宁夏沙坡头国家自然保护区鸟类景观生态安全格局构建

随着宁夏沙坡头国家自然保护区的旅游发展与荒漠化进程,保护区内不同类型的鸟类均面临着日益增加的自然及人为干扰胁迫,鸟类群落的丰富度下降趋势显著。为了改善保护区内鸟类生物多样性现状,优化鸟类栖息地空间结构,基于现有鸟类调查与研究资料,筛选影响鸟类活动的各类阻力指数,建立鸟类活动最小累积阻力面,运用最小阻力模型构建景观生态安全格局。研究结果表明:源地面积为1690.67 hm~2,占保护区总体面积的12.09%;廊道共13条;辐射道共85条;战略点共8个;保护关键区面积为2634.48 hm~2,占保护区总体面积的18.76%。在此基础上,针对不同类型的重点保护地块、保护热点及栖息地之间的联系廊道提出鸟类保护的空间格局优化建议。详细梳理了阻力面模型的构建方法,改进了相关技术环节,为我国自然保护区生物多样性景观安全格局优化提供了科学的方法与实践指导。

Construction of the landscape ecological security pattern for the conservation of birds at Shapotou National Nature Reserve, Ningxia

Shapotou National Nature Reserve is one of the earliest desert ecosystem reserves in China, which is located in northwest part of Ningxia Autonomous Region. Many different bird species have been recorded in the desert, wetlands, fixing sand forests, and the villages within this reserve. However, with the development of desert tourism and the West-to-East Gas Project, the distribution and constituents of the land-use has changed, which has affected ecosystem services. A major threat faced by many birds that needs to be addressed urgently is habitat loss, degradation, and fragmentation. It is obvious that with increased awareness of the importance of protecting biodiversity, the demands for addressing ecological security becomes an urgent need. Given this background, in this study, we aimed to identify significant bird habitats and their spatial distributional patterns, data that is of vital importance for informed conservation action for birds. This study applies Security Pattern Theory to identify landscape area or elements of critical significance to safeguard bird activity. We chose Shapotou National Nature Reserve as the study region for three reasons. (1) This reserve has a high percentage of rare bird species, and hence the results would have good representativeness; (2) Although the total area of this nature reserve is just 140.43 km², the habitats are becoming highly degraded and fragmented; (3) With the advent of human activity in the reserve, comprehensive planning for protection becomes very important. Our results show the following:(1) it is feasible to construct a landscape security pattern, based on GIS and "cost distance" analytical tool, and using environmental factors and human interference factors in the minimum cumulative resistance (MCR) model. This also provides a feasible approach to construct ecological security pattern for particular species in other nature reserve. (2) Through the minimum cumulative resistances surface, which was derived from the MCR model, we identified the components of ecological security pattern such as corridors, radiating routes, strategic points, etc, which can preserve or positively affect bird populations. (3) This security pattern addresses the environmental and economic scenario at Shapotou National Nature Reserve well. Based on this model output, the identified "source" habitats for the birds were concentrated, resulting in relatively low fragmentation, and allowing more effective and easily implementable actions for their protection. To connect the "sources" 13 corridors as well as 85 radiating routes were identified, which provide more space for "sources" expansion. Additionally, we identify the weakest position of bird activity as the strategic point combined with key regions to protect the whole structure of the bird''s activity. Our results provide an effective method to protect particular species within this nature reserve. Further studies will be valuable as more factors could be identified by the ecological security pattern, and the correlation between the various factors was not significantly reflected in this study.