Short-Term Vegetation Recovery at an Alaskan Arctic Coastal Plain Site

Abstract

Small bare areas created by removing debris that had lain on the tundra surface for 30 yr were observed to document recolonization. Recovery was rapid to moderately slow. After 4 yr average plant cover from vegetative colonizers on areas grouped by surrounding vegetation type was greater (9 to 26%) than cover from seedlings (0 to 3%) although seedlings were numerous. Bryophyte cover was 0 to 24%, and lichens were absent. Areas where burning of debris added nutrients had much higher seedling and bryophyte covers. Seedlings were most abundant on mesic or slightly moister sites, were rare on dry, intact organic mats, and absent in standing water. Buried seeds were not an important source of colonizers because they did not survive 30 yr of debris coverage. Seedlings on plots surrounded by successional willow and grass communities on mesic areas of a 30-yr-old disturbance were initially numerous, but then killed by thick litter accumulation. These communities apparently follow the inhibition model of succession and will persist for many years. Sites surrounded by vegetation recovering from disturbance 30 yr ago recolonized faster than plots surrounded by undisturbed vegetation. If possible, development activities that cause small-scale disturbances should be directed to areas of early successional vegetation or vegetation with a high disturbance regime, where recovery can be rapid.