---

作 者 ：武俊喜,焦加国,肖红生,王洪庆,杨林章,程序,Ellis Erle C

期 刊 ：生态学报 2008年 28卷 8期 页码：3606~3617

关键词：长江平原区；乡村景观；生态立地；尺度推绎；自助法取样；蒙特卡罗模拟；土壤氮磷；

Keywords:Yangtze Plain, rural landscape, ecotope, upscaling, bootstrapping re-sampling, Monte Carlo simulation, soil total nitrogen and total phosphorus,

摘 要 ：通过实地研究主要位于宜兴市域的区域乡村景观代表性样方，评价并阐明了人口密集的长江平原区乡村景观的结构、管理与土壤全氮、全磷密度和储量的关系。景观绘图是基于1m分辨率的IKONOS影像并采用生态立地分类及绘图标准，通过直接解译和实地检验对均质景观缀块进行分类和绘图；依据区域权重分层取样方法，在生态立地缀块中随机设定取样点进行土壤或底泥取样；通过自助法对12个样方重取样，用区域多变量最优化方法计算样方的区域权重，并结合不确定性分析模型评价区域土地利用/覆被、土壤全氮和全磷储量。结果表明：在85.24×103km2的长江平原区乡村景观面积范围内，0~30cm土壤全氮、全磷储量分别为29.87Tg N和 19.79Tg P。最大的5种土地利用/覆被的类型为水田、水产养殖、非渗漏性建筑用地、旱地1年生作物和闲置水域，占区域总面积的82.9%；其土壤全氮、全磷储量分别占区域总量的82.6%和80.8%。其中平原稻田面积为38.93×103km2，占总面积的45.5%；其0~30cm土壤全氮、全磷储量分别高达15.26Tg N和9.13Tg P，分别占总储量的51%和45%。揭示了人口密集的乡村景观中土地利用/覆被方式对区域土壤全氮、全磷的影响模式。这种在小尺度下对土地管理调查，土壤全氮、全磷及其它生态特征研究方法的精确度明显优于传统的基于30~1000m分辨率遥感影像的土地覆被研究。

Abstract:In this study, we examined interactions between landscape structure, land management and soil total nitrogen (TN; top 30 cm) and total phosphorus (TP; top 30 cm) within the densely populated rural landscapes of the Yangtze Plain, based on an intensive field study in a regionally-representative sample cells in Yixing County. The rural landscapes were mapped at a high spatial resolution and classified to ecologically-distinct features (ecotopes) by the direct interpretation and field validation of features in 2002 IKONOS imagery using a standardized mapping procedure. Then the samples of soils and sediments were collected for analysis at random points within ecotope selected by a cluster distance weighting stratified sampling design. The five most extensive land use/land cover categories in the Yangtze Plain were paddy, aquaculture, built structures with impervious cover, rainfed annual cropland and fallow water, which occupied 829% of the total area, contained 82.6% of the total nitrogen and 80.8% of the total phosphorus stored in the region′s rural landscapes, respectively. Regional scaling analysis indicated that 85.24×103 km2 of Yangtze Plain rural landscapes sequestered 29.87 Tg of the total nitrogen and 19.79 Tg of the total phosphorus, of which 51% and 45% were in paddy land respectively (15.26 Tg of TN and 9.13 Tg of TP), covering 45.5% of the region′s total surface area (38.93×103 km2). Regional estimates of landscape class areas, soil total nitrogen and soil total phosphorus were made by upscaling data obtained from the sample cells by using a multivariate regional optimization procedure combined with bootstrapping and Monte Carlo uncertainty analysis.Then the role of land use/land cover in determining local total nitrogen and total phosphorus patterns and the regional consequences of these patterns were revealed across a densely populated rural region of China′s Yangtze Plain. This fine-scale approach to investigating land management practices and their impacts on total nitrogen, total phosphorus and other ecosystem properties offers significant advantages of accuracy rate over conventional lower-resolution (30-1000m) methods for land cover.

---