海南红树林的海陆蛙分布与种群密度调查

Survey on Distribution and Population Density of Crab-eating Frog (Fejervarya cancrivora) in Mangoves,Hainan

为掌握海南红树林中海陆蛙(Fejervarya cancrivora)分布和种群数量状况,于2008年4～8月选择12个红树林进行了海陆蛙分布状况调查,同时采用样带法对4个调查地点的海陆蛙生境和种群密度进行了调查。结果表明,海陆蛙只分布于海南东寨港红树林国家级自然保护区、文昌清澜港红树林省级自然保护区、儋州新英港红树林和澄迈五村红树林保护区,这些红树林都具有面积较大(>100 hm2)、植物种类组成丰富和潮汐不能全部淹没红树林底部的共同特征。在红树林、虾塘和滩涂3种生境中,海陆蛙的平均种群密度分别为(132±71)只/hm2、(65±50)只/hm2和(37±22)只/hm2,且3种生境之间差异显著;整体而言,海南东寨港红树林国家级自然保护区的海陆蛙种群密度最高,其次为文昌清澜港红树林省级自然保护区和儋州新英港红树林,两地之间的海陆蛙种群密度差异不显著(P>0.05),而澄迈五村红树林保护区的海陆蛙种群密度最低。分析表明,生境破坏、水污染及非法捕捉是导致海南红树林海陆蛙分布区缩小和种群数量急剧下降的主要因素。

In order to understand the status of distribution and population density of Crab-eating Frog （Fejervarya cancrivora） ,we made field surveys at 12 sites of mangrove in Hainan from April to August 2008, and measured the population density and habitat by line transects at the four mangroves. The Crab-eating Frog only found in 4 nature reserves, named Hainan Dongzhai Harbor Mangrove National Nature Reserve, Qinglan Harbor Mangrove Provincial Nature Reserve, Wenchang, Xinying Harbor Mangrove, Danzhou, and Wueun Mangrove Nature Reserve, Chengmai. All the four mangroves have larger area （ 〉 100 hm2） , rich plant species and exposed bottom at high tide. The average population densities of Crab-eating Frog in mangrove, shrimp pond and intertidal mudflat are 132± 71 individuals/hm2 , 65± 50 individuals/hm2 and 37 ± 22 individuals/hm2 respectively, and the population densities are significantly different among the three habitats. In the four mangroves,the highest population density occurs at Hainan Dongzhai Harbor Mangrove National Nature Reserve and lowest at Wucun Mangrove Nature Reserve respectively. The population density is not different between Qinglan Harbor Mangrove Provincial Nature Reserve and Xinying Harbor Mangrove （ P 〉 0. 05 ）. The population decline and distribution region reduction of Crab-eating Frog are mainly caused by habitat destruction, water pollution and illegal harvest.