Effect Of Litter Diversity On Decomposition Of Soil Organic Matter In Alpine Meadow On The Qinghai-Tibet Plateau

With greenhouse gas emission increasing and biodiversity decreasing,ecosystem carbon sink has changed dramatically.We selected four litter species(Kobresia humilis,Elymus nutans,Poa annua and Scirpus distigmaticus)and analyzed the effect of litter diversity on the decomposition of soil organic matter in the Haibei alpine meadow on the Qinghai Tibetan Plateau.The results showed that:1)Litter diversity had no significant effect on decomposition rate and weight loss rate.However,for Poa annua,litter diversity had significant effect on the decomposition rate and weight loss rate.2)Litter diversity significantly affected CH4 emission,but not on CO2 and N2O emissions.For E.nutans,S.distigmaticus and Poa spp.,litter diversity had a significant effect on CH4 emissions.Litter diversity had no significant effect on CO2 equivalent.3)Litter diversity had a significant effect on the content of soil ammonium nitrogen(NH4+-N),but not on soil nitrate nitrogen(NO3--N),inorganic nitrogen and soil net mineralization rate.4)Litter diversity had no significant effect on soil total soluble carbon(DTC),soluble organic carbon(DOC)and soluble inorganic carbon(DIC).In summary,litter diversity had a significant effect on CH4 emissions and soil NH4+-N content.The effect of different litter species and their functional combinations on greenhouse gas emissions should be further studied in future.