侵蚀红壤区植被恢复对表层与深层土壤有机碳矿化的影响  

Effect of Vegetation Restoration on Topsoil and Subsoil Organic Carbon Mineralization in Red Soil Erosion Area

作　　者：张浩[1,2] 吕茂奎[1,2] 江军[1,2] 蒲晓婷[1,2] 王恩熙[1,2] 邱曦[1,2] 谢锦升[1,2] 

机构地区：[1]湿润亚热带山地生态国家重点实验室培育基地,福州350007 [2]福建师范大学地理科学学院,福州35007

出　　处：《水土保持学报》2016年第1期244-249,314,共7页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(31370465);"973"计划前期专项(2012CB722203)

摘　　要：试验研究了典型红壤侵蚀区不同植被恢复年限(0,11,31a)的表层(0—10cm)和深层(60—80cm)土壤有机碳矿化特征。结果表明:深层土壤有机碳84d累积矿化量或潜在矿化量显著低于表层土壤,植被恢复则显著增加了表层和深层土壤累积矿化量或潜在矿化量(P<0.05),相关分析显示土壤有机碳累积矿化量或潜在矿化量与WSOC、MBC和SOC显著(P<0.05)或极显著(P<0.01)相关,表明碳矿化底物数量是决定土壤碳累积矿化量或潜在矿化量的主导因子;对照表层土壤的矿化速率常数(k)高于深层土壤的,植被恢复降低了表层土壤的k值(P<0.05),对深层土壤的k值却没有显著影响;而深层土壤矿化率显著高于表层土壤,且植被恢复后均显著降低(P<0.05),相关分析显示土壤有机碳矿化率与微生物代谢熵呈极显著的正相关(P<0.01),表明微生物碳利用效率是影响土壤碳矿化率的重要因素,而深层土壤微生物碳利用效率显著低于表层土壤,但植被恢复可以改善侵蚀红壤的环境条件,提高土壤微生物的碳利用效率,从而增强土壤固碳能力。This paper studied the organic carbon mineralization characteristics of topsoil（0—10cm）and subsoil（60—80cm）in typical red soil erosion area under vegetation of different restoration years（0,11,31years）.The results showed that,the cumulative amount of SOC mineralization in 84 days or the amount of potentially mineralized carbon（Cp）were lower in subsoil than those in topsoil（p〈0.05）,which were all significantly increased by vegetation restoration（p〈0.05）.The correlation analysis showed that the cumulative amount of SOC mineralization or the amount of potentially mineralized carbon showed significant（p〈0.05）or highly significant（p〈0.01）correlations with the contents of soil WSOC,MBC or SOC,indicating that the quantity of carbon substrates was the dominant factor of determining the cumulative amount of SOC mineralization or the amount of potentially mineralized carbon（Cp）.In the control treatment with 0year vegetation restoration,the mineralization rate constant（k）of topsoil was higher than that of subsoil.Vegetation restoration significantly decreased k value of topsoil（p〈0.05）,but had no significant effect on that of subsoil.We also found that the organic carbon mineralization ratio of subsoil was significantly higher than that of topsoil,both of which greatly decreased with the vegetation restoration（p〈0.05）.There was significantly positive correlation between mineralization rate of SOC and microbial metabolic quotient（p〈0.01）,indicating that the utilization efficiency of organic carbon by microorganisms was the key factors affecting mineralization rate of SOC.The utilization efficiency of organic carbon by microorganisms was significantly lower in subsoil thantopsoil.However,the environment condition of red soil erosion area can be improved by vegetation restoration,which can further improve the utilization efficiency of organic carbon by microorganisms and enhance the soil carbon sequestration.

关 键 词：侵蚀红壤 植被恢复 有机碳矿化 土壤有机碳矿化率 微生物代谢熵 

分 类 号：S157.2[农业科学—土壤学] S157.5[农业科学—农业基础科学]