Assessing cumulative effects and restoration potential in forested watersheds

This dissertation provides a framework for analyzing cumulative effects as it applies to rural forested watersheds and developing restoration priorities. The Noyo and Big River watersheds, encompassing the Jackson Demonstration State Forest (JDSF) in central Mendocino County, are used as a case study for examining cumulative watershed effects. The study of cumulative effects is focused on the major issues of concern which are primarily related to water quality and wildlife habitat. These two themes are examined as separate case studies. The presence of cumulative effects in the watershed has lead to strong controversy over the management objectives for the forested lands in these watersheds. Following a systematic framework an evaluation of watershed condition was conducted and used to develop a model for interpreting watershed recovery potential.;Chapter 1 reviews the main environmental processes that are influenced by timber harvesting in coastal watersheds and establishes a framework for evaluating cumulative watershed effects (CWE). This provides the theoretical and conceptual basis for addressing cumulative effects across a range of spatial and temporal scales. In chapter 2 the CWE framework is applied to studying a range of environmental impacts that has occurred through timber harvesting in the Noyo and Big River watersheds. A series of GIS-based models are developed and used to conduct a watersheds assessment of the forest lands in these watersheds. The results show that many of the streams are bordered by early and mid seral stage forest stands.;In chapter 3 I developed a model to evaluate the recovery potential of watersheds based on the integration of existing disturbance (natural and management induced) and habitat factors. The results demonstrate that watersheds express a range of conditions and are different paths for recovery. In chapter 4, an evaluation of NSO habitat was conducted. The results suggest that habitat conditions are distinctly different among land ownership classes. However, when evaluating expected habitat conditions based on a range of forest management alternatives there was little distinction among alternatives after a 10 year time period. Finally, chapter 5 provides a summary of research results and discusses there implication. In addition, in this final chapter I explore the changes in land ownership and the opportunities arising from new markets for carbon sequestration and the use of forest biomass as a source of renewable energy. The chapter concludes by speculating that minimizing management impacts and CWEs will require a broader view of sustainable forest management and one that provides landowners with financial incentives to maintain and enhance the environmental services and natural resources that their forests provide.