土地利用方式对土壤水稳性团聚体有机碳的影响  

Effects of Land Use on Soil Organic Carbon in Water-stable Aggregates

作　　者：毛艳玲[1] 杨玉盛[2] 刑世和[1] 陈光水[2] 崔纪超[1] 

机构地区：[1]福建农林大学资源与环境学院,福建福州350002 [2]福建师范大学地理科学学院,福建福州350007

出　　处：《水土保持学报》2008年第4期132-137,共6页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(30571488);福建省自然科学基金计划资助项目(D0710003);福建省省属高校项目(2006F5018)

摘　　要：对福建省建瓯市山地红壤的农业用地（坡耕地、茶园、桔园）、林地（杉木、木荷、封育）不同土层（0-10，10-20cm）土壤团聚体有机碳含量与贮量进行研究。结果表明：林地开垦作为农地后，〉2mm土壤大团聚体的数量明显下降，〈0．25mm团聚体含量显著上升。不同土地利用方式的土壤大团聚体呈现粒径越大，团聚体有机碳含量越高的趋势，林地不同粒径团聚体有机碳含量都显著高于农业用地。林地随着团聚体粒径增大，土壤碳贮量增加；而农地正好相反，随着团聚体粒径增大，土壤碳贮量反而下降。土壤总有机碳增加主要受到大团聚体有机碳增加的影响，其中〉2mm和0．5～2mm粒径土壤团聚体对土壤总有机碳贡献最为突出。因此亚热带山地红壤内林地开垦为农业用地会导致富含碳的土壤大团聚体有机碳含量大幅度下降，团聚体的稳定性也随之下降。There is considerable concern that land use change may be leading to a depletion of soil carbon and consequent increase in atmospheric COz. Cultivation reduces soil C content and changes the distribution and stability of soil aggregates. The aim of this study was to investigate the impacts of land use change on the stability of water-stable aggregates and carbon stabilization in subtropics region. The aggregate distribution and the contents of soil organic carbon（SOC） of water-stable aggregates of surface soil samples（0-10,10-20 cm）were investigated at six different land use sites in Jianou city, Fujian province,China. Slaked soils were separated into four aggregate-size classes （〈0.25,0.25-0.5,0.5-2,and 〉2 mm ） by wet sieving. Results showed that the proportion of large macroaggregates （〉2 mm） increased significantly with an reduction in microaggregates while woodland conversed into agricultural land. At all sites, the contents of SOC in macroaggregates size groups increased with increasing sizes of wet-sieved aggregates. We found nonsignificant differences in aggregate carbon among woodland,the similar results were observed among agricultural land, except the Citrus aurantiurn. The aggregate carbon concentrations in woodland was substantially higher than that in agricultural land. The storages of SOC in macroaggregates in woodlands increased with increasing of aggregate sizes,and the trend in agricultural land was different . There was no significant difference in small aggregates（〈0.5mm） organic carbon of bulk soil at all sites. The total content of SOC was mainly affected by the carbon of macroaggregate , especially the large macroaggregate（〉2 mm and 0.5～2 mm）. We conclude that the conversion of woodland into agricultural land leads to a loss of C-rich macroaggregates and a decrease of stability of soil aggregates.

关 键 词：土地利用 水稳性团聚体 土壤有机碳 红壤 亚热带 

分 类 号：S153.6[农业科学—土壤学]