Physiological acclimation dampens initial effects of elevated temperature and atmospheric CO2 concentration in mature boreal Norway spruce

Research output: Contribution to journalArticle

Abstract

Physiological processes of terrestrial plants regulate the land-atmosphere exchange of carbon, water, and energy, yet few studies have explored the acclimation responses of mature boreal conifer trees to climate change. Here we explored the acclimation responses of photosynthesis, respiration, and stomatal conductance to elevated temperature and/or CO2 concentration ([CO2]) in a 3-year field experiment with mature boreal Norway spruce. We found that elevated [CO2] decreased photosynthetic carboxylation capacity (-23% at 25 °C) and increased shoot respiration (+64% at 15 °C), while warming had no significant effects. Shoot respiration, but not photosynthetic capacity, exhibited seasonal acclimation. Stomatal conductance at light saturation and a vapour pressure deficit of 1 kPa was unaffected by elevated [CO2] but significantly decreased (-27%) by warming, and the ratio of intercellular to ambient [CO2] was enhanced (+17%) by elevated [CO2] and decreased (-12%) by warming. Many of these responses differ from those typically observed in temperate tree species. Our results show that long-term physiological acclimation dampens the initial stimulation of plant net carbon assimilation to elevated [CO2], and of plant water use to warming. Models that do not account for these responses may thus overestimate the impacts of climate change on future boreal vegetation-atmosphere interactions.

Details

Authors
  • Shubhangi Lamba
  • Marianne Hall
  • Mats Räntfors
  • Nitin Chaudhary
  • Sune Linder
  • Danielle Way
  • Johan Uddling
  • Göran Wallin
Organisations
External organisations
  • Duke University
  • University of Gothenburg
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Climate Research
  • Forest Science

Keywords

  • Carboxylation efficiency, Intercellular CO concentration, Picea abies, Transpiration, V, Whole-tree chambers
Original languageEnglish
Pages (from-to)300-313
JournalPlant Cell and Environment
Volume41
Issue number2
Early online date2017 Dec 11
Publication statusPublished - 2018 Feb
Publication categoryResearch
Peer-reviewedYes