Holocene carbon accumulation in lakes of the current east Asian monsoonal margin: Implications under a changing climate
Holocene carbon accumulation in lakes of the current east Asian monsoonal margin: Implications under a changing climate
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当前东亚季风边缘湖泊的全新世碳积累：气候变化的影响
DOI：
10.1016/j.scitotenv.2020.139723
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发表时间：
2020
影响因子：
9.8
通讯作者：
Wang Hailong
中科院分区：
文献类型：
--
作者：
Hao Qian;Yang Shilei;Song Zhaoliang;Ran Xiangbin;Yu Changxun;Chen Chunmei;Van Zwieten Lukas;Quine Timothy A.;Liu Hongyan;Wang Zhengang;Wang Hailong
湖泊沉积物中的碳(C)是全球重要的CO2汇；然而，对气候变率及其相关植被变化对沉积物C动态的影响仍缺乏深入的认识。以13个湖泊为研究对象，量化了气候和植被对现代东亚季风边缘湖泊沉积物全新世碳积累速率（CAR）的影响。分析了相应的古气候信息，包括温度（北半球30 ~ 90°N）和降水（由三宝洞、东哥洞和葫芦洞的δ18O表示）。通过花粉记录，包括树栖花粉/非树栖花粉和花粉百分比，推断出全新世的植被条件。结果表明，CAR的峰值出现在全新世中期，与东亚夏季风最强时期和森林扩张时期相吻合。温带草原区湖泊的平均CAR值为13.41±0.88 g C m−2yr−1，显著高于温带荒漠区（TD）和高原草甸/草原区（HMS: 6.76±0.29和7.39±0.73 g C m−2yr−1）。对TS子区域的影响因子主要是植被动态，尤其是乔木植被比例，而温度和植被覆盖度对HMS的影响更为重要。这些结果表明，湖泊沉积物中C的积累与气候和植被变化有关；但在全新世中期，三个子区域的气候变化具有明显的时空异质性，主要影响因子不同。干旱化和森林损失会降低碳储量。然而，在未来气候变化条件下，由于CAR - C的空间异质性和CAR - C与各种因子的相互作用，对CAR - C积累的预测仍然很困难。
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−2yr−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−2yr−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.