亚洲小车蝗的多尺度分布格局

Multi-scale spatial distributions of Oedaleus decorus asiaticus

探讨亚洲小车蝗的空间分布,以及在不同尺度上影响其分布的生境因子。基于在内蒙古锡林郭勒盟镶黄旗敖包音高勒调查和实测的亚洲小车蝗密度与生境条件数据,获得研究区蝗虫生境适宜性评分值(S值)的空间分布图。对整个研究区的S值和相关生境变量分别进行Morans’I空间自相关分析、融合Moran’s I空间自相关尺度图的尺度方差分析、小波分析、或空隙度分析,以识别其等级结构和特征尺度。结果表明,亚洲小车蝗在<0.3 km、<0.7~1.0 km和<1.9 km这3个尺度域上出现斑块化分布。这是不同尺度上相关生境因子共同作用的结果。植被类型和植被盖度对蝗虫在这3个尺度域上的分布均有影响;坡度、坡向和地形湿度指数对蝗虫在中小尺度域上的分布有影响;高程对蝗虫在中大尺度域上的分布有影响;土壤沙粒含量、pH、有机质含量和植物叶片含氮量对蝗虫在中尺度域上的分布有影响。

This study discusses the spatial distributions of Oedaleus decorus asiaticus （O. d. asiaticus） and the habitat factors which are responsible for the spatial distributions of O. d. asiaticus at different scales. Using the field survey data of O. d. asiaticus density and habitat conditions in Aobaoyingaole village, Xianghuangqi County of Xilingol League, Inner Mongolia, China, we obtained the spatial distribution of grasshopper habitat suitability value （S） within the study area. Then we carried out the spatial autocorrelation analysis of Moran＇s I, scale variance analysis coupled with Moran＇s I scalogram, wavelet analysis, or lacunarity analysis to detect the spatial patterns of S value and other related habitat variables. The results showed that O. d. asiaticus exhibited patchy distributions within the three scale domains ： 〈 0.3 kin, 〈 0.7 - 1.0 km, and 〈 1.9 km, which might result from the combined effects of vegetation coverage were responsible for many habitat factors at different scales. Vegetation type and the distributions of grasshopper individuals within all thethree scale domains; slope, aspect, and topographic wetness index were responsible for the distributions within the moderate and small scale domains; elevation was responsible for the distributions within the large and moderate scale domains; and soil sand content, soil pH value, soil organic matter content, and Xeaf nitrogen content were responsible for the distribution within the moderate scale domain.