宁夏固原苜蓿斑蚜种群发生的适宜生境

针对宁夏首蓿斑蚜Therioaphis trifolii适宜生境不明,监测预报技术落后的局面,在大尺度上对首蓿斑蚜适宜生境进行分析.将宁夏固原市不同时期首蓿斑蚜种群分布插值图与生态气候图、数字高程图叠加,分析首蓿斑蚜密度与生态环境和地理之间的关系.结果显示,首蓿斑蚜的分布和发生程度与气候、地貌和海拔密切相关,其适宜生境为海拔1501～2 100 m的半干旱丘陵区和半干旱川道区,最易暴发成灾的区域为海拔1701～2100m的半干旱丘陵区.表明首蓿斑蚜的适宜生境与不同时期的空间分布插值图相结合,可定量分析各生态区首蓿斑蚜种群的空间动态.

Suitable habitat of the spotted alfalfa aphid Therioaphis trifolii populationsin Guyuan City, Ningxia

As the suitable habitats of the spotted alfalfa aphid, Therioaphis trifolii, were not clear and the prediction technology was fallen behind in Ningxia, we analyzed the suitable habitat of T.trifolii in a large scale based on GIS. The interpolation maps of T.trifolii population in Guyuan City in different periods were overlapped with the ecological regionalization map and digital altitude map, aimed to analyze the relationships of T.trifolii population density with its ecological environment and geographical distribution. The results showed, in the study area, the occurrence and distribution of T.trifolii had close relations with climate, geomorphology, and altitude. The suitable habitat of T.trifolii was located in the semi-arid plain area and semi-arid holly area at the altitude 1 501-2 100 m, while the most possible occurrence area was the semi-arid plain at the altitude 1 701-2 100 m. By combining the suitable habitat with the interpolation maps of T.trifolii population in different periods, the spatial dynamics of T.trifolii population in variety of ecological areas could be analyzed quantitatively.