An analysis of the vegetation-microenvironmental complex on prairie slopes in Saskatchewan
Ayyad, Mohamed A.G.
One of the basic questions of plant ecology is "why do plants grow where they grow?". Elucidation of any of the complex interrelationships between plant growth, plant distribution, and the physical environment is at least a contribution towards an appreciation of this question. Studies on the interrelations between slope-induced variations in microenvironment and vegetational composition appear to offer a particularly promising approach to the subject. Studies on forest vegetation in North America have given considerable attention to the interrelations between plant distribution and environmental factors (Cantlon 1953, Cooper 1961, Loucks 1962). In contrast, grassland studies dealing with the environment-plant complex are few and not comprehensive in nature. This study was therefore initiated to fill this void. The present study attempts to add to our comprehension of the complex interrelations between the microenvironment and vegetational pattems in grasslands, particularly as these are influenced by slopes within local areas. The main objectives of this investigation are: (a) to study the variations in the composition of grassland vegetation as they are correlated with slope aspect and position, (b) to analyse the variations in the environmental factors which may be responsible for species distribution, (c) to evaluate the degree of correlation between environmental factors, species behavior, and vegetation pattern, and (d) to ascertain the degree of abruptness of: vegetational variations which if great, would permit the recognition of separable units. The rolling moraine topography of portions of central Saskatchewan provides, on a local scale, a variety of slopes which display a varied habitat spectrum. The study was carried out in an area about 25 miles east of Saskatoon. The field work was conducted during the summers of 1960, 1961 and 1962.