黔南马尾松人工林土壤有机碳的研究

Study on soil organic carbon of Pinus massoniana Lamb plantation in southern Guizhou province

以黔南地区独山县国有林场不同林龄马尾松人工林土壤有机碳为研究对象,对独山县国有林场土壤有机碳含量和土壤有机碳密度进行了研究。结果表明:①不同林龄马尾松林土壤有机碳含量及密度分别在9.98～15.93 g/kg和9.69～14.48 kg/m2范围之间,平均值为11.98 g/kg和11.20 kg/m2,土壤有机碳含量及密度均表现为随土层深度的增加而逐渐降低的趋势;②不同林龄马尾松林土壤有机碳含量及密度均表现为中龄林>成熟林>近熟林>幼龄林,但差异不显著(p>0.05);③土壤有机碳含量与土壤容重呈极显著负相关。除土壤全K外,土壤有机碳含量和密度与土壤养分(N、P的全量和N、P、K有效量)均呈显著或极显著正相关,但与土壤pH呈显著负相关;④不同林龄阶段土壤有机碳含量回归方程的回归精度均较高。比较标准化回归系数法处理显示,土壤N状况是影响土壤有机碳变异的主导因子。

The content and density of soil organic carbon （SOC） in different ages of P. massoniana plantation were studied, which locate in state owned forest farm in Dushan country of Southern Guizhou Province. The results are as follows： （1）The content and density of SOC of different age of P.massoniana were at the range of 9.98 ～ 15.93 g/kg and 9.69 ～ 14.48 kg/m 2 , the mean values were 11.98 g/ kg and 11.20 kg/m 2 , and they decreased with the increase of the soil depth. （2） The content and density of SOC at different age of P. massoniana show that middle-aged forest 〉 mature forest 〉 near mature forest 〉 young forest, but the differences were not significant （p 〉 0.05）. （3） The content of SOC and the soil bulk density had negative significant correlations. Except for total K, the content and density of SOC had very significant or significant positive correlations with the soil nutrients （total N and total P, available N, available P and available K）, but pH was on the contrary. （4） The regression equations of the content of SOC at different ages of P. massoniana plantation were established with high estimation precision. Having compared the treatments by standardized regression coefficient method,it is showed that the soil nitrogen was the dominant factor for the variation of SOC .