竹林是热带和亚热带地区一种分布广泛的森林资源类型。由于其优良的固碳功能,在林业应对气候变化的背景下,以积累碳汇和实现碳汇交易为目的的毛竹Phyllostachys edulis林营造活动日益增多。跟踪调查整个毛竹造林过程,连年监测毛竹碳储量变化和土壤有机碳变化,结合基线碳储量和造林活动过程排放泄漏估测,探究净碳汇量变化积累特征。结果表明:①项目区毛竹碳汇造林初期(1~5 a)净碳汇量二氧化碳当量(CO_2-e)为443.77 t,累计净碳汇量二氧化碳当量为9.30 t ?hm~(-2);②项目区在组成净碳汇量的多个分量中,只有毛竹碳储量变化起正面影响,而土壤有机碳变化、施肥排放和运输泄漏均对净碳汇量积累造成负面影响,5 a二氧化碳当量分别为-292.90,-18.99和-8.27 t;③毛竹造林初期(1~5 a),毛竹碳储量(地上、地下)变化和净碳汇量变化速率并不均匀;④毛竹造林过程中的土壤扰动,对净碳汇量会带来显著影响,造林初期甚至会出现净排放。
英文摘要:
Due to climate change problems, afforestation activities with bamboo, a widely distributed forest-type resource in tropical and subtropical regions, to accumulate carbon sinks and to foster carbon sink trade have been increasing because of bamboo's strong carbon sequestration capability. This study followed the entire carbon process in bamboo stands to monitor the annual storage change of moso bamboo (Phyllostachys edulis) carbon and soil organic carbon (SOC) by establishing 36 plots with 20m * 20m size, and then explored the accumulation and change characteristics of net carbon sequestration by considering baseline carbon storage and emission leakage estimates with afforestation activities. Results showed that 1) in the initial stage (1-5 years) for moso bamboo carbon sink stands, the net carbon sink was 443.77 t CO_2-equivalent (e), and the cumulative net carbon sink was 9.30 t CO_2-e per hectare. 2) Only moso Bamboo carbon sink change had a positive impact on the project' s net carbon sink; whereas, five year accumulation changes in t CO_2-e for SOC (-292.90),fertilization emission (-18.99),and transportation leakage (-8.27) revealed adverse effects. 3) However, the rate-of-change for bamboo carbon (aboveground and underground) was not uniform. 4) Also, soil disturbance during moso bamboo afforestation had a strong negative influence on the net carbon sink, even causing net emissions (-116.31) in the early stages of afforestation.