Declining winter snowpack offsets carbon storage enhancement from growing season warming in northern temperate forest ecosystems

• 成果类型: Article
• 署名作者: Rooney, Emerson Conrad-; Reinmann, Andrew B.; Templer, Pamela H.
• 署名单位: Boston University; City University of New York (CUNY) System; City University of New York (CUNY) System; City University of New York (CUNY) System; City University of New York (CUNY) System; Hunter College (CUNY)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10996
• DOI: 10.1073/pnas.2412873122
• 发表日期: 2025-07-15
• 关键词: soil frost; future changes; CLIMATE-CHANGE; root; biomass; trees

摘要

Northeastern US temperate forests are currently net carbon (C) sinks and play an important role offsetting anthropogenic C emissions, but projected climatic changes, including increased temperatures and decreased winter snowpack, may influence this C sink over the next century. Past studies show that growing season warming increases forest C storage through greater soil nutrient availability that contributes to greater rates of net photosynthesis, while reduced winter snowpack induces soil freeze/thaw cycles that reduce tree root vitality, nutrient uptake, and forest C storage. The year- round effects of climate change on this C sink are not well understood. We report here decade- long Brook Experimental Forest, which determines the combined effects of growing season warming and a smaller winter snowpack on C storage in northern temperate forests. We found after a decade of treatments that growing season warming increases cumulative tree stem biomass C by 63%. However, winter soil freeze/thaw cycles offset half of this growing season warming effect. The amount of C stored in stem biomass of trees experiencing both growing season warming plus smaller winter snowpack is only 31% higher than the reference plots, but this difference is not significant. Our results suggest that current Earth system models are likely to overestimate the C sink capacity of northern temperate forests because they do not incorporate the negative impacts of a shrinking snowpack and increased frequency of soil freeze/thaw cycles on C uptake and storage by trees.