[Effects of precipitation intensity on soil organic carbon fractions and their distribution under subtropical forests of South China].
From December 2006 to June 2008, a field experiment was conducted to study the effects of natural precipitation, doubled precipitation, and no precipitation on the soil organic carbon fractions and their distribution under a successional series of monsoon evergreen broad-leaf forest, pine and broad-leaf mixed forest, and pine forest in Dinghushan Mountain of Southern China. Different precipitation treatments had no significant effects on the total organic carbon (TOC) concentration in the same soil layer under the same forest type (P > 0.05). In treatment no precipitation, particulate organic carbon (POC) and light fraction organic carbon (LFOC) were mainly accumulated in surface soil layer (0-10 cm); but in treatments natural precipitation and doubled precipitation, the two fractions were infiltrated to deeper soil layers. Under pine forest, soil readily oxidizable organic carbon (ROC) was significantly higher in treatment no precipitation than in treatments natural precipitation and doubled precipitation (P < 0.05). The percentage of soil POC, ROC, and LFOC to soil TOC was much greater under the forests at early successional stage than at climax stage, suggesting that the forest at early successional stage might not be an ideal place for soil organic carbon storage. Precipitation intensity less affected TOC, but had greater effects on the labile components POC, ROC, and LFOC.
Chen
Xiao-mei
XM
South China Botanical Garden, Chinese Academy of Sciences, Guangzhou. chxm-009@163.com
Liu
Ju-xiu
JX
Deng
Qi
Q
Chu
Guo-wei
GW
Zhou
Guo-yi
GY
Zhang
De-qiang
DQ
D002244:Carbon / Q000032:analysis*; D002681:China; D017753:Ecosystem; D009930:Organic Chemicals / Q000032:analysis*; D011891:Rain; D012987:Soil / Q000032:analysis*; D014329:Tropical Climate
D009930:Organic Chemicals; D012987:Soil; D002244:Carbon