Spatial heterogeneity of DTPA-extractable zinc in cultivated soils induced by city pollution and land use

查看全文 作　　者：JIANG Yong, LIANG Wenju, WEN Dazhong, ZHANG Yuge & CHEN Wenbo Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China;Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, Shenyang 110016, China;College of Land and Environment, Shenyang Agricultural University, Shenyang 110161, China 出　　处：《Science China(Life Sciences)》索引2005年第48卷第z1期,共10页 摘　　要：The spatial heterogeneity of DTPA-extractable zinc in the cultivated soils of Shenyang suburbs in Liaoning Province of China was investigated, and its map was drawn by the methods of geostatistics combined with geographic information system. The data of soil DTPA-extractable zinc fitted normal distribution after logarithm transformation, and its semivariogram fitted a spherical model. The semivariogram indicated that the spatial dependence of soil DTPA-extractable zinc content was moderate, with the spatial dependence range of 1.69 km and the fractal dimension of 1.96. Stochastic factors contributed to 49.9% of the spatial variability, while structural factors contributed to 50.1% of it. The spatial heterogeneity of soil DTPA-extractable zinc shown by a kriged interpolation map was deeply influenced by stochastic factors such as city pollution, land use pattern and crop distributions. For example, the average content of Zn in vegetable garden soils was 2.5-4 times as much as in their originated soils, and was lower in paddy soils than in their originated soils. The areas with a higher content of soil DTPA-extractable zinc appeared in the near suburbs and the riverside along Hunhe River and the wastewater drainage of Xihe River, and the extremely high values in the near suburb of the city's residential area were a striking feature, indicating the key role of city pollution in the spatial heterogeneity of soil DTPA-extractable zinc. When recorded in the form of a soil pollution map,the results of such a survey make it possible to identify the unusually polluted areas, and to provide more information for precise agriculture and environmental control. 关 键 词：soil zinc, SPATIAL heterogeneity, city pollution, LAND use, geostatisics.