[Profile distribution of soil aggregates organic carbon in primary forests in Karst cluster-peak depression region].
Soil profiles were collected from three primary forests (Itoa orientalis, Platycladus orientalis, and Radermachera sinica) in Karst cluster-peak depression region to study the composition of soil aggregates, their organic carbon contents, and the profile distribution of the organic carbon. In the three forests, >2 mm soil aggregates were dominant, occupying about 76% of the total. The content of soil total organic carbon ranged from 12.73 to 68.66 g x kg(-1), with a significant difference among the forests. The organic carbon content in <1 mm soil aggregates was slightly higher than that in >2 mm soil aggregates, but most of soil organic carbon was stored in the soil aggregates with greater particle sizes. About 70% of soil organic carbon came from >2 mm soil aggregates. There was a significant positive relationship between the contents of 2-5 and 5-8 mm soil aggregates and the content of soil organic carbon. To increase the contents of 2-8 mm soil aggregates could effectively improve the soil carbon sequestration in Karst region. In Itoa orientalis forest, 2-8 mm soil aggregates accounted for 46% of the total, and the content of soil total organic carbon reached to 37.62 g x kg(-1), which implied that Itoa orientalis could be the suitable tree species for the ecological restoration in Karst region.
Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China. lulingxiaogood@163.com
Ling-Xiao
LX
Lu
Tong-Qing
TQ
Song
Wan-Xia
WX
Peng
Fu-Ping
FP
Zeng
Ke-Lin
KL
Wang
Yun-Lei
YL
Xu
Zi
Z
Yu
Yan
Y
Liu
D002244:Carbon / Q000032:analysis*; D057965:Carbon Sequestration; D002681:China; D017753:Ecosystem; D009930:Organic Chemicals / Q000032:analysis; D012987:Soil / Q000032:analysis*; D014197:Trees / Q000254:growth & development*
D009930:Organic Chemicals; D012987:Soil; D002244:Carbon