Stephen Zoltai

 

Wetland Regions of Canada

 

 

Introduction and summary Ecoclimatic Regions of Canada


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ecoclimatic Regions of Canada

One of the most signifcant results achieved by the Canada Committee on Ecological Land Classification is the production of the map and report: Ecoclimatic Regions of Canada. This map is one of the most powerful ecospatial tools available in Canada to develop ecosystem based climate change adaptation strategies and develop ecoregion based sustainable development scenarios.

The CCELC formed the National Ecoregion Working Group in 1978, following its successful first steps in developing a wetland classification and map for Canada. In both these initiatives, Steve Zoltai, chaired the working groups to compile the maps and the knowledge base. In 1989, this map and report were printed as publication No. 28 of the Ecological Land Classification Series.

 

Ecoclimatic regions are typically broad areas on the earth's surface characterized by distinctive ecological responses to climate, as expressed by vegetation and reflected in soils, wildlife, biodiversity and water. Within ecoclimatic regions, the ecologically effective climate will result in the development of similar trends in vegetation succession on similar soils occurring on similar parent materials and positions on the landscape.

Climatic factors provide the incoming energy available to plants and to a great extent determine the amount of moisture available to the vegetation. Such factors as the distribution of oceans and continents, their configuration, the tilt of the earth in relation to the sun, and large-scale airmass circulation influence the broad climatic patterns that provide the basic necessities for life: energy and water.

Vegetative life, however, also requires soil, which develops on various soil parent materials having a variety of surface forms. Vegetation will develop on the abiotic base (climate, parent material, surface form), with particular species composition for each soil parent material (e.g., sand or clay, nutrient-poor or nutrient-rich), each soil moisture regime, and each local climate, as modified by the landform or the vegetation itself. A further complication is vegetation succession -- i.e., the fact that the present vegetation is generally only one link in a long chain of vegetation communities. In nature, setbacks often occur (e.g., a fire can destroy the living vegetation and modify the upper part of the soil) . Initially, species present will be those which are adapted to such 'pioneering' conditions; these species will be replaced later by other plants as the environment for the maturing community changes. Theoretically, the ecosystem could reach a 'steady state', in which the vegetation community could renew itself indefinitely, without change. In most instances, however, this state is seldom reached, as disturbances will re-set the cycle to a new beginning.

Within a broad framework of climate, local influences will result in a multitude of ecosystems, each with its developmental sequence. However, similar ecosystems will develop on similar soils and landforms in the same area. A small difference in climate may not produce a recognizable difference in the composition or growth of the ecosystem, but a pronounced difference may result in a considerable effect on the vegetation composition. Similarly, if the vegetation of the same landform, soil, and parent material is examined in a somewhat different climate, a subtle difference will be noticed. The greater the differences in the climate of two areas, the greater will be the differences in the ecosystems occurring there. This fact forms the basis for ecoclimatic regions.

The term 'ecoclimatic regions' requires explanation. The delineation of 'regions' is based on ecological relationships between the living and non-living components of the environment. They are thus 'ecoregions'. There are several ways of recognizing ecoregions: total landscape ecoregions (physiography-vegetation), habitat ecoregions (wildlife habitat-vegetation-physiography), soil ecoregions (soil-vegetation), etc. We have chosen gradients of ecologically effective macroclimate (as expressed by vegetation) as the defining criteria. The term should be 'ecoclimatic ecoregions', which can be abbreviated to 'ecoclimatic regions' or 'climatic

This report presents the broad ecoclimatic regions of Canada. Not all possible ecosystems on all landforms, soils, and parent materials can be possibly described: we lack both the knowledge and the time. As a shortcut, we have attempted to characterize each ecoclimatic region on the basis of 'normal' sites. Normal sites are represented by deep loamy soils, with neither a lack nor an excess of soil nutrients, and are located in well-drained positions in the landscape which are neither protected from nor exposed to local climatic extremes. In this manner, when the vegetation development of normal sites on widely separated areas is compared, the local effects of soil or landform differences are eliminated. Consequently, any differences in the vegetation chronosequence should be due to the ecologically effective regional climate.


In the following descriptions, each ecoclimatic region is characterized by a brief description of the vegetation and soils on normal sites, drier-than-normal sites, and wetter-than-normal sites, along with some climatic information from a representative climate station. Notes on wildlife characteristic to the ecoclimatic region and land uses affecting the natural resources are also provided.

Figure 1 summarizes the types of information provided in each climate diagram, as taken from published records. Where several alternatives were available, the climatic stations were chosen to be as representative as possible of the entire ecoclimatic region.
Throughout the report, the descriptions are organized within 'ecoclimatic provinces', which are groupings of ecoclimatic regions. The ecoclimatic provinces, being more generalized, include more variations within their borders than the ecoclimatic regions. Nevertheless, there is a resemblance in the vegetation development within ecoclimatic provinces that makes them different from the neighbouring provinces. These generalized relationships give the ecoclimatic provinces an ecological meaning which is useful at a global scale of detail. The table provides a brief characterization of ecoclimatic provinces.


The concept of ecoclimatic regions is based on the pioneering studies of a number of eminent Canadian ecologists, including G.A. Hills, V.J. Krajina, and M. Jurdant. Their ideas, although different in form or emphasis, were similar in essence. The Ecoregions Working Group, a body created by the Canada Committee on Ecological Land Classification in 1979, was organized on the basis of two interlocking tiers, one working at the national level and one working at the level of the province or geographic region.

The National Working Group Members:
S.C. Zoltai (Chairman); R.M. Annas (British Columbia); D. Burger (Ontario); G. Gilbert (Quebec); H. Hirvonen (Maritimes); A. Kabzems (Saskatchewan); W.J. Meades (Newfoundland); G.F. Mills (Manitoba)
; E. Oswald (Yukon Territory); W.W. Pettapiece (Alberta)
; C. Tarnocai (national soil survey specialist); E.B. Wiken (Northwest Territories). These individuals are collectively responsible for the final content of this report.


Regional Working Groups and Other Contributors: Each regional specialist on the National Working Group organized a Regional Working Group whose views were presented to the national group. The following individuals served on regional working groups or were consulted through the years, freely contributing thier time and expertise:

P. Achuff (Alberta); C.J. Acton (Ontario); R.E. Bailey (Nova Scotia); J.L. Belair (Quebec); T. Braumandl (British Columbia); J. Bursey (Newfoundland); M. Cahill (Newfoundland); R. Coupe (British Columbia); W. Erickson (British Columbia); I.R. Goudie (Newfoundland); E. Hamilton (British Columbia); W.C. Harris (Saskatchewan); G. Ironside (Northwest Territories); R.K. Jones (Ontario); M. Ketcheson (British Columbia); K. Klinka (British Columbia); W.H. Koonz (Manitoba); A.L. Kosowan (Saskatchewan); G. Krumlik (Alberta); K.R. Leggat (Alberta); D.C. MacIver (Ontario); K.L. McInnes (Northwest Territories); D. Meidinger (British Columbia); W. Mitchell (British Columbia); A. Nicholson (British Columbia); T. Pierce (Northwest Territories); G. Pierpoint (Ontario); J. Pojar (British Columbia); J.S. Rowe (Saskatchewan); J.P. Senyk (Yukon Territory); I. Sneddon (Northwest Territories) J.M. Stewart (Manitoba); W.L. Strong (Alberta); G. Utzig (British Columbia); B. van den Broek (Ontario); H. Van Groenewoud (New Brunswick); H. Veldhuis (Manitoba)
W. Weatherall (Northwest Territories); G.M. Wickware (Ontario)