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Abstract:
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There has been an increased awareness of the complexity of forest ecosystems, and the need to manage them as complex systems. Forest managers increasingly have a range of societal and ecological as well as economic goals. As such, a greater variety of silvicultural techniques are required. In this study the effects of five silvicultural cutting treatments on forest composition, structure and advanced regeneration are examined. Thinning from below, thinning from above, patch clearcut, the initial cut of a shelterwood system, and improvement cut treatments were applied to adjacent two acre blocks at three Appalachian hardwood sites approximately 15 years ago, and their compostional and structural development over time analyzed using multivariate statistical techniques. The control plots changed over time, indicating succession is ongoing in these forests with increases in structural diversity. The patch clearcut treatment resulted in the resetting of succession, with the current dominance of pioneering species. The thinning from above resulted in intial changes similar but less extreme than the clearcut, followed by a recovery period with current composition being relatively similar to pre-treatment. The remaining partial cutting treatments resulted in disturbance mediated succession, with increases in structural diversity. In comparison to the control, succession was accelerated in many of the plots. The effects of these treatments on the advanced regeneration were not as clear; however, there were increases in the amount of both the total and shade tolerant regeneration in the initial cut of the shelterwood system treatment and increases in shade tolerance regeneration in the thinning from above. This study suggests that forest management could be used to increase structural complexity.
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