摘要:Little is known about the dynamics of coarse woody debris (CWD) in forests that were originally characterized by frequent, low-moderate intensity fires. We investigated effects of prescribed burning at the Blacks Mountain Experimental Forest in northeastern California following creation of two stand structure conditions: 1) high structural diversity (HiD) that included retaining large, old-growth trees while thinning smaller trees in the understory through whole-tree harvesting, and 2) low structural diversity (LoD) simulating a more traditional approach that removed overstory trees by individual tree selection while thinning the vigorous younger trees and removing the suppressed understory by whole-tree harvesting. Each of the two structures was replicated six times in a randomized block design for a total of 12 approximately 100 ha factorial plots. Each factorial plot was split and prescribed fire applied to one half of each plot. We classified CWD as either: sound or decayed. Coarse woody debris was abundant on all plots regardless of stand structure. Statistically significant differences (α = 0.05) were found in the mass of the CWD between the burned and unburned splits across all experimental units combined for both sound and decayed material. However, when analyzed separately, the difference in the burned and unburned splits was statistically significant for LoD condition but not for HiD condition, likely due to greater heterogeneity of burn in the HiD condition. Coarse woody debris mass declined even in unburned units following treatments ( p ≤ 0.1).
关键词:Cascade Range ; coarse woody debris ; dead wood ; down wood ; fire effects ; interior ponderosa pine forest ; Pinus ponderosa ; prescribed fire ; stand structure