Species abundance and habitat distribution are two important aspects of species conservation studies and both are affected by similar environmental factors. Forest resource inventory data in 2010 were used to evaluate...Species abundance and habitat distribution are two important aspects of species conservation studies and both are affected by similar environmental factors. Forest resource inventory data in 2010 were used to evaluate the patterns of habitat for target species of Cervidae in six typical forestry bureaus of the Yichun forest area in the Lesser Xing’an Mountains, northeastern China. A habitat suitability index(HSI) model was used based on elevation, slope, aspect, vegetation and age of tree. These five environmental factors were selected by boosted regression tree(BRT) analysis from 14 environmental variables collected during field surveys. Changes in habitat caused by anthropogenic activities mainly involving settlement and road factors were also considered. The results identified 1780.49 km2 of most-suitable and 1770.70 km2 of unsuitable habitat areas under natural conditions, covering 16.38% and 16.29% of the entire study area, respectively. The area of most-suitable habitat had been reduced by 4.86% when human interference was taken into account, whereas the unsuitable habitat area had increased by 11.3%, indicating that anthropogenic disturbance turned some potential habitats into unsuitable ones. Landscape metrics indicated that average patch area declined while patch density and edge density increased. This suggests that as habitat becomes fragmented and its quality becomes degraded by human activities, cervid populations will be threatened with extirpation. The study helped identify the spatial extent of habitat influenced by anthropogenic interference for the local cervid population. As cervid species clearly avoid human activities, more attention should be paid on considering the way and intensity of human activities for habitat management as fully as possible.展开更多
文摘通过2014–2015年两次冬季野外调查,将收集的79处马鹿(Cervus elaphus)出现信息作为分布点数据,选取地形、景观类型、植被特征和人类干扰4类19种因子作为环境变量,利用最大熵(maximum entropy,Max Ent)模型,分析了小兴安岭铁力林业局辖区马鹿种群冬季潜在适宜生境分布特征和主要环境因子对马鹿分布的影响。结果显示:模型预测精度较高,训练集与验证集的平均AUC(area under the curve,受试工作者曲线下面积)值分别为0.949和0.958;Jackknife检验结果表明:景观类型因子对马鹿生境选择的影响较大;坡向、距大路距离、距混交林距离、距灌草地距离和距农田距离是影响马鹿生境分布的主要环境因子,其综合贡献值依次为27.8%、23.9%、19.5%、15.3%和10.4%;距小路距离对马鹿分布影响较小。我们依据Max Ent模型最大约登指数,找到最佳中断点0.22作为阈值将马鹿冬季栖息地划分为适宜和不适宜两个等级,其面积分别为663.49 km^2和1,378.85 km^2,分别占研究区总面积的32%和68%。马鹿的适宜生境主要分布在铁力林业局辖区的东部山地和中部林地等区域;南部地区接近铁力市区,人类活动频繁,不适宜马鹿栖息。对马鹿种群的保护管理措施提出3点建议:控制人为干扰;构建多样性景观;优先保护马鹿的潜在适宜生境分布区。
基金National Natural Science Foundation of China,No.41871197,No.41271201The Doctoral Scientific Research Foundation of Liaoning Province,No.20170520280The Fundamental Research Funds for the Central Universities of China,No.171104003
文摘Species abundance and habitat distribution are two important aspects of species conservation studies and both are affected by similar environmental factors. Forest resource inventory data in 2010 were used to evaluate the patterns of habitat for target species of Cervidae in six typical forestry bureaus of the Yichun forest area in the Lesser Xing’an Mountains, northeastern China. A habitat suitability index(HSI) model was used based on elevation, slope, aspect, vegetation and age of tree. These five environmental factors were selected by boosted regression tree(BRT) analysis from 14 environmental variables collected during field surveys. Changes in habitat caused by anthropogenic activities mainly involving settlement and road factors were also considered. The results identified 1780.49 km2 of most-suitable and 1770.70 km2 of unsuitable habitat areas under natural conditions, covering 16.38% and 16.29% of the entire study area, respectively. The area of most-suitable habitat had been reduced by 4.86% when human interference was taken into account, whereas the unsuitable habitat area had increased by 11.3%, indicating that anthropogenic disturbance turned some potential habitats into unsuitable ones. Landscape metrics indicated that average patch area declined while patch density and edge density increased. This suggests that as habitat becomes fragmented and its quality becomes degraded by human activities, cervid populations will be threatened with extirpation. The study helped identify the spatial extent of habitat influenced by anthropogenic interference for the local cervid population. As cervid species clearly avoid human activities, more attention should be paid on considering the way and intensity of human activities for habitat management as fully as possible.
