Foothills Fescue Range Plant Community Guide - Sustainable ...

With the development of AGRASID (Agricultural Region of Alberta Soil Inventory
Database, ASIC 2001), it is possible to establish site and soil characteristics within an
acceptable degree of accuracy from the AGRASID for lands in the agricultural settlement
area of the province. The soil/range site correlation tables developed by LandWise Inc.
(1998, 2001) provide a crosswalk that allows users to apply information about soils and
other landscape variables to establish range sites. Range site descriptions are used to
predict reference plant communities in the current project.
Grassland plant communities are defined in an ecological classification system in a
similar fashion to forest communities by grouping vegetation data (from research plots
and range surveys) “into similar functional units that respond to disturbance in a similar
and predictable manner (Archibald and Beckingham 1996)”. An important part of this
classification process is to correlate the plant communities with recognizable range sites
in the prairie landscape. The plant communities presented in this project represent the
first approximation for the soil correlation areas (SCAs) and Natural Subregions in
question and will be further revised and refined when additional vegetation survey data
becomes available.
2.0 Physiography, Climate and Soils of the Foothills Fescue Grassland
2.1 Overview 4
The Foothills Fescue Natural Subregion is one of four Natural Subregions in the
Grassland Natural Region, along with the Dry Mixedgrass, Mixedgrass and Northern
Fescue (Fig. 1). The Foothills Fescue accounts for 1.95 % of the area of Alberta and it
covers 13.45% of the Grassland Natural Region (ASIC, 2001). The boundaries of Natural
Subregions correspond closely to the boundaries of the Agricultural Regions of Alberta
Soil Information Database (AGRASID) Soil Correlation Areas (SCAs) (ASIC 2001).
The Foothills Fescue Natural Subregion is correlated with SCA 5 in the south (Del
Bonita through Cardston to the Pekisko area), and with SCA6 in the north (Stavely north
to Crossfield and Trochu). We estimate that about 16.8% of the original grassland area
of the Foothills Fescue is still intact, most of which is located in SCA 5 (Fig. 2 - in
green).
The Foothills Fescue Natural Subregion occurs along the lower and eastern flanks of the
Foothills Geologic Belt. The Foothills Fescue displays a wide range of physiography due
to variation in glaciation and bedrock topography. Elevations in the Foothills Fescue are
much higher than in the other grassland subregions (Achuff 1994), but lower than in the
Foothills Parkland to the west. The Foothills Fescue Natural Subregion includes four
Ecodistricts 5 (Fig. 2). From south to north they are: a highland area on the Milk River
Ridge named the Del Bonita Plateau, the Cardston Plain, the Willow Creek Upland,
which occurs at lower to mid elevations on the flanks of the Porcupine Hills, and the
4
For a detailed description of physiography, climate and soils of the Grassland Natural Region,
see LandWise Inc. (2003).
5 Ecodistricts are based on distinct physiographic and/or geologic patterns. They are distinguished
by similar patterns of relief, geology, geomorphology and genesis of parent material.
3