Plant community composition and structure in a central Appalachian forest stand 25 years after timber stand improvement

Overstory, midstory, and understory vegetation was sampled on two watersheds in a mixed mesophytic forest in eastern Kentucky. One watershed had received timber stand improvement by tree girdling approximately 25 years prior to sampling; no trees were girdled on the other watershed. The importance values of species in the overstory and understory vegetation were similar between study areas, but patterns of species importance values in the midstory vegetation differed between study areas. The density of overstory trees was higher in the study area receiving the treatment. Use of timber stand improvement at a frequency greater than 25 years will not significantly increase understory vegetation density or diversity after 25 years, but midstory cover may increase following timber stand improvement over the 25-year period.