辽东山区次生林土壤主要化学性质空间异质性

The spatial heterogeneity of main soil chemical properties in secondary forest in montane region of eastern Liaoning Province in China

研究土壤化学性质的空间变异性不仅有助于了解土壤的形成、结构和功能,而且有助于了解植物与土壤的关系。本研究以辽东山区次生林4 hm2样地为平台,分析8种土壤化学性质(p H值、有机质、全氮、有效氮、全磷、有效磷、全钾、有效钾)的空间异质性。结果表明:辽东山区次生林土壤呈微酸性;p H值呈弱度变异,其他7个指标均表现为中等程度变异;样地土壤8种化学性质的半方差函数均表现出一定的空间结构特征,除p H的变异函数可拟合为球状模型外,其余7个指标均可拟合为指数模型,模型拟合度均较好,其中有效钾、p H值和有机质呈现出中等程度的空间相关性,其余5个指标均表现出较强的空间相关性;样地中p H值呈现出较为均匀的缀块性分布格局,其余7个指标的分布格局均表现为西高东低,可能与幼苗分布及土壤温度有关。

Studies of spatial variability of soil chemical properties are not only valuable for understanding soil formation,structure,and function,but also for understanding plant-soil relationships. We analyzed the spatial heterogeneity of eight main soil chemical properties in a 4 hm^2 secondary forest plot in the montane region of eastern Liaoning Province. The results showed that the soil was slightly acidic; the variation of p H was weak,while the variations of organic matter（ OM）,total nitrogen（ TN）,total phosphorus（ TP）,total potassium（ TK）,available nitrogen（ AN）,available phosphorus（ AP） and available potassium（ AK） were moderate. Spherical model fitted best for soil p H,and exponential model fitted best for the other soil chemical properties. Soil AK,p H,and OM showed moderate spatial autocorrelation,while the other chemical properties showed strong spatial autocorrelation. Soil p H showed a relatively uniform distribution pattern,while the distribution patterns of the other chemical properties were similar,being high in east but low in west of the plot. Soil temperature and spatial distributions of tree seedlings may be the main factors driving the spatial distribution of soil chemical properties in this area.