贵州岩下自然保护区的野生大鲵资源现状及历史动态

POPULATION STATUS AND HISTORY DYNAMICS OF WILD CHINESE GIANT SALAMANDER(ANDRIAS DAVIDIANUS)IN YANXIA NATURAL RESERVE IN GUIZHOU PROVINCE,CHINA

为了解野生大鲵在喀斯特区域的分布规律与种群历史动态,于2006年6月份、2007年8、10月份对长江支系沅江水域的贵州省贵定县岩下省级自然保护区野生大鲵(Andrias davidianus)种群资源状况与捕获量进行了调查,并对繁殖洞穴涌苗现象进行了分析。初步查明岩下野生大鲵种群集中分布在一个以地下水域为依托,地面水网与地下河流相连的集中区域,栖息地由地下(洞穴)与地面水域广布缩小到以地下水域为主;根据繁殖洞穴的鲵苗涌出量与大鲵繁殖特征,推算岩下野生大鲵种群密度约为0.085 kg/m2,总资源量约为1700 kg;捕获量表明,种群数量在20世纪80年代末后急剧减少,90年代中期至2000年后,数量变化趋于缓和。岩下保护区野生大鲵分布的集中性、生境自然条件的优越性以及繁殖洞穴的大规模涌苗现象在全国均属少见。由于受到外在致危因素影响,大鲵的生境遭到破坏、种群生存受胁,亟待加强资源的保护与管理。

To ascertain the quantity, habitat distribution and population dynamic of Chinese giant salamander （Andrias davidianus） ,a random sampling survey and native visit on wild population resources and its dynamics were conducted in Yanxia Natural Reserves of Guizhou province, China, in June of 2006, August and October of 2007. The results show that contribution of wild giant salamanders manly concentrates in a small region where is a water network consisted of underground water area and surface aquatic system. In terms of temporal dynamic of population,the quantity decreased sharply in 80s and trended to stable after the middle of 90s in last century. Due to habitat loss or human＇s disturb,there were few places in surface aquatic system suiting giant salamander and the range of habitat has dwindled into underground water are a. A great quantity of young giant salamanders （hatched at Sept. or Oct. annually） in breeding cavern Longdong streamed out with water from Xiyejing in annual winter,which maybe relate with water temperature, period of growth or population density. According to the breeding characteristics of giant salamander recorded from other researches and quantities streamed from breeding cavern, it was calculated that the population density was about 0. 085 kg/m^2 and the gross of resource was 1 700 kg. Because of exterior endangered factors, the habitats and quantity of giant salamanders have been suffering destruction and decline, so it is very urgent to enhance the conservation and management of resources.