RT Journal Article
SR Electronic
T1 Thermal adaptation constrains the temperature dependence of ecosystem metabolism
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 108696
DO 10.1101/108696
A1 Daniel Padfield
A1 Chris Lowe
A1 Angus Buckling
A1 Richard Ffrench-Constant
A1 Elisa Schaum
A1 Simon Jennings
A1 Felicity Shelley
A1 Jón S. Ólafsson
A1 Gabriel Yvon-Durocher
YR 2017
UL http://biorxiv.org/content/early/2017/02/15/108696.abstract
AB Gross primary production (GPP) is the largest flux in the carbon cycle, yet its response to global warming is highly uncertain. The temperature sensitivity 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 community structure and functional trait distributions. Here, we show that selection on photosynthetic traits within and across taxa dampen 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, rates of ecosystem-level GPP were independent of temperature, despite a 20 ºC thermal gradient. Our results suggest that thermal adaptation 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.