Forest light and structure in relation to disturbances: comparing mountain pine beetle, wildfire and salvage logging

In this research I characterize the early post-disturbance forest light environment and structure of lodgepole pine forests in the southern interior of British Columbia after mountain pine beetle attack, wildfire and salvage logging. These different, and at times sequential, disturbances influence structural complexity, overstory composition and the heterogeneity of light transmission in different ways. Beetle disturbance left complex patterns of gap light in the mixed-species canopy, which accelerated the growth release of surviving trees. After wildfire, there were predominantly dead structural legacies and high variability of light and residual structural elements. Salvage logging after fire or beetles significantly reduced the amount and diversity of biological legacies and led to a more homogeneous, bright light environment than after only the natural disturbances. The resulting homogeneity of post-salvaged stands and variability of light and structure in unsalvaged stands will influence patterns of forest development and have implications for management.