Marianne Hall
Forskningskoordinator
Physiological acclimation dampens initial effects of elevated temperature and atmospheric CO2 concentration in mature boreal Norway spruce
Författare
Summary, in English
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.
Avdelning/ar
- Centrum för miljö- och klimatvetenskap (CEC)
- Institutionen för naturgeografi och ekosystemvetenskap
- MERGE: ModElling the Regional and Global Earth system
Publiceringsår
2018-02
Språk
Engelska
Sidor
300-313
Publikation/Tidskrift/Serie
Plant, Cell and Environment
Volym
41
Issue
2
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley-Blackwell
Ämne
- Climate Research
- Forest Science
Nyckelord
- Carboxylation efficiency
- Intercellular CO concentration
- Picea abies
- Transpiration
- V
- Whole-tree chambers
Aktiv
Published
ISBN/ISSN/Övrigt
- ISSN: 0140-7791