Preliminary studies on the relationships between communities of small mammals and habitat types in Dujiangyan Region, Sichuan
都江堰地区小型哺乳动物群落与生境类型关系的初步研究

Variation in diversity of communities of small mammals in seven different habitats from the me-dian subtropical evergreen broad-leaved forest belt in the Dujiangyan Region was studied from the end ofOctober to the beginning of November 2000. Twelve species, comprising ten Muridae (Rodentia) andtwo Soricidae (Insectivora), were captured. The total rate of small mammals captured was 10. 7%. Ana-lyses of diversity of small mammals in different habitats show that species diversity index (1. 84) andevenness index (0. 95 ) are highest in secondary forest, where human disturbance has been moderate inrecent years. Those in shrubland, secondary foresVprimary forest and abandoned farmland are also high,while species are rare and the species dominance index is high (0. 57 ) in farmland, where human dis-turbance is most serious. Species diversity index (1. 34 ) and evenness index (0. 83 ) are also lower inplantation of Cryptomeria fortunei. Species diversity index in primary forest (1. 43 ) is slightly lower thanthat in secondary forests (1. 85 and 1. 46), shrubland (1. 64 ) or abandoned farmland (1. 66 ), whichresults from habitat degradation. Based on similatity indices, seven habitats can be clustered at the levelof 0. 095 with systematic clustering. Small mammals of forest type are mainly distributed in shrubland,secondary forests and primary forest, which are clustered into one group. Farmland and plantation of C.fortunei are dominated by Rattus nitidus and belong to the farmland type. Abandoned farmland is an eco-tone of farmland and forest, because of its higher diversity index (1. 66) and higher rate of small mam-mals of farmland type (46. 7% ). The results show that diversity is the lowest in habitats where disturb-ances are most serious (e. g. farmland and plantation of C. fortunei) and highest in moderately disturbedhabitats (e. g. secondary forest, shrub and abandoned farmlands) and slightly lower in disturbed hahitats(e. g. primary forest).