新疆额河河谷林区景观格局对杨树植食性昆虫危害的影响

开展森林景观格局与植食性昆虫危害关系的研究，是构建景观生态安全格局和实现有害生物生态调控的重要理论依据。在额河河谷林区开展实地调查获取杨树植食性昆虫危害数据，基于遥感数据提取景观格局相关指数，使用线性混合效应模型（Linear Mixed-Effects Models）分别从景观水平和景观类型水平上分析了林区景观格局与林地、耕地、草地和荒地的景观格局对两种植食性昆虫危害的影响。结果表明在额河河谷林区中，景观破碎化是造成两种植食性昆虫危害加重的关键，但食叶率和潜叶蛾虫口密度对景观格局的响应不完全一致；景观水平下，景观丰富度和景观连接度越高，食叶率越高，平均斑块面积与潜叶蛾虫口密度呈显著负相关；景观类型水平下，林地的斑块数量越多，额河河谷林区受到的植食性昆虫危害越严重，耕地面积的增加导致潜叶蛾虫口密度上升，荒地的景观凝聚力指数和草地的平均斑块分维数与食叶率呈显著正相关。因此在优化景观格局时，合理规划景观组成并减少景观破碎化有助于维持经济发展和生态保护的平衡，促进森林的可持续发展。

Effects of landscape pattern of XinJiang Irtysh river riparian forest on the damage of poplar herbivores insect

Researching the relationship between forest landscape pattern and the damage caused by herbivorous insects provides an important theoretical basis for constructing landscape ecological security pattern and realizing ecological regulation of pests. A field survey was carried out to obtain the data on damage caused by herbivorous insects in the Irtysh river riparian forest, and landscape index was extracted based on remote sensing data. This study analyzed the effects of forest landscape pattern and landscape characteristics of forest land, farmland, grassland and wasteland on the damage caused by two kinds of herbivorous insects, at the level of landscape and landscape type respectively with Linear Mixed-Effects Models. The results showed that landscape fragmentation was the key factor which compounded the damage caused by two herbivorous insects in the Irtysh river riparian forests, but the responses of leaf chewers and leaf miner to the landscape pattern were not completely consistent. At the landscape level, the damage caused by leaf chewers was significantly positively correlated with landscape richness and landscape connectivity, while the damage caused by leaf miner was significantly negatively correlated with mean patch area. At the level of landscape type, the damage caused by herbivorous insects in the Irtysh river riparian forest was positively correlated with the number of patches in the forest. The increase of cultivated land area led to the increase of population density of leaf miners. The landscape cohesion index of wasteland and the average patch fractal dimension of grassland were significantly positively correlated with the rate of damage caused by leaf chewers. Therefore, when optimizing the landscape pattern, making a reasonable landscape composition and reducing landscape fragmentation can help maintain a balance between economic development and ecological protection and promote the sustainable development of forests.