Holocene carbon accumulation in lakes of the current east Asian monsoonal margin: Implications under a changing climate

Qian Hao; Shilei Yang; Zhaoliang Song; Xiangbin Ran; Changxun Yu; Chunmei Chen; Lukas Van Zwieten; Timothy A Quine; Hongyan Liu; Zhengang Wang; Hailong Wang

doi:10.1016/j.scitotenv.2020.139723

Holocene carbon accumulation in lakes of the current east Asian monsoonal margin: Implications under a changing climate

Sci Total Environ. 2020 Oct 1:737:139723. doi: 10.1016/j.scitotenv.2020.139723. Epub 2020 May 29.

Authors

Qian Hao¹, Shilei Yang¹, Zhaoliang Song², Xiangbin Ran³, Changxun Yu⁴, Chunmei Chen¹, Lukas Van Zwieten⁵, Timothy A Quine⁶, Hongyan Liu⁷, Zhengang Wang⁸, Hailong Wang⁹

Affiliations

¹ Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China; School of Earth System Science, Tianjin University, Tianjin 300072, China.
² Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China; School of Earth System Science, Tianjin University, Tianjin 300072, China. Electronic address: songzhaoliang78@163.com.
³ Research Center for Marine Ecology, First Institute of Oceanography, State Oceanic Administration, Qingdao, Shandong 266061, China.
⁴ Department of Biology and Environmental Science, Linnaeus University, SE-39182 Kalmar, Sweden.
⁵ New South Wales Department of Primary Industries, 1243 Bruxner Highway, Wollongbar, NSW 2477, Australia.
⁶ Geography, Amory Building, University of Exeter, Rennes Drive, Exeter EX4 4RJ, United Kingdom.
⁷ College of Urban and Environmental Sciences, Peking University, Peking 100871, China.
⁸ School of Geography and Planning, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China.
⁹ School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong 528000, China; School of Environmental and Resource Sciences, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China.

PMID: 32554037
DOI: 10.1016/j.scitotenv.2020.139723

Abstract

Carbon (C) present in lake sediments is an important global sink for CO₂; however, an in-depth understanding of the impact of climate variability and the associated changes in vegetation on sediment C dynamics is still lacking. A total of 13 lakes were studied to quantify the influence of climate and vegetation on the reconstructed Holocene C accumulation rate (CAR) in lake sediments of the modern East Asian monsoonal margin. The corresponding paleoclimate information was assessed, including the temperature (30-90°N in the Northern Hemisphere) and precipitation (indicated by the δ¹⁸O of the Sanbao, Dongge, and Hulu caves). The Holocene vegetation conditions were inferred by pollen records, including arboreal pollen/non-arboreal pollen and pollen percentages. The results showed that the peak CAR occurred during the mid-Holocene, coinciding with the strongest period of the East Asian summer monsoon and expansion of forests. Lakes in the temperate steppe (TS) regions had a mean CAR of 13.41 ± 0.88 g C m^-2 yr^-1, which was significantly greater than the CARs of temperate desert (TD) and highland meadow/steppe (HMS; 6.76 ± 0.29 and 7.39 ± 0.73 g C m^-2 yr^-1, respectively). The major influencing factor for the TS sub-region was vegetation dynamics, especially the proportion of arboreal vegetation, while temperature and vegetation coverage were more important for the HMS. These findings indicate that C accumulation in lake sediments is linked with climate and vegetation changes over long timescales; however, there was notable spatial heterogeneity in the CARs, such as opposing temporal changes and different major influencing factors among the three sub-regions during the mid-Holocene. Aridification and forest loss would decrease C storage. However, prediction of C accumulation remains difficult because of the spatial heterogeneity in CARs and the interaction between the CAR and various factors under future climate change conditions.

Keywords: Carbon sequestration; Highland meadow/steppe; Pollen records; Temperate desert; Temperate steppe.