The total uptake of carbon dioxide by ecosystems via photosynthesis (gross primary productivity, GPP) is the largest flux in the global carbon cycle. A key ecosystem functional property determining GPP is the photosynthetic capacity at light saturation (GPPsat), and its interannual variability (IAV) is propagated to the net land–atmosphere exchange of CO2. Given the importance of understanding the IAV in CO2 fluxes for improving the predictability of the global carbon cycle, we have tested a range of alternative hypotheses to identify potential drivers of the magnitude of IAV in GPPsat in forest ecosystems. Our results show that while the IAV in GPPsat within sites is closely related to air temperature and soil water availability fluctuations, the magnitude of IAV in GPPsat is related to stand age and biodiversity (R2 = 0.55, P < 0.0001). We find that the IAV of GPPsat is greatly reduced in older and more diverse forests, and is higher in younger forests with few dominant species. Older and more diverse forests seem to dampen the effect of climate variability on the carbon cycle irrespective of forest type. Preserving old forests and their diversity would therefore be beneficial in reducing the effect of climate variability on Earth's forest ecosystems

Musavi, T.; Migliavacca, M.; Reichstein, M.; Kattge, J.; Wirth, C.; Black, T.A.; Janssens, I.; Knohl, A.; Loustau, D.; Roupsard, O.; Varlagin, A.; Rambal, S.; Cescatti, A.; Gianelle, D.; Kondo, H.; Tamrakar, R.; Mahecha, M.D. (2017). Stand age and species richness dampen interannual variation of ecosystem-level photosynthetic capacity. NATURE ECOLOGY & EVOLUTION, 1: 0048. doi: 10.1038/s41559-016-0048 handle: http://hdl.handle.net/10449/37007

Stand age and species richness dampen interannual variation of ecosystem-level photosynthetic capacity

Gianelle, Damiano;
2017-01-01

Abstract

The total uptake of carbon dioxide by ecosystems via photosynthesis (gross primary productivity, GPP) is the largest flux in the global carbon cycle. A key ecosystem functional property determining GPP is the photosynthetic capacity at light saturation (GPPsat), and its interannual variability (IAV) is propagated to the net land–atmosphere exchange of CO2. Given the importance of understanding the IAV in CO2 fluxes for improving the predictability of the global carbon cycle, we have tested a range of alternative hypotheses to identify potential drivers of the magnitude of IAV in GPPsat in forest ecosystems. Our results show that while the IAV in GPPsat within sites is closely related to air temperature and soil water availability fluctuations, the magnitude of IAV in GPPsat is related to stand age and biodiversity (R2 = 0.55, P < 0.0001). We find that the IAV of GPPsat is greatly reduced in older and more diverse forests, and is higher in younger forests with few dominant species. Older and more diverse forests seem to dampen the effect of climate variability on the carbon cycle irrespective of forest type. Preserving old forests and their diversity would therefore be beneficial in reducing the effect of climate variability on Earth's forest ecosystems
Ecophysiology
Carbon cycle
Earth observation
Forest ecology
Settore BIO/07 - ECOLOGIA
Musavi, T.; Migliavacca, M.; Reichstein, M.; Kattge, J.; Wirth, C.; Black, T.A.; Janssens, I.; Knohl, A.; Loustau, D.; Roupsard, O.; Varlagin, A.; Rambal, S.; Cescatti, A.; Gianelle, D.; Kondo, H.; Tamrakar, R.; Mahecha, M.D. (2017). Stand age and species richness dampen interannual variation of ecosystem-level photosynthetic capacity. NATURE ECOLOGY & EVOLUTION, 1: 0048. doi: 10.1038/s41559-016-0048 handle: http://hdl.handle.net/10449/37007
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10449/37007
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