Forest succession: a study of biotic and abiotic factors in the UMBS burn plots.

Abstract

Secondary forest succession was assessed in the 1911, 1936, 1954 and 1980 UMBS burn plots. Effects on forest succession with respect to abiotic factors and the presence of Cladina rangiferina were considered. A 20m x 20m plot was set up in each year and all woody plants were classified as either overstory, understory, or groundcover. Abiotic measurements for light, soil temperature, organic carbon, soil moisture, soil nutrients and pH were taken at each plot corner. Five transects were run, and eight, meter square plots were sampled along each transect for the percentage of Cladina. The 1980 plot had no overstory species and was dominated in the understory by bigtooth aspen (Populus grandidentata). Aspen declined in the next three plots as white pine (Pinus strobus), red oak (Quercus rubra) and red maple (Acer rubrum) increased. Succession towards these species suggests a move towards a pine-Northern hardwood community. Some abiotic measurements supported our succession theory while others did not. Cladina appeared insignificant with respect to forest succession yet, older trees may facilitate the establishment of seedlings by shading out Cladina.