两个丘陵山地粘棕壤土壤剖面不同土层有机碳与比重的关系

采样分析位于黄渤海分界线的旅顺南端丘陵山地松树林、玉米田两种土地利用方式下0～50cm土壤有机碳含量与土壤比重。结果表明：2种土地利用方式下土壤有机碳含量分布存在极显著差异（P〈0．01），松树林0～50cm土壤有机碳总含量（3．57％）高于玉米田（2．41％），松树林平均土壤比重（2．55g·cm^-3）低于玉米田（2．67g·cm^-3）。不同层次土壤有机碳富集系数显示，土壤有机碳主要富集在表层（0～20cm）土壤，土壤有机碳含量随着土壤深度增加而递减，土壤比重则有相反规律。同时看出土壤比重越大，相应层次的土壤有机碳含量就越低。相关分析表明，土壤有机碳与土壤比重之间相关性达到极显著水平（R松树林^2=0．9297，R玉米田^2=0．9214），认为林地在增加碳储量和改善环境方面具有很大的潜力。

Relation of Clay Organic Carbon and Proportion of Different |Soil Layers in Two Hilly Clay Sections

An attempt had been made to estimate the soil organic carbon contents and soil proportion under two typical land-use types including pine forest and corn field located at the boundary between the Yellow Sea and Bohai in southern Lvshun. The results showed that the difference of the soil organic carbon contents at two typical land-use types was highly significant （P 〈 0.01 ） and the total soil organic content of pine forest （3.57%） are higher than that of corn field （2.41%）. But the soil proportion of corn field （2.67 g·cm^-3） is higher than that of pine forest （2.55 g· cm^-3）. The enrichment modulus of different levels soil organic carbon showed that the soll organic carbon mainly enriched in the surface soil （0～20cm）. Contents of soil organic carbon decreased with soil depth increasing,while the soll proportion reversed. Also, the soil proportion was high while the soil organic carbon content was low. There was a  Rpiowfaons^2= 0.9297,Rconseld^2 =0.921 significant positive relationship between soil organic carbon and soil proportion （Rpine forest Room field 4）. It is suggested that woodland has a great potential in making a significant contribution to C storage and environmment improvement.