土地利用变化对鸟类栖息地连通性的影响--以鄂州市为例

Impact of land use change on bird habitat connectivity: a case study in Ezhou City

土地利用变化是造成栖息地破碎、缺失与退化的重要原因。生态网络能保护重要栖息地,促进栖息地之间的物质与能量流动,对区域土地利用规划和生物多样性保护具有重要意义。以鄂州市为研究区,基于CLUE-S模型预测现状延续、生态保护和城市扩张3种土地利用情景,将生境质量作为遴选生境斑块的依据之一,以鸟类最大迁徙距离为阈值构建生态网络,从连通概率指数PC和斑块重要性指数dPC两方面,探讨土地利用变化对鸟类栖息地连通性的影响。结果表明:(1)不同情景的地类数量和空间结构均有差异,与生态保护相比,城市扩张情景的建设用地增加11603.52 hm^(2),林地、耕地和水体减少5041.8 hm^(2)、2540.16 hm^(2)、3385.8 hm^(2),新城区、山地风景区与水体周边是主要变化区域;(2)现状延续和城市扩张情景的生境斑块降至235块和216块,网络出现破碎化,生态保护情景增至367块,网络结构完整但空间位置改变;(3)2004-2024年PC表现为先上升后下降再上升的趋势,生态保护的PC高于现状延续和城市扩张,且利于保护短距离迁徙鸟类;(4)生态保护情景边缘型和关键小型斑块得到保护,第一等级斑块增加,城市扩张情景第二等级斑块增加,现状延续情景部分斑块的重要性提高。在新一轮发展规划中,鄂州市要协调城市发展与生态保护的关系,优先保护受到土地利用变化威胁的大型与关键小型栖息地,重点保护短迁徙鸟类的栖息地连通性。

Land use change is an important cause of habitat fragmentation, loss, and degradation. The ecological network can protect essential habitats and promote the flow of material and energy between habitats, which is significant to regional land use planning and biodiversity conservation. Taking Ezhou City as the research area, three land use change scenarios were predicted based on the CLUE-S model. Using habitat quality as one of the criteria for selecting habitat patches, an ecological network was constructed based on the maximum migration distance of birds. The effect of land use change on bird habitat connectivity using the probability of connectivity(PC) and delta probability of connectivity(dPC). The results showed that:(1) the number of land use types and spatial structure differed in the three scenarios. Compared with ecological conservation, construction land increased by 11603.52 hm^(2), while forest, farmland, and water decreased by 5041.8 hm^(2), 2540.16 hm^(2) and 3385.8 hm^(2) in urban expansion. The main changing areas were new urban areas, scenic mountain areas, and water surrounding areas.(2) Habitat patches decreased to 235 and 216 in the present continuation and urban expansion scenario. Habitat patches increased to 367 in the ecological conservation scenario. The network structure was complete, but the spatial location changed.(3) The PC showed a trend of first increased, then decreased and increased again in 2004-2024. The PC of ecological conservation was higher than the present situation continuation and urban expansion, which benefited short-distance migratory birds.(4) The first level patches increased in the ecological conservation, the marginal and critical small patches were protected, and the second level patches increased in the urban expansion. The importance of some habitat patches increased in the present situation. The new development planning of Ezhou City should coordinate the relationship between urban development and ecological conservation. The priority should be given to protecting large and critical small habitat patches that are potential threats to land use change. It is necessary to focus on protecting the landscape connectivity of short-migratory birds.