龙溪-虹口国家级自然保护区川金丝猴栖息地现状及震后影响

The Impact of Earthquake on Habitat of Rhinopithecus Roxellanae and Its Habitat Status in Longxi-Hongkou National Nature Reserve

采用直线包线法(Rectilinear envelope method),选取海拔、植被、水源距离、坡度、坡位指数、坡向、人类干扰7类生态环境因子,利用栖息地选择文献描述确定川金丝猴栖息地生态因子包线,在此基础上确定了龙溪-虹口自然保护区内川金丝猴(Rhinopithecus roxellanae)适宜栖息地分布,并通过2 km半径邻域平均估算适生指数。以保护区川金丝猴历年分布记录进行模型验证,受试者特征曲线(ROC)分析显示曲线下面积(Area Under Curve,AUC)为0.733,模型有较好的诊断效果。当研究区域的物种分布资料缺乏,而被研究物种又有着较为丰富的栖息地选择研究资料时,这一方法有较高的实用价值。通过此评估方法对比了保护区5.12地震前、后的适生指数分布,发现由于广泛分布的滑坡体,保护区川金丝猴栖息地质量已经出现了全面下降,适生指数均值由震前的41.3±24.8(SD)降为震后14.8±11.5(SD)。

Rectilinear envelope method is adopted to estimate the suitable habitat distribution of Rhinopithecus roxellanae in Longxi-Hongkou National Nature Reserve.Seven classes of ecological environment factors,including elevation,vegetation cover,distance to water,slope,topographic position index,slope direction,and humanity disturbance,are selected for the estimation.The envelope rules are concluded from the published researches and its suitable habitat distribution is also given.Habitat suitability index is evaluated by neighborhood averaging with radius of 2 km.By Receiver Operator Characteristic curve(ROC)analysis,the result is tested with the presence records of Rhinopithecus roxellanae in recent years.The area under curve is 0.7330,which indicates that the evaluation is good.It is suggested that rectilinear envelope method could be a good choice when presence records of research object are rare while its habitat selection information is well studied.By comparing the habitat suitability before and after the 5·12 Earthquake,it shows that the habitat suitable index has decreased from 41.3±24.8(SD)to 14.8±11.5(SD)as a result of widely distributed slopes.It indicates that overall habitat degradation has already taken place.