不同鸟类生境网络复合与优化——以苏锡常地区白鹭、鸳鸯、雉鸡为例

通过复合优化不同焦点物种的生境网络表征多数物种生境网络实现物种多样性保护,具有重要理论价值和实践意义。以苏锡常地区为研究区域,以白鹭、鸳鸯和雉鸡3种鸟类为焦点物种,通过采用生境斑块约束条件模型与最小成本路径法相结合的方法识别出生境网络;从满足集合覆盖问题视角出发,通过采用网络构成要素复合的方法进行网络复合,其中廊道与廊道的复合通过采用评价生态系统服务价值的方法实现;通过采用观测数据为生境斑块和迁移廊道增补依据的方法进行复合生境网络优化。结果表明:生境网络经过复合,廊道总面积、总长度及生态系统服务价值在分别减少了16%、68%和10%的情况下,保持了斑块间的连接度、兼顾到经济效益和生态效益最大化、覆盖了占总数86%以上的75处观测点;复合生境网络经过优化,覆盖了2010年及以后所有84处观测点,廊道总面积、总长度及生态系统服务价值分别增加了19%、21%和27%;说明生境网络复合优化定量分析方法和思路具有可行性,为网络复合研究提供了借鉴。

Recombination and optimization of bird habitat networks: a case study of the Little Egret (Egretta garzetta), Mandarin Duck (Aix galericulata) and Ring- necked Pheasant (Phasianus colchicus) in Su-Xi-Chang area

Habitat networks play an important role in species survival and biodiversity conservation. However, habitat networks vary among species; habitat networks generated by simply overlapping networks of a few species do not meet the needs of most species. It is necessary to develop theories and methods of network recombination so that different habitat networks can be combined into one complex network for empirical implementation in rapidly urbanizing areas. The purpose of this paper was to examine methods of recombining and optimizing habitat networks. The Su-Xi-Chang area of the Yangtze River Delta region was selected for study, and the Little Egret (Egretta garzetta), Mandarin Duck (Aix galericulata), and Ring-necked Pheasant (Phasianus colchicus) were selected as focal species because of their different biological characteristics, habitats, and diets. The habitats of these species were identified using our previously developed method, the Conceptual Constraint Model of Species Habitat Patch (CCMSHP) from land-use data for 2010. Potential corridors were identified based on the identified habitats using the least-cost path method. The habitat networks of the three focal species were overlapped using ArcGIS. From the perspective of the set covering problem, these three habitat networks were combined by recombining network structural elements, i.e., patches with patches, patches with corridors, and corridors with corridors. Among these scenarios, the recombination of corridors with corridors was the most complex. A method for evaluating the ecosystem service value of corridors was developed, and the combined corridors and habitat network were identified with the model. Optimization of the habitat network was simulated by applying observation points as newly added habitats and corridors, using a dataset (2003-2014) obtained from the website of China Bird Report. All data were calculated using ArcGIS version 10.0. After recombination, the total area, length, and ecosystem service value of all corridors were reduced by 16%, 68%, and 10%, respectively, relative to the original values; however, the connectivity of the network remained the same. The combined network covered 75 observation points (more than 86% of all points) and achieved the target of simultaneously maximizing the economic and ecological benefits. After model optimization, the habitat network covered all 84 observation points after 2010, and the total area, length, and ecosystem service value of all corridors increased by 19%, 21%, and 27%, respectively, relative to the original values. These results demonstrate that the combined quantitative analysis method developed here is reasonable and feasible. This method will be useful for theoretical research on habitat network recombination.