The Resources Inventory Committee defines coarse woody debris (CWD) as dead woody material, in various stages of decomposition, located above the soil, larger than 7.5cm diameter and not self-supporting (B.C. MELP and MoF, 1998). It plays several major roles in forest ecosystems, including maintaining forest productivity, providing habitat for vertebrates and invertebrates, contributing to soil and slope stability, and providing long-term carbon storage (Stevens, 1997).
Recent studies have shown that forest harvesting results in changes to CWD attributes, relative to those found in unharvested stands (e.g. Adams, 2002; Lloyd, 2003; Densmore et al., 2004). In particular, while overall CWD volumes are often lower after harvest, there is a marked decrease in volume contributed by large diameter and long pieces. This has negative implications for CWD-dependent wildlife, invertebrate and plant species, many of which prefer or require large pieces, and also for CWD longevity in the ecosystem as small pieces decay more quickly and will not last the rotation.The Morice TSA Sustainable Forest Management (SFM) plan (Tesera, 2008) recognizes the importance of CWD management and retention of associated structural habitat elements in maintenance of biological diversity during forest harvesting. In 2001-2004, a number of studies were conducted through the Morice-Lakes IFPA that investigated the volume and attributes of CWD and other structural elements in mature/old forests and in recent clearcuts (Lloyd, 2003, 2005). These included a pilot project co-sponsored by MoF, HFP and FERIC that was intended to field-test methods of retaining CWD in an operational setting, and a set of operational trials intended to field-test a refined and regionally-appropriate methodology in the three biogeoclimatic subzones most commonly harvested in the Morice and Lakes TSAs. As a result of these studies, a set of Best Management Practices (BMPs) were drawn up in 2004 to improve the management of CWD and associated elements, and a draft set of targets were prepared (Morice SFM Plan, Appendix D) which provided quantitative figures against which retention performance could be measured. The purpose of this project is to assess performance of operational guidelines in terms of retention of CWD and other structural elements relative to expected ranges, and to recommend where and how best to focus future efforts to retain stand structure during harvesting operations.