基于 DNDC(DeNitrification-DeComposition)和 IBIS(Integrated Biosphere Simulator)模型模拟农田、林地、草地生态系统的温室气体排放量和碳汇通量,进而评估2000-2020年长江三角洲城市群建设用地扩张和新增耕地对陆地生态系统碳汇的影响.结果表明:①2020年长江三角洲城市群林地、草地和农田生态系统均承担碳汇功能,总碳汇平均值为4 439.56±3 257.83 kg C hm-2·a-1,呈现北高南低的空间分布特征;②2000-2020年长江三角洲城市群新增建设用地13 702.09 km2,引起陆地生态系统碳汇损失8.21 Tg C,若不考虑碳汇的空间异质性,则碳汇损失7.87 Tg C;③2000-2020年长江三角洲城市群新增耕地1 236.58 km2(27.42％和25.85％转入源分别为林地和草地),导致碳汇增加0.28 Tg C;④长江三角洲城市群农田生态系统具有较高的固碳能力且其碳汇具有较强的空间异质性,耕地保护政策降低了建设用地扩张引起的碳汇损失.
Abstract
Based on the models of DNDC(DeNitrification-DeComposition)and IBIS(Integrated Biosphere Simulator),this paper estimated the greenhousegas emission and carbon sink fluxes in the forest,grassland,farmland ecosystems,and then evaluated the influences of built-up land expansion and farmland protection policies on the carbon sinks in the Yangtze River Delta urban agglomeration from 2000 to 2020.It is found as follows.① In 2020,the terrestrial ecosystems in the Yangtze River Delta urban agglomeration bear the carbon sink function,and the average carbon sink is 4 439.56±3 257.83 kg C hm 2·a-1,showing the spatial distribution characteristics of high in the north and low in the south.② The built-up land expanded 13 702.09 km2 from 2000 to 2020,resulted in 8.21 Tg C carbon loss of the terrestrial ecosystems.If the spatial heterogeneity of carbon sinks is not considered,the carbon loss would be 7.87 Tg C.③ From 2000 to 2020,the increased farmland was 1 236.58 km2,among which 27.42％and 25.85％were transferred from forest and grassland.The increased farmland enhanced carbon sink by 0.28 Tg C.④ The farmland ecosystem in the Yangtze River Delta urban agglomeration has high carbon sequestration capacity and its car-bon sink has strong spatial heterogeneity.The farmland protection polices decrease the loss of carbon sink caused by built-up land expansion.
关键词
陆地生态系统碳汇/建设用地扩张/耕地保护/长江三角洲城市群
Key words
carbon sinks of terrestrial ecosystems/built-up land expansion/farmland protection/the Yangtze River Delta urban agglomeration
维普
万方数据