大沙鼠在中国的地理分布

DISTRIBUTION OF GREAT GERBIL (RHOMBOMYS OPIMUS) IN CHINA

搜集了大沙鼠在中国的分布资料 ,运用地理信息系统 (GIS)的叠加和空间分析功能 ,结合生境 ,利用 1:40 0 0 0 0 0比例尺中国植被图和 1:10 0 0 0 0 0比例尺中国草地资源图 ,对我国大沙鼠的地理分布进行了系统研究。根据大沙鼠对梭梭和盐爪爪有突出的依赖特性 ,将大沙鼠的生境归纳为梭梭沙漠 ,盐爪爪盐漠 ,梭梭、红砂壤漠 ,梭梭砾漠 ,沙拐枣沙漠 ,荒漠盐生草甸的盐地柽柳灌丛和柽柳包 ,极稀疏的柽柳沙漠 ,红砂砾漠 ,禾草、杂类草盐生草甸等 9大类 ,以梭梭和盐爪爪为建群植物的前 4类为最适生境。生境分析表明 ,目前文献中的分布区远较实际分布区大。根据现有的生境资料 ,参照以往的记录 ,重新标定了分布点 。

Based on available distribution information of Great gerbil (Rhombomys opimus) and vegetation cover maps (1:4 000 000 and 1:1 000 000) of China, GIS was applied to the systemic study of the distribution of the Great gerbil. According to distribution patterns of Haloxylon and Kalidium, the Great gerbil's habitats were divided into nine types, namely Haloxylon desert, Kalidium saline desert, Haloxylon ammodendron and Reaumuria soongarica loamy desert, Haloxylon gravelly desert, Calligonum desert, Tamarix scrub on arid saline meadow soil, spare Tamarix desert, Reaumuria soongarica gravelly desert, halophytic grass and forb meadow. The former four with Haloxylon and Kalidium as dominant plants were most suitable habitats. A distribution map of habitats of the animal by counties linked its habitats to vegetation types in vegetation cover map of China on a scale of 1:4 000 000 Depending on the localities of specimen collections and the habitats by counties, suitable habitats of the Great gerbil were identified. By assessing the habitat suitability, we studied the map of distribution patterns. Compared with the GIS model of species distributions in this paper, the distribution ranges in scientific literatures were larger than the actual ones. Some distribution localities verified against the species occurrence records were given in this paper. Based on the atlas of grassland resources of China on a scale of 1:1 000 000, we determined more reliable distribution limits of the Great gerbil. Results showed that distribution of Great gerbil has been changed by human activities.