中文摘要：

为把握关键控制因子，揭示土壤有机质的变化机制，利用通径分析和敏感性分析研究了江西大岗山杉木人工林土壤相关变量对土壤有机质含量的影响。结果表明：各土壤相关变量通过不同的方式和强度影响着土壤有机质含量，土壤碱解氮量和土壤密度主要通过强烈的间接作用产生影响，孔隙度、速效钾量、细菌数量和真菌数量的影响主要来自较强的直接作用，有效磷量和放线菌数量的影响力较低；各变量对土壤有机质含量的敏感性依次为：碱解氮量〉真菌数量〉细菌数量〉有效磷量〉放线菌数量〉总孔隙度〉速效钾量〉土壤密度；土壤碱解氮量、细菌数量和真菌数量的重要性和敏感性较大，是土壤有机质变异的重要影响因素；较小的分析误差表明所用的分析方法在考察土壤有机质含量与其他土壤变量关系上是可行的。

英文摘要：

To ascertain the key control factors of soil organic matter （SOM） and provide theory to reveal its changing mechanism, effects of correlated variables on SOM content in Chinese fir plantations were studied with path analysis and sensitivity analysis in Dagang Mountain of Jiangxi Province, eastern China. Results showed that SOM content was affected by the variables in different ways and intensities,indirectly but strongly by alkali-hydrolyzable nitrogen content and soil density, and directly by total porosity,readily available potassium, and the number of bacteria and fungi. Available phosphorus content and the number of actinomycetes had the least effect on SOM content. The sensitivity of variables correlated to SOM content was in the order of alkali-hydrolyzable nitrogen content 〉 the number of fungi 〉 the number of bacteria 〉 available phosphorus content 〉 the number of actinomycetes 〉 total porosity 〉 readily available potassium 〉 soil density. Soil alkali-hydrolyzable nitrogen content and the number of bacteria and fungi had higher importance and sensitivity, and determined most variation of SOM content. The smaller analysis error indicats that path analysis and sensitivity analysis are feasible in studying the relation between SOM content and soil-correlated variables.