Increases in plant diversity following disturbance are well studied in ecology. Disturbances increase landscape heterogeneity which, in turn, increases plant diversity. What is less understood is how disturbance and other factors interact to influence plant diversity recovery. In this study we evaluate woody species regeneration following a large-scale blowdown in eastern deciduous forest of western Pennsylvania. Following blowdowns, forests are commonly “salvage logged” to recoup losses of valuable timber. Because this practice can result in destruction of seedlings and cause soil compaction, there is some evidence that this has negative ecological impacts. Additionally, forests in western Pennsylvania are subject to widespread browsing by overabundant white tail deer. This overbrowsing causes declines in plant diversity by favoring browse tolerant and non-palatable species. This study is the first manipulative study investigating the effects of salvage logging in combination with other key forest drivers. In western Pennsylvania, a 2012 tornado caused four large blowdowns. We salvage logged half of each blowdown and within each salvaged and non-salvaged control portions we erected deer exclosure fences and control plots and removed competing vegetation in half of all plots. We predicted that salvage logging would negatively affect species recovery and that overbrowsing by deer and presence of competing vegetation would exacerbate this effect.
Results/Conclusions
After 5 years, analyses suggest that contrary to predictions, salvage logging increased woody species diversity regardless of deer exclusion. However, deer exclusion also increased species diversity. We found little impact of competitor removal. Thus, disturbance and browsers together and separately regulated forest regeneration in this system.