Evaluating the effects of varying levels and patterns of green-tree retention: Experimental design of the DEMO study

In western Oregon and Washington, recent changes in federal forest management policy contained in the Northwest Forest Plan have led to new harvest prescriptions on millions of acres of public lands. For example, on upland sites, standards and guidelines now require that live (green) trees are retained in at least 15% of the area within each harvest unit and recommend that at least 70% of this retention is in patches of moderate to larger size (0.2-1.0 ha or more). These prescriptions for green-tree retention were based on the professional judgement and collective knowledge of many of the biologists who have studied the organisms and ecological processes that characterize these forests, but they have not been rigorously tested nor implemented on a broad geographic scale. Several prescriptions for green-tree retention are being evaluated experimentally by the Demonstration of Ecosystem Management Options (DEMO) study. In this paper, we briefly review recent changes in forest management policy and existing information gaps that led to the establishment of the DEMO study. We then provide an overview of the criteria for site selection, the experimental design and harvest prescriptions, the scope of scientific inquiry, and the collaboration that has occurred between scientists and land managers. These discussions provide the context and experimental framework for the individual research papers that comprise the remainder of this volume