区域农田景观格局对麦蚜种群数量的影响

明确农田景观格局对麦田蚜虫种群的影响,是开展区域性害虫生态调控的重要理论依据之一。以区域性小麦种植区为研究对象,基于遥感影像与土地覆盖分类数据以及田间调查的蚜虫种群数据,计算景观格局指数,使用负二项分布的广义线性模型从农田景观、非作物生境景观和区域景观3个方面分析了区域农田景观格局对麦田蚜虫种群的影响。结果表明,蚜虫种群的数量与草地的平均斑块面积和最大斑块指数显著正相关,与县域的平均几何最邻近距离和面积加权平均斑块面积显著负相关,与耕地的面积加权平均斑块面积显著负相关,与耕地的斑块密度显著正相关。草地斑块面积的增大、区域景观与耕地的破碎化、区域景观的聚集会促进蚜虫种群数量的增加。使用草地的斑块面积和最大斑块指数、区域景观的平均几何最邻近距离可以预测蚜虫种群的发生量。非作物生境草地的斑块面积、耕地的破碎化、区域景观的空间分布及破碎化是影响麦田蚜虫种群发生的重要景观因素。

Effects of regional agricultural landscape patterns on populations of wheat aphids

Knowing the effects of agricultural landscape patterns on wheat aphid populations is an important theoretical basis for ecological regulation and management of insect pests. Based on remote sensing data, land cover classification, and wheat aphid abundance survey data, we took a wheat planting region as a typical example and calculated the landscape pattern metrics and analyzed the effects of landscape patterns of farmland, non-crop habitat, and the regional agricultural landscape on wheat aphid abundances using a negative binomial generalized linear model. The results showed that aphid abundance was positively correlated with mean patch area and largest patch index of grassland and patch density of farmland, and was negatively correlated with mean Euclidean nearest neighbor distance and area-weighted mean patch area of the regional landscape and area-weighted mean patch area of farmland. The increase in patch area of grassland, fragmentation of the regional landscape and farmland, and the aggregation of the regional landscape promoted an increase in aphid abundance. The patch area and largest patch index of grassland and mean Euclidean nearest neighbor distance of the regional landscape best predicted aphid abundance. The patch area of grassland, the fragmentation of farmland, and the spatial distribution and fragmentation of the regional landscape and were important landscape factors affecting the occurrence of wheat aphids.