Plant respiration constitutes a massive carbon flux to the atmosphere, and a major control on the evolution of the global carbon cycle. It therefore has the potential to modulate levels of climate change due to the human burning of fossil fuels. Neither current physiological nor terrestrial biosphere models adequately describe its short-term temperature response, and even minor differences in the shape of the response curve can significantly impact estimates of ecosystem carbon release and/or storage. Given this, it is critical to establish whether there are predictable patterns in the shape of the respiration-temperature response curve, and thus in the intrinsic temperature sensitivity of respiration across the globe. Analyzing measurements in a comprehensive database for 231 species spanning 7 biomes, we demonstrate that temperature-dependent increases in leaf respiration do not follow a commonly used exponential function. Instead,we find a decelerating function as leaves warm, reflecting a declining sensitivity to higher temperatures that is remarkably uniform across all biomes and plant functional types. Such convergence in the temperature sensitivity of leaf respiration suggests that there are universally applicable controls on the temperature response of plant energy metabolism, such that a single new function can predict the temperature dependence of leaf respiration for global vegetation. This simple function enables straightforward description of plant respiration in the land-surface components of coupled earth system models. Our cross-biome analyses shows significant implications for such fluxes in cold climates, generally projecting lower values compared with previous estimates.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Apr 5 2016|
Bibliographical noteFunding Information:
This work was funded by the Australian Research Council Grants/Fellowships DP0986823, DP130101252, CE140100008, and FT0991448 (to O.K.A.), FT110100457 (to P.M.), and DP140103415 (to M.G.T.); Natural Environment Research Council (UK) Grant NE/F002149/1 (to P.M.); Award DE-FG02-07ER64456 from the US Department of Energy, Office of Science, Office of Biological and Environmental Research (to P.B.R.); and National Science Foundation International Polar Year Grant (to K.L.G.). A.M.-d.l.T., and C.H. acknowledge the Centre for Ecology and Hydrology (UK) National Capability fund.
- Carbon exchange
- Climate models
- Temperature sensitivity
- Thermal response