ASPEN SEEDLINGS IN RECENTLY BURNED AREAS OF GRAND TETON AND YELLOWSTONE NATIONAL-PARKS

Although aspen (Populus tremuloides) produces viable seeds most years, seedling establishment has seldom been reported in the western United States. This paper documents the natural establishment of large numbe rs of aspen seedlings on recently burned areas in Grand Teton and Yell owstone National Parks. Though a few aspen seedlings were widely scatt ered throughout the 1985 Beaver Creek burn in Grand Teton National Par k, the greatest concentrations occurred at the bottom of kettles or ot her topographic depressions where densities ranged from 925 to 2,708/h a in 1989. In Yellowstone National Park, aspen seedlings were widely d istributed over the area burned by the 1988 wildfires on the northern range but the greatest concentrations occurred in riparian zones that had been burned down to bare mineral soil. In those locations aspen se edling densities as high as 11.5 x 10(6)/ha were recorded and averaged 142,645/ha on permanent plots established in 1989. On permanent plots in the Beaver Creek Burn, the average aspen seedling density increase d by 16% from 1989 to 1991 white on permanent plots in Yellowstone Par k, aspen seedling densities declined 78% during the same interval. Whi le an abundance of naturally occurring aspen seedlings has not been re ported before, evidence suggests that these seedlings may not lead to the growth of mature trees or the development of aspen clones.