Seventeen Years of Forest Succession Following the Waterfalls Canyon Fire in Grand Teton National Park, Wyoming

Abstract

Plant species composition has been sampled periodically since the 1974 Waterfalls Canyon Fire in Grand Teton National Park, Wyoming. Prior to the fire, the forests were dominated by mature Abies lasiocarpa, Picea engelmannii and Finns contorta. All three tree species have reestablished. After 17 years, P. engelmannii sapling density was 1.2-11.2 times greater than the other tree species. A. lasiocarpa and P. contorta saplings were second in density to P. engelmannii in the moderate and severely burned stands, respectively. The understory shrub and herbaceous species that were most abundant during the first 17 years were common the first year after the fire and were also found in the unburned mature forest. Species present in the unburned forest contributed 91-100% of the understory cover in the moderate burn, and 55-74% in the severe burn. Species richness was greatest in the severely burned stand and has increased during the 17 years of succession. While sprouting is the primary mechanism for understory plant establishment in the moderate burn, most species appear to have grown from seeds in the severe burn.