贺兰山马麝(Moschus chrysogaster)生境适宜性评价

马麝(Moschus chrysogaster)是我国特有种，在贺兰山分布数量不足百头，对贺兰山马麝进行生境适宜性评价是保护和恢复贺兰山马麝种群的前提和依据。2014—2016年通过样线法对贺兰山马麝的野外分布情况进行调查，确定了750个马麝出现位点，结合13个环境因子变量，利用最大熵(MAXENT)模型，并根据最大约登指数划分贺兰山马麝适宜生境及不适宜生境的分布区，对贺兰山地区马麝的生境适宜性进行评价。研究结果表明：在众多影响贺兰山马麝分布的环境因子中，针叶林、距水源距离、距护林点距离、海拔高度、距矿区距离和距道路距离六种环境因子影响较大；贺兰山地区适宜马麝分布的生境面积极小，仅占贺兰山地区总面积的3.27%,面积为120.24 km²,而不适宜生境面积为3 555.72 km²。利用受试者工作特征性曲线对模型进行检测，结果表明预测水平达到优秀，可以为马麝保护工作提供参考。为保护和恢复马麝种群，建议管理部门加强管理力度，严格控制人为干扰，识别和建立马麝各适宜生境之间的生态廊道，加强对零散分布的潜在适宜生境区域的利用。

Habitat suitability assessment of Moschus chrysogaster in Helan Mountain

Moschus chrysogaster is endemic to China, and now its number is less than one hundred in Helan Mountain. Habitat suitability assessment of Moschus chrysogaster in Helan Mountain is the premise and basis for protecting and restoring the population of Moschus chrysogaster in Helan Mountain. 750 occurrence points of Moschus chrysogaster were confirmed by using the line transect method. Combining 13 kinds of environmental factors, the MAXENT model was used to determine the main factors affecting the distribution of Moschus chrysogaster, and to assess its potentially suitable habitat in Helan Mountain. The distribution map of suitable habitat and unsuitable habitat of Moschus chrysogaster could be obtained according to the Jorden index. The results showed that the coniferous forest, the distance from water source, the distance from forest ridge, altitude, the distance from mining area and the distance from road were the most important environmental factors affecting the suitable habitat distribution of Moschus chrysogaster. The suitable habitat of Moschus chrysogaster was mainly distributed in the central part of Helan Mountain. The suitable habitat area covered 120.24 km², which accounted for 3.27% of the total area, and the unsuitable habitat area was 3555.72 km². The results showed that the AUC (the area under the receiver operating characteristic curve) value was 0.992, suggesting perfectly predictive effect of the model. It is suggested that the management organizations should strictly control the human disturbance, identify and establish ecological corridors between suitable habitats, and attach the importance to the use of scattered potentially suitable habitat of Moschus chrysogaster to ensure the development of this population.