous ways: Bevan Locke, Stora Enso; Peter Jones, Bowater Mersey; and Steve Rutledge, Kimberly-Clark. Many thanks to Susan Mader-Zinck, N.S.D.N.R. for proof-reading the document. Continuing thanks to Richard Morash and the G.I.S. staff of the Department of Natural Resources in Truro for all their help in digitizing databases, preparation of digital data and mapping products. Many thanks to Wayne Burt, Supervisor Graphic Services for the preparation of the hard copy map, DNR Map 2000-1 and congratulations on his Best in Show Award for this map at a recent national gathering of cartographers. Our appreciation and thanks to Jeff Poole, Geologist, DNR Halifax, for his assistance in preparing and designing the web site for the maps and database. Special thanks to Penny Chapman and Sandy Anderson, DNR Truro for their hard work in getting these products to the Department's web site. Users of this classification are encouraged to reference the following as they have been extremely helpful in the development of this classification: Ecoregions and Ecodistricts of Nova Scotia. Environment Canada. 1999. K.T.Webb and I.B.Marshall The Natural History of Nova Scotia - Theme Regions. 1996. Nova Scotia Museum. D.S.Davis and S.Browne Finally, appreciation is expressed for the contributions made by staff of the Nova Scotia Department of Natural Resources and in particular the following: Doug Archibald, Biologist; Dan Banks, Biologist; Alonza Fahey, Forest Technician; Greg Fraser, Forester; John Gillis, Forester; Andrew Hanam, Forester; Ian Lawyer, Geologist; Eric Leighton, Forest Technician; Dan MacLean, Forest Technician; Don MacNeil, Geologist; Robert Muise, Forester; Mark Pulsifer, Biologist; David Stoddard, Forester, as well as all those who have been supportive of this project over the past several years. The authors acknowledge the significant contributions of Dr. R. E. (Ed) Bailey and staff of the Forest Capability Section of the N. S. Department of Lands and Forests who developed the 1
provincial Biophysical Land Classification in the late 1970's. This work provided the backbone for the Ecological Land Classification. 2
INTRODUCTION When land is classified from an ecological perspective areas of similar ecology are identified and mapped in an ecological land classification (ELC). Within the classification the ecological information is presented in a hierarchy of ecosystems where broad to specific levels of detail are presented on a series of maps. In this framework the ELC provides a description of the physical and biological environment affecting the ecological structures and processes and the biodiversity of ecosystems. As one of the major tools required for planning and managing sustainable forests an ELC provides a common language for discussions concerning biodiversity, forest ecosystems and resource management. Within an ELC an appropriate level of ecosystem information and representation can be selected to use in the planning and managing for the various elements of biodiversity such as individual species, habitats, ecosystem structures, age class, species associations or genetics. As a signatory to the National Forest Strategy (1998) and the Canadian Biodivesity Strategy (1995) Nova Scotia has recognized the importance of an ELC for forest ecosystem management. The ecological information in an ELC concerning the structures and functions and distribution of forest ecosystems will assist forest planners and managers of all Land Tenures in Nova Scotia. The following text will provide the methodology for mapping Nova Scotia's ecological land classification. A description of the various units is also provided. Volume 2 (in progress) will provide an interpretation for the natural disturbance regimes within an ELC and Volume 3 (in progress) will examine the potential climax forests for each of the levels of the ELC. Mapping ELC Units Matson and Power (1996) state that there is more to an ELC than just the identification and mapping of ecosystems since it provides an understanding of ecosystem form and function by linking abiotic and biotic components of each system. Ecosystems within the ELC must be more than a concept to be useful, they must be delineated on the landscape and described in order to manage ecologically. In Ontario, Hills (1959) recognized the effects of interactions of climate, landform and soils on the distribution of vegetation and divided the province into broad macroclimatic regions within which distinct physiographic areas were delineated. Webb and Marshall (1999) suggest that the fundamental basis for delineation of ecological units is to capture the major ecological composition and the linkages between the various components (e.g., landforms, soils, water, and vegetation) rather than treating each component as a separate characteristic of the landscape. The key elements in the application of ecological land classification in delineating map units are as follows (Wiken and Gauthier 1996; Commission for Environmental Cooperation 1997): S an ELC incorporates all the major components of ecosystems: air, water, land and biota. S the ELC is holistic since "the whole is greater than the sum of its parts". S the number and relative importance of factors helpful in delineating ecological units vary from one area to another, regardless of the level of generalization. 3
S the ELC is based on a hierarchy, with ecosystems nested within ecosystems. S an ELC involves integration of knowledge and is not simply an overlay. S an ELC recognizes that ecosystems are interactive and that characteristics of one ecosystem blend with those of another. S map lines in an ELC generally depict the location of zones of transition. Even though ELC is science based there is a need to recognize that some interpretation is required in order to reduce the complexity of ecosystems and to make map units workable and understandable. Ecosystems are best described based on enduring components that will not change significantly over time, such as geology, surficial materials, landform and topography. The differentiating criteria of ecosystems at each level of generalization may vary since not all components may be equally significant throughout the classification. Therefore, the spatial expression will be determined by the dominant component of the ecosystem which may vary from one ecological unit to the next, as well as their relationships and processes. Ecosystem boundaries on a map represent a consistent or significant degree of change when compared to adjacent units. Since multiple factors contribute to the placement of boundaries on an ecological map it is important to be able to understand how these will ultimately influence biodiversity when the physical or biological components of an ecosystem are changed. Climate can be used to separate ecodistricts on Cape Breton Island and most notably along the Atlantic coastline as reflected by changes in vegetation. Other parts of Nova Scotia will notice changes in vegetation due to changes in landform/topography such as the drumlinized till plain of the Lunenburg Drumlins ecodistrict and the adjacent gently undulating topography of the Rossignol ecodistrict. A Hierarchical Classification Nova Scotia's ELC provides a systematic methodology for explaining the distribution and composition of the terrestrial landscapes. By nesting the ecosystems within a hierarchy and providing a linkage between those the size of forest stands to those the size of climate regions, an effective mechanism is now available that permits the choice of detail that suits management objectives and use. Nova Scotia's Ecological Land Classification (ELC) is comprised of five levels (Table 1) and uses abiotic (physical) and biotic (biological) environmental attributes to define ecosystems. The ecological units are on a series of maps (NSDNR, 2001a ) with further detail available in the accompanying text of this document. Digital data as Arc/Info Coverages and Arc/Info Export E00 files is also available (NSDNR, 2001b). Maps and text can also be viewed on the Department of Natural Resources website (http://www.gov.ns.ca/natr/). 4
Table 1. Hierarchical levels of the Nova Scotia Ecological Land Classification
Ecological Unit
Map Scale
# of Units
Criteria for Delineating Unit
Ecozone
1:1,000,0 1 global or continental climate as reflected by
00
vegetation
Ecoregion
1:500,000 9 provincial climate as expressed through soils and vegetation
Ecodistrict
1:250,000 40 subdivisions of ecoregions characterized by distinctive assemblages of relief, geology, landform, soils and vegetation
Ecosection
1:50,000
6371 a repeating pattern of landform/topography, soils and vegetation throughout an ecodistrict. A maximum of 63 combinations of the physical attributes are possible.
Ecosite
1:10,000 n.a. a uniformity of parent material, soils, vegetation
and hydrology as expressed by slope, position on
slope, aspect and exposure
1 Approximate since not all ecosections are found in every ecodistrict. Assumes that a level of
uniqueness exists between similar ecosections in different ecodistricts.
n.a. - not available
METHODOLOGY There are many data sources available for Nova Scotia which describe the various criteria required for delineating ecosystems within a hierarchical classification (Table 2). The Department of Natural Resources (formerly Department of Lands and Forests) completed a hierarchical biophysical land classification in 1986. The physical attributes of the smallest units, land systems, were delineated on 1:63,560 infrared aerial photographs and transferred to maps at a scale of 1:50,000. The land system polygons were digitized and their attributes (Appendix 1) coded within the Department's geographic information system (GIS). This digital data became known as the BIOSYS layer within the GIS. An evaluation of the 10 mapped physical attributes (Table 3) determined that forest ecosystems and their associated biodiversity could accurately be reflected by using soil texture, soil drainage, landform and topographic pattern (relief was also used to define boundaries). Further analysis and field checking revealed that the complexity of the biophysical land system could be reduced by aggregating similar polygons (Appendix 1). By using these enduring features as a building block for a hierarchical classification of ecosystems, mapping can progress to delineate the various levels of ecosystems within an ELC. As a nested hierarchy the boundaries of each polygon/ecosystem are constrained by the level of the ELC immediately above.
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Classification and mapping of an ELC is hierarchical because climate (ecoregion) exerts an influence on the forest composition that cannot be explained by the lower levels (Matson and Power 1996). For example, along the Atlantic coast of Nova Scotia forest communities developing on similar geology/landforms and soils that are found inland will be different due to the influence of the coastal climate. Thus by separating the climatic influence at an upper level of the ELC the differences in forest composition within an ecoregion or ecodistrict can be explained by knowing that their compositional differences are controlled by landform and soil fertility/moisture relationships and not climate.
Table 2.
Sources of information used to delineate Nova Scotia's Ecological Land Classification.
Ecological Unit
Sources of Information Used to Delineate Units
Ecozone
Forest Regions of Canada (Rowe 1972) National Ecological Framework for Canada (Ecological Stratification Working Group 1996)
Ecoregion
Climatic Regions of Nova Scotia (Nova Scotia 1986) Canadian Climate Normals 1961-90 (Environment Canada 1997) The Climate for Agriculture in Canada (Dzikowski 1985)
Ecodistrict
3-D Radarsat-1 Mosaic (COGS 1999) photography National Topographic Series 1:50,000 contour mapping Surficial and bedrock geology mapping of Nova Scotia. Forest classification (Loucks 1962)
Ecosection
Biophysical Land Classification for Nova Scotia Forestry Cover Type Mapping Provincial Soils Mapping 1:63,560 infrared aerial photographs (1975,1976) 1:10,000 true colour aerial photographs (1988 +)
GIS Aggregation of the BIOSYS Layer An algorithm was designed to group similar land system polygons within the BIOSYS layer. Maps were produced at a scale of 1:50,000 which showed the results of the aggregation and which now represent a potential boundary for the ecosections level of the ELC. Each of the ecosections were assigned unique colours and a four digit code to describe the soil drainage, soil texture and topographic/landform pattern. Every map sheet was reviewed for the following: - a systematic search for errors or inconsistency in the assignment of biophysical attributes (required spot re-interpretation of the 1:63,560 aerial infrared photography; re-examination of soil mapping, surficial and bedrock geology mapping) - transfer errors during digitizing of the land systems from the 1:50,000 maps to the GIS
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- evaluation of small and/or unique ecosections from the aggregation routine (often required field checking)
Table 3.
Biophysical attributes delineated in Nova Scotia's Biophysical Land Classification
Biophysical Attribute Number of Classes
Description
Topographic pattern
10*
the physical features of an area such as
land shape and relief
Slope class
5
percent slope of the land
Relief class
5*
the difference between extreme
elevations within a given area
Landform
23
various shapes of the land resulting
from a variety of geological processes
Soil drainage class
3**
describes the removal of excess soil
water
Soil texture class
7
describes the relative proportion of
sand, silt, clay and coarser materials in a
mineral soil
Stoniness code
6
surficial stoniness and the degree of
interference to mechanical equipment
Parent rock type
17
the rock from which the parent materials
of soils are formed
Bedrock exposure
%
proportion of area with bedrock exposed
or within 15-25 cm of the surface
C
Complex types of up to two could be described.
** Percentages were determined for each of the three drainage classes for each land system
Areas with similar biophysical attributes as coded within the GIS BIOSYS layer were combined if the differences were considered to have an insignificant impact on biodiversity at the ecosection level of mapping. The three attributes used from the BIOSYS land system layer were soil texture, soil drainage and topographic pattern.
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Soil Drainage Soil drainage is described for each land system polygon as a percentage of the well drained, imperfectly drained and poorly drained soils. For the purpose of delineating ecosections the following was used:
ELC Code W P I
Description
Definition
Well drained soils
Land Systems comprised of soils >60% well drained
Poorly drained soils
Land Systems comprised of soils >60% poorly drained
Imperfectly drained soils Land Systems not well or poorly drained.
Soil Texture There are seven land system attributes for soil texture. For the purpose of delineating ecosections the following was used:
ELC Code C M F
Description
Definition
Coarse textured soils
gravel, coarse sand, sand, loamy sand and coarse sandy loam (note: soils with a high content of gravel were also included in this category)
Medium textured soils sandy loam, fine sandy loam, very fine sandy loam, loam
Fine textured soils
silt, sandy clay loam, clay loam, sandy clay, silty clay, clay
8
Topographic Pattern There are eight land system attributes for topographic pattern. These attributes can occur singularly or paired within a land system complex.
ELC Code
Description
SM
Smooth or Flat (Level)
e.g. floodplain, lake plain, deltas,
intervales, and open bogs and
wetlands
HO
Hummocky
KK
Hills
DM
Drumlinoid
R
Ridges
DS
Canyons and Steep Slopes
WTLD Wetlands
DKLD Dykelands
Definition land with no particular pattern, flat or very gently sloping, uni-directional surface with a generally constant slope not broken by marked elevations and depressions. Slopes are generally less than 1%. a series of small rounded hills with a gentle slope usually never exceeding 15% a series of knobs and knolls with moderate to steep slopes between 530%. Relief amplitude ranges from 15 60 m. a pattern of elongated landforms caused by glacial ice movement (drumlins and flutes) often occurring in clusters a pattern of linear or curvilinear ridges Sharply sloped terrain along rivers/streams or associated with hilly topography. Slopes usually between 20 80 %. smooth or flat topography associated with inland bogs, swamps and marshes and most often underlain by organic soils. smooth or flat topography associated with tidal zones along rivers flowing into the Bay of Fundy and along the Northumberland Strait. The construction of dykes prevents the daily saturation with sea waters. They are almost entirely underlain by marine sediments. 9
RESULTS The classification has five hierarchical levels whose cartographic boundaries fit together perfectly. Each level is defined by a set of ecological factors. The number and precision of these increase from the continental scale to the local scale. The following text describes each level of the ELC. The ecoregions and ecodistricts are illustrated in Figure 1 http://gis1.gov.ns.ca/website/nselcmap . The maps were produced from different sources of data available systematically for the entire area. It results from the spatial integration of climatic data, ecological land classification results and synthetic mapping units of Physical Environment features. The requirement to identify meaningful units that fulfill an opportunity for management necessitated that some ecological uniqueness may be compromised for logistical reasons. Nonetheless, a hierarchical system still allows for this uniqueness to be identified and acted upon accordingly as part of any management strategy for ecological resources. Ecozone Ecosystems at this scale are usually described on a global/continental scale. In Canada it is representative of large and very generalized ecological units characterized by interactive and adjusting abiotic and biotic factors. Basically they are the broad mosaics formed by the interaction of macroclimate, human activity, vegetation, soils, geological and physiographic features of the country (Ecological Stratification Working Group, 1996). Usually the forest vegetation is a reflection of the macroclimatic elements such as solar radiation and heat totals. In Nova Scotia, the Acadian Forest, as described by Rowe (1972) is " a major geographic belt or zone, characterized vegetationally by a broad uniformity both in physiognomy and in the composition of the dominant tree species". This unit has been adopted as the Acadian Ecozone, and is the only ecozone within the province. It is called the Atlantic Maritime ecozone by the Ecological Stratification Working Group (1996). Ecoregions Ecoregions are subdivisions of the larger Acadian ecozone and express macroclimate as a distinctive ecological response to climate through soils and vegetation. Rowe (1972) defines ecoregions as representations of broad provincial climatic patterns as expressed by the macrofeatures of vegetation: the distribution and range of conspicuous tree species, their life-forms (broadleaved or needle-leaved), the physiognomy and relative areal extent of the communities in which they are associated, and the patterning of the total vegetation. In Nova Scotia climate is often conferred as a result of the proximity to the cool salt waters along the coast or by elevation. Therefore, at this scale, boundaries drawn on the basis of these criteria are often coincident with the major physiographic features and ecoregions can be delineated around topography that has distinct differences in climate and/or proximity to the ocean. Regardless, the delineation of climatic zones in the province is rendered difficult and the boundaries are fuzzy due to the often mixing effects of 10
coastal proximity and elevation. Climatic factors that affect the variety of biodiversity on terrestrial ecosystems also includes some elements of weather data that are not always used when determining the typical climatic zone. Minimum winter temperatures and snowfall are two factors that were considered in the determination of ecoregional boundaries in Nova Scotia. Soil, water and fauna also mirror the interaction of climate and vegetation at this scale. Vegetation patterns are strongly correlated with these climatic influences and the terrestrial ecosystems of each region display distinctive characteristics. Nine ecoregions have been mapped for Nova Scotia (Figure 1) http://gis1.gov.ns.ca/website/nselcmap ranging in size from 444 km2 to 16,870 km2. Ecodistricts Ecodistricts are subdivisions of the ecoregions and reflect macroelements of the physical and biological attributes of the ecosystems which will ultimately influence biodiversity. Ecodistricts are major landforms within an ecoregion with geology and soils distinct from adjacent ecodistricts. Matson and Power (1996) state that ecodistricts indicate the principal regulators of meso-scale climate influences and the supply of soil nutrients (and moisture) which together influences all terrestrial and aquatic ecosystems. These elements of the ecodistricts include microclimate, physiography, geology, geomorphology, soils and moisture. One dominant element can usually be selected as the defining characteristic and is reflected in the biodiversity of the ecodistrict. In Nova Scotia physiographical features resulting from geological history can be used to separate the uplands and lowlands. Due to the diversity of landform caused by glacial activity many of the province's ecodistricts can also be identified by landforms and surficial geology. Variation at an ecodistrict level will also be recognized along the coastal areas of Nova Scotia due to the influence of warmer and colder off-shore currents. Other districts can be distinguished based on the underlying effects of bedrock geology as expressed through soil lithology. Within ecodistricts there will be a variability of biodiversity expressed due to the complexity of the interactions between the physical and biological attributes of the ecodistrict. This often confuses the mapping effort at this scale but if a strict application of the delineating criteria is maintained a meaningful and manageable unit can be described. The benefits of a hierarchical classification can be utilized at this level as this detail and complexity can be mapped at lower levels of the ELC. Nonetheless, as more data is collected and analyzed boundaries of any ecological unit can be adjusted to reflect and capture the complexity. Forty ecodistricts have been mapped for Nova Scotia (Figure 1) http://gis1.gov.ns.ca/website/nselcmap ranging in size from 31 km2 to 4,451 km2. Climatic data for the ecodistricts is presented in Appendix I. 11
Ecosections These are the smallest mapped units of this current version of the ELC and are repetitive subdivisions of the ecodistrict. As the building block for the ELC this unit describes the enduring physical features - topographic pattern, soil texture and soil drainage. At this level biological processes such as climax forest association and natural disturbance regime can be determined. Together the physical and biological attributes of the ecosection determine the ecological processes and structures affecting biodiversity. Each ecodistrict will have several dominant ecosections repeating across the landscape which may be unique to that ecodistrict. Ecodistricts within the same ecoregion are more than likely to share ecosections with perhaps no noticeable physiognomic differences. However, floristic variability and contrasting response to management inputs can be expected. Significant differences in both physiognomic and floristic components as well as response to management inputs will be expected between ecosections of different ecoregions. Ecosections have a natural disturbance regime that maintains or rejuvenates the forest ecosystem. The frequency of these natural disturbances is a function of the forest species that occur in the ecosection. Forest ecosystems unaffected by human disturbances such as tree harvesting or protection from fire and insect damage can be expected to reach a climax or steady state at which time the natural disturbance can be expected to occur as conditions (climatic or biological) dictate. Wetland ecosystems are classified as poorly drained ecosections of smooth topography, i.e. PCSM, PMSM and PFSM. In this classification these wetlands include areas which are forested and nonforested. A further classification of wetlands has been undertaken to describe such features regarding water and nutrient source, vegetation, etc. ( NSDNR 2000).
Ecosites
As a subdivision of an ecosection, ecosites describe a suite of site conditions including
elevation, slope, slope position, aspect, soil drainage and soil texture that can be used to predict
forest communities, their species, successional development and productivity. These units are
usually mapped at a scale of 1:10,000 to 1:50,000 but in Nova Scotia will most likely be at the finer
scale in order to be compatible with currently used inventories such as the forest cover layer in the
provincial GIS. Management applications for ecosites will include forest/landscape level planning,
forest ecosystem management prescriptions (including habitat supply modeling), silviculture
prescriptions and estimating wood supply.
Ma pping of ecosites scheduled for 2006.
12
OTHER CLASSIFICATIONS There have been several other classifications for Nova Scotia which have prepared maps and documentation describing various components of the province's natural ecology. These classifications include: - Natural History of Nova Scotia Theme Regions, Volume 2 (Davis and Browne, 1996) - Natural Landscapes of Nova Scotia (NSDNR, 1997) - Biophysical Land Classification for Nova Scotia (NSDLF, 1986) - A Forest Classification for the Maritime Provinces (Loucks, 1962) - National Ecological Framework for Canada (Ecological Stratification Working Group, 1996) - Ecoregions and Ecodistricts of Nova Scotia (Webb and Marshall, 1999) Each of the above classifications have been used extensively for the purposes that they were designed. Not surprisingly the classifications have many similarities to the ELC for Nova Scotia. The strong influence of the maritime climate on soils and vegetation and the diversity of the province's geology has created an environment that is complex yet consistent and thus can be mapped with a fair degree of accuracy. The use of the above classifications has been of great assistance in the preparation of this classification and report.
FUTURE DEVELOPMENT OF THE ELC Resource managers have had an interest in land classification for at least a hundred years. This particular ELC is a result of the need to describe Nova Scotia's terrestrial ecosystems within a classification that will enable the management and conservation of a wide range of values. Any ELC should never be considered to be a finished product. As Loucks (1962) stated - maps and descriptions are only as good as the knowledge available at the time of writing (preparation). As more information accumulates, revision is to be expected. The improvement of the ecoregional boundaries, particularly along the coastal areas will be one such example of potential revision. The influence of such a strong, climate inducing feature as the Atlantic Ocean adds to the complexities of vegetation classification and will be a source of on-going Research and Development.
Barrens
DEFINITIONS Land devoid of trees or having only very stunted trees. Typical of extreme climatic conditions due to moisture or wind. In Nova Scotia these areas include lands subjected to repeated wildfires which have depleted soil constituents such as organic matter and created heath like vegetation communities which have contributed to the formation of hardpans within the soil profile.
13
Drumlin
A smooth, elongated hill created by flowing glacial ice. They often occur in clusters and have a parallel arrangement. In Nova Scotia, most drumlins are 15m to 50 m high and 800 m to 1,200 m long with a length to width ratio of 2 to 1 and a slope of 5-40%.
Dykelands Lands where the daily influence of tidal waters has been removed by the construction of dykes on tidal rivers and marshes.
Flute
A low relief moraine with linear furrows and ridges parallel to the direction of glacier flow. Most flutes in Nova Scotia have a slope of 15% or less.
Hummocks A series of small rounded hills with a height less than 1.5 times their base and a relief amplitude up to 15 m.
Intervales The smooth to level land located along streams and rivers comprised of alluvial soils.
Knobs
A series of small rounded hills with a height greater than1.5 times their base and a relief amplitude up to 45 m.
Knolls
A series of hills with a height less than 1.5 times their base and a relief amplitude ranging from 15 to 60 m.
Kettles
A series of steep sided conical depressions (donut-like appearance) associated with glacial fluvial deposits. Ranging in depth from 5-20 m.
Marshlands Lands that are or have been inundated with tidal waters.
Sink Holes A series of depressions most often steep sided, flat bottomed and associated with lowland areas underlain by gypsum and/or limestone.
Soil Drainage Poorly Drained - water is removed so slowly in relation to the supply that the soil remains wet for a comparatively large part of the time the soil is not frozen (includes CANSIS (1982) categories poorly and very poorly).
Imperfectly Drained - water is removed from the soil slowly enough in relation to the supply to keep the soil wet for a significant part of the growing season (includes
CANSIS (1982) categories moderately well and imperfectly).
Well Drained - water is removed from the soil readily but not rapidly (includes CANSIS (1982) categories very rapidly, rapidly and well).
14
Soil Texture The relative proportions (in per cent) by size of sand, silt and clay particles in a soil. It is normally assessed in the field by touch or in the laboratory by the use of sieves and with reference to the standard soil texture chart.
Wetlands
Land that is saturated with water long enough to promote hydric (characterized by considerable moisture) soils or aquatic processes as indicated by poorly drained soils, hydrophytic (water tolerant) vegetation, and various kinds of biological activity that are adapted to wet environments.
15
DESCRIPTIONS OF THE ECOLOGICAL LEVELS Acadian Forest Ecozone All of Nova Scotia is within the Acadian Forest (eco) Region as described by Rowe (1972). The region includes Prince Edward Island and much of New Brunswick and Maine. A Government of Canada ecological framework (Ecological Stratification Working Group, 1995) described a similar ecozone, including Quebec's Gaspe Peninsula and eastern townships, as the Atlantic Maritime Ecozone. Nova Scotia's climate has been described as robust winters, reluctant springs, fresh summers and lingering falls (Environment Canada, 2002). Two main factors govern the province's climate. The first is the position of the province, halfway between the equator and the north pole, which produces a temperate climate. The second is the maritime (sea coast) location which results in high humidity. Almost completely surrounded by the cold salt waters of the Atlantic Ocean, the Bay of Fundy and the Gulf of St. Lawrence, Nova Scotia's climate is strongly affected by the seas. However, being on the east coast of the continent in a zone where the prevailing winds are from the west, gives Nova Scotia a modified continental climate, which is characterized by a wide temperature range. The modifying influence of the ocean reduces this range somewhat, resulting in cooler summers and milder winters than the interior of the continent. The Acadian Ecozone in Nova Scotia has a mixed-forest species composition consisting predominately of conifers, especially on sites where drainage is impeded. The major conifers include red, white, and black spruce; balsam fir; eastern white and red pine; and eastern hemlock. Common hardwoods include red and sugar maple; white and yellow birch; trembling and largetooth aspen; and beech. Stand-replacing fires are less frequent in the Acadian Ecozone than in other boreal and temperate forests (Wein and Moore 1979). Common, natural disturbances caused by insect epidemics and wind storms often result in sporadic and partial stand mortality. These disturbances may occur only once during the life span of the relatively short-lived balsam fir, but several times during the life of spruce, hemlock and pine. Natural regeneration following a disturbance is usually prolific on most sites due to more than ample precipitation, abundant seed crops of the early successional species such as white birch, red maple and aspen, and the shade tolerance of balsam fir and red spruce. The late successional softwood forests are dominated by red spruce, hemlock and white pine. Yellow birch, beech and sugar maple dominate the hardwood climax associations. White spruce, which is a minor component of the natural forest, forms pure stands on abandoned farmland in most of the ecozone. White pine occurs in pure stands on old fields located on drumlins, primarily in western Nova Scotia. 16
100 - Cape Breton Taiga Ecoregion The Cape Breton Taiga Ecoregion is located atop the highlands plateau, with most of the region contained within the boundaries of the Cape Breton Highlands National Park. It also includes the disjunct area known as Jim Campbells Barren southeast of Cheticamp. The terrain is gently undulating with large expanses of exposed bedrock, ombrotrophic bogs and stunted conifers. This region forms the headwaters for several major rivers in northern Cape Breton and contains the Cheticamp Reservoir, a key component in the Wreck Cove hydroelectric project. The bedrock is primarily composed of igneous and metamorphic rocks. The maximum elevation is 532 m, the highest point in Nova Scotia, while much of the region exceeds 425 m. The total area of this ecoregion is 445 km2 or 1 % of the province. The climate of the Taiga Ecoregion is one of the coldest and wettest in Nova Scotia, with harsh, long winters of heavy snowfall, short growing seasons and almost constant winds. The average daily temperature is about 6o C, with an annual precipitation estimated to be 1600 mm, the largest amount in Nova Scotia. In sheltered areas, isolated patches of snow can be found in July. Typically, taiga is a transition zone between boreal forest and tundra which favors stunted conifers. The barrens of the Cape Breton Taiga are made up of areas of exposed bedrock that may be completely devoid of vegetation or may be covered in lichens predominately of the genus Cladina. Where a thin layer of mineral soil has developed on this bedrock, various mosses, and other plants, including rock polypody, bracken, and three-toothed cinquefoil will establish as well as vigorous populations of ericaceous (heath-like) vegetation such as black crowberry, alpine whortleberry, lowbush blueberry, and mountain cranberry. Stunted black spruce and balsam fir form scattered patches where soil availability permits. Wetter areas are dominated by black spruce and eastern larch, whereas upper slopes contain predominately balsam fir. Nichols (1918) found it common for dwarf trees, only three feet in height, to be 50 years old with some trees reaching ages of at least 150 years. These krummholz (tuckamore) associations develop into relatively closed stands, which are difficult to pass through. They are often devoid of the lichens and ericaceous plants that are common on the barrens. Instead, these plants are replaced with other herbaceous plants, including blue bead lily, goldthread and twinflower, and other mosses and liverworts typical of most coniferous forests. Alder, dwarf birch and mountain ash form buffers along streams. Sedge (Carex spp.) and Sphagnum spp. moss bogs are another common association of the Taiga Ecoregion. They occur in the form of raised bogs, flat bogs, sloping bogs, and depressions where a great variety of sphagnum species occur in association with low ericaceous plants and sedges. Although climate seems to be the defining characteristic limiting forest growth in this ecoregion, natural disturbances attributed to insects, windstorms and fire have played a role in shaping the forest ecosystems of the ecoregion . Ecologists with Parks Canada have suggested, based on GIS analysis of inventory data and field sampling, a fire origin for much of the Taiga Ecoregion. Human disturbance in the Taiga Ecoregion is fairly recent. Woodland caribou, which would have certainly used the area for summer grazing, were extirpated by hunting in the mid 1920s. In 1936, much of the area became part of the Cape Breton Highlands National Park. In the late 1970s water was diverted 17
as the area surrounding the Cheticamp Lakes was flooded to establish a hydroelectric power generating station at Wreck Cove. There is no history of logging since the stunted trees of the ecoregion are of no commercial importance.
Ecosections Area (ha)
WMKK IMKK WCHO WT LD IMRD IMHO
11163 10204 6333 4952 4677 2977
% District Cumulative %
25.1
25.1
23.0
48.1
14.3
62.4
11.1
73.5
10.5
84.0
6.7
90.7
Distinguishing Ecoregion Feature: Elevations exceeding 450 m above sea level. Stunted trees, raised bogs, barrens and extreme weather conditions.
200 - Cape Breton Highlands Ecoregion
The Cape Breton Highlands Ecoregion, which includes lowlands, steep slopes and plateau,
extends from the waters of the Cabot Strait to the mountains east of Lake Ainslie. With the exception
of the northern part of the ecoregion, which extends from sea level to the plateau, the elevation for
most of the region is between 300 and 450 m. The plateau is gently undulating, while the walls of
the escarpment are extremely steep (see insert). These steep slopes are relatively unstable, indicated
by the prominent colluvial deposits of soils and rocks at their base. Narrow bands of Windsor Group
rocks stretch from Cape Smokey south to Indian Brook at the base of the escarpment. Some of the
oldest rocks in Nova Scotia occur here, dating back to the Precambrian period. Gneiss at Blair River
has been dated at over one billion years. A dominant geological feature of this ecoregion is the Aspy
Fault, which runs 40 km south-southwest into the interior of Cape Breton Island. More minor faults
and sheers are fairly common with various orientations, commonly sub-parallel to the Aspy Fault.
The soils are generally sandy loams, with coarser sands occurring on the eastern side of the ecoregion
where the till is thinner and there is more exposed
bedrock. While the slopes are well drained with extremely high seepage potential, the plateau has
Slope Gradient (exp ressed as % )
% of Cape Breton Highlands Ecodistrict
large areas of imperfectly and poorly drained
sites. The total area of the region is 3296 km2 or
Level (0-8)
3
6.0 % of the province.
Undulating (9-15)
68
Rolling (16-30)
14
The Cape Breton Highlands, as a land
mass, are not high enough to block the movement
Steep (31-60)
14
of air masses but their elevation is sufficient to
Very Steep (61+)
1
wring additional moisture from passing weather
18
systems and to cool temperatures by 1 or 2 degrees Celsius. Although the climate of the Cape Breton Highlands Ecoegion is similar it is not quite as harsh as that of the higher elevations of the Taiga Ecoegion. Fog is common and precipitation averages 1400 - 1600 mm annually, with about 400 cm of snow. With a more rolling landscape on the plateau, the effect of the wind is lessened. While the deeply incised valleys offer some protection from the winds, they also create long shadows and reduce direct sunlight to north facing slopes.
On the plateau, the forest is boreal in appearance and the dominant tree is balsam fir followed distantly by white spruce and white birch, with black spruce occurring in the wetter areas. Tolerant hardwoods prevail on the slopes, along with scattered conifers and other hardwoods. The ecoregion is home to many rare and local plants and rare animals including lynx, Gaspe shrew, and rock vole.
The dominant natural disturbance on the plateau is the spruce budworm. The recurring nature
of infestations has done much to guide successional pathways and shape the fir-spruce forests of the
Cape Breton Highlands. Balsam fir is the preferred food source, although white spruce is also
susceptible. In parts of the Maritimes, outbreaks can be traced back more than 200 years. In Nova
Scotia, early outbreaks are known only
from Cape Breton Island. Known
Distinguishing Ecoregion Feature: Elevations 300-450 m above sea level. Mountainous terrain, cold winters with high snow cover, boreal forest, and moose.
infestations occurred in 1846, 1891 and 1896. After the turn of the century there was an outbreak around 1916 that
crossed the Strait of Canso. A less
extensive outbreak occurred in the mid
1920s. In 1950, an outbreak occurred that lasted until 1957. In 1974 mature balsam fir forest
conditions on the Island created an environment susceptible to a build up of the spruce budworm
population, which eventually caused widespread mortality of the fir forest until the population crashed
in 1985.
With the completion of the Cabot Trail in 1932 and the opening of the Cape Breton Highlands National Park in 1936, the area became accessible as a tourism destination. Today, thousands of people visit the park annually but the mountainous topography keeps much of the ecoregion in isolation.
Ecodistricts of the Cape Breton Highlands Ecoregion
210 - Cape Breton Highlands 220 - Victoria Lowlands
3169 km2 127 km2
19
210 - Cape Breton Highlands
The Cape Breton Highlands Ecodistrict includes the steep, generally well drained slopes which define the plateau that rises 300 - 450 m above sea level on northern Cape Breton Island. From a distance the top of the highlands looks perfectly flat, however, once on top of the plateau the topography becomes more evident. Underlain with old erosion resistant rocks, the plateau is gently rolling with knolls, small hills or hummocks, and gently sloping valleys. On the plateau, residuum and bedrock are partially covered with a thin discontinuous veneer of moderately coarse textured stony till, 1 - 4 m thick. Extensive areas of exposed bedrock occur in the ecosection and account for 6% of the ecodistrict or 19,100 hectares. The ecodistrict has cold, late springs and snow cover lasts into May. Despite the high elevation, the ecodistrict is not the coldest in the province. The average winter temperature is -4.2 C, compared to -6.1 C in the Northumberland Lowlands Ecodistrict (530). Heavy snowfalls of about 347 cm are typical and the Highlands are subjected to some of the highest winds in the province (Webb and Marshall, 1999). The ecodistrict covers 3169 km2 or 96 % of the Cape Breton Highlands Ecoregion.
The soils of the Highlands have not been extensively surveyed aside from the few agricultural
areas. Much of the area has had the soils categorized as "rough mountain land" and described as well
drained, moderately coarse textured soils. The parent material is a thin veneer of moderately coarse
textured stony till over bedrock, with variable permeability. On the east side of the plateau, north of
Ingonish, on the well drained, coarse textured, knolls there are large areas of exposed bedrock (70%)
where there are very few trees. However, the majority of the plateau is covered in a boreal fir spruce
forest. The dominant species is balsam fir mixed with black spruce and scattered white spruce and
white birch. Black spruce and eastern larch occupy the wetter areas with high populations of
Sphagnum mosses and Carex species (sedges). Ringing the highlands are steep slopes forested with
the tolerant hardwoods such as sugar maple, beech and yellow birch. Where these steep slopes meet
the plateau of the highlands a forest of yellow birch and balsam fir will be found. On the lower
slopes, sugar maple, beech and yellow birch prevail, along with scattered red oak, white ash, white
birch, red maple, hemlock and white pine. White pine and hemlock will be found in the ravines,
especially on the east side
of the highlands. In the Ecosection Rockland % Area (ha) % E codistrict Cumulative %
broad valley intervals
there are stands of
hemlock, red oak, white WMKK
1.1
112971
35.6
35.6
ash and elm, along with WMDS
2.2
78851
24.9
60.5
other trees. On the east
side, near Neil's Harbour, WCKK
33.2
39320
12.4
72.9
there are rare open stands WMHO
0.2
27672
8.7
81.7
of jack pine. The
ecodistrict has also acted IMHO
1.2
17607
5.6
87.2
as a refuge for rare arctic- WCDS
10.1
14913
4.7
91.9
alpine and Cordilleran
plants. No where is this
20
more evident than at Corney Brook where one may find purple alpine saxifrage, yellow mountain saxifrage, Diapensia lapponica, small flowered wood rush, giant rattlesnake plantain, Epilobium hornemannii, and Northern bedstraw. Repeated attacks by the spruce budworm has been the major disturbance to the fir dominated forests of the Cape Breton Highlands Ecodistrict. The mortality caused by the budworm during the last outbreak in the late 1970s has led to the re-establishment of the balsam fir forest, much of which is being intensively managed in an effort to reduce the impact of the next outbreak on the wood supply. Along with budworm infestations, fire has also been a stand initiating disturbance. Ecologists at the Highlands National Park have reported that 20% of the park displays characteristics of fire origin (Bridgland et al). In the 1830s, settlement began as the mountains surrounding Middle River were cleared and farmed. By the late 1950s much of this farmland was abandoned and today areas such as Crowdis, Gairloch, and Gillanders Mountains have regenerated to old field white spruce.
220 - Victoria Lowlands
The Victoria Lowlands is the second smallest ecodistrict in Nova Scotia and includes several
low-lying coastal areas on the north and east side of the Cape Breton Highlands. These areas are
located on outwash plains, alluvial terraces and fans isolated due to their location between the
highland escarpment and the Atlantic Ocean. The underlying
Ecosection Area (ha) % E codistrict Cumulative %
rocks are shale, limestone and WCHO*
7499
59.0
59.0
sandstone characteristic of the
WFKK
2145
16.9
75.9
carboniferous lowlands. Where
gypsum occurs there is karst WMKK
604
4.8
80.7
topography with sinkholes. Along
WCKK
545
4.3
85
the coast, the sea is constantly
eroding edges of the ecodistrict. The
WMHO
340
2.7
87.7
soils are well drained, moderately coarse textured on rolling plains with slopes of 2 - 30%. In areas
*These ecosections have karst topography with sinkholes: 2,331 hectares have been identified.
where coarse sandy loams of the
Hebert soil series occur, drainage can be rapid. The total area is 127 km2 or 4% of the Cape Breton
Highlands ecoregion.
At Ingonish, the annual precipitation averages 1676 mm, about 10% higher than any other weather station in Nova Scotia. The ecodistrict is also subjected to the same heavy snowfalls that occur on the steep slopes and plateau of the Highlands, with an average snowfall of 358 cm (Webb and Marshall, 1999). This ecodistrict contains most of the land suitable for farming in the northern part of Cape Breton and where old fields and clearings have been abandoned white spruce has reforested the sites.
21
300 - Nova Scotia Uplands Ecoregion The Nova Scotia Uplands Ecoregion stretches from Parrsboro in Cumberland County to Kellys Mountain in Cape Breton. There are eight ecodistricts within this ecoregion, with elevations of 150 to 300 m on both the mainland and Cape Breton Island. The only exception is the Inverness Lowlands Ecodistrict (320), which is comprised of the valley floors of the rivers flowing from the uplands and highlands. It has been included in this ecoregion due to the influence of the surrounding uplands on the microclimate. The ecoregion is geologically diverse and complex with remnants of the Cretaceous peneplain surface, composed of metamorphic, intrusive and volcanic rocks of the Precambrian to Paleozoic eras. The lowlands within this ecoregion are underlain by Paleozoic sedimentary rocks. Several major faults border or transect this ecoregion, most notably the CobequidChedabucto Fault zone and the Hollow Fault. On the hills, the parent materials are generally sandy loams. Clay loams occur on the flats of southern Inverness County and loams are found on the Mulgrave plateau. Where the topography is gently rolling, the soils are usually well to moderately well-drained. Many of the slopes are steep with rapid to well-drained soils, but middle and lower slope positions have a significant potential for enrichment due to seepage. Extensive areas of smooth or level topography at the tops of these hills tend to have imperfectly to poorly drained soils, which support forests of coniferous species. The total area of the ecoregion is 9,712 km2 or approximately 17.6% of the province. The hilly topography of the uplands creates microclimatic environments where sheltered and Distinguishing Ecoregion Features: exposed conditions can varythe local weather, especially Elevations 150 - 300 m above sea level. temperatures. Overall, summers tend to be warm and Warm summ ers and long cold winters, winters are long and cold. Average precipitation is upland areas. between 1200 - 1500 mm, with 250 - 350 cm of snow. The greatest snowfall occurs on the Cobequid Hills and Cape Breton Hills. Wind and ice damage are significant limiting factors to tree growth, especially for the hardwoods on the crests and upper slopes, resulting in stunted forests of beech and sugar maple. On the hardwood hills, sugar maple, beech, red maple and yellow birch pre-dominate. White spruce, red spruce, and balsam fir form mixedwoods with the above hardwoods on some valleys and slopes. Hemlock is commonly found in ravines. On the hummocky terrain of the Mulgrave Plateau, St. Mary's River and Central Uplands, red spruce, balsam fir, white pine and hemlock are common on the well-drained soils. Occasionally these tolerant softwoods mix with the tolerant hardwoods to create diverse mixedwoods, especially on the lower slopes where seepage has enriched the soils with nutrients and moisture. Black spruce and eastern larch occur on the imperfect and poorly drained soils. There are also large areas of barrens caused by repeated burning where bracken fern and sheep laurel are dominant. The river valleys were quickly cleared of forest cover by the European settlers in the 1700s and 1800s. These original forests of white ash, sugar maple, American elm and balsam poplar (Stanley, 1970) are now uncommon. The settlers also cleared much of the upland areas for 22
fields and pastures, but with increased urbanization after the Second World War this abandoned farmland has been recolonized by white spruce. In the hardwood forests of the uplands, mortality is usually confined to individual trees or species and may be due to insects, disease, blowdown, old age, or physical damage due to wind, snow, ice or lightning. These types of mortality are called gap or patch disturbances and create uneven-aged stands. In the softwood forests, which occur on the level plateaus of the uplands or in the lowlands of the river valleys, fire, insect and blowdown act as the natural disturbance and may create large areas of destroyed forests. This type of natural disturbance is called a stand-initiating event. The interval for such disturbances is generally more frequent than the average longevity of the climax species and results in even-aged forests.
Ecodistricts of the Nova Scotia Uplands Ecoregions
310 - Cape Breton Hills
2442 km2
320 - Inverness Lowlands
488 km2
330 - Pictou Antigonish Highlands 1334 km2
340 - Cobequid Hills
1904 km2
350 - Cobequid Slopes 360 - Mulgrave Plateau 370 - St. Mary's River 380 - Central Uplands
371 km2 1028 km2 852 km2 1292 km2
310 - Cape Breton Hills Ecodistrict
Most elevations in the Cape Breton Hills Ecodistrict fall between 150 - 300 m above sea level.
This includes the more recognizable hills of Kelly's Mountain, Cape Mabou, Cregnish Hills, North
Mountain, Boisdale Hills, Sporting Mountain, East Bay Hills, Whycocomagh and Lewis Mountain.
Also falling into this district are several lower elevation hills, including Mount Young,
Washabuck/Cains Mountains, Southwest Mabou Ridge, Beinn Bhreagh and Rear Forks Baddeck.
The ecodistrict is influenced by the strong, cold winds of the Gulf of St. Lawrence. Temperatures are
slow to warm in the spring resulting in a short growing season. The area receives between 1400 -
1550 mm of precipitation annually. The total area is 2442 km2 or 25% of the Nova Scotia Uplands
Ecoregion.
The higher steep-sloped hills are underlain with older resistant rocks and are covered with well
drained, moderately coarse textured tills. In general, the lower more gradually
Ecosection Area (ha) % E codistrict Cumulative %
sloping hills are underlain by coarse
WMKK
83511
34.2
34.2
carboniferous sediments. The soils tend
WMDS
50374
20.6
54.8
to be imperfectly drained, fine textured
tills. Seepage sites are common on the
WFKK
34479
14.1
69.0
slopes providing some of the richer sites
IMHO
32322
13.2
82.2
for tree and plant growth. Areas of karst
topography are found throughout the
WMHO
16849
6.9
89.1
district at lower elevations, most notably
IFHO
7828
3.2
92.3
on the Iona peninsula and at Marble
23
Mountain and near Mabou, Port Hood/Judique and Inverness. Freshwater accounts for 0.4% or 1,032 hectares of the ecodistrict. This ecodistrict is predominately a tolerant hardwood forest with scattered spruce and fir. In coastal areas, white spruce is more frequent. On ravines with well drained, medium textured soils eastern hemlock, white pine and scattered red spruce are found. On top of the larger hill complexes, level to hummocky topography underlain with imperfectly drained soils yield stands of black spruce and balsam fir. Yellow birch , sugar maple and red maple grow on the better drained soils. Much of the early land grants on the upland sites were cleared for farming, but once abandoned in the early to mid 1900s the fields and pastures reverted to pure stands of white spruce.
320 - Inverness Lowlands Ecodistrict
This is one of the smallest ecodistricts in the province, stretching from Cheticamp in the north
to Mull River and Whycocomagh Bay in the south. It includes the fault valleys of both the Margaree
and the Middle Rivers. The total area is 488 km2 or 5 % of the Nova Scotia Uplands Ecoregion. The
area tends to be somewhat sheltered by the surrounding uplands (Cape Breton Hills - 320, Cape
Breton Highlands - 210), with the exception of the Cheticamp area where a combination of
topography and temperature create a unique phenomenon, locally known as "les suetes". A suete
begins with winds blowing in off the Atlantic Ocean. When conditions are right, the swirling air
molecules slide up the eastern slope of the Cape Breton Highlands, then begin the steep downward
descent on the western side, gathering speed as they go. The strongest one recorded, which struck
on March 13, 1993, was officially clocked at 233 km/hour. The
Ecosection Area (ha) % E codistrict
Cumulative %
Margaree Valley is known for WCHO*
7484
15.3
15.3
having some of the coldest
IFHO
6769
13.9
29.2
temperatures and the shortest
recorded frost-free period in the
IMHO*
5373
11.0
40.2
province.
WFHO*
4209
8.6
48.8
The underlying geology is WMHO*
3913
8.0
56.8
comprised of carboniferous, clastic
IMSM*
2935
6.0
62.8
sediments, gypsum and limestone.
The terrain is gently undulating to WMKK*
2356
4.8
67.7
rolling. Lake Ainslie and the
WCKK
1678
3.4
71.0
Margaree River account for a large proportion of the freshwater in the ecodistrict (13.7% or 6702 hectares). Another significant portion of the ecodistrict is
ICSM
1636
3.3
74.3
*These ecosections have karst topography with sinkholes; 6,072 hectares have been identified on these and other ecosections within the ecodistrict.
comprised of freshwater wetlands
(3.6%) and salt marshes and coastal beaches (1.1%).
24
The first Europeans came to the area in the 1750s to establish fishing stations along the coast. Actual settlement began about 30 years later, with French emigrants settling at Cheticamp and United Empire Loyalists coming to Mabou. The terrain is comprised of gently undulating to rolling lowlying areas and is suitable for farming. Coal and gypsum have been mined at several locations. Due to heavy settlement in this area, most of the original forest has been severely disturbed, especially on the interval lands which account for almost 10% of the ecodistrict. On these interval lands sugar maple, white ash, balsam poplar and American elm formed the climax forest (Stanley, 1968). Extensive areas of black spruce forest are found on the moist soils of this ecodistrict.
330 - Pictou Antigonish Highlands Ecodistrict
This ecodistrict has been described by Roland (1982) as an elevated triangle of resistant strata separating the Northumberland lowlands of Pictou County (530) from the lowlands of St.George's Bay (520). The highlands abut the St. Mary's fault block to the south along the Chedabucto fault where the East River St. Mary's flows. This upland ecodistrict is crosscut by subsidiary faults trending north-south and northeast-southwest, creating many narrow valleys. The most notable fault is the Hollow Fault, which extends from Cape George to New Glasgow. The fault is marked by the 200 m scarp which has developed as a result of differential erosion. The total area of this ecodistrict is 1,334 km2 or 13% of the ecoregion.
Roland (1982) and Davis and Browne (1986) describe the geology of this ecodistrict as being
extremely complex. The rocks display strong metamorphism, folding and distortion. The underlying
bedrock consists of Precambrian to Paleozoic sediments and volcanics, strongly deformed and
Ecosection
Area (ha)
% E codistrict Cumulative %
metamorphosed, and intruded by pre-
WCKK
53126
39.8
39.8
carboniferous granitic to
WCHO
30729
23.0
gabbroic plutons. Much
62.9
of the province's
WFKK
14181
10.6
73.5
geological history can be
ICHO
10053
7.5
81.0
viewed in this ecodistrict
including ancient
IMHO
8129
6.1
87.1
volcanoes and the 400-
WCDS
6169
4.5
91.7
million-year-old fossils at
Arisaig. The elevation is
generally 210-245 m
above sea level and rises to 300 m at Eigg Mountain. Overall, the highlands summit to a rolling
plateau best exemplified by The Keppoch, an area once extensively settled. The dominant soils are
mostly sandy loams which are well drained and fairly stony. Other dominant soils include those
derived from shales. Typical of the upland ecodistricts, freshwater accounts for only 0.5% or 720
hectares.
25
The tolerant hardwood forests are especially notable on the crests and upper slopes of hills and larger hummocks. Otherwise, red spruce and hemlock are found on the lower slopes with black spruce occupying the imperfectly drained sites. Mixedwood, tolerant forests of beech, sugar maple, yellow birch and red spruce with scattered hemlock grow on the steep slopes adjacent to the streams and rivers which flow from the highlands. On the coarse textured soils derived from glacial outwash, usually found along the streams and rivers, pure stands of white pine will be found. Many of the old field, white spruce stands occupy ecosections previously forested with upland hardwoods. Good examples of this occur at Rossfield and The Keppoch.
340 - Cobequid Hills Ecodistrict
Webb and Marshall (1999) describe the 150 km long Cobequid Mountains as a cigar-shaped block running just west of Pictou to Parrsboro. These hills separate the two lowland ecodistricts, the Minas Lowlands (620) to the south and the Northumberland Lowlands (530) to the north. The highest points on the mainland are found on the Cobequids at Nuttby Mountain and Dalhousie Mountain which rise to 335 m above sea level. As Roland (1982) noted, the Cobequids from a distance give an appearance of a more irregular skyline than other uplands, an appearance he credits due to the narrowness of the upland surface. Of the ecodistricts within the Nova Scotia Upland Ecoregion (300), the Cobequids are the driest with only 1182 mm of precipitation per year. However, they receive the greatest snowfall on the mainland with over 300 cm of snow in an average year. The total area of the ecodistrict is 1,904 km2 or 20% of the ecoregion.
The geological history of the Cobequids is complex. Most of the strata are pre-carboniferous
and are resistant to erosion.
Many faults are expressed
Ecosection
Area (ha) % E codistrict Cumulative %
throughout the Cobequids, with
the most prominent, the
WCKK
118063
62.0
62.0
Cobequid fault, on the south
WCHO
25278
13.3
75.3
extending from Truro to Cape
Chignecto. Freshwater lakes and
ICHO
20059
10.5
85.8
streams account for only 0.5% of
WCDS
14001
7.4
93.2
the ecodistrict (964 hectares).
ICSM
4015
2.1
95.3
Many of the lakes are small and
shallow, but Folly Lake, which
appears to have resulted from glacial ice resting in the valley of an old river and choking both ends
with gravel deposits from the melting ice, is 80 hectares in size and over 100 m deep. The Cobequids
provide a watershed for streams running north or south which leave the mountains in deep, steep-
walled gorges as a series of falls or cascades. The soils of the Cobequids are dominated by coarse
gravelly to stony sandy loams derived from igneous and metamorphic rocks. In many areas, the soils
are shallow to bedrock, especially on the well drained, coarse textured soils found on hilly topography
(WCKK).
26
The Cobequids support pure stands of tolerant hardwoods extending from the crests to lower slopes of hills and large hummocks. In between these hills, extensive flats of imperfectly drained coarse textured soils on the level to hummocky terrain (ICSM and ICHO) are found where forests of red spruce and black spruce dominate. Another characteristic of the ecodistrict are the steep-sided ravines with well drained coarse to medium textured soils where forests of shade tolerant species including hemlock, white pine, white ash and ironwood can be found. The growth potential of the hardwood forests is seriously limited on the upper elevations where damage caused by snow and ice breakage reduces height and stem quality. However, on the sheltered lower slopes, hardwood potential is improved as the exposure to winds is diminished. Many stands of white spruce can be found in the ecodistrict, again on the abandoned farmland of the early settlers who must have found the environment a serious impediment to crop production.
350 - Cobequid Slopes Ecodistrict
Best described as the foothills of the Cobequids (340), the rolling topography of this ecodistrict eventually levels into the Minas Lowlands Ecodistrict (620). As a narrow band of rolling hills from North River in the east to Economy in the west, the southerly aspect of this ecodistrict provides significant winter habitat for large populations of deer who venture down from the higher elevations as snow accumulations restrict movement. The total area of this ecodistrict is 371 km2 or 3.8% of the ecoregion.
The Cobequid Fault provides the northern boundary of this ecodistrict and separates the older
more resistant pre- carboniferous rocks of the Cobequids (340) from the late Ecosection Area (ha) Ecodistrict% Cumulative %
carboniferous siltstone, shale and
IFKK
9432
25.4
25.4
conglomerate. The Portapique Fault
WCKK
7020
18.9
44.3
forms the southern boundary,
separating the slopes from the Triassic IMHO
6868
18.5
62.8
siltstone and sandstone of the Minas WMHO
4490
12.1
74.9
Lowlands (620). This ecodistrict has
an array of soils ranging from the very WMKK
3248
8.8
83.7
coarse, sandy loams associated with
IMRD
2136
5.8
89.5
outwash to the clay loams. All of the
freshwater within this ecodistrict, 0.4% of the area, is located in the streams and rivers flowing
through on their way to the Minas Basin.
The forests of the Cobequid Slopes Ecodistrict can best be described as tolerant mixedwood with pure and mixed stands of red spruce, sugar maple, yellow birch, beech and hemlock. On the ecosections with gentler slopes or fairly level terrain, pure stands of red spruce occur. For the most part, white pine is absent from the ecodistrict. Hemlock occurs on the steeper slopes along streams and rivers.
27
360 - Mulgrave Plateau Ecodistrict
The part of the Mulgrave Plateau north of the fault-controlled Roman Valley is underlain by strongly folded sedimentary rocks of the Horton Group. The area between Roman Valley and the Chedabucto Fault is underlain by the Guysborough Group, consisting of sedimentary and volcanic rocks. Both plateau portions are comprised of extensive areas of imperfectly drained level to hummocky topography. The steep slopes of these elevated plateaus, approximately 200m above sea level, are well drained and support a mixture of tolerant hardwoods and softwoods. The total area of the Mulgrave Plateau ecodistrict is 1,029 km2 or 10.6% of the ecoregion. The Roman Valley River flows towards Chedabucto Bay via the Milford Haven River which, along with Guysborough Harbour, is an example of a drowned estuary (the mouth of a river submerged due to a rise in sea level).
The eastern portion of the ecodistrict is appreciably wetter than the western portion and is drained by the St. Francis Harbour River which flows out of Goose Harbour Lake which has been dammed for use as an industrial water supply in Port Hawkesbury. Two other lakes, Grant and Summers, have also been dammed for water supply for Mulgrave, while another reservoir has been created at Melford Lake for future industrial use. However, only 2.9 % of the ecodistrict is covered in fresh water (3,034 hectares). Low relief drumlins dot the eastern portion of the ecodistrict around Goose Harbour Lake. The soils of the ecodistrict are mostly well drained, gravelly sandy loams except for the eastern portion which is imperfectly drained. Clay loams on the drumlinized till plain are also imperfectly drained.
The ecodistrict is bordered by the waters of the Northumberland Strait and the Strait of Canso
with both areas prone to strong coastal winds. The forests on the well drained, coarse textured hills
(WCKK) that border this water are similar to the coastal forests of the
Ecosection Area (ha) % E codistrict
Cumulative %
Atlantic Coastal Ecoregion (800). WMKK
40203
39.1
39.1
An association of red maple and
IMHO
21020
20.4
59.5
yellow birch dominate the drumlins
(WMDM) with scattered sugar WFKK
10243
10.0
69.5
maple on the lower slopes. Red
WMHO
9924
9.6
79.1
spruce and hemlock are more
prevalent in the sheltered ravines and
WFHO
5021
4.9
84.0
along streams and steep slopes of the WMDM
4099
4.0
88.0
WCKK ecosections. The forest is
mostly black spruce and red maple
IFHO
2206
2.1
90.1
on the wetter soils, with tolerant
hardwoods, red spruce and white pine on the better drained soils found on the hills and steeper
hummocks. Balsam fir usually regenerates on the better drained land and much of the area is used
for Christmas tree production.
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370 - St. Mary's River Ecodistrict
The physical boundaries of this ecodistrict are easily recognized, both on the ground and from aerial photography, due to the prominence of the two parallel faults that resulted in a graben (a downfaulted block lying between two faults) and the subsequent escarpments that delineate the ecodistrict. The East River St. Mary's parallels the Chedabucto Fault from Eden Lake to Melrose. The West River St. Mary's gathers its headwaters near Trafalgar and flows east along the St. Mary's Fault to Melrose to the confluence of the two rivers which then flow south to the Atlantic Ocean. The total area of the ecodistrict is 852 km2 or 8.8% of the ecoregion.
The ecodistrict is underlain by siltstones and sandstones of the Horton Group. For the most
Ecosection Area (ha) E co district% Cumulative %
part the topographic pattern of the ecodistrict is hummocky. Wetlands and
WMHO
24428
28.7
28.7
drumlins are associated with the level
IMHO
16342
19.2
terrain. Most of the soils are well 47.8 drained, stony to gravelly sandy loams
WMDM
14925
17.5
65.4
developed on till veneers of the Horton
WMKK
10747
12.6
78.0
sandstones and shales. Freshwater
totals 4.0% of the ecodistrict or 3,438
WFHO
3442
4.0
82.0
hectares.
WFDM
3068
3.6
85.6
The shallow coarse soils, for the
IMSM
2936
3.4
89.0
most part, support forests of black
IFHO
1526
1.8
90.8
spruce and white pine. The better
forests of red spruce and tolerant
hardwoods will be found on the drumlins and upper slopes of the hills. Historically, repeated
burnings have resulted in extensive barrens in the ecodistrict, for example, Eden Barrens and Barren
Brook. Fires on the shallow, sandy soils may also have reduced the fertility of the soils and their
ability to produce stands of better productivity contributing to the abundance of fire species such as
the black spruce. Smith (1857) in his travels along the east and west St. Mary's rivers often remarked
on the abundance of sugar maple as well as American elm and black cherry on the intervals. He
entered in his journal that "above the lakes [Glenelg] for two miles there is an interval from one half
to three quarters of a mile broad, very low and often flooded. The timber of a large size, chiefly sugar
maple, elm and yellow birch and some oak".
380 - Central Uplands Ecodistrict Referred to by Roland (1982) as the Horton Highlands, this upland extension of the St. Mary's fault block has some of the more productive red spruce forests in Nova Scotia. Partially wedged between the Cobequid Hills (340) to the north and the Pictou Antigonish Highlands (330) to the east, this ecodistrict occupies the gently rolling uplands of central Nova Scotia. Sloping easterly upwards from the St. Mary's River Ecodistrict (370), elevations average 300 m above sea level. This area
29
contains the headwaters of the Stewiacke and Calvary Rivers, which eventually make their way to Cobequid Bay. The total area of the ecodistrict is 1,292 km2 or 13.3% of the ecoregion.
The geology is somewhat similar to that of the St. Mary's River (370) and Cobequid Slopes (350) Ecodistricts. Soils are predominantly well drained to moderately well drained with mottling, an indication of restricted drainage during the growing season, present in many of the finer textured soils. First, second and third order streams with a trellised drainage pattern and a few small. Shallow lakes cover only 0.8% of the ecodistrict.
Ecosection IMHO WMKK WMHO IFKK WFKK IFHO IMRD WFHO
Area (ha) 29466 22531 16994 16976 11317 8659 4083 3236
% E codistrict 22.8 17.4 13.2 13.1 8.8 6.7 3.2 2.5
Cumulative % 22.8 40.2 53.4 66.5 75.3 82.0 85.1 87.6
Red spruce is the dominant forest species in the ecodistrict and occupies many of the moist sites, which in other ecodistricts would be covered by black spruce. Pure stands of tolerant hardwoods are present on the crests and upper slopes of hills and steeper hummocks (WMKK, WFKK, IFHO). Red spruce, yellow birch and sugar maple will form mixed stands on the finer textured soils, but following harvesting may revert to pure stands of red spruce. Hemlock prefers the sheltered moist sites of lower slopes along streams and rivers and white pine is scattered on the better drained, coarse textured soils.
400 - Eastern Ecoregion Extending from Bedford Basin to the town of Guysborough, this ecoregion is the eastern extension of the Appalachian peneplain which slopes towards the Atlantic Ocean (see also Western Ecoregion 700). It is bordered to the south by the Atlantic Coastal Ecoregion (800) and to the north by the St. Mary's Fault. The highest points of elevation, 220 m above sea level, are found in the Governor Lake Ecodistrict (450). The ecoregion is underlain by quartzite and slate of the Meguma Group, with granitic intrusives. Webb and Marshall (1999) describe the variety of landforms in this ecoregion, which includes rolling till plains, drumlin fields, extensive rockland, and wetlands. The ecoregion has been divided into five ecodistricts, of which two are comprised of disjunct areas. The Rawdon/Wittenburg Hills (410) are two individual slate ridges separated by the Shubenacadie River and about 20 km. The Eastern Drumlins (420) concentrate in three disjunct areas identified by the Sackville, Tangier and Moser Rivers which flow through them. The total area of the ecoregion is 6,427 km2 or 11.6% of the province. Removed from the immediate climatic influence of the Atlantic Ocean, the ecoregion is characterized by warmer summers and cooler winters. The mean winter temperature is colder (-5.0 C) than the Western Ecoregion where the mean winter temperature is -3.5 C (Webb and Marshall 1999).
30
The forests of the ecoregion are predominantly
Distinguishing Ecoregion Features:
coniferous, with red and black spruce occupying the
South sloping upland interior in eastern Nova Scotia with warm summers and cooler winters.
majority of sites. Scattered stands of hemlock are found in the sheltered and moist environments of narrow stream and river valleys and on the slopes of drumlins. Stands of white
pine are found on the deep, well drained coarser soils
associated with outwash till. Also, white pine is usually
scattered or a minor component of black spruce forests, especially on the fire barrens. Tolerant
hardwood forests dominated by yellow birch and sugar maple, with scattered beech are usually found
on the drumlins and upper slopes and crests of steeper hills. The dominant natural disturbances are
fire and hurricanes. The coarse textured soils associated with the granitic ecodistricts, Eastern Granite
Uplands (430) and Governor Lake (450), are subject to moisture deficit during the summer months
and prone to fires caused by lightning. Hurricanes originating in the Caribbean and traveling along
the eastern seaboard have frequently destroyed large areas of mature forests in this ecoregion,
particularly in the Eastern (440) and Eastern Drumlin ecodistricts (420).
Ecodistricts of the Eastern Ecoregions
410 - Rawdon\Wittenburg Hills 420 - Eastern Drumlins 430 - Eastern Granite Uplands 440 - Eastern Interior 450 - Governor Lake
613 km2 847 km2 603 km2 3731 km2 634 km2
410 - Rawdon\Wittenburg Hills Ecodistrict
These two slate ridges rise notably above the surrounding valleys of the Stewiacke,
Musquodoboit and Shubenacadie rivers in central Nova Scotia. With elevations of 180-210 m, the
Rawdon Hills and Wittenburg Mountain Ecosection Area (ha) % E codistrict Cumulative % contrast with these carboniferous
lowlands (Central Lowlands 630). WMKK
34610
56.5
56.5
Climatically, temperatures are cooler, IMHO
11210
18.3
74.8
especially in winter, and considerably
more moist than the adjacent lowlands. IFKK
8910
14.5
89.3
The total area of this ecodistrict is 613 WMHO
3769
6.2
95.5
km2 or 9.5% of the ecoregion.
The deeply dissected northeast trending ridges are comprised of folded Meguma Group slate. Even small streams along their margins occupy deep indentations. Sandy clay loams and clay loams occur on the side slopes of these ridges. On top of the ridges, well drained soils of sandy loams and loams derived from shales and slates will be found. Wittenburg Ridge, divides the St.Andrews River and the South Branch of the Stewiacke River from the Musquodoboit River. The Rawdon Hills, are
31
crosscut by the Herbert and Meander rivers and several major brooks, all of which have valley and interval ecosections. The Nine Mile River also drains the Rawdon Hills. In total, freshwater only accounts for 0.5% or 303 hectares of the ecodistrict. Red spruce forests are very common on both of these slate ridges, occurring predominantly on the hummocky terrain. However, a significant feature of this ecodistrict is the occurrence of mixedwood forests, especially on hilly topography underlain by moist, fine textured soils. On these ecosections, pure stands of either tolerant softwood or hardwood may occur or combine to form a classic mix of the sugar maple, yellow birch, beech, white ash, red spruce and hemlock with scattered white pine indicative of the Acadian ecozone.
420 - Eastern Drumlins Ecodistrict
This ecodistrict is comprised of three disjunct areas of drumlins within the eastern ecoregion and can be identified roughly by the watersheds of the Three Rivers that flow through them: Sackville River, Tangier River, and Moser River. Although drumlins are scattered elsewhere in the eastern ecoregion, these three areas represent the highest concentrations. Formed by glacial ice movement the drumlins in this ecodistrict are orientated north-south indicating the route of the glaciers toward the Atlantic Ocean. The total area of the ecodistrict is 847 km2 or 13.1% of the ecoregion. The eastern drumlin fields are underlain by Meguma Group greywacke and slate, blanketed by fine-textured tills derived from these underlying and adjacent rocks. The drumlins are derived from carboniferous rocks from the north as well as material from the Cobequid Hills and Pictou-Antigonish Highlands. This imparts a "red" hue to the soils compared to the "grey" drumlins derived from slates common in western Nova Scotia. The soils are predominantly fine textured loams over sandy clay loams. The ecodistrict is dotted with a significant number of freshwater lakes, for a total of 6.2% of the ecodistrict or 5,235 hectares.
In this ecodistrict, the well
drained drumlins and hummocks Ecosection
provide an opportunity for pure stands of tolerant hardwoods, such
IMHO
as yellow birch, sugar maple and WFDM
beech, to thrive on the crests and upper slopes. On the lower slopes, pure stands of red spruce will ring
WMDM WMHO
around the drumlins. Between
IMRD
drumlins black spruce occupy the wetter, imperfectly drained soils.
IMSM
White pine will occur on sites with WMKK
dry, coarse, shallow soils such as
those that occur on ridged ecosections.
Area (ha) 23666 18184 11387 6641 6620 4758 2587
% E codistrict 28.0 21.5 13.4 7.8 7.8 5.6 3.1
Cumulative % 28.0 49.4 62.9 70.7 78.5 84.1 87.2
32
430 - Eastern Granite Uplands Ecodistrict
Stretching in a narrow ridge (80 km long by 8-10 km wide) just east of Waverley to Sheet
Harbour this ecodistrict lies north of the coastal Eastern Shore (820) Ecodistrict. Rising sharply up
to 100 m above the adjacent coastal area, often with steep cliffs, this rocky ridge is dissected with
narrow river gorges, the most notable being the Musquodoboit. Also of note are long narrow lakes
that dissect the ecodistrict, Ecosection R ockla nd (% ) Area (ha) % E codistrict Cumulative % such as Lake Charlotte and
Porters Lake. The total WCKK
10.2
16000
26.5
26.5
area of this ecodistrict is
ICHO
4.2
9791
16.2
42.8
603 km2 or 9.4% of the
ecoregion.
WCRD
39.4
8513
14.1
56.9
ICKK
30
6772
11.2
68.2
The granite that
underlies this ecodistrict is
ICRD
21
4261
7.1
75.3
similar to the granite of the WCHO
17.2
3928
6.5
81.8
South Mountain
Ecodistrict (720) and other IMHO
0
1807
3.0
84.8
outcrops throughout the WCDM
11.2
705
1.2
86.0
western (700) and eastern
(400) ecoregions. Granite is very resistant to erosion and most of the soils associated with this
granite are coarse textured and shallow. Many ecosections in this ecodistrict have exposed bedrock
and are scattered with huge, sometimes house-size granite boulders deposited by the glaciers. It is
estimated that approximately 15% or 9000 hectares of the ecodistrict is exposed bedrock. This
ecodistrict also has one of the highest concentrations of freshwater lakes with 11.1% coverage or 6698
hectares.
The forests of this ecodistrict are predominantly softwood, with red spruce stands on the better drained and deeper soils associated with hummocky terrain. Elsewhere, the shallow soils give rise to scrubby forests of black spruce and white pine with scattered red pine indicating fire disturbances in the past. Jack pine are also found on the shallow soils of ridge tops. Only on the few scattered drumlins will any tolerant hardwoods be found. Stands of hemlock occur on the steep sided slopes of hills and hummocks alongside rivers and streams.
440 - Eastern Interior Ecodistrict One of the largest ecodistricts in the province with 3,731 km2 or 58.1% of the ecodistrict, occupies an area from Pockwock Lake in the west to the Town of Guysborough in the east. The bedrock is highly visible in those areas where the glacial till is very thin, exposing the ridge topography. Where the till is thicker, the ridged topography is masked and thick softwood forests occur. The ecodistrict is heavily covered with freshwater lakes (27,362 hectares or 7.3%). The complexity of the ecodistrict is reflected in the abundance of ecosections due to the glacial history and
33
movement of materials from northerly ecoregions. The eight largest ecosections (excluding water) make up 81% of the ecodistrict with the next eight making up 10.6%.
The ecodistrict is underlain by resistant
Ecosection Rockland % Area (ha) Ecodistrict % Cumulative %
Meguma Group quartzite WMKK
5.1
81453
21.8
21.8
and slate. The thickness
of the till is quite variable IMHO
6.2
80784
21.7
43.5
across the ecodistrict, IMRD
28.5
55443
14.9
58.3
ranging from 1 - 10 m but WMHO
5.1
31212
8.4
66.7
averaging less than 3 m.
Almost 9.3% of the WM RD
23.7
18449
4.9
71.6
e c o d i s t r i c t WTLD
0
14384
3.9
75.5
(approximately 343 km2 )
has been scraped clean by WFKK
0
10485
2.8
78.3
glaciers exposing large WFDM
0.1
9967
2.7
81.0
areas of bedrock. This
situation can be found on IMSM
17
6907
1.9
82.9
ridged ecosections WMDM
0
6109
1.6
84.5
(IMRD, WMRD) and
coarse textured hills WFHO
0
5644
1.5
86.0
(WCKK) near Seloam IFHO
0.7
5628
1.5
87.5
Lake and the Head Lakes
in the Liscombe Game ICHO
15.4
5557
1.5
89.0
Sanctuary. This situation
has also been exacerbated by repeated fires. The predominant soils are sandy loams, often quite stony
and well drained on till derived from quartzites. There are a few drumlins and hills scattered
throughout the ecodistrict with fine textured soils derived from slates.
The composition of the forests in this ecodistrict strongly reflect the depth of the soil profile. Thus, many climax compositions can be found throughout. On the shallow soils repeated fires have reduced forest cover to scrub hardwoods such as red maple and white birch, with scattered white pine and black spruce underlain by a dense layer of ericaceous vegetation. However, on the deeper, well drained soils stands of red spruce will be found. On the crests and upper slopes of hills, drumlins and some hummocks stands of tolerant hardwood occur. Both beech and hemlock occur on these deeper, well drained soils, but their presence is usually individual and seldom of a high percentage in any stand. On the imperfectly and poorly drained soils, black spruce will dominate the stand composition.
450 - Governor Lake Ecodistrict Located in the centre of the eastern mainland, the Governor Lake Ecodistrict is characterized as an upland of granitic rock. To the north, the ecodistrict drops sharply to the West River St. Mary's but on the other three sides it is less abrupt in its rise above the shales and quartzites of the Eastern
34
Interior Ecodistrict (440). At its highest point, the ecodistrict is 200 m above sea level. It occupies an area of approximately 634 km2 or 9.9% of the ecodistrict. The ecodistrict has both the hottest summer temperatures and the coldest winter temperatures in the ecoregion. Along with the Margaree Valley, it has the shortest frost free period, less than 90 days. On an annual basis, the ecodistrict receives 1300-1400 mm of precipitation which is similar for most of the eastern and western ecoregions.
The ecodistrict is underlain by intruding Meguma Group granite similar to that found in the
South Mountain (720)
and Eastern Granite Uplands (430) and it is resistant to erosion. The
Ecosection IMHO
Rockland % Area (ha) Ecodistrict %
0.2
16470
26.0
Cumulative % 26.0
terrain is thinly covered WCKK
2.3
10765
17.0
43.0
by coarse granitic till with
many large granite WMKK
0
9945
15.7
58.7
boulders. Some glacial ICHO
0.4
7127
11.2
69.9
activity has created
drumlins and eskers, WMHO
0
6849
10.8
80.7
which can be found WT LD
0
1771
2.8
83.5
scattered throughout the
WCHO
25.7
1759
2.8
86.3
ecodistrict. The
ecodistrict's geology can WFDM
0
1102
1.7
88.0
best be seen after a WMDM
0
1099
1.7
89.7
disturbance such as fire or
clearcut harvesting has WFKK
0
982
1.5
91.2
removed the vegetation
and exposed the boulder strewn landscape. Approximately 2% of the ecodistrict has exposed
bedrock, much of which is found in WCHO and WCKK ecosections around the Rocky Lake chain
in the Liscomb Game Sanctuary. Much of the ecodistrict, 5.7%, is covered with lakes and streams
(i.e. Ten-, Twelve-, Fifteen-, and Seventeen Mile) which merge to form the East River Sheet Harbour.
The soils are coarse textured, well drained, gravelly sandy loams.
On the well drained upper slopes and crests of hills and drumlins, tolerant hardwood forests with sugar maple, beech and yellow birch of impressive diameter are found. Elsewhere, softwood forests dominate the ecodistrict with stands of red spruce and scattered hemlock. Isolated pockets of white pine will be found on the coarse shallow soils of ridges associated with black spruce and ericaceous vegetation. The ecodistrict is prone to wildfire due to the dryness of the soils and to windthrow due to the shallowness of the soils.
500 - Northumberland Bras d'Or Lowlands Ecoregion Following the Northumberland Shore from the New Brunswick border to Port Hastings and bordering the shores of the Bras d'Or Lakes through to the Sydney coalfield, this lowland ecoregion
35
occupies a significant area in eastern and northern Nova Scotia. This ecoregion includes the rolling hills of Antigonish County, where elevations exceeding 150 m above sea level are common. However, the majority of the ecoregion is relatively low lying, with a range of elevations between 2550 m above sea level common along the Northumberland Strait and the Bras d'Or Lakes. The ecoregion is underlain by readily erodible Carboniferous sandstone, shale, limestone and gypsum. Where bedrock is Windsor Group limestone and gypsum, karst topography is common and sinkholes constitute a geo-hazard on some ecosections. The soils of the ecoregion range from well drained, moderately coarse to medium textured alluviums (sandy loams) common near Oxford, Pictou and Heatherton to the fine textured glacial tills (sandy clay loams) that predominate along the Bras d'Or Lakes and in northern Cumberland County. As well, large areas of imperfectly to poorly drained, moderately coarse to medium textured soils are common in the ecoregion. The soil drainage on these sites has been restricted due to a compacted basal till. The total area of the Northumberland Bras d'Or Lowlands is 8,394 km2 or 15.2% of the province.
Climatically, this ecoregion is quite variable. The Northumberland Shore experiences some of the province's warmer summer
Distinguishing Ecoregion Feature: Sheltered lowland in northern Nova Scotia with a climate moderated by proximity to warm bodies of salt water.
temperatures and overall, is one of the cooler
areas in winter. The waters of the
Northumberland Strait warm considerably in late August, with a maximum surface temperature of
18 degrees Celsius which is enough contrast between air and water temperatures to cause on-shore
sea breezes and to hold back the onset of frost for a few weeks. However, the eventual freezing over
of the Strait effectively cuts off any marine influence for the next few months of winter. The Bras
d'Or lowlands also experience rather cool winters, while summer temperatures are considerably
cooler than those along the Strait. The mean annual precipitation ranges between 1100-1400 mm,
with drier areas being along the Northumberland Strait. Despite the variability in climate, the
ecoregion benefits from its proximity to the warmer salt water of the Northumberland Strait and the
Bras d'Or Lakes compared to ecoregions near the colder waters of the Atlantic and Bay of Fundy.
The inland ecodistricts, Chignecto Ridges (560) and Cumberland Hills (540), have a climate
somewhat transitional between that of the lowland ecodistricts and the ecodistricts of the Upland
Ecoregion (300).
Because of the large areas of imperfectly drained soils, black spruce forests can be found throughout the ecoregion. A dry, warm summer climate contributes to a soil moisture deficit in parts of the ecoregion underlain by coarse textured soils. Fire adapted species, such as jack pine and black spruce, can be found here, especially in the ecosections near Oxford and Thomson Station, Cumberland County. On the hillier topography, where slopes improve the drainage, tolerant hardwoods will be found, for example, on Leicester Ridge, mixedwood stands of red spruce, hemlock, sugar maple, yellow birch and beech occur. Pure stands of red spruce are also common in Cumberland County, on the better drained soils and sites. Along the Bras d'Or Lakes, black spruce covers the lowland sites and tolerant hardwoods are found where the Cape Breton Hills drop steeply to the lake. Red spruce and hemlock occur on the steep slopes along streams and rivers, in dissected valleys, and on the valley floors but is rare elsewhere in the forests along the Bras d'Or Lakes. Prior
36
to the extensive clearing and farming of the interval lands Stanley (1968) suggests in his study that these lands supported forests of American elm, sugar maple and white ash with scattered white spruce and balsam poplar.
Ecodistricts of the Northumberland Bras d'Or Lowlands Ecoregion
510 - Bras d'Or Lowlands
2793 km2
520 - St.Georges Bay
893 km2
530 - Northumberland Lowlands 2868 km2
540 - Cumberland Hills
907 km2
550 - Cumberland Marshes 190 km2
560 - Chignecto Ridges
743 km2
510 - Bras d'Or Lowlands Ecodistrict
This ecodistrict encompasses the lowland areas around the Bras d'Or Lakes and the Sydney
coalfield, Boularderie Island and the Salmon River Valley on the east side of the East Bay Hills.
When compared to the climate of the surrounding uplands, this ecodistrict receives the benefit of a
moderated climate due to its proximity to the large body of inland salt water and by the shelter
afforded by the surrounding uplands of the Cape Breton Hills Ecodistrict (310). The Bras d'Or Lake
occupies nearly 260 km2 in the centre of Cape Breton Island, with West Bay being a wide extension
on the southwest side and the
long tapering East Bay extending
Ecosection Area (ha) % E codistrict Cumulative %
40 km in a northeasterly
IMHO
51151
18.3
18.3
direction. These bays and
channels have been carved mainly
WMKK
47687
17.1
35.4
from the easily erodible Windsor
IFHO*
29094
10.4
45.8
sediments. Locally, thick
deposits of gypsum, anhydrite,
WMDM
27502
9.8
55.7
and salt occur. The bays and
WMHO
22122
7.9
63.6
channels are elongate, parallel to
ridges of gypsum dominated
WFKK
16097
5.8
69.3
bedrock, with good examples of
IFKK
12789
4.6
73.9
this feature near the community
WM RD
9296
3.3
77.2
of Iona. Throughout the
ecodistrict, white gypsum cliffs
WCHO
9086
3.3
80.5
and red sandstone can be
WFHO*
8419
3.0
83.5
observed, especially along the
shoreline of the lakes. The
WT LD
8381
3.0
86.5
eastern half is covered predominately with shallow, stony, moderately coarse-textured glacial till derived from the underlying sandstones. The
IMRD
5175
1.9
88.4
*These ecosections have karst topography with sinkholes, 7,179 hectares have been identified on these and other ecosections within the ecodistrict.
western half of the ecodistrict is
37
dominated by imperfectly drained, loam to clay loam soils, whereas the soils on the eastern side have developed on shallow, stony, gravelly, sandy loam glacial till derived predominately from sandstone. Freshwater, excluding the Bras d'Or Lakes, makes up 2.6% of the ecodistrict or 5500 hectares. The total area of this ecodistrict is 2,793 km2 or 33.3% of the ecoregion. Balsam fir has re-established on most forested lands that have been disturbed by harvesting or by natural causes such as fire, blowdown or insect defoliation. However, the predominant species on the lowlands include black and white spruce. On steeper slopes, white pine can be found, while red spruce and hemlock will be found in the valley canyons, steep ravines and along some watercourses coming off the uplands. The better drained hills support stands of lower quality tolerant hardwoods such as sugar maple, yellow birch and beech. The clearing of land by early settlers and then subsequent abandonment of the fields and pastures has given rise to large areas of old field white spruce. Natural disturbances include losses to blowdown in exposed areas along the lakes and coast.
520 - St. Georges Bay Ecodistrict
The lowlands wrapping around St. Georges Bay extend inland to the Mulgrave Plateau (360) on the mainland and the Cape Breton Hills (310) on the island. Including most of Antigonish County and incorporating the Judique lowlands, this area has been used extensively for farming. It occupies roughly an area of 893 km2 or 10.6% of the ecoregion. Overall the climate is characterized by a late cold spring and moist summer, resulting in adequate moisture throughout the growing season. In eastern Nova Scotia this ecodistrict is one of the warmest during the summer with an average temperature of 16.7 C O. For the most part elevations are between 30-60 m above sea level although there is a consistent rise in elevation from the coast to about 150 m. Much of this elevation is on gently rolling hills that have been cleared and used for agriculture.
Ecosection Area (ha) % E codistrict
WFKK
37447
41.9
Cumulative % 41.9
IFHO
9274
10.4
52.3
WFHO
8201
9.2
61.5
IFKK
7111
8.0
69.4
IFSM
5265
5.9
75.3
WMHO
4800
5.4
80.7
WMKK
4485
5.0
85.7
WCHO
3689
4.1
89.9
WATER
809
0.9
90.8
Underlying the ecodistrict are Lower carboniferous sedimentary rocks. In some areas, gypsum outcrops and associated karst topography can be seen, for example the cliffs along St.Georges Bay north of Antigonish. Adjacent to the major rivers of the ecodistrict deposits of alluvium and ice-contact stratified sand and gravel can be found. The soils of the ecodistrict are dominated by moderately well and imperfectly drained gravelly loams and gravelly clay loams. Well drained sandy loams are predominant along the coast, with rapidly drained, gravelly sandy loams located on the glacially derived soils on the outwash
38
plains of the major rivers. The alluvial soils are usually moderately well drained silty, clay loams. The extensive agricultural history has removed most of the natural forest associations. Abandoned agricultural lands revert to stands of white spruce. In Antigonish County there are more than 10,000 hectares of forest stands where white spruce comprises at least 30% of the cover. However, presettlement forests most likely included tolerant hardwood stands of sugar maple, yellow birch and beech on the upper slopes, with tolerant softwood stands of red spruce, white pine and hemlock on the lower slopes. Imperfectly drained flats are dominated by black spruce as can be observed along the Judique shore. Recently disturbed forested sites will regenerate with balsam fir, red maple, white birch and, on the wetter sites, aspen and tamarack.
530 - Northumberland Lowlands Ecodistrict
This lowland area in northern Nova Scotia borders on the Northumberland Strait and extends into New Brunswick where the ecodistrict is called the Northumberland Coastal, which is within the Eastern Lowlands (NBDNRE 1997). On this low plain, elevations seldom exceed 50m. It is bounded on its southern border by the uplands of the Cobequid Mountains and the Pictou Antigonish Highlands and to the west by the Cumberland Hills. The only significant elevation included in the ecodistrict is the area near Streets Ridge, which rises only 100 m above sea level. The growing climate of this ecodistrict is one of the best in Nova Scotia. Because the ecodistrict is sheltered from storms from the south and the east, it has a significant moisture deficit second only to the Annapolis Valley. It also receives the lowest annual mean precipitation in the province at 1128 mm. The total area of the ecodistrict is 2868 km2 or 34.2% of the ecoregion.
The surficial till of the ecodistrict is derived from the underlying Carboniferous sediments,
Ecosection IMHO*
Area (ha) 101533
% E codistrict 35.4
Cumulative % 35.4
the most prominent being the fine
red sandstones which are
WMHO*
46351
16.2
51.6
conspicuous on the cliffs along the
IFHO*
37771
13.2
64.7
Northumberland shore. Scattered
WFKK*
17091
6.0
70.7
along the ecodistrict are occurrences
of gypsum and salt. The most
WMKK
12736
4.4
75.1
notable karst topography is near
IFRD
11211
3.9
79.0
Oxford where many of the smaller
sinkholes are filled with water. Of
IMRD
10932
3.8
82.9
all the watersheds in the ecodistrict,
ICHO
7747
2.7
85.6
only the Nappan drains westward to
the Cumberland Basin while the
WCHO
6624
2.3
87.9
remainder drain north to the
WCKK
4836
1.7
89.6
Northumberland Strait. In total only * Stands of jack pine, red pine and black spruce are com mon in areas 4485 ha (1.6%) of freshwater occurs of these ecosections that have a history of frequent wildfires.
39
in lakes and rivers. The ecodistrict is characterized by imperfectly drained soils found on compact, slowly permeable, basal tills derived mainly from red sandstones and shales. Due to the compacted nature of the subsoil most water must be removed laterally or through evapotranspiration. Imperfectly drained, reddish brown sandy loams, loams, and clay loams occupy extensive areas of the undulating to rolling plain. Better drained soils are found on the upper slopes on permeable sandy loam tills. Ridged topography, usually with a thick veneer of till, is prominent throughout the ecodistrict, especially in north Colchester county with a good example along the highway between Denmark and Brule. The ecodistrict is dominated by coniferous forest, with black and red spruce the dominant species. Following disturbance, either by natural causes or forest harvesting, sites are usually invaded by early successional species such as balsam fir, red maple, white birch and both trembling and largetooth aspen. A history of fire has produced several areas, most notable along both the Cobequid Pass and the Trans Canada Highway near Oxford and Springhill, where jack pine and black spruce produce an edaphic climax association. The better drained, upper slopes and hilltops will support a forest of tolerant hardwoods but these are rare throughout the ecodistrict. As mentioned earlier, fire is a significant natural disturbance in this ecodistrict due to the warm summers and significant moisture deficit that occurs in many of the ecosections. As well, wind throw is significant as many forests are shallow rooted trees on imperfectly or poorly drained soils. Another somewhat unique feature of this ecodistrict is the occurrence of tamarack on abandoned farmland where the soils were imperfectly drained. On other abandoned fields in the ecodistrict white spruce will follow alders. Eastern white cedar is found scattered throughout the ecodistrict, most notably near Oxford on imperfectly drained soils and where seepage on slopes provides the moisture and nutrients required for it to establish and compete with other softwoods.
540 - Cumberland Hills Ecodistrict
Rising above the lowlands of the Northumberland Lowlands Ecodistrict (530), but still in the
shadow of the Cobequid Mountains (340), lies the Cumberland Hills. These rounded hills seldom
exceed 150 m above sea level, with exceptions near Springhill and Leicester where elevations are just
over 180 m above sea level. The climate of the ecodistrict is slightly cooler than the adjacent
Ecosection
Area (ha)
% E codistrict Cumulative %
lowlands and receives slightly more moisture. The total area of
WCKK
35743
39.4
39.4
the ecodistrict is 907 km2 or
WCHO
18049
19.9
59.3
10.8% of the ecoregion.
The bedrock geology is generally
WMKK*
10498
11.6
70.9
Carboniferous era sedimentary
ICHO*
10033
11.1
WMHO*
4612
5.1
82.0
rocks. Leicester Ridge divides
two watersheds, with the Little
87.0
River draining east to the River
IMHO
3474
3.8
90.9
* Stands of jack pine, red pine and black spruce are common in areas of these ecosections that have a history of frequent wildfires.
Philip and the Little Forks River flowing west to the Maccan River. Near Springhill, the Black River
40
flows to the Maccan River. The majority of soils in this ecodistrict are derived from sandstones and conglomerates creating well drained, coarse textured, sandy loams. Finer textured soils such as clay loams have developed from shales and mudstone, and are imperfectly drained. The upland sites are a mixture of tolerant softwood and hardwood stands, including red spruce, sugar maple, beech and yellow birch. Imperfectly drained sites are occupied by black spruce. Areas with coarse textured soils are prone to moisture deficits in the summer and are susceptible to fire. Examples of jack pine, white pine and black spruce on fire disturbed sites are scattered near Springhill and along the Little Forks River. Along with fire, natural disturbances on the better drained sites with tolerant species include blowdown and insect mortality.
550 - Cumberland Marshes Ecodistrict
The smallest and one of the most distinctive ecodistricts in the province, the Cumberland Marshes provide a natural boundary between Nova Scotia and New Brunswick at the Isthmus of Chignecto. The flat terrain on tidal sediments is occupied by extensive grasslands which have replaced the salt water marshes along the Bay of Fundy. Dykes were constructed by early Acadian settlers to develop farmland on these salt marshes. The Cumberland Marshes Ecodistrict occupies 190 km2 or 2.3% of the ecoregion. The ecodistrict receives strong winds and experiences cooler than normal temperatures than elsewhere in the ecoregion due to its proximity to the bay.
The ecodistrict is
predominantly comprised of imperfectly drained to poorly drained
Ecosection
Area (ha) % E codistrict Cumulative %
soils. Approximately 52% of the
DKLD
7402
39.0
39.0
ecodistrict occurs as peat lands and
IMHO
4931
26.0
64.9
bogs. The peat lands are about one
metre thick and have formed in the
WT LD
1802
9.5
74.4
low lying depressions of the
XXMS
1147
6.0
80.4
ecodistrict. The mineral soils
reclaimed from the salt marshes are
IMSM
859
4.5
84.9
mainly silty clay loams showing
IMRD
544
2.9
87.8
minimal horizon development
because of the continuous deposition
of marine sediments prior to dyke construction. The mineral soils adjacent to the peat lands are
usually poorly drained sandy loams.
The Fort Lawrence ridge is the only portion of the ecodistrict where a tolerant mixedwood occurs. Ecosections which occur inland from the dykelands and marshes are occupied with black, red or hybrid spruce, red maple and tamarack.
41
560 - Chignecto Ridges Ecodistrict
The ridging in this ecodistrict is easily observed on aerial photographs. This folding of the underlying strata, made up of grey sandstones, siltstones and shales, can be found throughout the Chignecto Game Sanctuary. Another interesting glacial landform in this ecodistrict is the esker ( a linear to meandering ridge consisting of sorted sand and gravel deposits created by water flowing beneath a glacier (Cauboue et al 1996)). The Boar's Back Road through the sanctuary has been constructed on top of an esker. Occupying most of northern Cumberland County, this ecodistrict is a plain tilting towards Chignecto Bay. Elevation seldom exceeds 120 m above sea level. The total area of the ecodistrict is 743 km2 or 8.8% of the ecoregion. The western boundary is the Bay of Fundy and although there is a moderate influence on forest growth close to the water, this effect is not reflected very far inland. Therefore it did not seem to warrant further delineation of another ecodistrict. Overall the climate is similar to the Cumberland Hills Ecodistrict.
Underlying this Ecosection R ockla nd (% ) Area (ha) % E codistrict Cumulative % ecodistrict are the coal
ICHO
0
33340
44.8
44.8
bearing Carboniferous
WCHO
0.2
16268
21.9
ICRD
15.9
9419
12.7
66.7
strata, with coal seams
at Joggins, Springhill,
79.4
River Hebert and
WCRD
16.9
5511
7.4
IFHO
0
2486
3.3
86.8
Maccan. The strata
include coarse and fine
90.2
grained sandstones,
IMHO
0
1620
2.2
92.3
which are exposed in
* Stands of jack pine, red pine and black spruce are common in areas of these
some locations
ecosections that have a history of frequent wildfires.
(Chignecto Game
Sanctuary) and overlain
by sandy tills to the east of the River Hebert. For the most part this ecodistrict is characterized by
shallow, imperfectly drained soils derived from sandstones. In many of the soil landscapes, drainage
is influenced by the haphazard arrangement of the bedrock which creates a pattern of imperfectly and
poorly drained soils.
On the ridged ecosections, repeated wildfires have resulted in stands of jack pine, black spruce, red maple and white birch. Many of these stands over time would progress to include red spruce, white pine and hemlock. Fire and glacial activity have resulted in large area of thin soils and exposed bedrock in this ecodistrict. The steep slopes along the Bay of Fundy and the better drained, deeper soils inland support stands of red spruce. On upper slopes and crests of well-drained ecosections, stands of tolerant hardwoods include sugar maple and yellow birch.
42
600 - Valley & Central Lowlands Ecoregion Easily defined, the Valley & Central Lowlands Ecoregion includes the Annapolis Valley, the watersheds of the Minas Basin and the Musquodoboit Valley. The elevation of this lowland seldom exceeds 50 m above sea level, with only a few points reaching 100 m above sea level. Triassic sandstones underlie the Annapolis Valley and Minas shore portions of the ecoregion, while Carboniferous shale, sandstone, gypsum and limestone underlie the lowlands within Hants, Halifax and Colchester Counties. Locally, in the areas underlain by gypsum, karst Distinguishing Ecoregion Feature: Lowlands sheltered from topography with sinkholes and caves coastal climatic influences with warmer summer temperatures and can be expected. H ayes Cave near milder winters than elsewhere in the province. South Maitland is the best example of a well developed cave. Very coarse to moderately coarse sandy soils occupy much of the Annapolis Valley and along the Minas shore. Otherwise, imperfectly drained, fine textured soils predominate on the gently undulating to moderately rolling plains of the central river watersheds of Shubenacadie, Stewiacke, Kennetcook, Avon, St.Croix and Musquodoboit. Excluding the latter, all these rivers are influenced by the tides of the Bay of Fundy and muddy tidal flats extend inland for considerable distance. Another significant landform feature of the ecoregion are the extensive bogs in central Hants County, which include much of the area near Stanley. Notable bogs include the Collins and McDonald bogs both of which exceed 400 ha. Poorly drained clay loams underlay most of this area. The total area of the Valley & Central Lowlands Ecoregion is 4070km2 or 5 % of the province. Some of the ecoregion is protected from direct coastal influences by the North Mountain and its promontory, Cape Split. Two notable uplands bordering the ecoregion, the Rawdon Hills and Wittenburg Ridge, also shelter the adjacent lowlands. Other parts of the ecoregion are sheltered within the river valleys by the gently rolling topography. As a result, the ecoregion records some of the hotter summer temperatures within the province, particularly in the eastern portion of the Annapolis Valley. Winter temperatures tend to average - 4.5oC. The mean annual precipitation ranges from 1100 - 1300 mm. A wide range of forest species associations occur throughout the ecoregion. On the imperfectly drained, finer textured soils, red spruce and balsam fir are predominant. On sites where drainage is better, hemlock and white pine combine with red spruce to form stands more representative of the zonal sites. Since much of the area features heavy textured soils and poor drainage, black spruce and red maple occupy the sites capable of forest growth. On the better drained sites located on ridges and upper slopes, tolerant hardwood such as sugar maple, yellow birch and beech occur. These stands also include trees typical of wetter sites creating mixedwood opportunities. On the fire sites, red maple, red oak, red pine, jack pine, grey birch and black spruce occupy much of the lowland sites. Red pine can be found in pure stands on a range of sites, including the well drained, coarse textured soils of the Valley to the imperfectly drained, fine textured sites in Hants County. Wildfires have been the dominant natural disturbance throughout the ecoregion, but fire suppression and European settlement have reduced the impact of this disturbance on the forested 43
ecosystems. Much of the ecoregion is or has been farmed, and extensive land reclamation has occurred along the tidal shores through the use of dykes dating back to the time of the Acadians.
Ecodistricts of the Valley & Central Lowlands Ecoregion
610 - Annapolis Valley 620 - Minas Lowlands 630 - Central Lowlands
928 km2 437 km2 2704 km2
610 - Annapolis Valley Ecodistrict
The Annapolis Valley is bounded on the north by the North Mountain (920) and on the south by the Valley Slope (710). It is about 130 km long and varies in width from 3 to 11 km. The small nearby Gaspereau Valley has been included in this ecodistrict. The shelter provided by the North and South Mountains allows the Annapolis Valley to have early springs and hot summers, making it one of Nova Scotia's most prominent agricultural areas. The total area of the ecodistrict is 928 km2 or 22.8% of the ecoregion.
The valley is underlain by Triassic sedimentary deposits which have provided the parent
material for the sandy soils found in the ecodistrict. The valley is drained by two rivers: the
Annapolis River flows southwest to the Annapolis Basin and the Cornwallis River flows northeast
to the Minas Basin. The headwaters of both rivers is the large peat land, Caribou Bog, near Berwick.
The high tides of the Bay of Fundy affect both basins and have formed extensive areas of tidal salt
marsh. Most of this marshland, which is now protected from the saltwater by a system of dykes, is
used for agriculture. The dykes were originally built by the early French settlers in the 1600's. These
dykelands have fine-textured soils derived from marine silt. Aside from a few small ponds,
freshwater on the valley floor
is limited to streams and rivers
Ecosection
Area (ha) % E codistrict Cumulative %
and occupies only 1.8% of the
WMHO
16584
17.9
17.9
ecodistrict.
Since the climate and soil
ICSM
12148
13.1
31.0
are so favorable for agriculture,
WCHO
11086
11.9
42.9
there is little left of the original
WCSM
9531
10.3
53.2
forest. The well-drained sandy
soil supports pure stands of
IMHO
6535
7.0
60.2
white pine, red pine and red oak
WM SM
6259
6.7
66.9
or mixtures of all three of these
fire species. Some of the sandy
DKLD
6184
6.7
73.6
sites are somewhat barren,
WFHO
5521
5.9
79.6
probably as a result of repeated
fires. A few jack pine are found
IFHO
5346
5.8
85.3
here with the other pines. Areas
IFSM
3868
4.2
89.5
near the rivers, where there is
44
more silt in the soil, once supported a riparian hardwood forest with elm, black cherry, and black ash. There are still a few locations where cedar is found and it was probably more common at one time. Red spruce and hemlock grow on the north facing valley slope, and extend into the valley on the moist sites. In many locales the valley floor is not flat but comprised of small hills and hummocks where the soil is not excessively sandy. These sites would have supported tolerant hardwoods on the upper slopes and red spruce, hemlock and pine on the lower or shaded slopes. Black spruce and larch grow on the wetter sites. Scattered red pine will also be found on these imperfectly to poorly drained soils which is contrary to the silvics of the species but not unusual in this ecodistrict. Throughout the valley and on the better drained soils sugar maple, yellow birch, beech and ironwood will be found but they rarely ever form pure hardwood associations occurring instead with white pine, hemlock and red spruce.
620 - Minas Lowlands Ecodistrict
Surrounding the Cobequid Bay and encompassing the adjacent lowlands this ecodistrict covers an area of 437 km2 or 10.7% of the ecoregion. Along the southern shore of the bay the ecodistrict is fairly narrow until it approaches Truro, where it widens and extends inland to the Cobequid Slopes Ecodistrict (350). Several major rivers pass through the ecodistrict including the Shubenacadie, Salmon, Chiganois, Folly, Debert and Bass. Much of the area is close to sea level, with the highest elevation seldom exceeding 40 m above sea level. The climate is such that on the better soils, conditions permit the growing of many of the crops associated with the Annapolis Valley, such as corn and strawberries.
The entire ecodistrict is
underlain by the Triassic era red Ecosection
siltstones and sandstones. On the north shore of the Cobequid Bay
WMHO
most of the ecodistrict has been
IMHO
covered by glacial deposits of sand and gravel which have formed deep
WCHO
beds. Evidence of this can be seen
IMSM
in the extensive aggregate quarries outside of Truro. The soft sandstones along the bay have been
DKLD IFHO
gradually eroding and extensive
XXMS
tidal flats on both sides of the bay
are evidence of a once larger land mass.
Area (ha) 14932 10722 4227 3162 2982 1772 1355
% E codistrict 34.1 24.5 9.7 7.2 6.8 4.1 3.1
Cumulative % 34.1 58.7 68.3 75.6 82.4 86.4 89.5
The forests of this ecodistrict are predominantly comprised of softwood species, with very few stands of tolerant hardwood. Only on the few well-drained hills will the presence of sugar maple and beech be noted. Elsewhere, the tolerant hardwoods will be found growing in mixedwood associations with red spruce, hemlock and white pine, particularly on the steep-sided slopes of the streams and rivers flowing to the bay. Where the soils are imperfectly to poorly drained, the forests are dominated
45
by black spruce and scattered with white pine on the better drained microsites. These forests are replaced with stands of red spruce and a lesser component of hemlock on better drained soils. A few areas of the ecodistrict have deep, dry, coarse sandy soils where red pine and white pine occur which could have originated after fire. Similar to the Annapolis Valley Ecodistrict, the Minas Lowlands have very little in the way of lakes, with most of the freshwater resource (2% of the ecodistrict) occurring in streams and rivers and a few small ponds. Since European settlement the construction of dykes has been used to claim farmland from the tidal waters of the bay.
630 - Central Lowlands Ecodistrict
In central Nova Scotia lies a significant lowland encompassing much of Hants and Colchester
counties. A significant feature of this central basin is the extent to which it is drained by several large
rivers, all of which are affected by the tidal movements of the Bay of Fundy. The only exception is
the Musquodoboit River, which
drains to the Atlantic Ocean. Most of the ecodistrict is fairly level with hummocky to
Ecosection IFHO*
Area (ha) 56278
% E codistrict 20.8
Cumulative % 20.8
undulating topography, with
IFKK
44040
16.3
37.1
elevations seldom exceeding 90
m above sea level. The climate
WFHO*
27168
10.0
47.1
is conducive to farming and the
IFRD
24779
9.2
56.3
area has been extensively used for
WFKK
17834
6.6
62.9
dairy and beef production and the
growing of forage and cereal
IMHO
17570
6.5
69.4
crops, including corn. The total
IFSM
15595
5.8
75.2
area of the ecodistrict is 2,704
km2 or 66.4% of the ecoregion.
IMSM
10504
3.9
79.0
IMRD
8361
3.1
82.1
This ecodistrict is
underlain by Carboniferous shale,
WMKK
7814
2.9
85.0
limestone, sandstone and gypsum.
WT LD
7342
2.7
87.7
Karst topography (sink holes) is
common on areas underlain by
WMHO
6677
2.5
90.2
gypsum in the southwest of the
*These ecosections have karst topography with sinkholes;
ecodistrict. Glacial outwash
11,715 hectares has been identified on these and other ecosections
deposits, some of which have
within the ecodistrict.
been quarried for aggregate, are
abundant, especially alongside the rivers. However, most of the ecodistrict has fine textured soils
comprised of loams, silts and clays. These deep, reddish-brown soils are characteristic of the
ecodistrict and have been derived from the underlying Carboniferous rock. The drainage has been
restricted on most of the soils due to glacial compaction of these finer textured soils. An area of
sandier soils is found south of the river near Upper Kennetcook. A conspicuous feature of the
ecodistrict is the abundance of large peat lands and adjacent areas of imperfect to poorly drained
46
forests over impermeable clay loam till on level terrain near the Cogmagun and Tom Cod rivers. A few freshwater lakes dot the ecodistrict but when added to the streams and rivers the total area is only 3,976 hectares or 1.5% of the ecodistrict. As is characterized by the ecoregion, the forests of the Central Lowlands Ecodistrict are predominantly softwood. Only on a few well-drained hills will pure stands of tolerant upland hardwood be found. Usually yellow birch will grow in association with red spruce on the welldrained hummocks mixed with an occasional occurrence of beech, sugar maple and hemlock.. Red spruce with scattered white pine and hemlock may occur on the better drained sites, with the latter species being found predominantly on steeper slopes near streams and rivers. On sites where soils are derived from the glacial outwash till, white pine will occupy the coarser soils. Forests of black spruce and scattered white pine will be found on the imperfectly drained soils. An unusual association is the occurrence of red pine with black spruce on the imperfectly and poorly drained clay soil that is prominent on the smooth topography of the watersheds of the Tom Cod and Cogmagun rivers. Many of these spruce/pine sites have originated from fire. The suppression of fire in this ecosystem may lead to the absence of red pine in the future.
700 - Western Ecoregion
The Western Ecoregion extends from Yarmouth to Windsor and includes the Halifax
peninsula. The ecoregion excludes the Annapolis Valley and the coastal ecoregions along the Bay
of Fundy and the Atlantic Ocean. The surface of this region is part of the Appalachian peneplain
which tilts towards the southeast, creating some of the longest rivers in Nova Scotia. Elevations of
200 m or more are common on the South Mountain while still in view of the Valley floor (maximum
of 289 m near Salmontail Lake, Kings County) and gently tapers to the Atlantic coast with elevations
of 25-50 m above sea level. The
ecoregion is underlain by Meguma slate and quartzite, as well as the extensive granitic South Mountain
Distinguishing Ecoregion Feature: An upland tilting towards the Atlantic Ocean comprising the southwestern half of the peninsula of Nova Scotia and with milder weather conditions than the eastern
batholith (a massive intrusion of portion of the mainland.
igneous rock caused by upwelling
magma and forced into the
surrounding rocks). Significant portions of the ecoregion in the southwest are covered by wetlands.
The center of the ecoregion is occupied by an extensive drumlin field that is dissected by the LaHave
River. The total area of the Western Ecoregion is 16 870 km2 or 30.5 % of the province.
The climate of the Western Ecoregion is mild winters (average -3.5oC) and warm summers, with total precipitation between 1300-1500 mm per year. Since no part of the ecoregion is more than 60 km from the Atlantic Ocean or Bay of Fundy, significant temperature and precipitation variation can occur.
Forest stands of red spruce, hemlock and white pine are most prominent in the Western Ecoregion and perhaps more so than anywhere else in the province. Stands of this distinctive
47
Maritime forest occur on the sandy and generally shallow soils of the ecoregion. Other dominant trees include the fire species red oak and red pine. Pure stands of white pine can be found on the drumlins, eskers and flutes of the barren lands and occupying abandoned fields on the drumlins along the LaHave River and elsewhere. Although balsam fir occurs in most of the forest types, its dominance within stands has been reduced by the damaging effects of the balsam woolly adelgid (Adelges piceae) a gout-causing forest pest introduced from Europe circa 1910. Significant portions of the ecoregion are occupied by stunted forests of black spruce on the bogs. Large tracts of red maple occur on other wetlands associated with the western rivers. A conspicuous feature of this ecoregion are the extensive barrens occupied by sparse forests of black spruce and white pine with a shrub and herb layer dominated by a variety of ericaceous (heath) plants such as lambkill, huckleberry, rhodora, leather leaf, bearberry and black crowberry. Gorman (1955) reported a theory by Titus Smith on the anthropogenic origin of the heathland repeated fires for domestic forage production (circa 1780) produced a complete change in the forest. Smith stated that "the ground becomes so much exhausted that it produces only a growth of heathy shrubs" and that "it is probable that at no very distant period, many large tracts will present nearly the same appearance as the naked heaths and downs of the old world". Strang (1972) concluded in his study on these barrens that "although fire is undoubtedly a potent factor in maintaining the shrub cover, pollen analyses indicate that an open woodland developed many centuries ago in response to the soil conditions and prevailing climate. The present shrubby vegetation is thus an expression of inherent site factors as well as of the effects of burning." Most likely the early fires of the European settlers aggravated an already fragile environment, but as Smith also reported after his 1801-02 travels, as long as fire is not so frequent that turf cannot be re-established then trees may be reestablished. Fire suppression has significantly reduced the amount of area burnt by wildfire over the past century in the Western Ecoregion. The result of this can be seen in the increased acreage of young forest now occupying the barren lands. Natural disturbances such as fire and blowdown have been an important component in forest succession of the ecoregion. During his western tour of the province in 1802, Titus Smith described large areas destroyed by fire and blowdown. Between St. Margaret's Bay and Chester, Smith wrote that he had been "remarkably delayed by windfalls being sometimes obliged to spend Ѕ hour in going 100 yards...." The high hazard of fires and the frequent wind damage from hurricanes have the potential to create large openings in the forest cover. However, old growth forests of pine, hemlock and spruce can be found in the ecoregion, indicating the infrequency of catastrophic stand disturbances. A more recent impact on the ecosystems (terrestrial and water) of this region are the acidic inputs from precipitation that originates from industrial regions of the continent. Large areas of the ecoregion do not have the buffering capacity within the soils to neutralize these acidic depositions, therefore increasing the acidity of many fresh water rivers and lakes. Since early settlement by Europeans, most of this ecoregion has been extensively logged several times to provide timbers and pulpwood. 48
Ecodistricts of the Western Ecoregion
710 - Valley Slope
885 km2
720 - South Mountain 4551 km2
730 - Clare
1915 km2
740 - LaHave Drumlins 2751 km2
750 - Rossignol 760 - Sable 770 - Western Barrens 780- St Margaret's Bay
1179 km2 2944 km2 796 km2 1848 km2
710 - Valley Slope Ecodistrict
The Valley Slope Ecodistrict includes a series of hills and slopes with a northwesterly aspect. The ecodistrict is bounded by the Annapolis Valley (610) and the South Mountain (720) Ecodistricts and extends from the Bear River and Acacia Valleys in the west to Mount Denson in the east. With a climate warmed by the westerly exposure and far enough inland that the cold waters of the Bay of Fundy do not impact local climate, these slopes have been used extensively for apple orchards and mixed farming. The total area of the Valley Slope Ecodistrict is 885 km2 or 5.2% of the ecoregion.
Between Annapolis Royal and Middleton, Devonian granites constitute the bedrock. Soils on this parent material tend to be coarse to moderately coarse, well drained and commonly gravelly with surface stones limiting both machine operability and tree stocking levels. However, slates, schists and quartzites of the Meguma Group underlie the slopes in Kings County , providing well drained, moderately coarse to medium textured soils. There are only two areas of the ecodistrict where finer textured soils occur and these are underlain by Horton Group sandstones near Middleton and Hantsport.
On the upper slopes of the well-drained ecosections, tolerant hardwoods are the climax forests. Sugar maple, beech and yellow birch with scattered white pine dominate these sites. Further down the slope and in the shaded dissections (ravines), hemlock and red spruce are found with a good example at Kentville Ravine. On moist soils, the climax forest is comprised of tolerant softwoods, including red spruce, hemlock, white pine and balsam fir.
Ecosection WFKK WFHO WMHO WCKK WMKK WCHO IFHO WMDS
Area (ha) 27849 13190 11845 9949 6749 4704 4544 2712
% E codistrict 31.5 14.9 13.4 11.2 7.6 5.3 5.1 3.1
Cumulative % 31.5 46.4 59.7 71.0 78.6 83.9 89.0 92.1
49
720 - South Mountain Ecodistrict
The South Mountain Ecodistrict, the largest in the classification, is a fairly homogenous land mass underlain by Devonian granite (the South Mountain Batholith). It extends from the headwaters of the Tusket River to Panuke Lake wrapping around the LaHave Drumlin Ecodistrict (740). In western Nova Scotia, the highest elevations of 200-250 m above sea level are found within this ecodistrict in an area stretching roughly from Paradise Lake to Gaspereau Lake. The headwaters for some of the province's longest rivers, including the Tusket, Medway, Mersey, LaHave, Jordan, and Roseway are located in this ecodistrict. The climate consists of warm, early springs and warm, dry summers which, when combined with the coarse, shallow soils, creates periods in the growing season where moisture deficits can be significant. Winters are moderately mild, although if snow is going to accumulate in western Nova Scotia, it is most apt to do so in this ecodistrict due to the higher elevation. The total area of the South Mountain Ecodistrict, is 4,551 km2 or 27% of the ecoregion.
The predominant soils are well-drained, coarse sandy loams that have developed on granite till. For the most part the soils are shallow, stony and dry. Furthermore, the landscape is dotted with large granite boulders which restrict operability and, in some cases, limit stocking levels within forest stands. Approximately 5.5 % of the ecodistrict has exposed bedrock due, in part, to the absence or shallowness of the glacial till and repeated wildfires, which have prevented the accumulation of organic matter. Even in areas where the soil drainage is imperfect to poor, the soils are usually coarse textured, sandy loams. Approximately 7.5 % or 342 km2 of the ecodistrict is comprised of lakes and rivers.
Fire has played a dominant role in shaping the forests of this ecodistrict and fire species such
as white pine, red pine and red oak occur on sites where the soils are well drained, as would be found
on upper slopes and ridges. Many fire sites will reforest with black spruce and white pine and
develop a significant understory layer of ericaceous (heath) vegetation. Those areas where the soils
are moist, for example on middle to lower slopes, will be occupied by red spruce and hemlock. The
tolerant hardwoods will
also occupy the unburned Ecosection sites on upper slopes and
Rockland %
Area (ha)
% E codistrict Cumulative %
will include sugar maple,
beech, yellow birch and ICHO
4.3
183155
40.2
40.2
red oak.
WCHO
10.1
100042
22.0
62.2
WCKK
6.5
70147
15.4
77.6
Significant areas
of barren land occur in ICSM
2
23521
5.2
82.8
the vicinity of the WTLD
1.4
15339
3.4
86.2
Shelburne River. Here,
dense vegetation of WCDM
1.3
7409
1.6
87.8
huckleberry, rhodora and WMDM
0
5147
1.1
88.9
lambkill restrict softwood
regeneration creating IMHO
0
3630
0.8
89.7
50
sparse stands of white pine and black spruce. However, on sites that have been spared the effects of repeated fire, old growth red spruce, hemlock and white pine are found, with one of the province's best examples of old growth on Sporting Lake Island. This association of red spruce, white pine and hemlock is consistent and repeats throughout the ecodistrict and is associated with the WCKK and WCHO ecosections, coarse textured, well-drained soils on hills and large hummocks of the uplands. Smith (1857) reported extensive areas of the Acadian softwood climax forest of red spruce, hemlock and white pine during his western tour of the province in 1802. Where these ecosections have been repeatedly burned, especially in the western portion of the ecodistrict, forests of white and red pine and red oak are common. Repeated wildfires (both natural and anthropogenic) and a history of intensive harvesting since European settlement in the 1600's has influenced the composition of the forest. Large areas of red maple and white birch can be found in the ecodistrict, with the expectations that if fire can be eliminated from the site they will eventually revert to the tolerant hardwood and softwood associations as characterized by the few remaining old growth examples in the ecodistrict. An area of drumlins near Fisher Lake (Annapolis County) has been included as part of the ecodistrict. There are many drumlins scattered throughout the ecodistrict, but they do not dominate the landscape to the extent that they require a separate ecodistrict designation (less than 3% of the total area of the ecodistrict). Usually the tops and upper slopes of drumlins are occupied by forests of tolerant hardwoods such as sugar maple, yellow birch and beech, with occasional red oak on fire sites. Middle and lower slopes are occupied with tolerant softwood such as red spruce, white pine and hemlock. These same species will also occupy the well-drained matrix between drumlins or, where soils are imperfectly drained, will be replaced by black spruce and scattered white pine and red maple. The Panuke Lake old growth hemlock stand is on a well-drained, coarse textured drumlin ecosection (WCDM). Abandoned farmland on drumlins tends to reforest with white pine. 730 - Clare Ecodistrict This ecodistrict is easily separated from its two neighboring ecodisricts, the South Mountain ecodistrict (720) by soil texture and from the Sable ecodistrict (760) by soil drainage. It extends from Digby to Yarmouth. The ecodistrict is heavily covered with lakes and rivers (9.6%). Early, mild springs followed by cool summers and mild winters describes the climate of the ecodistrict. Approximately 1300-1400 mm of precipitation is received annually. The Clare Ecodistrict also has the longest growing season in the province, with 210 growing degree days (50C basis). The total area of the Clare Ecodistrict is 1,915 km2 or 11.4% of the ecoregion. The Clare Ecodistrict is located on an undulating to gently rolling, drumlinized till plain underlain by greywacke, slate, quartzite and schists. The soils that have developed on the slate and quartzite till plain are predominantly well-drained, stony, sandy loams on the gentle hummock topography and the drumlinized till plains. Imperfectly drained soils associated are found in the depressions between drumlins and hummocks, as well as in those areas where internal drainage has been restricted due to glacial soil compaction. 51
The forest associated with the
various landforms has been changed by Ecosection Area (ha) % E codistrict Cumulative %
the long period of European IMHO
66727
34.8
34.8
settlement. However, it appears the
upper slopes and tops of drumlins and WMDM
49503
25.8
60.7
hummocks supported stands of sugar WMHO
27582
14.4
75.1
maple, yellow birch and beech. On the
moist lower slopes and on flatter areas IMSM
13122
6.9
82.0
between drumlins, red spruce, hemlock WT LD
7297
3.8
85.8
and white pine occurred. On the
wetter, mineral soils, black spruce WMKK
2550
1.3
87.1
forests are common grading to red WCHO
2433
1.3
88.4
spruce, white pine and hemlock as
drainage improves. It could be
expected on the coastal areas where most of the natural forest has been cleared, that the well-drained
sites supported tolerant hardwoods, red spruce and white pine. Wildfires caused by lightning are
infrequent in this ecodistrict due to the amount of precipitation and the occurrence of fog in the
summer. Other natural disturbances include losses to storm damage (most likely winter ice) and the
occasional hurricane. Gap replacement events would include tree mortality due to insects and
diseases. It is most likely that the forests of Clare are not subjected to massive natural stand initiating
events unless it is the infrequent occurrence of fire.
740 - LaHave Drumlins Ecodistrict Perhaps one of the better examples of a drumlinized till plain in eastern North America, this ecodistrict encompasses an area from New Ross in the east to Kejimukujik National Park in the west. This drumlin field exhibits the classic streamlined, tear-drop shaped deposits of glacial till, with the tapered or narrow end pointing in the direction of glacier movement. The ecodistrict slopes in a southeasterly direction toward the Atlantic Ocean with an average elevation of 107 m above sea level. The Ecodistrict is bounded on the south by the South Shore Ecodistrict (830) and by the granitic soils of the South Mountain (720) and St. Margaret's Bay (780) to the north and east, respectively. This area of Nova Scotia has perhaps the most pleasant climate of the province with early, warm springs and a long growing season, followed by a relatively mild winter. The area receives approximately 1400 to 1500 mm of precipitation annually. The total area of the LaHave Ecodistrict is 2,751 km2 or 16.3% of the ecoregion.
52
Ecosection
Area (ha)
% D istrict
Cumulative %
Shallow, stony till derived from the underlying slates
WMDM
70732
25.7
25.7
dominates the ecodistrict. Most
WFDM
34304
12.5
IMSM
31857
11.6
38.2
of the soils can be characterized as
well-drained, shallow, sandy
49.8
loams except those developed on
IMHO
23236
8.4
58.2
drumlins, which tend to be deeper
WMHO
23133
8.4
and less stony. In the eastern
66.6
portion of the ecodistrict the soils
WFHO
18279
6.6
73.2
tend to be moderately well-
IMDM
15743
5.7
drained, shallow, stony, gravelly
78.9
sandy clay loams which are deeper
WT LD
6299
2.3
81.2
and less stony on the drumlins.
IMRD
5542
2.0
83.2
Variation does occur in the
drumlin field near New Ross
WMKK
5161
1.9
85.1
where a reddish, moderately fine-
WM RD
3252
1.2
86.3
textured till overlies the granite
bedrock and is stony and shallow.
Much of the area between the
drumlins tends to be shallow, imperfectly drained till where the slate bedrock is just below the surface
on hummocky terrain with poorly drained soils in the depressions. Total freshwater area in the
ecodistrict is 27,634 hectares or 10%.
The ecodistrict is dominated by coniferous forests, but tolerant hardwoods will be found on the tops of drumlins and on the upper slopes of well-drained hills. Sugar maple, red oak and beech are also found on the valley floors of the major waterways. Smith (1857), on returning home after his western tour in 1802, reported elm in the LaHave River valley and that this was the first they had seen since leaving Halifax. Hemlock, red spruce and white pine will be found on the side slopes of the drumlins and on the moist soils of lower slopes. Large areas of imperfectly drained soils occupy the areas between drumlins and, in most cases, forests of black spruce with white pine are dominant. After disturbance, balsam fir is an early component of the coniferous forest in this ecodistrict and has been developed as a significant commercial resource as a preferred species for Christmas tree cultivation.
750 - Rossignol Ecodistrict The Rossignol Ecodistrict is largely made up of low hills with elevations between 100-130 m above sea level. It includes Lake Rossignol, the largest lake on mainland Nova Scotia. The ecodistrict is bounded on the east by the LaHave Drumlins (740), on the west by the hills forming the valley of the Mersey River (Sable 760) and by the South Shore (830) Ecodistict. The Rossignol Ecodistrict has early springs, warm summers and mild winters. The total area of this ecodistrict is 1,179 km2 or 7% of the ecoregion.
53
The bedrock is mostly Meguma quartzite and the soils are derived from glacial drift. The soils
tend to be moderately coarse, stony and shallow making them unsuitable for agriculture. Forestry is
the principal land use in the
ecodistrict. Bogs are common in Ecosection Area (ha) % Ecodistrict
Cumulative %
the depressions of the undulating WMHO 50570
42.9
42.9
topography. Freshwater lakes and
rivers make up 18.3% of the
IMSM
14888
12.6
55.5
ecodistrict, with another 5.6 % in IMHO
12752
10.8
66.3
wetland ecosections underlain with
WT LD
3348
5.6
72.0
poorly drained, medium textured
soils on smooth or level topography IMDM
6441
5.5
77.4
(PMSM). Smith (1857) described WMDM
2471
2.1
79.5
Lake Rossignol as " not a regular
valley filled with water .... but a WM RD
1837
1.6
81.1
small concavity in a great plain of
rocks...."
Forests in this ecodistrict are vulnerable to fire and wind damage. Hurricanes sometimes cause considerable blowdown. Fires are common, but the effects have not been so severe as to cause the extensive barrens more common further southwest.
On the upper slopes of the well-drained ecosections, the climax forest is hardwood. Yellow birch is the most abundant tolerant hardwood, with some sugar maple. Red oak is fairly common and beech was formerly abundant. White pine and red spruce are found mixed with the hardwood. On lower slopes and better drained sites between hills, the climax forest is hemlock, red spruce and white pine. Black spruce becomes dominant on imperfectly drained sites and treeless bogs are found on the wettest sites.
760 - Sable Ecodistrict
The Sable Ecodistrict is easily separated from the adjacent ecodistricts by the abundance of
poorly drained soils
and extensive areas of Ecosection Rockland % Area (ha) % E codistrict
Cumulative %
bogs and wetlands. IMHO
4.0
113015
38.4
38.4
The Sable Ecodistrict
is bounded on the WT LD
1.2
45391
15.4
53.8
northeast by the hills WMHO
0.6
32128
10.9
64.7
bordering the valley of
the Mersey River. IMSM
2.0
29214
9.9
74.6
Although the bedrock PMHO
2.4
20280
6.9
81.5
and soils are similar to ICHO
0
18278
6.2
87.7
the adjacent Rossignol
Ecodistrict (750), the WCHO
0.8
7935
2.7
90.4
54
Sable Ecodistrict is somewhat less hilly with extensive areas of bogs - Dunraven Bog is one of the better known examples. Almost one-quarter of the ecodistrict is poorly drained. Only a few of the higher hills reach an elevation of 100m, and much of the ecodistrict is less than 60m above sea level. On the south it is bounded by the South Shore (830) Ecodistrict, which extends inland following inlets and harbors such as Port Joli, Port l'Hebert, Sable River, Jordan Bay and Shelburne Harbour. The Sable Ecodistrict extends west as far as Great Pubnico Lake, where it meets the coastal Tusket Islands Ecodistrict (840). On the northwest, the presence of drumlins and a higher percentage of welldrained ecosections serves to separate the Clare Ecodistrict (730). Coarse textured soils and granite bedrock delineate the boundaries of the Western Barrens (770) and South Mountain (720) ecodistricts on the north. The Sable Ecodistrict is the most southerly part of Nova Scotia, excluding the adjacent coastal ecodistricts which are cooled in summer by the ocean, so the summers are hot. The total area of the ecodistrict is 2,944 km2 or 17.4% of the ecoregion. The bedrock of the Sable Ecodistrict is mostly Meguma quartzite and slate. There are also extensive areas of granite in the western part of the ecodistrict, for example Spar Ridge. Soils are mostly moderately coarse, shallow and rocky. There are some extensive areas of coarse textured soil near Shelburne in the southwestern end of the ecodistrict. The well-drained sites can be somewhat dry during the growing season. Freshwater in lakes and rivers accounts for 5.8% of the total area of the ecodistrict. On the well-drained hills and hummocks (WCHO) with coarse textured soils, a climax forest of red oak, white and red pine will occur. Where the soil becomes less coarse (WMHO), these ecosections will support a forest of red spruce, hemlock and white pine. About one-quarter of the ecodistrict is treeless bog, or supports a stunted black spruce forest. Better drained hummocks in the boggy areas support a forest of white pine and black spruce. About half of the ecodistrict is covered by imperfectly drained, moderately coarse soils. These ecosections have a climax forest of black spruce, with white pine on the upper slopes of hills and on better drained microsites. The poorly drained sites support a forest of stunted black spruce. A total of 2.2% of the ecodistrict is exposed bedrock. 770 - Western Barrens Ecodistrict The Western Barrens Ecodistrict is located in the interior of western Nova Scotia. The topography, geology and soils are similar to the adjacent South Mountain (720), which surrounds the northern portion of the ecodistrict. The southern boundary is adjacent to the Sable (760) and Clare (730) ecodistricts. Its position in the interior of the province, away from the moderating influence of the ocean, means that summers are hotter and drier and winters are cooler than adjacent ecodistricts. Elevations reach about 200m. The total area of the ecodistrict is 796 km2 or 4.7% of the ecoregion. 55
Like the adjacent South
Ecosection Rockland % Area (ha) % E codistrict
Cumulative %
Mountain
ICHO
2.1
34447
43.3
43.3
Ecodistrict (720),
WCHO
6.4
33623
42.3
85.5
this area is
comprised of a
ICSM
2.7
4118
4.7
90.2
rolling till plain
WT LD
0
3722
4.1
94.3
underlain by a
massive granite
WCKK
0
423
0.5
94.8
batholith.
Repeated fires in this ecodistrict have caused widespread barrens, which have been slow to regenerate
tree species due to the frequency of the fires and the coarse, shallow and infertile soils. As well, many
of the soils in this ecodistrict are characterized by a massive orstein layer (locally known as hardpan)
which is impervious to water movement and significantly restricts rooting depth to a few centimeters
below the surface. Much of the ecodistrict is carpeted with dense layers of ericaceous (heath)
vegetation including huckleberry, rhodora and lambkill on drier sites and leatherleaf and Labrador
tea on the wetter sites. The extensive root mat created by these shrubby, acid loving plants severely
restricts regeneration of softwood species and only sparse stands of white pine and black spruce
occur. Scrubby red maple and white birch occur throughout the ecodistrict. If fire is removed from
the disturbance regime for this ecodistrict, many of the better sites may revert to the tolerant
hardwood and softwood associations as characterized by the few remaining old growth examples in
the ecodistrict. However, Strang (1972) concluded that the factors which mitigate against profitable
afforestation are such that other land use possibilities are equally circumscribed and that no useful
purpose will be served by expensive efforts to plant trees which will grow only slowly at best.
Freshwater lakes and rivers account for 4.9% of the ecodistrict. A total of 3.7% of the ecodistrict has
exposed bedrock although this may seem low given the significant amount of large boulders scattered
across the landscape giving the local name "flintstone theatre" to the area. Strang (1972) conclcuded
that this area "with its complex of streams, lakes, bizarre terrain and seasonally spectacular vegetation
might best be utilized as a wilderness area and ecological curiousity."
780 - St. Margaret's Bay Ecodistrict The St. Margaret's Bay ecodistrict encompasses the eastern portion of the South Mountain granitic batholith. Sloping in a south to southeasterly direction towards St. Margaret's Bay and Mahone Bay this gently tilting upland ranges from 150 m along its northern border at Panuke Lake to sea level along the Atlantic coast. The LaHave Drumlins (740) form the western boundary where elevation may exceed 200 m. The Halifax Peninsula, excluding the portion in the coastal Eastern Shore ecodistrict (820), is the southern most component with the Eastern Interior (440) forming the eastern border. The ecodistrict, when compared to the rest of the South Mountain uplands, which have similar parent materials and topography, has a moister climate. The effect of lower elevations adjacent to the coastal waters of St. Margaret's Bay and Mahone Bay create conditions for more rain and fog. There are also fewer growing degree days than are found in the remainder of the South Mountain
56
ecodistrict. The total area of the St. Margaret's Bay ecodistrict is 1,848 km2 or 11% of the Western
ecoregion.
The predominant soils are well drained sandy loams that have developed on granitic till and
are very similar to soils found in the South Mountain ecodistrict. For the most part the soils are
shallow and stony and the landscape is dotted with large granite boulders. Soils on this parent
material tend to be coarse to moderately coarse, well drained and commonly gravelly with surface
stones limiting both machine operability and stocking levels to Ecosection Area (ha) % Ecodistrict
Cumulative %
trees. The areas north of Big Indian WCKK
69971
37.9
37.9
Lake, surrounding Five Mile Lake and WCHO
37151
20.1
58.0
near Big Black Lake exhibit thin or
discontinuous till on glacially scoured ICHO
32380
17.5
75.5
basins and knobs. Here the topography WMHO
5762
3.1
78.6
is flat to rolling with ridges of exposed
bedrock. The topography has an ICRD
5012
2.7
81.3
irregular arrangement of low rounded WCDM
3437
1.9
83.2
hills and hummocks with pronounced
ridges , especially where the soil is ICSM
3371
1.8
85.0
thin and/or the bedrock is exposed.
Dispersed throughout this chaotic topography are small streams and rivers, bogs and swamps and
several large lakes. The largest river, the Gold River, drains the western portion of the ecodistrict. The
Pockwock Lake watershed is a significant water supply source for the municipality of Halifax and is
within the ecodistrict. Approximately 7.4 % or 13,657 hectares of the ecodistrict is comprised of lakes
and rivers.
The predominant feature of this ecodistrict is the red spruce forest which occupies all slope
positions throughout the area. Hemlock will be found on the lower and toe slopes near watercourses.
White pine and black spruce with a heavy cover of ericaeous shrubs will be found on the shallow and
drier soils of the ridges. Black spruce will occupy the poorly drained soils associated with the lower
level ecosites. Occasionally stands of tolerant hardwood will be found on the deeper well drained soils
of larger hills. Hurricanes have played a significant role in shaping the forests of this ecodistrict. Most
likely due to its geographic position near the Atlantic Coast and at the end of two major coastal bays
this area is impacted more frequently than the inland areas of the South Mountain. The added
moisture from rains and fog during the spring and summer seasons may also reduce the possibility
of fires as compared to the drier South Mountain ecodistrict where red and white pine, white birch
and red oak, indicators of a fire history, are more prevalent. The added moisture during the growing
season also assists in the re-establishment of red spruce forests after natural or human disturbances.
800 - Atlantic Coastal Ecoregion
This ecoregion extends along the Atlantic coast of the province from Yarmouth to Scaterie Island. The Atlantic Coastal Ecoregion
Distinguishing Ecoregion Feature: A coastal climate dominated by its proximity to the Atlantic Ocean and vegetation reflecting this climate.
57
seldom exceeds five km in width, except along the Cape Breton shoreline where the coastal influence can extend almost 12 km inland. In areas where bays, coves and rivers are indented inland for several kilometers from the ocean, for example, Mahone Bay, Shelburne Harbour, and Country Harbour, the effect of the coastal climate can be reduced or eliminated. The inland boundary of the ecoregion is more defined by the absence of certain vegetational species than by a geo-physical attribute. However, in some portions of the ecoregion, rising uplands (Mira Hills) and coastal islands (Clam Bay to Liscombe Point) reduce the influence of the coast further inland. The underlying geology is quite varied because of the extent of this ecoregion. However, since most of it is comprised of the lower elevations of the tilting Appalachian peneplain, the bedrock is predominately granite, quartzite or slate on the mainland. The Chedabucto Bay area is underlain by carboniferous sedimentary rocks. Along the east coast of Cape Breton Island, older precambrian rocks underlie the ecoregion. The soils of the ecoregion for the most part are thin and stony. However, thicker tills are found where drumlins extend into the ecoregion. Particularly in the east, significant portions of the ecoregion are covered with deep organic soils that have developed on flat or level topography where drainage has been impeded and the cool moist climate has favoured the development of the peat material. In areas where deeper sandy materials occur, a hardpan formation (also known as an ortstein layer) will be found restricting drainage and creating thick humus layers under forest stands. The total area of the Atlantic Coastal Ecoregion is 4691 km2 or 8.5 % of the province. There is no disputing the impact of the Atlantic Ocean on the climate of the ecoregion. The most notable impact of the coastal influence is that the ecoregion has the longest frost-free period in the Maritimes. Provincially, the ecoregion has the mildest winter, but this is offset by a slow spring warm-up and the lowest number of growing degree days in Nova Scotia. Annual precipitation is 1400-1500 mm, the bulk of which falls as rain with only an estimated 15% occurring as snow. Overall, the ecoregion is exposed to high winds, high humidity, salt spray, and fog during the summer and fall. The movement and mixing of the offshore currents, the warmer Gulf Stream and the colder Labrador Current, contribute to the significant variation in weather patterns from year to year. The late arrival of warmer offshore currents in the fall impacts the growing season and frost-free period. Another impact that, perhaps, is not completely understood at this time is the consequences of the construction of the Canso Causeway on ice movement through the Strait of Canso into Chedabucto Bay. The near absence of red spruce delineates this ecoregion from the adjacent Western and Eastern Ecoregions on the mainland. Only near Yarmouth and Lobster Bay (Tusket River Islands) can red spruce be found growing close to the coast. In the southwest, an indicator of the approximate inland boundary is the reappearance of red oak and white pine. White spruce is a common forest species on the most exposed sites in the Coastal Ecoregion, i.e. coastal islands and headlands, but becomes less abundant away from the water. Hardwood species take a subordinate role in the coastal forest with red maple and white birch common components of the understory of black spruce and balsam fir forests. Most notably on the nutritionally poor sites along the eastern shore, balsam fir will form dense stands with small diameters, an indication that site conditions do not allow self thinning. Much of the eastern portion is comprised of flat and raised bogs, fens and salt marshes. On sites with wet mineral soils, black spruce is the predominant tree species. Further east on the Canso 58
peninsula, large barren rock outcrops are presently covered only with scattered conifers and ericaceous (heath) vegetation. Most of the ecoregion is susceptible to windthrown and the area has experienced significant forest losses from hurricanes such as the Saxby Gale (1869). Loucks (1961) reports that fires have been common in the ecoregion but they appear to have been started by European settlers to extend their pasture land. He states, however, that the presence of jack pine in several places on the Canso peninsula and on Isle Madame suggests that the constant winds may create a drought condition that is conducive to wildfire.
Ecodistricts of the Atlantic Coastal Ecoregion
810 - Cape Breton Coastal 820 - Eastern Shore 830 - South Shore 840 - Tusket Islands 850 - Sable Island
1173 km2 1717 km2 1352 km2 418 km2 31 km2
810 - Cape Breton Coastal Ecodistrict
Extending along the north shore of Chedabucto Bay and along the coast of Cape Breton Island
this is the widest coastal ecodistrict in the province. Including both sheltered and exposed
ecosections, the coastal forest still dominates the vegetative cover of the area. The complexity of the
underlying geology is masked by the dominance of the coastal climate. Since the construction of the
Canso Causeway in 1953, there has been no movement of spring ice from the Gulf of St. Lawrence
through the Strait of Canso where currents once flowed at 4.26 x 103 to 8.46 x 103 cubic metres per
second from St. George's Bay (Fothergill, 1954). Spring ice still comes through Cabot Strait from
the Gulf of St. Lawrence and then gets blown against the Cape Breton coast. The impact of this
reduced quantity of offshore ice in the spring has yet to be determined, but it could be hypothesized
that the extent of coastal forest in this ecodistrict is in response to the late cool, wet springs when ice
remained offshore well into May. The total area of this ecodistrict is 1,173 km2 or 25% of the
Ecosection
Area (ha) % E codistrict Cumulative %
ecoregion. Sedimentary rocks, such as
IMHO
27951
23.8
23.8
siltstones, sandstones, shales and
WMKK
18362
15.7
39.5
conglomerates, predominate on
the Chedabucto north shore, Isle
WFKK
15279
13.0
52.5
Madame and northeasterly to
WMDM
11801
10.1
62.6
Loch Lomond. However, from
Point Michaud to Scaterie Island
WMHO
8974
7.7
70.2
the Forchu group of rocks
IFHO
6543
5.6
IMDM
6202
5.3
75.8
(volcanic granites, rhyolites and
andesite) as well as metamorphic
81.1
sediments (slate and quartzite)
WFHO
3442
2.9
84.0
underly a deep deposit of glacial
till, sand and gravels with the
59
underlying bedrock visible only along the coast. The glacial history of the Cape Breton portion of this ecodistrict includes various depths of glacial deposits and drumlins. Two dominant soils define the ecodistrict. On the north shore of Chedabucto Bay finer textured, well to imperfectly drained soils occur and extend to St. Peter's. From L'Ardoise to Mira Bay coarse, better drained soils are found, especially on the drumlins and elevated glacial deposits. However, several large areas of coarse textured, imperfectly drained soils will be found around the bays of Forchu and Gabarus and some poorly drained coarse soils occur at Little Lorraine. Lakes and rivers are significant within this ecodistrict, occupying 7,745 hectares or 6.6% of the ecodistrict. The dominant forest of the Cape Breton Coastal Ecodistrict is the white spruce, balsam fir and black spruce mix which is so prevalent in Nova Scotia's coastal forests and extends several kilometres inland. Species of the Acadian forest climax type start to appear as one moves inland from the coast. In sheltered areas occasional white pine will be noticed and tolerant hardwoods will be found in sheltered areas and on drumlins. For the most part, however, red maple and white birch predominate the hardwood component of the coastal forests. These coastal forests are also subjected to serious wind damage and both stand level disturbances and/or small gap disturbances will occur. The absence of white pine, sugar maple and beech are usually strong indicators of a coastal influence.
820 - Eastern Shore Ecodistrict
Starting on the east side of the Halifax peninsula and extending to the town of Canso, the Eastern Shore Ecodistrict spans a varied landscape of landforms, geology and soils. Nonetheless the influence of the Atlantic Ocean overrides these physical attributes to provide a consistent coastal climate reflected in the forests of the ecodistrict. In the west the ecodistrict is several kilometers narrower than in the east, where the coastal influence extends inward to encompass all of the Canso peninsula. For most of the ecodistrict, the influence of the ocean seems to extend inland until it reaches the 60 m contour except on the Canso peninsula, where coastal forests are found on elevations of 150 m. The total area of the ecodistrict is 1,717 km2 or 36.6% of the ecoregion.
At both ends of the ecodistrict granite barrens define the boundaries and inbetween are the greywackes and slates of the Goldenville formation. A variety of landforms occur across the ecodistrict. As one travels from the granite barrens of the Halifax peninsula eastward, sand beaches and dunes
Ecosection IMHO WCKK WMKK WCHO IMRD WM RD ICHO WMDM WCRD
Rockland % 5.2 8.1 66.4 37.1 14.0 38.7 0 22.0 13.7
Area (ha) 35327 28186 26864 14522 10115 7460 7327 6448 6118
% E codistrict 20.6 16.4 15.6 8.5 5.9 4.3 4.3 3.8 3.6
Cumulative % 20.6 37.0 52.6 61.1 67.0 71.3 75.6 79.4 83.0
60
give way to a proliferation of offshore islands, often drumlin in origin, to the coastal headlands of Guysborough County and finally to the granite barrens of the Canso peninsula. Where the soils are well-drained and sheltered from the coastal environment, the conditions for forest growth can be quite favourable for balsam fir. Lakes constitute a significant portion of the ecodistrict with 9,734 hectares or 5.7% of the ecodistrict covered in freshwater. Approximately 21.6% of the ecodistrict (36,350 hectares) is comprised of exposed bedrock, by far the greatest area of any ecodistrict. The absence of red spruce in the coastal forest is a strong indicator of coastal climatic influence. Other species absent because of the coastal influence are white pine, sugar maple and beech. Hardwoods, such as white birch and red maple, may also be absent in the overstory but are usually present in an intermediate or suppressed canopy position in the forest stand. A typical coastal forest is comprised primarily of balsam fir, black spruce and scattered white spruce. Where exposure to the ocean is extreme a narrow shoreline band of white spruce will form a krummholz type forest with extremely stunted growth. On the more sheltered sites with deeper soils, especially in the east, balsam fir will predominate over the spruces. These short-lived (usually less than 100 years) coastal forests, are constantly being renewed by stand initiating disturbance agents such as blowdown, disease, insects and occasional fires. The moist climate is conducive to regeneration establishment by balsam fir and black spruce and most stands will have already established a layer of advanced regeneration during the break-up of the overstory (McCurdy et al, 2003). 830 - South Shore Ecodistrict The South Shore Ecodistrict extends about 180 km along the Atlantic coast of Nova Scotia from the Halifax peninsula to Pubnico Harbour and extends inland approximately 10 km. The coastline is irregular, with many bays, inlets, headlands and islands. The climate of the South Shore is probably influenced by the warmer waters of the Gulf Stream more so than the Eastern Shore (820), which is cooled by the colder waters of the Labrador current before it deflects out into the Atlantic Ocean. The South Shore also shares the same topography and geology as the adjacent inland ecodistricts (720, 740, 750, 760) but is separated from them due to the impact of the coastal climate on biodiversity. Its location on the Atlantic coast means that the South Shore is cooler in summer and milder in winter than the adjacent inland ecodistricts, and fog is more common along the coast. The total area of the ecodistrict is 1,352 km2 or 28% of the ecoregion. The bedrock along the South Shore is mostly greywacke and granite. The soil is thin and moderately coarse-textured with imperfect to poor drainage. Sand beaches are common along the shoreline. Nearly 3.5% of the ecodistrict is covered with lakes and streams (4,673 ha). 61
Because the coast was the first part of Nova Scotia settled by Europeans, the forests have been
extensively harvested for a variety of products. Black and white spruce predominate the coastal forest
with scattered occurrences of balsam fir. The coastal headlands receive the brunt of the Atlantic
winds, which creates coastal forests of spruce where the trees are severely stunted. However, once
the impact of this exposure is diminished either by shelter from established spruce or distance from
the coast, other tree species will
establish in the ecodistrict
Ecosection
Area (ha) % E codistrict Cumulative %
although the thin soil can be a
IMHO
55580
41.1
41.1
serious impediment. The absence
of red spruce, except for the most
PMHO
17058
12.6
53.7
sheltered locations in the
WMHO
16580
12.3
66.0
ecodistrict, is usually an indicator
of the coastal influence of the
IMSM
7732
5.7
71.7
Atlantic Ocean. This ecodistrict
WT LD
5983
4.4
76.2
excludes the inner islands of
Mahone Bay which for the most
WMDM
5555
4.1
80.3
part are within the LaHave
WM RD
3626
2.7
83.0
Drumlin ecodistrict. The
vegetation of the forest
IMRD
3486
2.6
85.6
ecosystems on many of these
WCKK
2629
1.9
87.5
islands was studied recently
(SRES 2002). Red spruce and
WFDM
2074
1.5
89.0
white pine with scattered sugar
maple, yellow birch and hemlock were reported which indicates that these islands are afforded some
protection from the Atlantic Ocean.
840 - Tusket Islands Ecodistrict The Tusket Islands Ecodistrict includes the southern most part of Nova Scotia. The ecodistrict extends along the coast to Yarmouth Harbour where the Clare (730) Ecodistrict provides the northern limit. The Tusket Islands Ecodistrict has similar topography and geology to the adjacent ecodistricts (730,760) but can be separated from them due to the climatic influence of the Gulf of Maine. The ecodistrict has not been extended much past Yarmouth and along St. Mary's Bay since the coastal influence was determined to affect only a narrow band along this shore. The Tusket Islands Ecodistrict is made up of a submerged coastline with tidal rivers and inlets (Chebogue River), numerous islands (Tusket Islands) and saltmarshes. At any point the ecodistrict seldom exceeds 10 km in width. Overall, the moderating effect of the Gulf of Maine gives this area the mildest winters in the province and a frost free period for over half the year, longer than any other place in Atlantic Canada. Yarmouth's average January temperature is -2.7 degrees Celsius, the warmest of any mainland station in the Maritimes. However, summers are cool and fog is common. The total area of the ecodistrict is 418 km2 or 8.9% of the ecoregion.
62
The bedrock of the Tusket Islands Ecodistrict is mostly quartzite and slate. However, there
is an intrusion of granite near Wedgeport. Soils are derived largely from glacial drift with a
moderately coarse texture. An extensive area of salt marsh is found in this ecodistrict, comprising
approximately 4,977 hectares or 11.9% of the ecodistrict. Another 1,895 hectares (4.5% of the
ecodistrict) are classified as fresh water.
Forests in this ecodistrict have been heavily impacted by human activity. Black spruce is the
dominant species along the shore,
with white spruce and balsam fir.
Ecosection Area (ha) % E codistrict Cumulative %
In areas where shelter is provided
IMHO
27035
34.2
34.2
by topography, conditions are
suitable for other species such as
PMHO
8811
11.1
45.3
red spruce, white pine, red oak and
PMSM
7541
9.5
54.8
tolerant hardwoods. Red spruce
and white pine are the dominant
WMHO
6473
8.2
63.0
species on well-drained sites with
IMSM
6290
8.0
71.0
moderately coarse soil. The climax
forest on hills and drumlins with
WCHO
5830
7.4
78.3
well-drained, coarse-textured soils
WMDM
3069
3.9
82.2
is red oak and white pine. The
eastern limit of the ecodistrict
ICHO
2391
3.0
85.2
occurs at Pubnico Harbour.
Coastal influence southwest of that point is considered to be from the Gulf of Maine instead of the
Atlantic Ocean. The Gulf of Maine Working Group (Kelly 1999) use the Clyde River watershed as
the southerly limit of the Gulf of Maine watershed. There appears to be a climatic influence
associated with the Gulf of Maine, which allows the growth of red spruce and other tolerant species
such as white pine, sugar maple and yellow birch. The continuance of these species along the shore
to Cape Chignecto, around the Bay of Fundy and down the coast of Maine (Davis 1966) suggests that
the coastal influence of the Gulf of Maine is moderate compared to that of the Atlantic Ocean.
850 - Sable Island Ecodistrict Situated on the continental shelf 300 km east of Halifax is Sable island, a shallow, crescentshaped, 31 km2 island that is exposed to constant winds, salt spray and blowing sand. The island is oriented east-west and consists of two lines of high dunes, less than 50 m wide, and it is approximately 42 km by 1.4 km at low tide. The climate on Sable Island is warmer in winter and cooler in summer than the Nova Scotia mainland, but it receives similar precipitation. There are no trees on the island and the vegetation consists mainly of sea-beach sandwort, beachgrass and beachpea. Several shrubs can be found, including bayberry, wild rose, black crowberry, cranberries and common juniper. For a more detailed description of the geology, plant life and history of Sable Island a good reference is the Natural History of Nova Scotia, Volume 2 (1996).
63
900 - Fundy Shore Ecoregion
One of the smaller ecoregions, this narrow strip wraps around the Bay of Fundy starting at Sand River, Cumberland County to Five Islands before crossing over to Cape Split and continuing west to Brier Island. Loucks (1961), in his description of the forest regions, included a similar area from Cape Chignecto to Amherst. A significant feature of the geological history of this ecoregion is the basalt lava which flowed from rifts created by the movement of the continental plates as they drifted apart over 200 million years ago. This basalt underlies the North Mountain and can be found on the north shore of the Minas channel and eastward to Portapique. The topography can be quite variable, with sharply dissected slopes coming down to the Bay or gently undulating to rolling coastal plains skirting the shores. The highest elevations along the North Mountain rise up to 225 m above sea level, whereas the Parrsboro shore elevation seldom exceeds 125 m above sea level. Much of the soils in this ecoregion are moderately coarse, commonly stony to gravelly, and shallow to bedrock and well drained. However, there are large areas of finer textured, imperfectly drained soils occurring in the ecoregion where farming has occurred. The total area of the Fundy Shore Ecoregion is 1389 km2 or 2.5 % of the province.
The North Mountain bears the brunt of the weather coming off the cold waters of the Bay of
Fundy, protecting the Annapolis-Cornwallis valleys from the cooler climate and the fogs of the Fundy
shore. Summer temperatures are cooler and winters are
somewhat milder than the interior of the province.
Distinguishing Ecoregion Feature: A
However, the cold waters of the Bay of Fundy tend to
coastal climate dominated by its
prolong the arrival of spring. Total annual precipitation is
proximity to the Bay of Fundy.
1200-1400 mm and fog is frequent along the shores. A
narrow band of coastal forest is found along the shore and
is most notable on exposed cliffs. Here, white spruce
predominates but gives away quickly to mixedwood forests of balsam fir, red spruce, red maple, white
birch and yellow birch. Beech and sugar maple are found on the upper slopes and higher elevations.
White pine and hemlock are present but more common on the inland slopes of the North Mountain
and near the foothills of the Cobequid Mountains.
Ecodistricts of the Fundy Shore Ecoregion
910 - Parrsboro Shore 920 - North Mountain
409 km2 989 km2
910 - Parrsboro Shore Ecodistrict On the north shore of the Minas Basin, stretching from Economy Mountain in the east to Sand River in the west, is a narrow ecodistrict with a varied geological history. Nestled up against the Cobequid Hills Ecodistrict (340) the Parrsboro Shore can be best characterized as a series of small rolling hills dissected by the steep-sided canyons of rivers and streams flowing from the Cobequid Mountains. Several outwash plains are interspersed with this topography, with examples at
64
Parrsboro and Advocate. Overall, the elevation seldom exceeds 125 m above sea level, but the rapid descent to sea level affords the impression of a more significant rise. The local climate is significantly affected by the proximity to the cold waters of the Bay of Fundy. Summer temperatures are cool and fog is a common occurrence, even though hot and humid conditions may exist only kilometers away in Truro. The total area of the ecodistrict is 409 km2 or 29.2% of the ecoregion. Isle Haute in the Bay of Fundy is included in this ecodistrict.
The area has three major faults running its length, with a series of minor faults throughout.
This has created a varied landscape with resistant basalts and erodable sandstones side by side. The
lowlands are underlain by soft sandstone but where it is capped by basalt, high, steep-sided hills like
Economy Mountain are formed.
Large glacial outwash plains can Ecosection Area (ha) % E codistrict Cumulative %
be found at Parrsboro and
Advocate The predominant
WMKK
9699
23.7
23.7
shale-derived, sandy loam soils
WCKK
6003
14.7
38.4
cover the steep slopes from Five
WMDS
3691
9.0
47.4
Islands to Advocate. On the
lowlands, finer textured,
IFKK
2874
7.0
54.5
imperfectly drained soils are
WCHO
2796
6.8
61.3
found around Parrsboro. The
outwash valleys are underlain
IFHO
2741
6.7
68.0
with rapidly drained, coarser
WCSM
2371
5.8
73.8
textured soils, often with a high
content of gravel. Most of the
WCRD
2002
4.9
78.7
freshwater in the ecodistrict
WCDS
1820
4.5
83.2
occurs primarily in fast flowing,
narrow streams and rivers running off the Cobequids. The total freshwater area is 285 hectares or
0.7% of the ecodistrict.
Coastal forests of white spruce skirt the headlands along the Minas Basin, but they quickly revert to tolerant hardwoods and softwoods a short distance from the shore. Red spruce is the dominant softwood and will be associated with hemlock and white pine on the hummocky ecosections. Those ecosections with coarse textured, well-drained soils, and usually occurring on the slopes of hills and steeper hummocky terrain, will be dominated with forests of tolerant hardwoods such as beech, yellow birch and sugar maple. Adding to the complexity, both tolerant softwoods and hardwoods grow together on the moister, finer textured soils. Only in the steep-sided ravines will predominantly softwood forests of the tolerant species be found. Wind throw appears to be the dominant stand disturbance, although the spruce budworm has created large areas of evenaged spruce forests.
65
920 - North Mountain Ecodistrict
The North Mountain Ecodistrict is a narrow ridge parallel to the shoreline of the Bay of Fundy. It stretches for about 200 km, from Cape Blomidon to Brier Island. At the southwestern end, it is broken to form Digby Gut, Digby Neck, Long Island and Brier Island. A maximum elevation of about 240 m is attained. The North Mountain is the northern boundary of the Annapolis Valley Ecodistrict (610) and serves to shelter the valley from the cold waters of the Bay of Fundy. The south facing slope of the North Mountain can be quite steep in places, with escarpment-like features at several locations. Small steep-sided valleys, locally known as vaults, dissect the slope. On the Bay of Fundy side, the slopes are longer and more gradual, but usually end with vertical cliffs at the coastline as at Cape Split, Margaretsville and Keatings Sand Beach. The total area of the ecodistrict is 989 km2 or 70.7% of the ecoregion.
Ecosection
Area (ha) % E codistrict Cumulative %
The North Mountain is a ridge of basalt. Soils are mostly
WMHO
55681
56.3
56.3
moderately coarse and well-
WMKK
15350
15.5
71.8
drained. Although the soil is
stony, extensive areas on the
WMDS
9823
9.9
81.7
north slopes are suitable for
WFHO
7517
7.6
IMHO
5098
5.2
89.3
agriculture and can be used for
growing vegetables and forage.
94.5
Apple orchards extend up the
south facing slopes. Most of the
forest has been heavily harvested over the centuries and the current forest is a mixture of intolerant
hardwood species, white spruce and balsam fir, with scattered occurrences of red spruce and white
pine. Some of the less accessible sites near Cape Split and in the vaults suggest that the climax forest
consisted of both tolerant hardwood and softwood species. The total freshwater area is 373 hectares
or 0.4% of the ecodistrict.
On well-drained sites along the Fundy Shore, white spruce is the dominant tree species with black spruce on the wetter sites. A short distance inland, usually less than half a kilometer, red spruce will occur on the lower and middle slopes of the North Mountain while sugar maple and yellow birch are found on the upper slopes and crests. Beech was probably abundant at one time, but has been reduced to an understory species in most of the tolerant hardwood stands. However, there are still extensive areas on the steep slope overlooking the valley where beech, mostly low quality, is a dominant species. An example can be seen at the provincial park outside of Bridgetown. The vaults on the Fundy side support a varied forest with tolerant hardwoods, red spruce and a few white pine on the upper slopes. Shaded and lower slope of the vaults are red and black spruce and a few hemlocks. One of Nova Scotia's rarest native trees, white cedar, grows in a few locations near the southwestern end of the mountain.
66
REFERENCES Albion, R.G. 1965. Forests and sea power. Archon Books, Hamden, Connecticut, 485P. Basquill, S.P., S.J.Woodley and A.B.Pardy 2001. The history and ecology of fire in Kejimkujik National Park. Parks Canada, Tech.Reports in Ecosystem Science, Report 029, 189P. Bridgland, J., Cook, R., Power, R. and B. Pardy. Undated. Fire history of northern Cape Breton GIS analysis of biophysical inventory data. Unpublished manuscript. 14p. Cauboue, M. et al. 1996. Terminology of ecological land classification in Canada. Nat.Res.Can., Inf. Rep. LAU-X-114E, 62P. Clark, A.H. 1954. Titus Smith, Junior and the geography of Nova Scotia in 1801 and 1802. Annals Assoc. Am. Geographers, Vol. XLIV, No.4, p.291-314. COGS. 1999. 3-D Radarsat-1 Mosaic, Nova Scotia. Centre of Geographic Sciences, Annapolis Valley Campus, Nova Scotia. Map. 1:1,000,000 Davis, R.B. 1966. Spruce-fir forests of the coast of Maine. Ecological Monographs 36(2), pp.7994. Davis, D.S. and Browne, S. 1996. The Natural History of Nova Scotia (rev. ed.).Volume Two. Theme Regions. Nova Scotia Museum. Nimbus Publishing. 304 P and 1 map. Day, J.H. (Editor) 1983. The Canada Soil Information System (CanSIS) Manual for describing soils in the field 1982 Revised. Agriculture Canada, Land Resource Research Inst., Ottawa, Contribution No. 82-52. Dzikowski, P.A. et al. 1985. The climate for agriculture in Atlantic Canada. Publ. No. ACA 84-2500, Agdex N. 070, Atmospheric Environment Service, Bedford, Nova Scotia. 18 P +17 maps. Ecological Stratification Working Group. 1996. A national ecological framework for Canada. Agriculture and Agri-Food Canada and Environment Canada. Ottawa/Hull. Report and national map at 1:7 500 000 scale. Environment Canada. 1997 (revised). Canadian ecodistrict climate normals 1961-90. Environment Canada. http://sis.agr.gc.ca/cansis/nsdb/ecostrat/district/climate.html Environment Canada. 2002. The climate of Nova Scotia. The Green LineTM, Environment Canada's World Wide Web site http://www.atl.ec.gc.ca/climate/ns.html 67
Fernow, B.E. 1912. Forest conditions of Nova Scotia. Commission of Conservation, Canada. 93 P and 4 maps. Fothergill, N.O. 1954. Tidal circulation in the Strait of canso. In: report of tidal and current survey, Canadian Hydrographic Services (unpubl. MS), 17p. Referenced by the St. George's Bay Ecosystem Project (http://www.stfx.ca/research/gbayesp ) Gorham, E. 1955. Titus Smith: A pioneer of Plant Ecology in North America. Ecology 36(1):116123. Hills, G.A. 1959. A ready reference to the description of the land of Ontario and its productivity. Ontario Dept. of Lands and Forests, Div. Of Research, Maple, Ontario. Johnson, R.S. 1986. Forests of Nova Scotia. Co-published by N.S.Dept. of Lands and Forests. 407P. Kelly, R.D. 1999. Gulf of Maine Watershed with major river basins. In: Gulf of Maine Times, Vol.6(4). Map. Lacate, D.S. 1969. Guidelines for bio-physical land classification. Canada dept. of Fisheries & Forestry, CFS, Publ. No. 1264, 61p. Loucks, O.L. 1962. A forest classification for the Maritime provinces. Proc. Nova Scotia Inst. of Science, Vol.25, Part 2. pp.85-184 and 1 map. Matson, B.E. and R.G Power. 1996. Developing an ecological land classification for the Fundy Model Forest, Southeastern New Brunswick, Canada. Environmental Monitoring and Assessment 39:149-172. McCurdy, D. and B.J. Stewart. 2003. Coastal forest communities of the Nova Scotian Eastern Shore Ecodistrict. Unpublished. N. S. Dept. of Natural Resources, Ecosystem Management Group, Truro. NBDNRE. 1997. Ecological land classification for New Brunswick: Ecoregions, Ecodistricts and Ecosite Levels. New Brunswick Dept. of Natural Resources and Energy, forest management Br., 59p. Nichols, G.E. 1918. The vegetation of Northern Cape Breton Island, Nova Scotia. Conneticut Academy of Arts and Sciences. Vol.22. Yale University Press pp. 249-467 NSDLF. 1986. Biophysical Land Classification for Nova Scotia. Nova Scotia Dept. of Lands and Forests, Forestry Division, Truro. Maps and Digital Data. 68
NSDNR. 1997. Natural landscapes of Nova Scotia: Summary descriptions. (Draft) Parks and Recreation Div., N.S. Dept. of Natural Resources. NSDNR. 1999. Forest resources inventory report. Nova Scotia Dept. of Natural Resources, Renewable Resources/Forestry Div., Cat.Log. Report FOR 1999-1, 29p. + Tables. NSDNR. 2001a. Ecological Land Classification Map of the Province of Nova Scotia. N.S. Dept. of Natural Resources, Map DNR 2001-1. NSDNR 2001b. Ecological Land Classification for Nova Scotia - 2000. N.S. Dept. of Natural Resources, Digital Data DNR 2001-01. Nova Scotia 1986. The resource atlas of Nova Scotia. Dept. of Dev., Halifax, N.S. 76P. Roland, A.E. 1982. Geological background and physiography of Nova Scotia. Nova Scotia Institute of Science. Ford Publishing. 311 P and 1 map. Rowe, J.S. 1972. Forest regions of Canada. Dept. of the Environment, Canadian Forestry Service, Publ. No. 1300, 172 P and 1 map. Smith, T. 1857. A natural resources survey of Nova Scotia in 1801-1802. Public Archives of Nova Scotia, Vol.380, 179 pp. Abridged transcript prepared by Llyod Hawboldt, N.S.Dept. of Lands and Forests, 1955. SRES. 2002. Ecological assessment of the Mahone Bay Islands. Cooperative Project with the Bluenose Coastal Action Program and the School for Resource and Environmental Studies, Dalhousie U. Digital Data. Stanley, J.M. 1970. A study of some intervale forests in Central and Eastern Nova Scotia. Thesis. Dept. of Biology, Acadia University, 155 P + Appendix Strang, R.M. 1972. Ecology and land use of the barrens of western Nova Scotia. Can.J.For.Res. 2, 276-290. Webb, K.T. and Marshall, I.B. 1999. Ecoregions and ecodistricts of Nova Scotia. Crops and Livestock Research Centre. Research Branch, Agriculture and Agri-Food Canada, Truro, N.S.: Indicators and Assessment Office, Environmental Quality Branch, Environment Canada, Hull, Quebec. 39 P and 1 map. Wein, R.W. and Moore, J.M. 1979. Fire history and recent fire rotation periods in the Nova Scotian Acadian forest. Can.J.For.Res. 9, 166-178. 69
Climate: Geology: Landscape: Natural History: Soils: Wetlands: Wildlife:
Web Sites of Interest http://www.atl.ec.gc.ca/climate/index.html http://www.gov.ns.ca/natr/meb/pubs/pubs3.htm#maps http://sts.gsc.nrcan.gc.ca/clf/landscapes.asp http://www.gov.ns.ca/natr/meb/field/start.htm http://www.ednet.ns.ca/educ/museum/mnh/index.htm http://res.agr.ca/cansis/nsdb http://www.gov.ns.ca/natr/WILDLIFE/wetlands/page0.htm www.gov.ns.ca/natr/wildlife/genstatus/
70
Appendix I. Climatic Data for Nova Scotia's Ecodistrict (modified from Webb and Marshall,1999; Dzikowski et al., 1985; Environment Canada, 1997)
Ecoregion/Ecodistrict
Annual Precipitation (mm)
Growing Degree Days
Growing Season (days)
Mean Annual Temp. (C)
Mean Summer Temp. (C)1
Mean Winter Temp. (C)2
100 Cape Breton Taiga
1503+
1535
190-
6
16.7
-4.2
210 Cape Breton Highlands
1493+
1564
196-
6
16.7
-4.2
220 Victoria Lowlands
1676
1651
195
6.1
16.8
-4
310 C.B.Hills
1470
1538
192
6
16.6
-4.4
320 Inverness Lowlands
1377
1675
191
6.1
16.7
-4.1
330 Pict/Ant Highlands
1409
1521
192
5.4
16.6
-5.9
340 Cobequid Hills
1182
1524
195
5.5
16.5
-5.8
350 Cobequid Slopes
1373
1506
193
5.4
16.5
-5.9
360 Mulgrave Plateau
1528
1582
197
6
16.7
-4.5
370 St.Mary's River
1373
1506
193
5.4
16.5
-5.9
380 Central Uplands
1373
1506
193
5.4
16.5
-5.9
410 Rawdon\W'burg
1465
1591
196
5.9
16.8
-5.2
420 Eastern Drumlins
1440
1522
196
5.8
16.3
-5
430 Eastern Granite Up.
1440
1522
196
5.8
16.3
-5
440 Eastern Interior
1440
1522
196
5.8
16.3
-5
450 Governor Lake
1440
1522
196
5.8
16.3
-5
510 Bras d'Or Lowlands
1502
1512
193
5.8
16.4
-4.5
520 St.Georges Bay
1294
1660
194
6
16.7
-3.8
530 Northumberland L.
1128
1587
193
5.5
16.9
-6.1
540 Cumberland Hills
1193
1534
195
5.5
16.4
-6
550 Cumberland Marshes
1128
1587
193
5.5
16.9
-6.1
560 Chignecto Ridges
1193
1534
195
5.5
16.4
-6
610 Annapolis Valley
1183
1702
205
6.6
17.4
-4.4
620 Minas Lowlands
1250
1542
197
5.7
16.4
-5.6
630 Central Lowlands
1265
1621
198
6.1
17
-5
710 Valley Slope
1350
1663
203
6.5
17.2
-4.3
720 South Mountain
1350
1663
203
6.5
17.2
-4.3
730 Clare
1332
1582
210
6.9
16
-2.6
740 LaHave Drumlins
1441
1704
204
6.6
17.4
-4.4
71
Ecoregion/Ecodistrict 750 Rossignol 760 Sable 770 Western Barrens 810 Cape Breton Coastal 820 Eastern Shore 830 South Shore 840 Tusket Islands 910 Parrsboro Shore 920 North Mountain
Annual Precipitation (mm) 1470 1426 1350 1464 1426 1534 1238 1250 1234
Growing Degree Days 1731 1612 1663 1604 1447 1827 1337 1542 1584
Growing Season (days) 210 210 203 190195 205 210+ 197 207
Mean Annual Temp. (C)
Mean Summer Temp. (C)1
7.1
17.4
6.9
16.4
6.5
17.2
5.9
16.2
5.8
14.8
5.6
17.4
6.4
13.2
5.7
15.7
6.6
16.3
Mean Winter Temp. (C)2 -3.3 -2.9 -4.3 -4.1 -3.7 -3.2 -1 -5.8 -3.4
1 Average for June, July, and August. 2 Average for December, January, and February. Inverness Lowlands is determined from Canadian Climate Normals (CCN) for Cheticamp station. Victoria Lowlands is determined from Canadian Climate Normals (CCN) for Ingonish Beach St. Georges Bay is from Canadian Climate Normals (CCN) for Port Hood and Dept. of Agriculture & Marketing (DAM) report for Antigonish Sable is an average of Webbs 514 & 515 Parrsboro Shore is from CCN for Parrsboro and Alma, NB.
72

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