时空变化视角下北京市湿地优先保护格局

气候变化通过改变湿地水文过程等影响湿地的空间分布,城市化进程加剧了湿地破碎化程度并导致湿地生境退化,构建连续的湿地生态保护网络体系有利于应对气候变化和城市发展带来的负面影响、提高生物多样性保护水平。北京市现有湿地空间分布呈现斑块面积小、破碎化程度高等特点,为优化湿地保护区格局并应对气候变化和城市发展对北京市湿地生物多样性的影响,基于系统保护规划方法,以Marxan作为空间优化模型,结合PLUS模型和MaxEnt模型,模拟预测北京市湿地优先保护格局、识别湿地保护空缺并构建湿地分级保护区格局。研究表明:2020年北京市湿地存在80.15km²的保护空缺、2035年和2050年优化后湿地保护区占比分别为87.54%和85.95%,在满足本研究预设的生物多样性保护目标的前提下符合北京市湿地保护规划对湿地保护率的要求。为最优化资源分配,综合时空变化对湿地保护区空间分布的影响,构建了湿地分级保护区格局,将湿地保护区分为湿地永久保护区、湿地一级临时保护区和湿地二级临时保护区三个等级,以期为北京市分期建设湿地保护区、优化湿地生态保护网络体系和保护湿地生物多样性提供依据。

Priority conservation pattern of wetlands in Beijing from the perspective of time and space

Climate change affects the spatial distribution and ecological functions of wetlands by altering the hydrological processes, soil temperature, biogeochemical cycles, and vegetation conditions. The continuous high temperature and drought, as well as other extreme weather conditions, have led to the degradation of habitats of some urban wetlands, posing a serious threat to the safety of urban biodiversity. The increasingly rapid urbanization is exacerbating wetland fragmentation and reducing the hydrological connectivity of wetlands, and thereby increasing the fragility of wetland ecosystems and leading to the degradation of wetland habitats. Establishing a continuous wetland ecological protection network system is beneficial for mitigating the negative impacts of climate change and urban development and improving biodiversity conservation. The current spatial distribution of wetlands in Beijing is characterized by small patch size and high fragmentation. Despite facing numerous challenges such as water scarcity and fragile water environment, Beijing aims to increase the area of wetlands and promote efforts related to wetland protection and restoration. To optimize the priority conservation pattern of wetlands and address the impacts of climate change and urban development on wetland biodiversity in Beijing, this study adopts the approach of Systematic Conservation Planning which can resolve the conflict between biodiversity conservation and urban resource utilization based on the simulated annealing algorithm. In order to provide more scientific evidence and suggestions for the protection of biodiversity in Beijing, the Marxan spatial optimization model is used in combination with the PLUS and MaxEnt models to simulate and predict the priority areas for wetland protection in Beijing, identify protection gaps, and establish a classification system for wetland protected areas. The result showed that there was a protection gap of 80.15 km² of Beijing''s wetlands in 2020. After optimization, the proportion of protected wetland areas will be 87.54% in 2035 and 85.95% in 2050. Under the premise of satisfying the predetermined biodiversity conservation objectives, the result complies with the wetland conservation rate requirements outlined in the wetland conservation planning of Beijing. To optimize resource allocation, the study considers the impact of temporal and spatial changes on the spatial distribution of wetland protected areas and proposes a classification system comprising permanent wetland protected areas, the first-level temporary protected areas, and the second-level temporary protected areas. And the result showed that by 2050, their areas would reach to 488.61 km², 13.02 km² and 28.95 km² respectively. This provides a basis for the phased construction of wetland protected areas, optimization of the wetland ecological protection network system, and conservation of wetland biodiversity in Beijing.