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Maj-Lena Linderson

Maj-Lena Finnander Linderson

Researcher

Maj-Lena Linderson

Beyond cloud cover : Low- and high-altitude clouds have distinct impacts on tree sap flow and transpiration

Author

  • Sini Talvinen
  • Yann Salmon
  • Jose Gutierrez Lopez
  • Maj Lena Finnander Linderson
  • Štěpánka Řehořková
  • Ladislav Šigut
  • Abhay Devasthale
  • Ilona Ylivinkka
  • Caroline Greiser
  • Ekaterina Ezhova
  • Johannes Quaas
  • Natalia Kowalska
  • Marian Pavelka
  • Stanislav Juráň
  • Eric Larmanou
  • Teemu Paljakka
  • Claudia Mohr
  • Ilona Riipinen
  • Radovan Krejci
Show all

Summary, in English

Transpiration drives up to 40 % of terrestrial precipitation, with forests playing a critical role. This study combines long-term sap flow measurements and surface-based cloud observations to examine how different clouds affect tree transpiration across boreal and temperate European forests. Under specific cloudy conditions, sap flow can exceed clear-sky levels, reflecting distinct radiation effects of various cloud types. However, overall cloudiness reduces maximum sap flow by up to 40 %. A key finding is the contrasting influence of low- and high-altitude clouds: low-altitude clouds suppress transpiration by limiting incoming radiation, while high-altitude clouds have negligible impact even when overcast. Structural equation modelling further indicates a pathway linking transpiration to cloudiness when other meteorological and site factors are accounted for. Satellite data show a decline in low‑altitude cloud fraction over boreal forests, and a highly simplified model-based order‑of‑magnitude estimate suggests a potential associated increase in transpiration equivalent to ∼0.6–1.2 mm of precipitation annually. These results emphasize how climate change driven changes in cloud cover and type may alter the moisture flux to the atmosphere, impacting regional and global water cycles.

Department/s

  • Department of Earth and Environmental Sciences (MGeo)
  • MERGE: ModElling the Regional and Global Earth system
  • BECC: Biodiversity and Ecosystem services in a Changing Climate

Publishing year

2026

Language

English

Publication/Series

Agricultural and Forest Meteorology

Volume

384

Document type

Article

Publisher

Elsevier

Topic

  • Meteorology and Atmospheric Sciences

Keywords

  • Atmosphere-biosphere interactions
  • Atmospheric dryness
  • Boreal forests
  • Cloud height and cover
  • Sap flow
  • Soil moisture
  • SDG 13 - Climate Action
  • SDG 15 - Life on Land

Status

Published

ISBN/ISSN/Other

  • ISSN: 0168-1923