关键词: 土壤含水率, 四川, 栲木荷群系, 演替阶段, 中亚热带

Abstract: Based on the urban development features and green space planning, the plain area of Beijing from the urban center to the fringe was divided into five sub-regions, i.e., central urban area, first green belt, extended urban region, second green belt, and fringe area. The land use pattern and normalized difference vegetation index (NDVI) were interpreted with multi-period remote sensing images, and on this basis, the ecosystem services values of the sub-regions in 1999 and 2007 were calculated. From 1999 to 2007, the total amount of ecosystem services value in the central urban area and first green belt had somewhat increase, but that in the whole plain area had a greater decrease. From the urban center to the fringe, the proportion of the ecosystem services contributed by farmland and orchard increased gradually. The 58.8% loss of the ecosystem services value of the whole plain area was due to the change of land use, mainly the construction land sprawling farmland and woody land. Another 41.2% loss was due to the degrading of landscape quality, mainly the degrading of agricultural landscape, especially in the fringe area. With the scarceness of present land resources and the increasing pressure of construction land enlargement, it would be a promising way to bring good quality farmland into green space planning and to improve the quality and ecosystem services of the farmland to enhance the overall ecosystem services of Beijing green space.

Key words: Percentage of soil absolute moisture content (PSAMC), Sichuan, Castanopsis platyacantha Schima sinensis formation, Succession stage, Central subtropical zone