| A village area, which located in the towns Yunhe, Youxin, Jintang county, and the town Tashui, Jiangyang county, about 100 km~2, was selected as the typical area of interest (AOI) for the research project of long-term biogeochemical change of anthropogenic village landscapes in the middle of Sichuan hilly basin region, using GIS and GPS technology with the base imagery of Landsat 7 and IKONOS. 12 village landscape cells, including 91% information of this region, were sampled in the AOI. In this project, we based on the high resolution (1m) IKONOS imagery in 2002 and the aerophotos of WW2 taken in 1945, have carried out household landscape survey, elder historical interview and groudtruth, established the multi-stratification village landscape classifying system: landform → landuse (land management) → landcover → ecotope (group+type),finished more precisely the ecotope mapping work. Following this, the landscape components and patterning, village landscape productivity, carbon and nitrogen source/sink, and their long-term changes between 1945 and 2002 have been studied. The main results as following:1. Great changes has taken place in village landscapes since 1945 with increasing of population and more strong effects of human activities. The anthropogenic units in landforms, such as house buildings, roads and reservoirs etc, in 2002, increased by 231.23% over 1945, but bench plateau , stream reduced 11.99% and 91.60% respectively. Some steep slopes and summit changed to bench plateau. For landuse, rainfed cropland reduced, but built-up and disturbed area increased by 480.17%. Perennial plant landcover increased by 186.57% over 1945 and sealed landcover by 386.09%. There were 16 kinds of ecotopes reduced, mainly cropland on bench plateau (BPRAac04), mixed open woody land on steep slope (SSTMow02), rice paddy submerged and fallow in winter (FSPAri03) and annual crop land on summit, significantly. The number of increased ecotope types is 27. Perennial evergreen needle leaf tree on steep slope (SSTPen03) increased by 335.52%, multi-story houses with shared wall or courtyard (ANCSho03) by 769.57%. Increased brand-new ecotope types are mainly rice paddy with double cropping season (FSPAriOl, BPPAri01), orange orchard (BPRPoe33,SLRAoe33), mixed crop land (BPRMmc01), bamboo on bench plateau (BPTPtg24) and planted evergreen needle leaf tree on steep slope (SSTPenOl).2. The heterogeneity of village landscapes in different stratifications has significant difference, and especially Shannon-Weiner indexes, dominance and fragmentation have changed greatly. The Shannon-Weiner indexes and the fragmentations of landform, landuse, landcover and ecotope are 1.4667, 2.2286; 1.3282, 2.4621; 1.1824, 2.8291; and 2.4225, 4.9937 respectively. Comparing the landscape indexes in 2002 with those in 1945, the Shannon-Weiner indexes increased by 15.75~46.61%, the evenness by 13.63~46.61%; the dominance reduced by 3.84~29.53; the relative richness changed from -6.67 to 78.95% and the fragmentation increased by 80.55~153.58%.3. In 2002, the biomass of village landscape is 32.41 t/ha, increased by 57.71% over 1945; thelandscape productivity 27.46 t/ha, increased by 138% over 1945. The village landscape system is performing as the carbon sink with the carbon fixation ability of 97.11 t/km~2, while in 1945, the village landscape did as carbon source with carbon release 49.76 t/ha. That carbon source in 1945 transformed to carbon sink today resulted largely from the carbon sink enhance of paddy, orchard, forestry and woody bushes, which compensated the carbon release of rainfed cropland as carbon source. This discovery offered the first-hand data for the long-term dispute about questions such as warming gas release in crop field in the Southeast Asia and "missing carbon sink". As far as nitrogen flux in the village landscape, the input has always been bigger than the output. In 1945, the net N input was 0.08 t/ha, and that in 2002 0.56 t/ha. Nitrogen applying amount in 2002 reached to 484.48~1307.92 kg/ha, the chemical fertilizer N,...
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