大凉螈保护空缺分析与四川栗子坪国家级自然保护区保护成效评估

Conservation gap analysis on the Taliang Knobby Newt(Liangshantriton taliangensis)and conservation effectiveness assessment of Sichuan Liziping National Nature Reserve

栖息地丧失和退化严重威胁全球两栖类动物的生存与繁衍,栖息地保护在两栖动物保育中具有高的优先性。大凉螈(Liangshantriton taliangensis)是国内外广泛关注的横断山区特有珍稀有尾类物种。结合大凉螈33个分布位点和9个环境变量数据,本文运用最大熵(MaxEnt)模型预测了大凉螈当前潜在适宜分布区,再根据现有自然保护地(5个国家级和9个省级)分布进行了保护空缺分析,同时,借助比例体重指数法(SMI)衡量了7个种群共218个个体的身体状况,比较了保护区内外种群间的差异,利用归一化植被指数(NDVI)识别了保护区内植被变化,据此对四川栗子坪国家级自然保护区的保护成效进行了评估。结果表明,(1)影响大凉螈分布的最主要环境变量为NDVI(贡献值34.33%)、最干月份降水量(贡献值26.81%)和海拔(贡献值20.92%);(2)大凉螈适宜生境主要集中在小相岭和凉山山系,占研究区域总面积的15.38%,现有自然保护地覆盖了大凉螈23.62%的适宜生境,仍有3760.91km^(2)的保护空缺;(3)栗子坪保护区内雄性个体肥满度指数显著大于保护区外个体(t-test,P=0.006),雌性个体肥满度指数无显著差异(t-test,P=0.214),保护区内近6年NDVI值显著高于保护区建立前(Mann-Whitney U test,P<0.0001),均提示总体保护成效优。结合研究结果,提出了确立大凉螈为重要保护目标物种、扩大现有保护区、建立保护小区或拯救中心、建设生态廊道等保护地建设的物种恢复措施,以提升对大凉螈的保护能力。

The survival and reproduction of amphibians were seriously threatened by habitat loss and degradation globally,and natural habitat protection has a high priority in amphibian conservation.The Taliang Knobby Newt(Liangshantriton taliangensis)is a rare caudata species endemic to the Hengduan Mountains,Sichuan,southwestern China and its population status and conservation are widely concerned.In the current study,based on 33 distribution sites and 9 environmental variables data,we predicted the potential suitable distribution area of the Taliang Knobby Newt by MaxEnt model.A total of 14(five national and nine provincial)nature reserves were used for gap analysis.Scaled mass index(SMI)was quantified to estimate body conditions of 7 populations including 218 individuals,and the differences of SMI between populations inside and outside of Sichuan Liziping National Nature Reserve(LZP)and the variation of the normalized vegetation index(NDVI)in the reserve were further analyzed for assessing conservation effectiveness of the nature reserve.The results indicated that:(1)the most important environmental variables affecting the distribution of the Taliang Knobby Newt were NDVI(contribution 34.33%),the precipitation of driest month(26.81%),and altitude(20.92%).(2)The high suitable habitat of the Taliang Knobby Newt was mainly concentrated in the Xiaoxiangling(XXL)and Liangshan(LS)Mountains,accounting for 15.38%of the study area.23.62%of the high suitable habitats of the Taliang Knobby Newt were covered by the existing nature conservation network.There were still 3760.91km^(2)conservation gaps.(3)The male SMI in LZP was significantly higher than that of individuals outside the reserve(t-test,P=0.006),and the female SMI was no significant difference(t-test,P=0.214).The NDVI in the last 6 years of the reserve was significantly higher than that before the establishment of the reserve(Mann-Whitney U test,P<0.0001).All of these indicated that the conservation effectiveness of LZP was positive.Based on the results,we proposed systematic restoration measures to enhance the protection capacity on the Taliang Knobby Newt,including developing the salamander as important conservation target species,expanding current nature reserves,establishing conservation communities or rescue centers,and building ecological corridors.