Relationship Between Litter Decomposition And Litter Traits In Subtropical Evergreen Broad-leaved Forest In Gutianshan,China

Litter decomposition plays an important role in global nutrients and carborn cycling.Litter traits can be used to predict litter decomposition process.Litter traits include chemical and physical traits.Previous studies mostly focused on the effect of chemical traits on litter decomposition.However,how and to what extent physical traits affect litter decomposition are still unclear.We measured ten chemical traits(pH,C,N,P,K,total phenols,tannins,cellulose,lignin,and water-soluble compounds),four physical traits(leaf thickness,toughness,standard water holding capacity and maximum water holding capacity),and calculated four stoichiometric ratio(C/N,C/P,Lignin/N and Lignin/P)in this study to quantify the relationships between litter traits and decomposition rate.Functional diversity means the value and range of functional traits,and is an important part of biodiversity.The relationship between functional diversity and litter decomposition is largely unclear.In this study,different combinations of 2-6 leaf litter species were set up to explore the relatioship between litter decomposition rate and functional diversity.Soil fauna are an important actor during litter decomposition process.In this study,the litterbags were set with 25 ?m and 4 mm mesh size to explore the role of meso-and macrofauna in litter decomposition.The main findings are as follows:(1)After 400 days of decomposition,the mass loss of 26 species in different mesh size litterbags ranging from 29.6% to 80.6%.Mass loss of Camellia fraterna was the highest in both coarse-and fine-mesh litterbags,while mass loss of Pyrenaria microcarpa is the lowest in both coarse-and fine-mesh litterbags.Meso-and macrofauna promoted litter decomposition,and the mass loss rate of 26 species on average increased by 8.7%.(2)Different combinations of 26 species litter showed a mass loss ranging from 47.3%-62.4% in different mesh size litterbags.There was no significant correlation between species richness and litter mass loss.There were significant relationship between 12 CWM(community-weighted mean traits)and mass loss rate,there were significant positive relationship between 8 RAO'Q(Rao's quadratic entropy)variables and mass loss rate.Our result support that both of the mass ratio hypothesis and the niche complementarity hypothesis play a role in explaining the relationship between trait diversity and leaf litter decomposition,with the Mass ratio hypothesis slightly more importance.(3)The results showed that Lignin/N and toughness were the two funcitonal triats that most important in explaining the variaiton in litter mass loss.Meso-and macrofauna promote leaf litter decomposition,but the relationship between functional traits and leaf litter decomposition and the the relationship between trait diversity and leaf litter decoposition were not substantially modify by the presence of meso-and macrofauna.