【摘要】 以闽江河口湿地土壤有机质为研究对象,采用变异函数、多重分形分析和空间自相关法,从空间异质性和空间自相关性角度研究不同土层有机质的空间分布规律。结果表明:3个土层有机质含量均为中等变异程度,块金效应均小于25%,结构性因素对空间异质性起着主导作用。随着土层深度的增加,各土层有机质空间分形结构表现出差异性,0～20cm空间分布最不均匀,分形程度较高,空间变异性较大; 3个土层有机质的Moran I均大于1.96,呈现出显著的空间正相关,其中20～40 cm的土层有机质空间正相关最显著,空间聚集程度较高。联合变异函数、多重分形分析和空间自相关法能够较好地反映河口湿地不同土层有机质在水平上空间分布特征,为同类区域的土壤有机质空间分布研究提供方法支撑。更多还原

【Abstract】 A better understanding of the spatial distribution of soil organic matter( SOM) plays a key role in further studying cycling process of elements in estuary wetland soil. We examined the spatial distribution of SOM at different soil layers in Minjiang estuarine wetland by using variogram,multi-fractal and spatial autocorrelation analysis. The results showed that the coefficient of variation for SOM in the layers of 0-20,20-40 and 40-60 cm were generally similar and moderate,with values of 46.25%,49.01%,and 50.49%. All the ratios of nugget to sill were less than25%,suggesting that structural factors played a dominant role in spatial heterogeneity. With the increases of soil depth,the spatial fractal structures of SOM in different soil layers were different.The SOM content in 0-20 cm layer was the most uneven,suggesting a higher fractal degree and a larger spatial variability. The Moran’s I of SOM in all the three soil layers was more than 1.96,showing a significant positive spatial autocorrelation. The value of Moran’s I in layer 20-40 cm was the largest,showing a more significant spatial autocorrelation and a higher spatial aggregation degree than the other two layers. In brief,our results reveal horizontal distribution characteristics of SOM in estuarine wetlands and provide methodological support for researches on the SOM spatial distribution in similar regions.更多还原