Overview of Agents and Patterns of Mortality and Resulting Coarse Woody Debris Recruitment in Western Forests 1

摘要: We present an overview of many the mortality agents in western coniferous forests United States that are responsible for coarse woody debris recruitment under natural conditions. Patterns and scale occurrence six USDA Forest Service Regions examined at both historic projected-risk time periods. The data indicates bark beetles have been most important source U.S., with exception Northern Region, this trend is expected to continue. Defoliators, although growth loss, not had as large a impact. Recent-past indicate root disease may be even more factor tree than indicated recent literature. Although regional measures actual available, all show high impacts by dwarf mistletoe (Arceuthobium spp.) during past 20 years. Fire affects relatively few hectares compared insect disease, but effects on (recruitment conditioning) important. Additional concerns managers wishing augment also presented.