摘要：

Coniferous and broad-leaved trees represent different life types,and their litters differ in decomposition rates.Six species(Pinus massoniana,Metasequoia glyptostroboides,Cunninghamia lanceolata,Schima superb,Michelis chapensis,Cyclobalanopsis glauca) representing typical coniferous and broad-leaved trees were sampled as experimental material for studying leaf litter decomposition in the subtropical region of china.The collected leaf litters were put in litter bags and placed in the forests of the Qiandao Lake.The decomposition characteristics of different leaf litters were analyzed after one-year decomposition.The leaf litter decomposition processes of the six trees were calculated by Olson's exponential models,which were found well fit to the data.The K values of the three coniferous trees(P.massoniana,M.glyptostroboides,C.lanceolata) were 0.51,0.30 and 0.44,which were much lower than those(0.55,1.12 and 0.66) of the three broad-leaved trees(S.superb,M.chapensis,C.glauca).The litters of the coniferous trees required 1.36,2.31 and 1.78 years for 50% decomposition,and 5.87,9.99 and 7.68 years for 95% decomposition respectively,while those of the broad-leaved trees needed 1.26,0.62 and 1.05 years for 50% decomposition,and 5.45,2.68 and 4.54 years for 95% decomposition.There was a significant correlation between the litter decomposition rates and the initial K concentrations(P0.05) according to multiple regression analysis.Also,there were signif icant correlations between the litter decomposition rates and the initial K and Lignin concentrations(P0.05) based on the linear regression analysis.The difference in litter decomposition between coniferous and broad-leaved trees was significantly related to their own qualities.It was found that the initial lignin and K concentrations were the key factors controlling the litter decomposition.Fig 2,Tab 2,Ref 23

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