2000—2020 年中国陆地土壤碳储量及土地管理碳汇核算

Estimation of soil carbon storage change from land use and management at a high spatial resolution in China during 2000-2020

中国陆地土壤碳储量和土壤碳汇及管理碳汇对全球碳循环有重要的影响;然而,已有的土壤碳储量和碳汇估算研究主要采用较低分辨率的土地利用数据开展,且生态系统的管理碳汇较少被学者关注。为了解决这个问题,本文基于2000年、2020年中国30 m分辨率土地利用数据、中国气候区、中国温度带等多源数据,汇总国内土壤碳储量、土壤碳汇及土地利用管理碳汇相关的文献成果,采用土壤碳储量、土壤碳储量变化、土地管理碳汇、土地利用转变土壤碳变化核算模型,综合评估了中国2000—2020年农田和草地管理土壤(0-100 cm)碳汇、2000—2020年森林管理碳汇、2000年及2020年中国土壤碳储量(0-100 cm)、2000—2020年土壤碳储量的变化及土地利用转变土壤碳储量的变化。研究发现:①2000—2020年中国农田管理土壤碳汇达17.918 Tg C a^(-1),草地管理土壤碳汇约为20.171 Tg C a^(-1);②2000—2020年中国森林管理碳汇约为81.622 Tg C a^(-1)。③2000年和2020年中国土壤碳储量分别达到86.074 Pg C、86.771 Pg C;④2000—2020年土壤碳增加约34.850 Tg C a^(-1);⑤研究时间段内,中国土地利用转变导致土壤碳储量减少约17.621 Tg C a^(-1)。本文研究成果有助于理清中国21世纪土壤碳储量和土壤碳汇及管理碳汇状况,为中国实现“双碳”目标提供科学的数据支持。

Soil organic carbon(SOC)storage and soil carbon sinks play a crucial role in the global carbon cycle of terrestrial ecosystem.However,many previous studies of soil carbon storage and sinks utilized low-resolution land use dataset,with limited focus on soil carbon sinks from farmland and grassland management.To address this issue,this study employed a series of accounting models to estimate the carbon sink from farmland and grassland management,the carbon sink from forest management,changes in soil carbon storage,changes in carbon storage due to land use conversion from 2000 to 2020,as well as the soil carbon storage in China in 2000 and 2020 using a 30 m-resolution land use dataset.The results showed that the national carbon sink from farmland management in China was approximately 17.918 Tg C a^(-1) and the carbon sink from grassland management was approximately 20.171 Tg C a^(-1) during 2000-2020.The carbon sink from forest management in China was approximately 81.622 Tg C a^(-1) during 2000-2020.The soil carbon storage(0-100 cm)in China increased from 86.074 Pg C in 2000 to 86.771 Pg C in 2020.The soil carbon storage increased by approximately 34.850 Tg C a^(-1) from 2000 to 2020.The land use transformation during the study period resulted in a decrease of approximately 17.621 Tg C a^(-1) in soil carbon storage.The findings of this study can help researchers understand China's carbon storage and provide scientific data to China's 2060 Carbon Neutrality Target.