TY - JOUR
T1 - Depth-dependent response of particulate and mineral-associated organic carbon to long-term throughfall reduction in a subtropical natural forest
AU - Sun, Siyi
AU - Liu, Xiaofei
AU - Lu, Shengxu
AU - Cao, Pingli
AU - Hui, Dafeng
AU - Chen, Ji
AU - Guo, Jianfen
AU - Yang, Yusheng
PY - 2023/4
Y1 - 2023/4
N2 - Climate change has altered the precipitation patterns and prolonged the drought season in subtropical areas, which affects forest productivity and soil carbon (C) cycling. However, the response of different soil organic C (SOC) fractions to the reduction in precipitation and the potential mechanisms remain poorly understood in subtropical forests. In this study, we examined the effects of long-term (9 years) throughfall reduction on SOC fractions, including particulate organic C (POC) and mineral-associated organic C (MAOC), dissolved organic C (DOC), microbial biomass C (MBC), mycorrhizal fungal biomass, and fine-root biomass of two soil layers (0–10 cm and 40–60 cm) in a subtropical Castanopsis carlesii forest. The results showed that throughfall reduction had a significant effect on soil C cycling in the topsoil but not in the subsoil. Throughfall reduction significantly decreased soil POC but increased soil MAOC in the topsoil. Meanwhile, soil MBC, DOC, fine-root biomass, and mycorrhizal fungal biomass were reduced with throughfall reduction. Regression and partial least squares path modeling analyses revealed that soil POC was positively correlated with fine-root biomass, necromass, and mycorrhizal fungal biomass, whereas negative relationships were observed for topsoil MAOC. The results from this study implied that fine roots play an important role in the contrasting responses of POC and MAOC to throughfall reduction in the topsoil. Such information is essential for understanding the roles of plant roots and mycorrhizal fungi in the soil C cycle in subtropical forests under drought conditions.
AB - Climate change has altered the precipitation patterns and prolonged the drought season in subtropical areas, which affects forest productivity and soil carbon (C) cycling. However, the response of different soil organic C (SOC) fractions to the reduction in precipitation and the potential mechanisms remain poorly understood in subtropical forests. In this study, we examined the effects of long-term (9 years) throughfall reduction on SOC fractions, including particulate organic C (POC) and mineral-associated organic C (MAOC), dissolved organic C (DOC), microbial biomass C (MBC), mycorrhizal fungal biomass, and fine-root biomass of two soil layers (0–10 cm and 40–60 cm) in a subtropical Castanopsis carlesii forest. The results showed that throughfall reduction had a significant effect on soil C cycling in the topsoil but not in the subsoil. Throughfall reduction significantly decreased soil POC but increased soil MAOC in the topsoil. Meanwhile, soil MBC, DOC, fine-root biomass, and mycorrhizal fungal biomass were reduced with throughfall reduction. Regression and partial least squares path modeling analyses revealed that soil POC was positively correlated with fine-root biomass, necromass, and mycorrhizal fungal biomass, whereas negative relationships were observed for topsoil MAOC. The results from this study implied that fine roots play an important role in the contrasting responses of POC and MAOC to throughfall reduction in the topsoil. Such information is essential for understanding the roles of plant roots and mycorrhizal fungi in the soil C cycle in subtropical forests under drought conditions.
KW - Mineral-associated organic carbon
KW - Mycorrhizal fungi
KW - Particulate organic carbon
KW - Root biomass
KW - Soil organic carbon
KW - Throughfall reduction
UR - http://www.scopus.com/inward/record.url?scp=85145992352&partnerID=8YFLogxK
U2 - 10.1016/j.catena.2022.106904
DO - 10.1016/j.catena.2022.106904
M3 - Journal article
AN - SCOPUS:85145992352
SN - 0341-8162
VL - 223
JO - Catena
JF - Catena
M1 - 106904
ER -