Anomalous wet summers and rising atmospheric CO2 concentrations increase the CO2 sink in a poorly drained forest on permafrost

• 成果类型: Article
• 署名作者: Ueyama, Masahito; Iwata, Hiroki; Nagano, Hirohiko; Kukuu, Naoki; Harazono, Yoshinobu
• 署名单位: Osaka Metropolitan University; University of Alaska System; University of Alaska Fairbanks; Shinshu University; Niigata University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11112
• DOI: 10.1073/pnas.2414539121
• 发表日期: 2024-10-29
• 关键词: black spruce forest; biochemical-model; carbon-dioxide; CLIMATE-CHANGE; exchange; alaska; amplification; sensitivity; balance; LIMITS

摘要

At the northern high latitudes, rapid warming, associated changes in the hydrological cycle, and rising atmospheric CO2 concentrations, [CO2], are observed at present. Under rapid environmental changes, it is important to understand the current and future trajectories of the CO2 budget in high- latitude ecosystems. In this study, we present the importance of anomalous wet conditions and rising [CO2] on the long- term CO2 budget based on two decades (2003-2022) of quasicontinuous measurements of CO2 flux at a poorly drained black spruce forest on permafrost peat in interior Alaska. The long- term CO2 budget for the black spruce forest was a small sink of -53 +/- 63 g C m-2 for the second decade. The increased CO2 sink was attributed to an 11.3% increase in gross primary productivity (GPP) among which 9% increase in GPP was explained by a recent increase in precipitation. Furthermore, a 3% increase in GPP in response to a 37- ppm increase in [CO2] was estimated from the data- model fusion. Our study shows fertilization effect is important for understanding the current and future carbon budgets of high- latitude ecosystems in permafrost regions.