Trend Analysis of Coverage Variation in Pinus yunnanensis Franch. Forests under the Influence of Pests and Abiotic Factors

The Yunnan pine (Pinus yunnanensis Franch.) is one of the primary forest vegetation types in Province and has prominent economic value ecological significance. Monitoring changes forests contributes to their health management. normalized differential index (NDVI) an essential indicator for studying regional change. Landsat images were used analyze NDVI rainy dry seasons as well from 2009 2020. results showed that opposite trends seasons, with increase season a decrease season. areas decline during are mainly located at edges area, very few within area. main reason area was pests. From 2020, where increased decreased 92.23% 7.77% forests, respectively. decreasing sporadic distribution areas. drought led significant 2010 2013. Due lack protective measures, Xijiekou Town severely infested pests, complex strong fluctuations, severe pest infestation could be detected by imagery. This study meaningful protection explores potential capability imagery detection.