Biomass carbon density and its dynamics for young and middle aged plantation of Pinus kesiya var. langbianensis
思茅松中幼龄人工林的生物量碳密度及其动态变化

Based on biomass data collected from field surveys and plant carbon contents determined in laboratory,biomass carbon density and its dynamics for the young and middle aged plantation of Pinus kesiya var.langbianensis were studied.Results showed that： 1） Biomass carbon density for the plantations of age 3-5,6-10,11-20 and 26 years were（20.15±3.09）,（27.24±2.25）,（94.89±9.90） and 147.58t/hm2 respectively.Over stand age,biomass carbon density increased significantly for stand,arbor layer and litter layer,while decreased slightly for shrub layer and grass layer.Relations between biomass carbon density and stand age for stand,arbor layer and litter layer could be performed well by a logistic model,while the fitting effects for shrub and grass layer were not satisfied.2） Mean annual rate of biomass carbon sequestration for the plantations of age 3-5,6-10,11-20 and 26 years were（4.92±0.63）,（3.52±0.25）,（6.44±0.30） and 5.68t/（hm2·a） respectively.The rates were positively related to stand age for arbor layer and stand and negatively related for shrub and grass layers.The relations between the rates and stand age could be well performed by a logistic model for arbor and grass layer,and by a Gauss model for shrub layer,while the fitting effects for the relation for stand were not satisfied.