基于水文分析的动物通道选址——以龙栖山自然保护区为例

Location Selection of Wildlife Corridors Based on Hydrological Analysis:A Case Study of the Longqi Mountain Nature Reserve

自然保护区内道路等基础设施的建设不可避免地会对动物生境产生影响,造成动物死亡率提升。动物通道的设置是改善由道路建设引起的生境破碎化的有效途径,而正确选择动物通道的位置才能使其真正发挥作用。以福建省将乐县龙栖山国家级自然保护区为对象,选取对林区生境影响较大的6种环境因子:树种类型、树种平均年龄、胸径、坡度、海拔以及郁闭度,使用层次分析法(AHP)进行权重分析,相对权重依次为0.296、0.235、0.163、0.085、0.076、0.145。将因子进行叠加构建出生境适宜性指数(HSI)评价模型,并对研究区的生境适宜性进行评价。在此基础上采用ArcGIS的水文分析模块模拟动物潜在的活动路径与道路叠加,从而确定合适的动物通道位置。结果表明,HSI较高的区域多集中在自然保护区中部高海拔地区与缓坡地带,植被主要以天然阔叶林为主,树种的平均年龄大,覆盖面积广,郁闭度高,能够为大中型的走兽提供较好的觅食、隐蔽、繁殖场所,结合量化出的动物活动路径,得到2处动物通道的理想位置。此经HSI模型模拟出的路线只能是一种大概率情况,所建议的通道建设完成后,还需进行持续的野生动物利用情况监测,以评估通道的有效性,进而进行有针对性的改造设计,直到野生动物通道的利用效果良好。对于所得到的动物活动路径,不仅可以为动物通道选址提供参考,也可为动物迁移廊道修正、林区择伐等提供科学依据。

The construction and operation of the roads and other facilities in nature reserve will inevitably affect the habitat of animals and increase the mortality rate of animals.The setting of the wildlife corridor is an effective way to improve the habitat fragmentation caused by road construction.Only when the corridors are set in correct locations,can they play really role in wildlife protection.In this paper,taking the Jiangle Longqi Mountain National Nature Reserve as the research area,6 environmental factors that had great impacts on the habitat were selected in the forest area,namely tree species type,average tree age,DBH,slope,elevation,and canopy closure.Weight analysis was performed using the analytic hierarchy process(AHP)with relative weights of 0.296,0.235,0.163,0.085,0.076,and 0.145,respectively for the factors above mentioned.The factors were superimposed to construct a habitat suitability index(HSI)evaluation model,and the habitat suitability of the study area was evaluated.Based on the evaluation,the hydrological analysis module of ArcGIS was used to simulate the active paths of animals and superimpose with the road to determine the appropriate animal channel position.The results showed that the areas with higher HSI were concentrated in the high altitude areas and gentle slope areas in the middle of the nature reserve.The vegetations in these areas were mainly natural broad-leaved forests with the characteristics of old age,wide coverage area,high degree of closeness,which could meet the needs of large and medium-sized beasts for their foraging,concealing and breeding.Combined with the quantified animal activity path,the ideal locations of two animal passage ways were found.However,the routes were theoretical results of the simulation from the HSI model with maximum probability,practical test should be conducted after the proposed channel construction was completed.Continuous monitoring of wildlife that would use the passageways to be established should be carried out to assess the effectiveness of the passageways,from which further improvement and modification could be made to achieve satisfactory results.The simulated wildlife passageways can not only provide references for the site selection of wildlife corridor but also provide a scientific basis for animal migration corridor modification and forest selective cutting.