Landscape structure, management and soil total nitrogen, total phosphorus in the densely populated rural landscapes of China’s Yangtze Plain Changes in land use and land cover and soil organic carbon storage in the densely populated village landscapes of China′s Yangtze Plain from the 1940 to 2002 Long-term changes in area and soil total nitrogen and total phosphorus storage in croplands of the densely populated village landscapes of China′s Yangtze Plain