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在湖南省长沙县大山冲国有林场南酸枣落叶阔叶林建立1 hm2固定样地,基于植物群落学调查数据和等距离网格布点取样的土壤养分测定数据,采用地统计学和GIS相结合的方法,研究土壤P含量的空间变异特征及其影响因子.结果表明:腐殖质层及0~10、10~20、20~30 cm土层的全P、有效P含量的均为中等强度变异,同一土层有效P含量的变异程度较全P含量高,随着土壤深度增加,全P、有效P含量下降,变异程度增大.土壤全P、有效P含量具有较高的空间自相关性,主要受结构性因素影响.有效P含量的空间异质性较全P强,各土层全P、有效P含量空间自相关范围分别为92.80~168.90 m、79.43~106.20 m.同一土层全P含量分维数高于有效P,空间格局较有效P复杂,有效P含量空间依赖性更强,具有更好的结构性.腐殖质层及0~10、10~20、20~30 cm土层的全P、有效P含量呈现条带状和斑块状梯度性分布,且全P、有效P含量的空间变化趋势基本一致,高值出现在洼地,低值则出现在山脊.全P、有效P含量与高程、地表凋落物现存量呈显著负相关,与凹凸度、树种种数、株数、土壤p H相关性不显著,与土壤有机C、全N含量呈显著正相关.这反映出土壤P的淋溶特性,其空间变异性受到多种因子相互作用的影响.
A 1 hm 2 fixed plot was established in Dashanchong National Forest Farm, Changsha County, Hunan Province. Based on the plant community investigation data and the soil nutrient measurement data sampled from the equidistant grid distribution point, a combination of geostatistics and GIS Method was used to study the spatial variation characteristics of P content in soil and its influencing factors.The results showed that all P and P contents in humus layer and 0 ~ 10, 10 ~ 20 and 20 ~ 30 cm soil layers were medium intensity variation, The content of available P in soil was higher than that in total P, and with the increase of soil depth, the content of total P and available P decreased and the degree of variation increased.The total P and available P in soil had higher spatial autocorrelation, Affected by the structural factors, the spatial heterogeneity of available P content was stronger than that of the whole P, and the spatial autocorrelation ranges of total P and available P were 92.80-168.90 m and 79.43-106.20 m, respectively.The P content The fractal dimension is higher than the effective P, the spatial pattern is more effective, P is complex, the effective P content is more space-dependent, and has better structure.The total content of humus and 0-10, 10-20, 20-30 cm P, effective P content showed striped and plaque-like gradient distribution, and all P, there There was a significant negative correlation between total P, available P, and litter, and the existing abundance of litter, with the degree of asperity, the number of tree species, There was no significant correlation between soil p H and plant number, but significant positive correlation with soil organic C and total N content, which reflected the leaching characteristics of soil P. The spatial variability was affected by the interaction of many factors.