THE CONDITION AND TREND OF ASPEN, POPULUS-TREMULOIDES, IN KOOTENAY AND YOHO NATIONAL-PARKS - IMPLICATIONS FOR ECOLOGICAL INTEGRITY

Aspen (Populus tremuloides) communities were measured in and near Yoho and Kootenay National Parks to determine condition and trend. Most as pen stands were heavily invaded by conifers as they had not burned in 60 years or more due to modem fire suppression and the elimination of aboriginal burning. Aspen is also declining due to repeated ungulate b rowsing, primarily by Elk (Cervus elaphus). Even where disturbed by lo gging and burning outside the parks, many aspen stands failed to produ ce new stems greater than 2 m tall because all the suckers were repeat edly browsed. Only where ungulate numbers were low was aspen able to s uccessfully regenerate. Aspen, though, is not ''seral,'' as that term is commonly used because the species seldom grows from seed due to its demanding seed bed requirements. This, coupled with high biodiversity , makes aspen an excellent indicator of ecological integrity as mandat ed by Parks Canada statute.