Leaf-litter Decomposition Characteristics and Carbon Dynamics Affected by Forest Agesin Rubber Plantations
An experiment was con ducted to study the decomposition characteristics and carbon dynamics of leaf litter in rubber plantation of different ages(6 a, 12 a, 20 a, 28 a) during one year of decomposition using mesh bag method. And the results showed as following:(1)The leaf litter decomposition dynamics was basically consistent between four different age groups, and the residues of litter in rubber plantation of different ages was 28.33%,30.53%, 31.59%, 33.89%, respectively, and a non-significant difference was observed between different age groups.(2)The decomposition constant ranged from 1.376 2 to 1.608 8, with an average of 1.498 2, the times required for 50% and 95% of leaf decomposition was 0.43 a, 0.45 a, 0.47 a, 0.50 a and 1.86 a, 1.96 a, 2.03 a, 2.18 a,respectively.( 3)Apart from the contents of C, lignin, and C/N ratio, the initial N content, P content, lignin/N ratio, C/P ratio, and lignin/P ratio of leaf-litter were significantly affected by plantation ages.(4)The decomposition rates of leaf litter in rubber plantation of different ages were significant negatively correlated with the initial C/N ration, and a weak negatively correlated with the P contend.(5)During the whole decomposition process, the release of carbon in 4 rubber plantations accumulated 75.02%~79.41%, and it's release process was significantly in line with polynomial model, the coefficient of determination(R2)more than 0.88.