Vegetation indicators for terrain evaluation in a prairie environment

Abstract

Natural vegetation can be a useful indicator of terrain conditions and thus has significant geotechnical implications especially in identifying moisture, groundwater conditions, and strati-graphic changes. A pilot study was initiated to study physiographic, climatic, biotic, and compensating factors as they affect plant communities in the Langham area, near Saskatoon, Saskatchewan. The study area is located at the transition between the Dark Brown and Black Soil Zones, which are colour zones of the surface soil horizon as influenced by climate and vegetation. It is suggested that the findings at Langham can be extrapolated over a wide band across the province where the soil zones and geomorphic units are similar. It was found that trees or shrubs are more reliable indicators of soil moisture conditions than low-growing plants and that plant communities are better indicators than individual species. In some places, the recognition of changes in vegetation patterns could make a significant contribution to geotechnical projects. A direct correlation was found between the number of species occurring in a plant community and soil moisture conditions. Drier sites had fewer species.