2009-王义东-APJAS.pdf

Title:Contribution of aboveground litter decomposition to soil respiration in a subtropical coniferous plantation in southern China

Authors: Wang Yidong, Wang Huimin, Ma Zeqing, Wen Xuefa, Li Qingkang, Liu Yunfen, Sun Xiaomin, Yu Guirui.

Journal: Asia-Pacific Journal of Atmospheric Sciences

Abstract: Soil CO₂ efflux (R_S) was monitored in a 23-year-old subtropical coniferous plantation in southern China from January 2004 to December 2006. Field measurements of R_S with litterfall (CK) and without litterfall (NL) were conducted to evaluate the contribution of aboveground litter decomposition to RS. The results indicated that annual RS from CK ranged from 11.5 mg (C) m^-2h^-1 in 2004 to 186.2 mg (C) m^-2h^-1 in 2006. The RS of NL was significantly lower than the R_S of CK. RS was mainly determined by soil temperature (T_S), but it was also affected by soil moisture. Together, both factors explained > 70% of the observed variations in R_S. The temperature sensitivity (Q₁₀) of R_S from NLwas lower than that from CK by considering the soil moisture effect. On average, the annual RS of the coniferous plantation was estimated to be 669 g (C)m^-2yr^-1 over the study period. The litterfall greatly enhanced the RS, and the respiration from aboveground litter accounted for about 33% of the total RS, in which the fresh litterfall decomposition accounted for a large proportion.The carbon pool of aboveground litter in this young conifer forest is expected to increase continuously.