[Effects of landscape pattern on the damage of pine wilt disease in the head region of the Three Gorges Reservoir].

The spread of pine wilt disease (PWD) is related to the spatial heterogeneity of the landscape within the affected area. Investigating the effects of landscape patterns on PWD severity can facilitate the construction of landscape ecological security patterns and contribute to long-term regional prevention and control strategies. Based on unmanned aerial vehicle (UAV) remote sensing data and forest resource inventory data, we adopted correlation analysis method and hierarchical segmentation in the linear mixed-effects model to evaluate the impacts of landscape patterns on PWD at both landscape and patch levels in the head region of the Three Gorges Reservoir. The results showed that larger patch sizes and higher landscape fragmentation were associated with lower PWD severity at the landscape level. Area characteristics and aggregation explained 45.9% and 29.3% of the variation in disease den-sity, respectively. At the patch level, the fragmentation of pure pine forest (host) patches was significantly positively correlated with disease density, while more regular patch shapes were associated with greater PWD severity. The area and connectivity of native dominant forest (non-host) patches were significantly positively correlated with disease density. The aggregation and connectivity of farmland and water (non-host) patches were significantly negatively correlated with the disease density. Therefore, fine-scale patch classification and integrated consideration of the landscape ecological processes in different patches would be crucial for accurately understanding the occurrence and spread of the PWD.