Technical Bulletin No. 0908: Riparian Zone Forest Management and the Protection of Biodiversity: A Problem Analysis

<p align="justify"><strong>Authors:</strong> Daniel A. Sarr, Ph.D., National Park Service (Ashland, Oregon); Dennis C. Odion, Ph.D., Institute for Computational Earth Systems Science, University of California (Santa Barbara, California); David E. Hibbs, Ph.D., Department of Forest Science, Oregon State University (Corvallis, Oregon); Jennifer Weikel (Corvallis, Oregon); Robert E. Gresswell, Ph.D., and R. Bruce Bury, Ph.D., US Geological Survey (Corvallis, Oregon); Nicole M. Czarnomski, Robert J. Pabst, Jeff Shatford and Andrew R. Moldenke, Ph.D., Oregon State University (Corvallis, Oregon). <br /><br />This report evaluates the general effects of forestry practices on biodiversity along streams in the Pacific Northwest and northern California. There are four parts to the report. In Part I, we present concepts of biodiversity and the processes underlying it. Biodiversity is expressed as a general concept for species, habitat, and genetic diversity of all groups of organisms. We describe the interacting processes that govern riparian biodiversity by integrating those operating over large spatial extents, such as climate, with interrelated ones that have more localized influences, such as disturbance and habitat heterogeneity. The effects of forestry on biodiversity are then analyzed in the context of these controls, and how they are influenced by disturbances. We predict that habitat heterogeneity and retention of pre-disturbance biological legacies (trees, snags, logs, seed and spore banks that can be important to growth of populations of organisms after disturbance) are two of four key determinants of biodiversity because they may act as mechanisms that promote species coexistence. Habitat heterogeneity is especially scale-dependent.</p>