Stand age and species richness dampen interannual variation of ecosystem-level photosynthetic capacity
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 (GPP sat ), and its interannual variability (IA...
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Published in | Nature ecology & evolution Vol. 1; no. 2; p. 48 |
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Main Authors | , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
23.01.2017
Nature Publishing Group Nature |
Subjects | |
Online Access | Get full text |
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Summary: | 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 (GPP
sat
), and its interannual variability (IAV) is propagated to the net land–atmosphere exchange of CO
2
. Given the importance of understanding the IAV in CO
2
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 GPP
sat
in forest ecosystems. Our results show that while the IAV in GPP
sat
within sites is closely related to air temperature and soil water availability fluctuations, the magnitude of IAV in GPP
sat
is related to stand age and biodiversity (
R
2
= 0.55,
P
< 0.0001). We find that the IAV of GPP
sat
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.
The photosynthetic capacity of forest ecosystems is an important variable in the global carbon cycle. Here, it is shown that older, more diverse forests have less fluctuation between years in photosynthetic capacity. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2397-334X 2397-334X |
DOI: | 10.1038/s41559-016-0048 |