Metabolic compensation constrains the temperature dependence of gross primary production
Wiley / Centre National de la Recherche Scientifique (CNRS)
© 2017 The Authors Ecology Letters published by CNRS and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Gross primary production (GPP) is the largest flux in the carbon cycle, yet its response to global warming is highly uncertain. The temperature-dependence of GPP is directly linked to photosynthetic physiology, but the response of GPP to warming over longer timescales could also be shaped by ecological and evolutionary processes that drive variation in community structure and functional trait distributions. Here, we show that selection on photosynthetic traits within and across taxa dampens the effects of temperature on GPP across a catchment of geothermally heated streams. Autotrophs from cold streams had higher photosynthetic rates and after accounting for differences in biomass among sites, biomass-specific GPP was independent of temperature in spite of a 20 ºC thermal gradient. Our results suggest that temperature-compensation of photosynthetic rates constrains the long-term temperature- dependence of GPP, and highlights the importance of considering physiological, ecological and evolutionary mechanisms when predicting how ecosystem-level processes respond to warming.
This study was supported by a NERC Case studentship awarded to DP, GYD, AB and SJ, an ERC starting grant awarded to GYD, and the University of Exeter.
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.
Published online 29 August 2017
Except where otherwise noted, this item's license is described as © 2017 The Authors Ecology Letters published by CNRS and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.