Proceedings of the National Academy of Sciences of the United States of America (PNAS)
2016
113
14
0027-8424 (impreso), 1091-6490 (en línea)
https://doi.org/10.1073/pnas.1520282113
0027-8424
temperature sensitivity, climate models, carbon exchange, Q10, thermal response
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.
© Mary A. Heskel, Odhran S. O’Sullivan, Peter B. Reich, +15 , and Owen K. Atkin
Heskel Mary A. , O’Sullivan Odhran S., Reich Peter B., Tjoelkerd Mark G., Weerasinghe Lasantha K., Penillard Aurore, Egerton John J. G., Creeka Danielle, Bloomfield Keith J., Xiang Jen, Sinca Felipe, Stangli Zsofia R., Martinez-de la Torre Alberto, Griffin Kevin L., Huntingfordj Chris, Hurrym Vaughan, Meira Patrick , Turnbull Matthew H., Atkin Owen K.
National Academy of Sciences
Washington D. C
Inglés
Articulo de revista academica