Abstract:

To study the effects of land use pattern change on habitat quality in the background of urbanization, InVEST model was applied to calculate the contributions of habitat threats (urban area, rural construction area, main roads and agriculture land) to habitat degradation, and to assess habitat quality changes between 1990 and 2010 in Beijing. The results showed that the most severe habitat degradation problems occurred in Haidian, Chaoyang, Shijingshan and Fengtai districts, Yongding River, Chaobai River, and the mountain-plain border area (at an elevation about 75-100 m). Agriculture lands had the largest effect on habitat degradation, followed by urban areas, rural construction areas and main roads. During these two decades, the contribution of agriculture lands decreased from 77.79% to 61.15%, but the contribution of urban areas increased from 18.10% to 31.54%. Between 1990 and 2000, habitat quality declined dramatically in Haidian, Chaoyang, Shijingshan and Fengtai districts, which were located at the rim of Dongcheng and Xicheng districts. The total habitat quality value decreased by 2.3%. During 2000 and 2010, the deterioration of habitat quality expanded to most of the plain areas. In the mountain area of Fangshan and the mountain-plain border area (at an elevation about 75-100 m) in Miyun, Huairou, Changping and Fangshan, the value decreased significantly. However, habitat quality had been restored notably in northern and western mountain areas. The total habitat quality value declined by 1.2%, which indicated that habitat deterioration had been mitigated to some extent compared with the last decade. For habitat conservation and urban planning in the future, more attention should be paid to mountain-plain border areas. The current study played an active role in land use policy-making and biodiversity conservation.

Key words: land use, InVEST model, habitat quality

摘要：

为了探究城市化背景下土地利用格局变化对生境质量的影响, 应用InVEST模型计算北京主要威胁源(城市、农村、主要交通干道、耕地)对生境退化的贡献, 评估北京1990—2010 年的生境质量变化。研究结果显示, 生境退化最严重的区域, 主要集中在海淀、朝阳、石景山和丰台四区, 永定、潮白两河以及海拔75~100 m左右的平原?山区交界地带。威胁源对生境退化的影响从大到小依次是耕地、城镇用地、农村居民点以及主要交通干道。20年间, 耕地的贡献率逐渐减小(从77.79%降至61.15%), 城镇用地的贡献率则从18.10%提高到31.54%。1990—2000年间, 生境质量在东城、西城外围的海淀、朝阳、石景山、丰台四区呈环形集中退化趋势, 生境质量总值下降2.3%。2000—2010年间生境质量在平原区呈现大范围分散式退化趋势; 在房山西部山区以及密云、怀柔、昌平、房山海拔75~100 m左右的平原?山区交界地带呈现集中退化趋势; 西北部和西部山区生境则得到明显恢复。总体看, 第二个10年生境质量总值下降1.2%, 退化程度较第一个10年有所减轻。未来的生境保护以及城市规划应重点关注生境退化最为突出的平原与山区交界区域。研究结果对制定合理的土地利用政策以及保护生物多样性具有一定的积极作用。

关键词: 土地利用, InVEST模型, 生境质量