@Article{ChristoffersenRABCCFGGGDIIJLMPRSSSSVYAKMRRMBCGZS:2014:MeWaSu,
author = "Christoffersen, Bradley O. and Restrepo-Coupe, Natalia and Arain,
M Altaf and Baker, Ian T. and Cestaro, Bruno P. and Ciais,
Phillippe and Fisher, Joshua B. and Galbraith, David and Guan,
Xiaodan and Gulden, Lindsey and van Den Hurk, Bart and Ichii,
Kazuhito and Imbuzeiro, Hewlley and Jain, Atul and Levine, Naomi
and Miguez-Macho, Gonzalo and Poulter, Ben and Roberti, Debora R.
and Sakaguchi, Koichi and Sahoo, Alok and Schaefer, Kevin and Shi,
Mingjie and Verbeeck, Hans and Yang, Zong-Liang and Ara{\'u}jo,
Alessandro C. and Kruijt, Bart and Manzi, Antonio O. and Rocha,
Humberto Ribeiro da and von Randow, Celso and Muza, Michel N. and
Borak, Jordan and Costa, Marcos H. and Gon{\c{c}}alves de
Gon{\c{c}}alves, Luis Gustavo and Zeng, Xubin and Saleska, Scott
R.",
affiliation = "{University of Arizona} and {University of Arizona} and {McMaster
University} and {Colorado State University} and {Universidade de
S{\~a}o Paulo} and {LSCE CEA-CNRS-UVSQ} and {California Institute
of Technology} and {University of Oxford} and {The University of
Texas at Austin} and {The University of Texas at Austin} and
{Royal Netherlands Meteorological Institute (KNMI)} and {Fukushima
University} and {Federal University of Vi{\c{c}}osa} and
{University of Illinois at Urbana-Champaign} and {Harvard
University} and {Universidade de Santiago de Compostela} and
{Swiss Federal Research Institute WSL} and {Federal University of
Santa Maria} and {University of Arizona} and {Center for Research
on Environment and Water} and {University of Colorado at Boulder}
and {The University of Texas at Austin} and {Ghent University} and
{The University of Texas at Austin} and {Embrapa Amaz{\^o}nia
Oriental} and {Wageningen University \& Research Center} and
{Instituto Nacional de Pesquisas da Amaz{\^o}nia (INPA)} and
{Universidade de S{\~a}o Paulo} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {University of Maryland} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Federal
University of Vi{\c{c}}osa} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {University of Arizona} and {University of
Arizona}",
title = "Mechanisms of water supply and vegetation demand govern the
seasonality and magnitude of evapotranspiration in Amazonia and
Cerrado",
journal = "Agricultural and Forest Meteorology",
year = "2014",
volume = "191",
pages = "33--50",
month = "June",
note = "Supplementary data associated with this article can be found,in
the online version, at
http://dx.doi.org/10.1016/j.agrformet.2014.02.008.",
keywords = "Amazonian forest, carbon cycle, tropical forest,
evapotranspiration, deep roots, groundwater, canopy stomatal
conductance, intrinsic water use efficiency.",
abstract = "Evapotranspiration (E) in the Amazon connects forest function and
regional climate via its role in pre-cipitation recycling However,
the mechanisms regulating water supply to vegetation and its
demand forwater remain poorly understood, especially during
periods of seasonal water deficits In this study, we
efficiencyaddress two main questions: First, how do mechanisms of
water supply (indicated by rooting depth andgroundwater) and
vegetation water demand (indicated by stomatal conductance and
intrinsic water useefficiency) control evapotranspiration (E)
along broad gradients of climate and vegetation from
equatorialAmazonia to Cerrado, and second, how do these inferred
mechanisms of supply and demand compareto those employed by a
suite of ecosystem models? We used a network of eddy covariance
towers inBrazil coupled with ancillary measurements to address
these questions With respect to the magnitudeand seasonality of E,
models have much improved in equatorial tropical forests by
eliminating most dryseason water limitation, diverge in
performance in transitional forests where seasonal water deficits
aregreater, and mostly capture the observed seasonal depressions
in E at Cerrado However, many mod-els depended universally on
either deep roots or groundwater to mitigate dry season water
deficits, therelative importance of which we found does not vary
as a simple function of climate or vegetation In addi-tion, canopy
stomatal conductance (gs) regulates dry season vegetation demand
for water at all exceptthe wettest sites even as the seasonal
cycle of E follows that of net radiation In contrast, some models
sim-ulated no seasonality in gs, even while matching the observed
seasonal cycle of E. We suggest that canopydynamics mediated by
leaf phenology may play a significant role in such seasonality, a
process poorlyrepresented in models Model bias in gsand E, in
turn, was related to biases arising from the simulatedlight
response (gross primary productivity, GPP) or the intrinsic water
use efficiency of photosynthesis(iWUE). We identified deficiencies
in models which would not otherwise be apparent based on a
simplecomparison of simulated and observed rates of E. While some
deficiencies can be remedied by parame-ter tuning, in most models
they highlight the need for continued process development of
belowgroundhydrology and in particular, the biological processes
of root dynamics and leaf phenology, which via theircontrols on E,
mediate vegetation-climate feedbacks in the tropics.",
doi = "10.1016/j.agrformet.2014.02.008",
url = "http://dx.doi.org/10.1016/j.agrformet.2014.02.008",
issn = "0168-1923",
label = "lattes: 0535860239259102 29
ChristoffersenRABCCFGGGVIIJLMPRSSSSVYAKMRRMBCGZS:2014:MeWaSu",
language = "en",
targetfile = "1-s2.0-S0168192314000471-main.pdf",
url = "http://dx.doi.org/10.1016/j.agrformet.2014.02.008",
urlaccessdate = "27 abr. 2024"
}