TY - JOUR
T1 - Ecosystem respiration and net primary productivity after 8-10 years of experimental through-fall reduction in an eastern Amazon forest
AU - da Costa, Antonio C.L.
AU - Metcalfe, Daniel B.
AU - Doughty, Chris E.
AU - de Oliveira, Alexandre A.R.
AU - Neto, Guilherme F.C.
AU - da Costa, Mauricio C.
AU - Silva Junior, João de Athaydes
AU - Aragão, Luiz E.O.C.
AU - Almeida, Samuel
AU - Galbraith, David R.
AU - Rowland, Lucy M.
AU - Meir, Patrick
AU - Malhi, Yadvinder
PY - 2014
Y1 - 2014
N2 - Background: There is much interest in how the Amazon rainforest may respond to future rainfall reduction. However, there are relatively few ecosystem-scale studies to inform this debate. Aims: We described the carbon cycle in a 1 ha rainforest plot subjected to 8-10 consecutive years of ca. 50% through-fall reduction (TFR) and compare these results with those from a nearby, unmodified control plot in eastern Amazonia. Methods: We quantified the components of net primary productivity (NPP), autotrophic (R a) and heterotrophic respiration, and estimate gross primary productivity (GPP, the sum of NPP and R a) and carbon-use efficiency (CUE, the ratio of NPP/GPP). Results: The TFR forest exhibited slightly lower NPP but slightly higher R a, such that forest CUE was 0.29 ± 0.04 on the control plot but 0.25 ± 0.03 on the TFR plot. Compared with four years earlier, TFR plot leaf area index and small tree growth recovered and soil heterotrophic respiration had risen. Conclusions: This analysis tested and extended the key findings of a similar analysis 4 years earlier in the TFR treatment. The results indicated that, while the forest recovered from extended drought in some respects, it maintained higher overall R a relative to the undroughted control, potentially causing the droughted forest to act as a net source of CO2.
AB - Background: There is much interest in how the Amazon rainforest may respond to future rainfall reduction. However, there are relatively few ecosystem-scale studies to inform this debate. Aims: We described the carbon cycle in a 1 ha rainforest plot subjected to 8-10 consecutive years of ca. 50% through-fall reduction (TFR) and compare these results with those from a nearby, unmodified control plot in eastern Amazonia. Methods: We quantified the components of net primary productivity (NPP), autotrophic (R a) and heterotrophic respiration, and estimate gross primary productivity (GPP, the sum of NPP and R a) and carbon-use efficiency (CUE, the ratio of NPP/GPP). Results: The TFR forest exhibited slightly lower NPP but slightly higher R a, such that forest CUE was 0.29 ± 0.04 on the control plot but 0.25 ± 0.03 on the TFR plot. Compared with four years earlier, TFR plot leaf area index and small tree growth recovered and soil heterotrophic respiration had risen. Conclusions: This analysis tested and extended the key findings of a similar analysis 4 years earlier in the TFR treatment. The results indicated that, while the forest recovered from extended drought in some respects, it maintained higher overall R a relative to the undroughted control, potentially causing the droughted forest to act as a net source of CO2.
KW - CUE
KW - Caxiuanã National Forest Reserve
KW - GPP
KW - NPP
KW - PCE
KW - biomass allocation
KW - carbon cycling
KW - climate change
KW - drought
KW - tropical rainforest
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U2 - 10.1080/17550874.2013.798366
DO - 10.1080/17550874.2013.798366
M3 - Article
AN - SCOPUS:84893214546
SN - 1755-0874
VL - 7
SP - 7
EP - 24
JO - Plant Ecology and Diversity
JF - Plant Ecology and Diversity
IS - 1-2
ER -