Relative influence of the components of timber harvest strategies on landscape pattern

Abstract

Forest managers seek to produce healthy landscape patterns by implementing harvest strategies that are composed of multiple management components such as cutblock size, rotation length, even-aged or uneven-aged residual stand structure, conversion to plantations, and the spatial dispersion of harvest units. With use of the HARVEST model and neutral landscapes, a factorial simulation experiment was conducted to determine how each management component influenced measures of spatial pattern. There was a significant overall effect of all components on response variables defined by age class and on all but the rotation length component for response variables defined by forest type. Increasing cutblock size, rotation length, and clustering of cutblocks generally reduces measures of age class fragmentation, and increasing the use of even-aged management increases fragmentation. The response of forest type variables was consistently dominated by the component (percent plantation) that changed the abundance of a forest type. Dispersion also had a significant effect because conversions were allocated in space through the dispersion treatment. The results can be used to develop strategies to mitigate negative effects of certain silvicultural activities by showing which other components have opposite effects. Managers can better predict how specific strategy components will contribute to the cumulative landscape pattern. Copyright © 2007 by the Society of American Foresters.