EGU24-20980, updated on 11 Mar 2024
https://doi.org/10.5194/egusphere-egu24-20980
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Contrasting water use strategies to climate warming in white birch and larch in a boreal permafrost region

Xi Qi1,2, Kerstin Treydte2, Matthias Saurer2, Keyan Fang3, Wenling Ann2,4,5, Marco Lehmann2, Kuyuan Liu1, Zhengfang Wu1, Hong He6, Haibo Du1,7, and Mai-He Li2,1,8
Xi Qi et al.
  • 1Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China
  • 2Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland
  • 3Key Laboratory of Humid Subtropical Eco-Geographical Process, Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
  • 4Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
  • 5CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China
  • 6School of Natural Resources, University of Missouri, Columbia, MO 65211, USA
  • 7Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun 130024, China
  • 8School of Life Science, Hebei University, 071000 Baoding, China

The effects of rising atmospheric CO2 concentrations (Ca) with climate warming on intrinsic water-use efficiency (iWUE) and radial growth in boreal forests are still poorly understood. We measured tree-ring cellulose δ13C,δ18O, and tree-ring width in Larix dahurica (larch) and Betula platyphylla (white birch), and analyzed their relationships with climate variables in a boreal permafrost region of northeast China over past 70 years covering a pre-warming period (1951-1979; base period) and a rapid-warming period (1980-2018; warming period). We found that white birch but not larch significantly increased their radial growth over the warming period. The increased iWUE in both species was mainly driven by elevated Ca but not climate. White birch but not larch showed significant positive correlations between tree-ring δ13C,δ18O and summer maximum temperature as well as vapor pressure deficit in the warming period, suggesting a strong stomatal response in the deciduous birch but not in the conifer larch to climate warming. The climate-warming induced radial growth enhancement in white birch is associated with a more ‘conservative’ (low gs, constant A) water use strategy than in larch (constant gs, high A), suggesting an advantage for the former than the latter in a warming world in the permafrost regions.

How to cite: Qi, X., Treydte, K., Saurer, M., Fang, K., Ann, W., Lehmann, M., Liu, K., Wu, Z., He, H., Du, H., and Li, M.-H.: Contrasting water use strategies to climate warming in white birch and larch in a boreal permafrost region, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20980, https://doi.org/10.5194/egusphere-egu24-20980, 2024.