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基于我国第二次土壤普查数据,利用Arc GIS和GS+地统计软件,分析东北地区土壤有机碳含量(SOCC)和土壤全氮含量(STNC)空间分布特征,并从8个自然因子和土地利用方式(LUT)中辨析主控因素及人类活动和自然因素影响的相对重要性。结果表明:东北地区SOCC、STNC属于养分分级的中等偏上水平;SOCC、STNC的最优半方差函数模型均为高斯模型,块金效应分别为36.56%和43.76%,具有中等强度空间自相关性;SOCC、STNC空间分布为从东北向西南方向逐渐降低。SOCC、STNC与土壤阳离子交换量(CEC)、经度(Lo)、纬度(La)、海拔高度(H)呈显著正相关,与年均温(MAT)、p H、土层厚度(d)均呈显著负相关,而与年均降水量(MAP)相关性均不显著(P>0.01);东北地区影响SOCC、STNC的主控因素为CEC、Lo、LUT、p H和MAT;所有相关性因子共同解释SOCC、STNC变异性的30.10%和29.20%,其中LUT解释部分分别占总解释程度的10.96%和5.82%。自然因素特别是土壤性质对该区土壤碳氮空间分布的影响仍然起到主导作用,但耕地条件下农业生产活动可能在一定程度上削弱自然因子对土壤碳氮的影响。
Based on the data of China’s second soil census, the spatial distribution characteristics of soil organic carbon (SOCC) and soil total nitrogen (STNC) in northeastern China were analyzed using ArcGIS and GS + geostatistical software. Eight natural factors and land use patterns (LUT) to analyze the relative importance of the controlling factors and the influence of human activities and natural factors. The results showed that the SOCC and STNC in northeastern China belonged to the medium upper level of nutrient classification. The optimal semi-variance function models of SOCC and STNC were all Gaussian models, with a bulk gold effect of 36.56% and 43.76% respectively, with medium intensity spatial autocorrelation ; SOCC, STNC spatial distribution from northeast to southwest gradually decreased. SOCC and STNC were positively correlated with soil CEC, Lo, La and H, but not with MAT, p H and soil thickness (d) (P> 0.01). The main controlling factors affecting SOCC and STNC in northeastern China were CEC, Lo, LUT, p H and MAT, and all the correlations The factors jointly explained 30.10% and 29.20% of the variability of SOCC and STNC, of which, the interpretation of LUT accounted for 10.96% and 5.82% of the total interpretation respectively. Natural factors, especially soil properties, still play a dominant role in the spatial distribution of soil carbon and nitrogen in the area. However, agricultural activities under cultivated conditions may weaken the impact of natural factors on soil carbon and nitrogen.