思茅松中幼龄人工林的生物量碳密度及其动态变化

Biomass carbon density and its dynamics for young and middle aged plantation of Pinus kesiya var. langbianensis

通过样地实测生物量和采用重铬酸钾法测定植物碳素含量,研究了思茅松中幼龄人工林生物量碳密度的分配特征及随林龄的动态变化规律。结果表明:1)林龄为3～5、6～10、11～20和21～30 a思茅松人工林的生物量碳密度分别为(20.15±3.09)、(27.24±2.25)、(94.89±9.90)和147.58 t/hm2。随林龄增长,乔木层、枯落物层和林分的碳密度显著增加,灌木层和草本层的碳密度有所减少。林分、乔木层和枯落物层的生物量碳密度随林龄的变化用逻辑斯蒂模型可实现良好拟合,而灌木层和草本层拟合效果差。2)林龄为3～5、6～10、11～20和26 a思茅松人工林的年均固碳量分别为(4.92±0.63)、(3.52±0.25)、(6.44±0.30)和5.68 t/(hm2.a)。乔木层的年均固碳量与林龄存在显著正相关,灌木层和草本层的年均固碳量与林龄存在显著负相关,林分年均固碳量与林龄呈较弱的正相关。乔木层和草本层的年均固碳量与林龄的关系以逻辑斯蒂模型拟合效果较好,灌木层年均固碳量和林龄关系以Gauss模型拟合效果较好,林分的年均固碳量与林龄的拟合效果差。

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.