甘肃安西极旱荒漠国家级自然保护区野马生境适宜性评价和景观特征分析

Habitat Suitability Assessment and Landscape Feature Analysis of Przewalski’s Horse in Anxi Extreme-arid Desert National Nature Reserve,Gansu

甘肃安西极旱荒漠国家级自然保护区是我国野马(Equus ferus)重引入及野放项目的重要成员之一,开展生境适宜性评价是制定该物种保护规划的前提和基础。综合考虑植被、地理环境等影响野马生境选择的关键因子,以及道路和放牧等人为干扰因子,在地理信息系统(GIS)和遥感(RS)技术的支持下,采用层次分析法(AHP)确定各评价因子的权重,运用生境适宜性指数(HSI)模型得到野马生境适宜性综合评价分级图并计算各分区面积。同时,利用Fragstats 4.2景观分析软件从斑块水平对其生境进行景观格局特征分析。结果显示:不考虑人类活动影响时,潜在适宜生境面积为283082.76 hm2,占研究区总面积的59.99%。受道路、工矿区和放牧等人类活动的影响时,实际适宜生境的面积减少27405.90 hm2,其中,道路是导致适宜生境丧失的主要因素,占55.92%。景观特征分析显示,潜在生境和实际生境内部都存在几个面积较大的高适宜生境斑块。景观指数一致显示,在人为干扰下实际生境的景观连接性变差,生境破碎化程度增加。建议控制家畜数量,改造或修建人工水源提高生境质量,加大迁徙廊道监测与保护,以确保该物种的长期生存。

Gansu Anxi Extreme-arid Desert National Nature Reserve is one of the important members of Przewalski’s horse(Equus ferus)reintroduction project in China.Habitat suitability assessment is the prerequisite and basis for formulat⁃ing conservation planning of the species.In this study,three groups of parameters including biological factors(vegetation type,coverage,edible plant resources),non-biological factors(slope,distance from water),and the human interference factors(distance from the road,distance to pasture,distance to mining area)were considered comprehensively for habitat suitability assessment of Przewalski’s horse.The analytic hierarchy process(AHP)method was used to determine the weight of each evaluation factor and a criterion for Przewalski’s horse habitat suitability was established.With help of geo⁃graphic information system(GIS)and remote sensing(RS),habitat suitability index(HSI)was used to evaluate habitat suitability and a comprehensive distribution map of Przewalski’s horse.At the same time,at patch level,the landscape pat⁃tern and the characteristics of the landscape index were analyzed by the Fragstats 4.2.The results showed that if not con⁃sidering human activities,the potential suitable habitat areas within the reserve was 283,082.76 hm2,accounting for 59.99%of the total assessment area.However,in the presence of impacts of human activities such as national highway,mine exploration and grazing livestock,the actual suitable habitat decreased by 27,405.90 hm2.Among them,road was the most severe human interference leading to the loss of suitable habitat,accounting for 55.92%.The landscape analysis showed that there were a few highly suitable habitat patches with large area and high connectivity in both potential habitat and actual habitats.The landscape metrics consistently showed that the landscape and patch connectivity became poorer and fragmentation increased under human interference.In combination with effective conservation measures,we suggest controlling the number of livestock,as well as establishing artificial water source to improve habitat quality of Przewalski’s horses.In addition,it is also necessary to establish and restore ecological corridors to bridge the Przewalski’s horse suit⁃able habitats,so as to ensure the long-term survival of this species.