Changes in above- versus belowground biomass distribution in permafrost regions in response to climate warming

• 成果类型: Article
• 署名作者: Yun, Hanbo; Ciais, Philippe; Zhu, Qing; Chen, Deliang; Zohner, Constantin M.; Tang, Jing; Qu, Yang; Zhou, Hao; Schimel, Joshua; Zhu, Peng; Shao, Ming; Christensen, Jens Hesselbjerg; Wu, Qingbai; Chen, Anping; Elberling, Bo
• 署名单位: Chinese Academy of Sciences; Chinese Academy of Sciences; University of Copenhagen; Purdue University System; Purdue University; Universite Paris Saclay; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; University of Gothenburg; Swiss Federal Institutes of Technology Domain; ETH Zurich; University of Copenhagen; Lund University; East China Normal University; University of California System; University of California Santa Barbara; University of Hong Kong; University of Hong Kong; Chinese Academy of Sciences; University of Copenhagen; Niels Bohr Institute; Colorado State University System; Colorado State University Fort Collins; Colorado State University System; Colorado State University Fort Collins
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9100
• DOI: 10.1073/pnas.2314036121
• 发表日期: 2024-06-18
• 关键词: arctic tundra; vegetation; allocation; DYNAMICS; roots; term; PRODUCTIVITY; performance; latitudes; grassland

摘要

Permafrost regions contain approximately half of the carbon stored in land ecosystems and have warmed at least twice as much as any other biome. This warming has influenced vegetation activity, leading to changes in plant composition, physiology, and biomass storage in aboveground and belowground components, ultimately impacting ecosystem carbon balance. Yet, little is known about the causes and magnitude of long- term changes in the above- to belowground biomass ratio of plants (eta). Here, we analyzed eta values using 3,013 plots and 26,337 species- specific measurements across eight sites on the Tibetan Plateau from 1995 to 2021. Our analysis revealed distinct temporal trends in eta for three vegetation types: a 17% increase in alpine wetlands, and a decrease of 26% and 48% in alpine meadows and alpine steppes, respectively. These trends were primarily driven by temperature- induced growth preferences rather than shifts in plant species composition. Our findings indicate that in wetter ecosystems, climate warming promotes aboveground plant growth, while in drier ecosystems, such as alpine meadows and alpine steppes, plants allocate more biomass belowground. Furthermore, we observed a threefold strengthening of the warming effect on eta over the past 27 y. Soil moisture was found to modulate the sensitivity of eta to soil temperature in alpine meadows and alpine steppes, but not in alpine wetlands. Our results contribute to a better understanding of the processes driving the response of biomass distribution to climate warming, which is crucial for predicting the future carbon trajectory of permafrost ecosystems and climate feedback.