Studies On Rodent Community, Harmful Division For Region And GIS Analysis In Semi-desert And Desert Region Of Inner Mongolia

The species and abundance, the structure and distribution of rodent communities, the changing tendency of the communities pattern, the sensitive response of the dominant species , the Canonical Correlation Analysis (CCA) between the rodent and plant communities , regional division of rodent harm and GIS analysis of zone rodent communities were comprehensively studied by mainly using trap-day and mark–recapture methods in semi–desert and desert region of Inner Mongolia from 1988to 1993 and from 1998 to 2004.The region belongs to arid and super-arid region of Inner Mongolia (37°24'~44°59' N, 97°10'~114°10' E) including northwest part of Xilingguole league, center-west part of Wulanchabu league, center-north part of Bayenaoer league and the total area of Alashan league. It contained various types of grassland: temperature desert–grassland, grassland–desert and typical desert. The total of 317 sampling plots were arranged in an area of 380,000 km2, and total of 157,702 trap-days were completed, the four plots (respectively prohibited grazing site, over grazing site, rotated – grazing site, planting site) under different disturbance were selected. The results showed: The rodents of the region were classified as two orders, 6 families, 24 genera, 39 species, of which Ochotona cansus and Salpingotus crassicauda were first reported in Inner Mongolia and Allactaga sibirica, Dipus sagitta, Phodopus roborovskii and Meriones meridianus were dominant species. Cardiocranius paradoxus, Salpingotus kozlovi, Salpingotus crassicauda, Ochotona cansus and Marmota himalayana were rare species. In accordance with the results of fast cluster method and on the basis of previous study and the vegetation characteristics of the region the zone rodent community were divided into 9 types: Ⅰ: Citellus dauricus + Cricetulus longicaudatus + Eutamias sibiricus community;Ⅱ: Phodopus roborovskii + Cricetulus barabensis + Cricetulus longicaudatus community; Ⅲ : Meriones unguiculatus + Phodopus roborovskii + Cricetulus longicaudatus community;Ⅳ: Allactaga sibirica + Allactaga bullata + Citellus dauricus community;Ⅴ: Allactaga bullata + Dipus sagitta + Meriones unguiculatus community; Ⅵ : Meriones meridianus + Citellus dauricus + Allactaga sibirica community; Ⅶ: Allactaga sibirica + Allactaga bullata + Dipus sagitta community; Ⅷ Phodopus roborovskii + Dipus sagitta + Allactaga sibirica community; Ⅸ: Meriones meridianus + Allactaga sibirica + Dipus sagitta community. The community I was located in secondary forest and front mountain grassland; The community Ⅱand Ⅲwere located in farmland of on the top and north of middle part of Yinshan mountains, they continuously distributed in Chayouhou banner, Wuchuan and north part of Sizhiwang banner, after habitat was critically fragmented in the semi–desert region. The community Ⅳ and Ⅴ were special communities of the region, the former was grassland desert and latter was transition area which was transiting from grassland–desert to typical desert grassland. They concentrate distributed in west part of Suniteyou banner, north part of Sizhiwang and Wulatehou banner; The community Ⅵ concentrate distributed in center south part of Sisu, Damao and Sizhiwang banners, it was the region where there was the most serious disturbance from mankind in desert-grassland. The community Ⅶ was the whole desert-grassland of the region; The community Ⅷ distributed in sandy desert; The Community　 Ⅸ was located in vast desert of the region. There were remarkable differences in the pattern of component species of communities under different disturbance on larger spatial scale (40hm2). There were only 6 species rodents, Meriones unguiculatus appeared and a large number of Cricetulus barabensis in planting–site, Dipus sagitta completely disappeared. There were a large number of Dipus sagitta in over–grazing site. The numbers of Dipus sagitta increased greatly in rotated–grazing site, and numbers of Allactaga sibirica were absolutely dominant in prohibited-grazing site. There were not obvious differences...