基于土地利用格局变化的北京市生境质量时空演变研究

城市生境质量对生物多样性保护有至关重要的作用,以北京市为例分析2000—2015年北京市不同土地利用类型的空间分布特征和不同区域之间的差异,并借助In VEST-Habitat Quality模型评估了北京市4个时期(2000年、2005年、2010年和2015年)、4个区域(首都功能核心区、城市发展新区、城市功能拓展区、生态涵养发展区)的生境退化程度和生境质量变化情况。结果表明:(1)从2000年到2015年,建设用地增加了近40%,耕地、湿地是其快速扩张的主要来源,城市发展新区的建设用地增加了60%;(2)主要的生态用地(林地、草地、湿地)所占比例总体增加了5.71%,但是总体景观结构异质性减弱,斑块破碎化程度加大;(3)生境质量总体下降了2%,表现出明显的区域差异,首都功能核心区和生态涵养发展区的生境质量总值逐渐升高;生境退化度逐渐增加,最严重的区域在城市功能拓展区以及平原-山区交界地带。对区域生态服务价值评估的有益探索,为今后进一步城市景观格局的构建和优化提供依据和参考。

Spatio-temporal variability of habitat quality based on land use pattern change in Beijing

Habitat quality plays an important role in the conservation of biodiversity. However, with changes in land use, many natural habitats in urban landscapes have been destroyed, leading to the aggravation of habitat fragmentation, and thus, it is crucial to assess habitat quality for biodiversity conservation. In this study, we selected Beijing as the research area and analyzed the spatial distribution characteristics of different land use types and differences between 4 function regions in Beijing in 2000-2015. The InVEST-Habitat Quality model was used to assess changes in habitat degradation and habitat quality in four periods (2000, 2005, 2010, and 2015) and four districts (core functional zone, urban function extended zone, new urban development zone, and ecological conservation zone) in Beijing. The results showed that (1) from 2000 to 2015, construction land area in Beijing increased by nearly 40%. Cultivated land and wetland were the main sources of rapid expansion of construction land, and the construction land of new urban development zones increased by 60%. (2) The proportion of the main ecological land (forestland, grassland, and wetland) increased by 5.71% overall, but the overall landscape structure heterogeneity weakened and degree of patch fragmentation increased. (3) The habitat quality of Beijing showed a decreasing trend, and the total value of habitat quality decreased by 2%, showing obvious differences in different regions; however, the habitat quality in the core functional zone and ecological conservation zone increased gradually. (4) Habitat degradation increased gradually, and the most serious areas were the new urban development zone and districts of a plain-mountain junction. This study revealed the value of regional ecological services and can provide a scientific basis for the construction and optimization of urban landscape patterns in the future.