The Soil Available Carbon In A Quercus Variabilis Forest And Pinus Taeda Plantation In Xiashu Forest Experimental Site, Southeastern China

Soil available carbon plays an important role in global cycle.We have conducted an experiment to examine the soil available carbon,using the sequential fumigation-incubation method in a Quercus variabilis forest and Pinus taeda plantation in Xiashu forest experimental site,southeastern China.Two treatments (Litter Exclusion and Control)were set in both forests in order to compare the differences between themselves.The results show:1.The soil available carbon,soil microbial biomass and total organic carbon in the Quercus variabilis forest were higher than the pine plantation.2.The soil available carbon,soil microbial biomass and total organic carbon between litter exclusion treatment and litter control treatment were significantly different(P＜0.05).The soil available carbon,soil microbial biomass and total organic carbon of litter control treatment were higher than litter exclusion treatment.The litter was the important origin of soil available carbon.3.The seasonal dynamics of soil available carbon in different sites: Autumn＞Summer＞Spring＞Winter.The seasonal dynamics of soil available carbon was decided by soil microbial biomass when the litter disposed. The seasonal dynamics of soil available carbon was the same to the soil microbial biomass's in litter exclusion treatment.4.Correlation between soil available carbon and total organic carbon was positively significant at the 0.01 level(P＜0.01).Correlation between soil microbial biomass and total organic carbon was positively significant at the 0.01 level(P＜0.01).The minor changes of soil available carbon and soil microbial biomass can reflect the quality of soil.Our findings show that:the Quercus variabilis forest had more soil available carbon,which indicated that Quercus variabilis forest might have greater influence on local carbon cycle.