Native and nonnative plant colonization in pits and adjacent blowdown area after a hurricane.

摘要

Soil disturbance from hurricane blowdowns may contribute to an increase in nonnative plant species invasion. Two years after a wind disturbance in a Mid-Atlantic hardwood forest, I compared fifty-two, 1.0 m x 0.5 m tree blowdown pit plots and paired nonpit plots for plant percent cover. Native plant species were not able to colonize pit plots as well as they could colonize nonpit plots. However, nonnative species achieved comparable percent cover in pit as well as nonpit plots. Relatively greater cover percentages of nonnative compared to native plant species were present in the disturbed soil of the pit plots. Although light levels were higher at 2 m above soil than at 10 cm above soil, light did not have significant effects on percent cover of native or nonnative species in pit or nonpit plots. The percent cover of nonnative species was significantly higher if coarse woody debris were present. Variables also tested but not found to have significant effects on native versus nonnative species included: distance from each pit center and distance between paired nonpit plot, blow down tree species, and blow down tree diameter at breast height. Most plant species in both pit and nonpit plots had a perennial life history. Nonnative plant species that can initially colonize in wind disturbed environments may disrupt forest succession dynamics.