LAKE ARE VARIABILITY ACROSS A CLIMATIC AND VEGETATIONAL TRANSECT IN SOUTHEASTERN ALBERTA

Areas of 34 small lakes forming a transect across the southern margin of the Boreal Forest into the Grassland in southern Alberta were obtai ned from 326 aerial photographs, with at least six photographs for eac h lake in different months and different years from 1949 to 1992. Stan dard deviations of standardised lake areas (used as an index of lake a rea sensitivity to short term climate fluctuations) were plotted again st a climatic moisture index; the resulting scatter of points is const rained by a function relating lake sensitivity to long-term regional c limatic moisture. The lakes show high sensitivity in the Grassland whe re Potential evapotranspiration exceeds precipitation, a steep drop in sensitivity over a small range of climatic moisture values in the Asp en Parkland, and very low sensitivity in the Boreal Forest where preci pitation exceeds potential evapotranspiration.