珠江三角洲森林生态系统碳密度分配及其储量动态特征

 在测定植被的含碳率与土壤有机碳含量的基础上,研究了南亚热带珠江三角洲地区森林生态系统碳密度分配及其储量动态.结果表明:植被平均含碳率为35.81%~51.60%,按照生物量加权的含碳率为46.57%~52.45%;土壤有机碳含量及其差异程度为表层最高,随土壤深度增加,有机碳含量及其差异逐渐减小;相同龄级的植被含碳率与土壤含碳量均表现为阔叶林>针阔混交林>针叶林,不同龄级的森林均表现为成龄林>中龄林>幼龄林.植被碳密度与土壤碳密度范围分别为23.58~139.18,55.54~151.16t/hm2,而且土壤分配比例均大于植被分配比例,但土壤分配比例随着龄级的增长呈下降趋势.1989~2003年间,珠江三角洲森林生态系统总体碳储量及其碳密度均呈上升趋势,这说明在改革开放高速发展时期珠江三角洲森林生态系统由于生物量的增加,起到了重要的碳汇功能,而且其碳汇功能正逐步提高.

Carbon density distribution and storage dynamics of forest ecosystem in Pearl River Delta of low subtropical China

Based on the vegetation carbon content rate and soil organic carbon (SOC) content that determined, we studied the carbon density and storage dynamics of forest ecosystem in the Pearl River Delta of low subtropical China. The results showed that the average vegetation content rate was ranging from 35.81% to 51.60%, and the average carbon content rate weighted by biomass was ranging from 46.57% to 52.45%. SOC content and its significance were all at the highest level in soil surface layer, and they all faded away with the deepening of soil profile. Moreover, vegetation content rate and soil organic carbon (SOC) content were all in order of broad-leaved forest> mixed conifer and deciduous forest > conifer forest in the same age forest, while mature forest>middle-age forest>young forest in the successive forest. The carbon density range of vegetation and soil were 23.58~139.18t/hm2and 55.54~151.16t/hm2respectively, and the allocation ratio of soil was higher than that of vegetation, but the allocation ratio of soil decreased with the rise of forest age class. During the years of 1989~2003, the total carbon storage and carbon density of forest ecosystem in the Pearl River Delta all increased, which indicated that, during the rapid development period of reform and opening-up, because of increase of biomass, forest ecosystem in the Pearl River Delta played an important role on accumulating carbon sink, and the accumulating function of carbon sink is being promoted step by step.