TY - JOUR
T1 - Global distribution of groundwater-vegetation spatial covariation
AU - Koirala, Sujan
AU - Jung, Martin
AU - Reichstein, Markus
AU - de Graaf, Inge E.M.
AU - Camps-Valls, Gustau
AU - Ichii, Kazuhito
AU - Papale, Dario
AU - Ráduly, Botond
AU - Schwalm, Christopher R.
AU - Tramontana, Gianluca
AU - Carvalhais, Nuno
N1 - Funding Information:
S.K. was financially supported by the ClimAfrica and EMBRACE (283201) projects of the European Commission under the 7th Framework Programme (FP7). M.J. and M.R. acknowledge the support of BACI project funded by the European Union's Horizon 2020 Research and Innovation program under grant agreement 640176. I.D.G. was supported by the Netherlands Organization for Scientific Research (NWO) under the program “Planetary boundaries of the global freshwater cycle.” G.C.-V. was supported by the EU under the European Research Council (ERC) consolidator grant SEDAL-647423. K.I. was supported by the JSPS KAKENHI (25281003) and the Environment Research and Technology Development Funds (2-1401) from the Ministry of the Environment of Japan. C.R.S. was also supported by the National Aeronautics and Space Administration (NASA) grants NNX12AK12G, NNX12AP74G, NNX10AG01A, and NNX11AO08A. N.C. acknowledges the support of NOVA grant UID/AMB/04085/2013. The data for mean seasonal cycles of gross primary productivity and net radiation from FLUXCOM (http://www.fluxcom.org) and water table depth are available from the data portal of Max Planck Institute for Biogeochemistry (https://www.bgc-jena.mpg.de/geodb/FluxCom/gw-veg.php) after registration. For convenience, the sources of other publicly available data sets used in this study are also consolidated in the above webpage. We express our gratitude to Fabian Gans and Gerhard Boenisch at Max Planck Institute for Biogeochemistry for setting up the data portal and webpage.
Publisher Copyright:
©2017. American Geophysical Union. All Rights Reserved.
PY - 2017/5/16
Y1 - 2017/5/16
N2 - Groundwater is an integral component of the water cycle, and it also influences the carbon cycle by supplying moisture to ecosystems. However, the extent and determinants of groundwater-vegetation interactions are poorly understood at the global scale. Using several high-resolution data products, we show that the spatial patterns of ecosystem gross primary productivity and groundwater table depth are correlated during at least one season in more than two thirds of the global vegetated area. Positive relationships, i.e., larger productivity under shallower groundwater table, predominate in moisture-limited dry to mesic conditions with herbaceous and shrub vegetation. Negative relationships, i.e., larger productivity under deeper groundwater, predominate in humid climates with forests, possibly indicating a drawdown of groundwater table due to substantial ecosystem water use. Interestingly, these opposite groundwater-vegetation interactions are primarily associated with differences in vegetation than with climate and surface characteristics. These findings put forth the first evidence, and a need for better representation, of extensive and non-negligible groundwater-vegetation interactions at the global scale.
AB - Groundwater is an integral component of the water cycle, and it also influences the carbon cycle by supplying moisture to ecosystems. However, the extent and determinants of groundwater-vegetation interactions are poorly understood at the global scale. Using several high-resolution data products, we show that the spatial patterns of ecosystem gross primary productivity and groundwater table depth are correlated during at least one season in more than two thirds of the global vegetated area. Positive relationships, i.e., larger productivity under shallower groundwater table, predominate in moisture-limited dry to mesic conditions with herbaceous and shrub vegetation. Negative relationships, i.e., larger productivity under deeper groundwater, predominate in humid climates with forests, possibly indicating a drawdown of groundwater table due to substantial ecosystem water use. Interestingly, these opposite groundwater-vegetation interactions are primarily associated with differences in vegetation than with climate and surface characteristics. These findings put forth the first evidence, and a need for better representation, of extensive and non-negligible groundwater-vegetation interactions at the global scale.
KW - ecohydrological patterns
KW - ecosystem
KW - groundwater
KW - plant productivity
KW - spatial covariation
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U2 - 10.1002/2017GL072885
DO - 10.1002/2017GL072885
M3 - Article
AN - SCOPUS:85018872474
SN - 0094-8276
VL - 44
SP - 4134
EP - 4142
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 9
ER -