Taking a good long look : disturbance, succession, landscape change and repeat photography in the upper Blakiston Valley, Waterton Lakes National Park

Abstract

Understanding historical disturbance and succession is critical in park management and restoration. I examined successional patterns and disturbance dynamics in the Blakiston Valley, Waterton Lakes National Park, by analyzing changes in forest structure using field research and repeat photography. I sampled forest structural attributes in 23 stands and interpreted forest cover from oblique and aerial photographs from 1881, 1914, 1947 and 2004. I quantitatively compared the interpretation from oblique photographs to aerial photographs and geographic information system (GIS) data and related succession to environmental factors and historical disturbances. Successional patterns were dominated by transitions from open meadows and shrublands to woodlands and closed forests, and were related to a small number of environment and disturbance variables, especially elevation, potential radiation, and time since last recorded fire. Accompanying these trends is a decline in landscape diversity. These findings have implications for restoration and conservation of subalpine forests in the park and across the region. The GIS methods capture spatially approximate vegetation patterns from oblique photographs and show potential for further research, especially in combination with the photograph collection of the Mountain Legacy Project.