%0 Journal Article %A Jing-Juan WAN %A Jian-Fen GUO %A Shu-Rong JI %A Wei-Ling REN %A You-Tao SI %A Yu-Sheng YANG %T Effects of different sources of dissolved organic matter on soil CO2 emission in subtropical forests %D 2015 %R 10.17521/cjpe.2015.0064 %J Chinese Journal of Plant Ecology %P 674-681 %V 39 %N 7 %X Aims Dissolved organic matter (DOM) is an important carbon and nutrient pool, but the effects of different sources of DOM on soil carbon cycling are less well understood. Our objective in this study was to investigate how differences in the quantity and quality of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata and Castanopsis carlesii affected soil CO2 fluxes in a laboratory incubation experiment. Methods Mineral soils (0-10 cm) from an 11-year-old Cunninghamia lanceolata plantation in Sanming of Fujian Province, China, were incubated for 59 days after adding the DOM from fresh leaves and leaf litter of Cunninghamia lanceolata and Castanopsis carlesii. Carbon (C) mineralization during incubation was determined using CO2 respiration method. Important findings Compared to the controls, the rates of C mineralization significantly increased by 91.5%, 12.8%, 61.0% and 113.3% on day 1, following additions of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata and Castanopsis carlesii, respectively; the magnitudes of the increases declined to 24.1%, 8.3%, 14.6% and 13.2% by day 5, indicating that addition of DOM had significant but short-term influences on soil CO2 emission. DOM from different sources had significant effects on the cumulative CO2 production following addition of DOM by day 31 (p < 0.05). After 59 days of incubation, the cumulative quantity of mineralized C following addition of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata was significantly greater than that from those of Castanopsis carlesii, while there was no significant difference in the cumulative CO2 production between DOM from fresh leaves and leaf litter of the same tree species, suggesting that difference in tree species had a greater influence on C mineralization than difference in the degree of leaf decay. Addition of DOM originated from fresh leaves and leaf litter of Castanopsis carlesii resulted in increased C mineralization by 22.5% and 50.0% of C added over the course of 59 day incubation, whereas increases by additions of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata were 1.76 times and 2.56 times, respectively. Thus, a single addition of different sources of DOM may lead to diverse effects on total soil carbon stocks. %U https://www.plant-ecology.com/EN/10.17521/cjpe.2015.0064