Seasonal carbon dynamics and water fluxes in an Amazon rainforest |
| |
| Authors: | Yeonjoo Kim Ryan G Knox Marcos Longo David Medvigy Lucy R Hutyra Elizabeth H Pyle Steven C Wofsy Rafael L Bras Paul R Moorcroft |
| |
| Institution: | 1. Department of Organismic and Evolutionary Biology, Harvard University, , Cambridge, MA 02138, USA;2. Korea Adaptation Center for Climate Change, Korea Environment Institute, , Seoul 122‐706, Korea;3. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, , Cambridge, MA 02139, USA;4. Department of Earth and Planetary Sciences, Harvard University, , Cambridge, MA 02138, USA;5. Department of Geosciences, Princeton University, , Princeton, NJ 08544, USA;6. Department of Geography and Environment, Boston University, , Boston, MA 02215, USA;7. Departments of Civil and Environmental Engineering and of Earth and Atmospheric Sciences, Georgia Institute of Technology, , Atlanta, GA 30332, USA |
| |
| Abstract: | Satellite‐based observations indicate that seasonal patterns in canopy greenness and productivity in the Amazon are negatively correlated with precipitation, with increased greenness occurring during the dry months. Flux tower measurements indicate that the canopy greening that occurs during the dry season is associated with increases in net ecosystem productivity (NEP) and evapotranspiration (ET). Land surface and terrestrial biosphere model simulations for the region have predicted the opposite of these observed patterns, with significant declines in greenness, NEP, and ET during the dry season. In this study, we address this issue mainly by developing an empirically constrained, light‐controlled phenology submodel within the Ecosystem Demography model version 2 (ED2). The constrained ED2 model with a suite of field observations shows markedly improved predictions of seasonal ecosystem dynamics, more accurately capturing the observed patterns of seasonality in water, carbon, and litter fluxes seen at the Tapajos National Forest, Brazil (2.86°S, 54.96°W). Long‐term simulations indicate that this light‐controlled phenology increases the resilience of Amazon forest NEP to interannual variability in climate forcing. |
| |
| Keywords: | Amazon ecosystem model evapotranspiration light‐controlled phenology net ecosystem productivity root water uptake tropical forests |
|
|
