土地利用方式对红壤和黄壤颗粒有机碳和碳黑积累的影响

颗粒有机碳和碳黑是土壤中两类性质不同的碳库,它们的数量可反映土壤有机质的稳定性。结果表明,浙江省红壤和黄壤中这两类碳库有很大的变化,并与土地利用方式存在联系。颗粒有机碳的数量及其占总有机碳的比例:林地>茶园>旱地;而碳黑占总有机碳的比例一般是:旱地、茶园>次生林地>原生林地。颗粒有机碳是土壤碳库的易变组分,易受利用方式改变而变化,颗粒有机碳占总有机碳的比例随土壤有机质的积累而增加。相同土地利用方式土壤中碳黑数量与粘粒呈正比。土壤中>1 mm水稳定性团聚体与颗粒有机碳含量相关,而土壤<0.25 mm团聚体与碳黑含量相关。

Effects of Land Use on Particulate Organic Carbon and Black Carbon Accumulation in Red and Yellow Soils

Particulate organic C(POC,an active organic C fraction) and black C(a stable organic C fraction) are two important C pools in soils,and their content could reflect stability of organic C in soils.In this study,173 red and yellow soil samples were collected for characterizing content of the POC and black C.The results showed that these two rinds of carbon pools in the red and yellow soils of Zhejiang province varied greatly and were affected by land use.The content of POC and the proportion of total organic C decreased in the order of forestry land > tea garden > upland,whereas the amount of black C in the soils decreased in the order of upland,tea garden > affroested land > natural forestry land.The POC was an sensitive component of soil organic C,being easily changed with land use.The proportion of POC in total organic C increased with accumulation of organic C.For same land use manner,the content of black C was correlated positively with clay content of soils.The content of POC was correlated with the amount of >1 mm water stable aggregates,while black carbon was correlated with <0.25 mm water stable aggregates.