Analysis Of Terrestrial Molluscs Fauna And Zoogeography In The Southern Gansu Province, China

The southern Gansu province is the dividing line between the Palaearctic realm and Oriental realm in the zoogeographical fauna of the world. So it plays an important role in the zoogeographical regions. It is warm and wet in the area. It has complicated physiography and diverse vegetation. There are abundant terrestrial mollusca resources which have both various species and abundant individuals, containing many species of special terrestrial mollusca of our country and some species of snail in the Palaearctic realm and Oriental realm. So it is very significant to research the animal population or plant population in this zone. We investigated the terrestrial mollusca in this zone in 1998-2002 and got a set of terrestrial mollusca specimen with153 species and subspecies belonging to 2 subclass,3 orders, 14 families, 38 genus. Two dominant families are Enidae and Bradybaenidae, with 48 species and 84 species respectively, accounting for 31.37% and 54.90% for the individual amount respectively. The statistic result of area elements indicates that the terrestrial mollusca community in the investigating area is dominant by the area special species, containing both some species of the Palaearctic realm and Oriental realm. Zoogeography analysis suggests that this zone has high regional specificity and evident intersection character between the Palaearctic realm and Oriental realm, with obvious transition zone character compared with the surrounding area. The zoogeography distribution of this zone belongs to West Mountains Plateau Subregion, Central China Region, Oriental Realm.