关键词: 分解, 中小型土壤节肢动物群落, 相对密度,

AbstractA survey of wild Chinese Alligator was conducted from July to August 1999 and from August to September 2000 by direct counting after dark (20 z00pm) using headlamps or a 12v portable spotlight. At each site visited , the authors mapped the ponds using laser rangefinder and compass , characterized the physical nature of the ponds and vegetation , and conducted interviews with local residents. The location of all sites was recorded using a hand2held GPS. There are 26 sites in 5 counties that were surveyed where wild Chinese Alligators still exist in Anhui province , including 13 designated conservation sites of the National Chinese Alligator Reserve. The current wild alligator populations mainly exist in the best type of habitat , which totals 17.4 ha with estimated populations of 50.7 % in 1999 and 40.0 % in 2000. This can be compared with the other two types of habitat , which total 22. 0 ha and 19. 0 ha , with their estimated population numbers of 24.0 % in 1999 and 30.9 % in 2000 , and 25.3 % in 1999 and 29.1 % in 2000 respectively. The average ecological densities of the alligators in the two years were 1.3 ind. / ha and 1.8 ind. / ha , with an estimated population of 145 individuals. However , the population has been evidently divided into 18 isolated small local populations with different numbers of individuals. We suggest that habitat should be restored and captive-reared alligators should be reint roduced into the area to rebuild a viable population.

Key words: decomposition, soil meso-microarthropod community, relative density, diversity, Xishuangbanna, Chin