LAUSR

BACKGROUND Pine wilt disease (PWD) outbreaks have affected extensive areas of South China's forests, but the factors explaining landscape patterns of pine mortality are poorly understood. The objective of this study was to determine the relative importance of stand structure, topography, landscape context, and beetle pressure in explaining the PWD severity. During 2020-21, we identified 66 plots based on mapped PWD infestation severity. We built the PWD infestation maps for 2019-2021 through field surveys. Stand structure and topography were obtained from Forest Resources Management "One Map" and elevation raster data. We then used "One Map" and PWD infestation maps to determine landscape context and beetle pressure variables at different spatial scales. The relative importance of twelve explanatory variables was analyzed using multi-model inference. RESULTS In this study, we show that (i) One kilometer was the best spatial scale related to pine mortality, and (ii) models including landscape context and beetle pressure were much better at predicting pine mortality than models using only stand-level variables. CONCLUSION Landscape-level variables, particularly beetle pressure, were the most consistent predictors of subsequent pine mortality within susceptible stands. These results may help forest managers identify locations vulnerable to PWD and improve existing strategies for outbreak control. This article is protected by copyright. All rights reserved.