坡位对思茅松人工林土壤微生物量碳的影响

Effects of Slope Position on Soil Microbial Biomass Carbon of Pinus kesiya var. langbianensis Plantation

为了探讨坡位对思茅松人工林土壤微生物量碳的影响,以12年生的思茅松人工林为研究对象,对不同坡位0-50cm土层土壤微生物量碳含量及密度进行调查。结果表明:思茅松人工林土壤有机碳质量分数随着海拔的升高而增加,土壤微生物量碳主要集中于0-10cm的土壤层,0-50cm土层深度的土壤微生物量碳的平均含量下坡位>中坡位>上坡位;在0-30cm土壤层,土壤微生物量碳占土壤有机碳的比值随着海拔的升高而下降,下坡位更有利于土壤有机碳的积累;50cm土层深度土壤微生物量碳密度数值范围为0.85-1.56t/hm^2,下坡位最大,上坡位最小。研究表明思茅松人工林土壤易分解性有机碳库在下坡位最大。

In order to explore the effect of slope position on soil microbial biomass carbon(MBC)pool of Pinus kesiya var. langbianensis plantation,microbial biomass carbon(MBC)and density in the depth of 0-50 cm soil in different slope position of 12 years P.kesiya var. langbianensis plantation were investigated.The results showed that the soil organic carbon(SOC)contents of P.kesiya var. langbianensis plantations increased with the increase of elevation, and soil MBC mainly concentrated on the layer of 0-10 cm,the order of MBC content in the depth of 50 cm was bottom slope position>middle slope position>top slope position;the proportions of MBC in SOC in the depth of 0-30 cm decreased with the increase of elevation,bottom slope position was more beneficial to the accumulation of soil organic carbon;The values of MBC density in the depth of 50 cm ranged from 0.85 to 1.56 t/hm^2,the maximum and minimum were bottom slope position and top slope position respectively.The results of this study verified that the soil easy decomposable organic carbon pool of P.kesiya var. langbianensis plantation was the largest in the bottom slope position.