气候变化对义乌市义乌小鲵栖息地适宜性影响

Effects of climate change on habitat suitability of Hynobius yiwuensis in Yiwu city

义乌小鲵(Hynobius yiwuensis)是中国特有的易危小鲵科动物,仅分布于浙江省的部分丘陵山地.为更好地保护其野生种群资源、维持生物多样性,于2017年11月—2019年3月开展野外调查,并采用MaxEnt模型对义乌市义乌小鲵的栖息地进行了分析和评价.结果表明:调查发现义乌市义乌小鲵野外繁殖坑共计18处,包含成体2尾,幼体1 575尾,卵袋151对;气候变量重要性分析表明,降水量为最主要因子,累计贡献率为49.1%,其他重要因子分别为最冷季降水量(43.0%)、最湿季平均温度(40.3%)、降雨量季节性变化(4.7%)、最干季降水量(3.9%)、季节性变动率(3.7%);当前义乌小鲵在义乌市适宜面积共计438.88 km~2,其中,高适宜区面积为49.75 km~2,次适宜区面积为127.13 km~2,低适宜区面积为262.00 km~2;在3种气候情景下(RCP2.6,RCP4.5,RCP8.5),2050年高适宜分布区面积较当前分别增长58.3%,12.8%和18.1%,2070年高适宜分布区面积较当前分别增长45.5%,15.2%和19.0%.基于野外调查和模型结果,揭示了义乌小鲵当前栖息地环境及未来气候条件下对潜在栖息地的预测,对义乌小鲵野外资源的保护和管理有重要意义.

Hynobius yiwuensis was classified as a unique vulnerable salamander in China,which was known so far only distributed in some hills and mountains of Zhejiang Province.In order to better protect its wild population resources and maintain biodiversity,a field survey was carried out from November 2017 to March 2019,MaxEnt model was used to analyze and evaluate the habitat of H.yiwuensis in Yiwu City.The results showed that there were 18 field breeding pits of H.yiwuensis,including 2 adults,1 575 larvae and 151 pairs of egg bags;The importance analysis of climate variables showed that precipitation was the most important factor,and the cumulative contribution rate was 49.1%.The important factors was precipitation in the coldest season(43.0%),average temperature in the wettest season(40.3%),seasonal variation of precipitation(4.7%),precipitation in the driest season(3.9%) and seasonal variation rate(3.7%);The total suitable area of H.yiwuensis in Yiwu city was 438.88 km~2(the area of high suitable area was 49.75 km~2;the area of sub suitable area was 127.13 km~2;the area of low suitable area was 262.00 km~2).Under three climate scenarios(RCP2.6,RCP4.5,RCP8.5),the area of high suitable distribution area in 2050 would increase by 58.3%,12.8% and 18.1% respectively;The area of high suitable distribution area in 2070 would increased by 45.5%,15.2% and 19.0% respectively.Based on the results of field investigation and model,the prediction of potential habitat under current habitat environment and future climate conditions of H.yiwuensis was revealed,which would be of great significance to the protection and management of field resources of H.yiwuensis.