DEVELOPING SILVICULTURAL STRATEGIES FOR GUIDING FOREST STRUCTURAL COMPLEXITY TO ACHIEVE DESIRED ECOSYSTEM SERVICES

The focus of this research is on (1) expanding knowledge about the relationship between forest stand structures and the important ecosystem services desired by our society and provided by forested ecosystems and (2) developing tools and strategies to translate that knowledge into management to enhance our natural resource base, facilitate environmental stewardship, and promote economic and social welfare for generations to come. Forest stakeholders in the U.S. have expressed serious concerns about the ability of managed forests to safeguard biodiversity while also supplying products for human needs (Pinchot Institute 2006). Although the forestry profession has a vast store of experience in managing for timber production, it is now widely acknowledged that foresters have often failed to safeguard other ecosystem services of equal or greater importance to society, such as biodiversity. Consequently, silvicultural strategies that expressly aim to bridge the gap between conflicting values are needed. The premise of this proposal is that a more thorough understanding of forest structure and its spatial and temporal variability is the key to developing more successful silvicultural approaches. After all, forest structure, i.e., the 3-dimensional distribution of tree attributes among neighbors in space, which is characterized by the spatial arrangement of trees into more or less heterogeneous clusters of trees (Zenner and Hibbs 2000), is what is directly manipulated via silvicultural interventions (OHara 1998). In addition, forest structure is the outcome of processes that operate in forests across temporal and spatial scales and thus provides many functions expected from forests, such as habitat provision. If we can determine the physical structural conditions that permit biodiversity to flourish within our forested ecosystems, we can develop silvicultural prescriptions that specify the creation of those conditions when and where they are desired. The same approach can be used to achieve any desired forest ecosystem service, from higher growth rates for timber production to specific species compositions and arrangements that maintain water quality. Because forests are slow-growing and long-lived and the outcomes of research may require decades to improve the lives of individuals, silvicultural research is concerned with perpetuity rather than immediacy. However, through the dissemination of research results to private and public land managers, changes in forest management practices can be expected within only a few years and we expect the cost-effective approaches we develop to linking forest structure to biodiversity responses at multiple scales to be applied by managers within this short time frame. Toward that end, we will spend the next five years focusing on three primary projects necessary to the development of silvicultural strategies to achieving desired ecosystem services.