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以2011年盐源县实地采样数据和1980年代第二次土壤普查资料为基础,采用地统计学、方差分析及相关分析等研究方法,分析了该区域近30年来耕层土壤有机碳时空变化特征,并探讨不同影响因素的显著性变化特征。结果表明,研究区土壤有机碳含量平均值从23.02 g kg-1下降到16.69 g kg-1,整体呈下降趋势。土壤有机碳初始含量较高的土类、海拔段和地貌区下降幅度明显较大,导致研究区土壤有机碳空间分布格局发生明显变化,高值区由西北部中高山地区变为东部区域。半方差分析表明,近30年间研究区耕层土壤有机碳空间变化的变程由67.5 km缩短至55.8 km,块金值和基台值之比从42.8%增加至50.0%,表明人类施肥耕作等随机因素使得结构性因素的作用减弱,空间自相关程度和范围降低。影响因素的显著性变化分析表明,土类和海拔的作用由极显著(p<0.01)变为显著(p<0.05);土壤有机碳与主要养分因子中全氮的相关程度减弱,与全磷和p H的相关关系不再显著,这进一步说明施肥耕作等随机性因素对研究区土壤有机碳时空变异的影响在增强。
Based on the field sampling data of Yanyuan County in 2011 and the second soil census data in the 1980s, the temporal and spatial variations of soil organic carbon in topsoil in the past 30 years were analyzed by means of geostatistics, variance analysis and correlation analysis. , And explore the significant changes in different influencing factors. The results showed that the average value of soil organic carbon in the study area decreased from 23.02 g kg-1 to 16.69 g kg-1, showing a downward trend. The decline range of soil, elevation and topography area with high initial soil organic carbon content was significantly larger, leading to significant changes of spatial pattern of soil organic carbon in the study area. The high value area changed from the middle-high mountain area in the northwest to the eastern area. Semi-ANOVA analysis showed that within 30 years, the range of soil organic carbon spatial variability in the topsoil decreased from 67.5 km to 55.8 km, and the ratio of nugget value to abutment value increased from 42.8% to 50.0%, indicating that human fertilization and other farming practices Stochastic factors make the role of structural factors weakened, the degree and extent of spatial autocorrelation decreases. Significant changes of the influencing factors showed that the effects of soil type and altitude changed from extremely significant (p <0.01) to significant (p <0.05). The correlation between soil organic carbon and total nitrogen in the main nutrients was weakened, And p H is no longer significant, which further indicates that the impact of random factors such as fertilization and tillage on the spatio-temporal variations of soil organic carbon in the study area is increasing.