Loading...
Publication
Shifts in plant respiration and carbon use efficiency at a large-scale drought experiment in the eastern Amazon
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 565.18 KB | Adobe PDF |
Advisor(s)
Abstract(s)
The effects of drought on the Amazon rainforest are potentially large but remain
poorly understood. Here, carbon (C) cycling after 5 yr of a large-scale through-fall
exclusion (TFE) experiment excluding about 50% of incident rainfall from an eastern
Amazon rainforest was compared with a nearby control plot.
• Principal C stocks and fluxes were intensively measured in 2005. Additional
minor components were either quantified in later site measurements or derived
from the available literature.
• Total ecosystem respiration (Reco) and total plant C expenditure (PCE, the sum
of net primary productivity (NPP) and autotrophic respiration (Rauto)), were elevated
on the TFE plot relative to the control. The increase in PCE and Reco was
mainly caused by a rise in Rauto from foliage and roots. Heterotrophic respiration
did not differ substantially between plots. NPP was 2.4 ± 1.4 t C ha)1 yr)1 lower
on the TFE than the control. Ecosystem carbon use efficiency, the proportion of
PCE invested in NPP, was lower in the TFE plot (0.24 ± 0.04) than in the control
(0.32 ± 0.04).
• Drought caused by the TFE treatment appeared to drive fundamental shifts in
ecosystem C cycling with potentially important consequences for long-term forest
C storage.
Description
Keywords
Amazon rain forest Carbon cycling Carbon dioxide Carbon use efficiency Drought Gross primary productivity Net primary productivity Partitioning
Citation
New Phytologist, 187, 608-621