Effects of site on the demographics of standing dead trees in eastside pine forests

In the last several decades there has been a growing awareness of the value of snags in forests. Recent work has resulted in management standards and guidelines that set objectives for species such as cavity-nesting birds, but the numbers of snags required may not be attainable or sustainable across the landscape. Work reported here on snag demography in eastside pine forests was initiated in 1989. While snags have been present on most of the sites throughout the study period, the number of snags and their “life-spans ” depends on tree species, tree size, soil characteristics, and topography. Snags persisted for longer periods at Lassen Volcanic National Park sites where the soils are covered by up to 0.5 m of volcanic ash, but snag density was less than our other sites because of the low tree density. These findings suggest that standards and guidelines for snag management incorporate variation at local scales.