Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Spatiotemporal origin of soil water taken up by vegetation


Vegetation modulates Earth’s water, energy and carbon cycles. How its functions might change in the future largely depends on how it copes with droughts1,2,3,4. There is evidence that, in places and times of drought, vegetation shifts water uptake to deeper soil5,6,7 and rock8,9 moisture as well as groundwater10,11,12. Here we differentiate and assess plant use of four types of water sources: precipitation in the current month (source 1), past precipitation stored in deeper unsaturated soils and/or rocks (source 2), past precipitation stored in groundwater (source 3, locally recharged) and groundwater from precipitation fallen on uplands via river–groundwater convergence toward lowlands (source 4, remotely recharged). We examine global and seasonal patterns and drivers in plant uptake of the four sources using inverse modelling and isotope-based estimates. We find that (1), globally and annually, 70% of plant transpiration relies on source 1, 18% relies on source 2, only 1% relies on source 3 and 10% relies on source 4; (2) regionally and seasonally, source 1 is only 19% in semi-arid, 32% in Mediterranean and 17% in winter-dry tropics in the driest months; and (3) at landscape scales, source 2, taken up by deep roots in the deep vadose zone, is critical in uplands in dry months, but source 4 is up to 47% in valleys where riparian forests and desert oases are found. Because the four sources originate from different places and times, move at different spatiotemporal scales and respond with different sensitivity to climate and anthropogenic forces, understanding the space and time origins of plant water sources can inform ecosystem management and Earth system models on the critical hydrological pathways linking precipitation to vegetation.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Schematic of four plant water sources.
Fig. 2: Modelled fractional source contributions to transpiration.
Fig. 3: Monthly source contribution to transpiration for the 12 climate types in the model.
Fig. 4: Modelled source contributions in South America at the continent-to-hillslope scale.

Data availability

All model input data are generated by government and research agencies and are in the public domain. Links to download these data are provided in Supplementary Table 2. Modelled monthly transpiration and source contributions (sources 1, 2, 3 and 4) for each continent and month can be downloaded at the following public repository via ftp: The isotope compilation can also be found in an Excel spreadsheet at the above ftp site.

Code availability

Our model code, written in Fortran, was uploaded to GitHub:


  1. 1.

    Graven, H. D. et al. Enhanced seasonal exchange of CO2 by Northern ecosystems since 1960. Science 341, 1085–1089 (2013).

    CAS  Article  ADS  Google Scholar 

  2. 2.

    Humphrey, V. et al. Sensitivity of atmospheric CO2 growth rate to observed changes in terrestrial water storage. Nature 560, 628–631 (2018).

    CAS  Article  ADS  Google Scholar 

  3. 3.

    Bonan, G. B. Forests and climate change: forcings, feedbacks, and the climate benefits of forests. Science 320, 1444–1449 (2008).

    CAS  Article  ADS  Google Scholar 

  4. 4.

    Schlesinger, W. H. & Jasechko, S. Agricultural and forest meteorology transpiration in the global water cycle. Agric. For. Meteorol. 189–190, 115–117 (2014).

    Article  ADS  Google Scholar 

  5. 5.

    Dawson, T. E. & Pate, J. S. Seasonal water uptake and movement in root systems of Australian phraeatophytic plants of dimorphic root morphology: a stable isotope investigation. Oecologia 107, 13–20 (1996).

    Article  ADS  Google Scholar 

  6. 6.

    Voltas, J., Devon, L., Maria Regina, C. & Juan Pedro, F. Intraspecific variation in the use of water sources by the circum-Mediterranean conifer Pinus halepensis. New Phytol. 208, 1031–1041 (2015).

    Article  Google Scholar 

  7. 7.

    Grossiord, C. et al. Prolonged warming and drought modify belowground interactions for water among coexisting plants. Tree Physiol. 39, 55–63 (2018).

    Article  Google Scholar 

  8. 8.

    Rempe, D. M. & Dietrich, W. E. Direct observations of rock moisture, a hidden component of the hydrologic cycle. Proc. Natl Acad. Sci. USA 115, 2664–2669 (2018).

    CAS  Article  ADS  Google Scholar 

  9. 9.

    Querejeta, J. I., Estrada-Medina, H., Allen, M. F. & Jiménez-Osornio, J. J. Water source partitioning among trees growing on shallow karst soils in a seasonally dry tropical climate. Oecologia 152, 26–36 (2007).

    Article  ADS  Google Scholar 

  10. 10.

    Evaristo, J. & McDonnell, J. J. Prevalence and magnitude of groundwater use by vegetation: a global stable isotope meta-analysis. Sci Rep. 7, 44110 (2017).

    Article  ADS  Google Scholar 

  11. 11.

    Barbeta, A. & Peñuelas, J. Relative contribution of groundwater to plant transpiration estimated with stable isotopes. Sci Rep. 7, 10580 (2017).

    Article  ADS  Google Scholar 

  12. 12.

    Jobbágy, E. G., Nosetto, M. D., Villagra, P. E. & Jackson, R. B. Water subsidies from mountains to deserts: their role in sustaining groundwater-fed oases in a sandy landscape. Ecol. Appl. 21, 678–694 (2011).

    Article  Google Scholar 

  13. 13.

    Fan, Y., Miguez-Macho, G., Jobbágy, E. G., Jackson, R. B. & Otero-Casal, C. Hydrologic regulation of plant rooting depth. Proc. Natl Acad. Sci. USA 114, 10572–10577 (2017).

    CAS  Article  ADS  Google Scholar 

  14. 14.

    Ellsworth, P. Z. & Sternberg, L. S. L. Seasonal water use by deciduous and evergreen woody species in a scrub community is based on water availability and root distribution. Ecohydrology 551, 538–551 (2015).

    Article  Google Scholar 

  15. 15.

    Sohel, S. Spatial and Temporal Variation of Sources of Water Across Multiple Tropical Rainforest Trees. PhD thesis, Univ. Queensland (2019).

  16. 16.

    Williams, D. G. & Ehleringer, J. R. Intra- and interspecific variation for summer precipitation use in pinyon-juniper woodlands. Ecol. Monogr. 70, 517–537 (2000).

    Google Scholar 

  17. 17.

    Allen, S. T., Kirchner, J. W., Braun, S., Siegwolf, R., T. W. & Goldsmith, G. R. Seasonal origins of soil water used by trees. Hydrol. Earth Syst. Sci. 23, 1199–1210 (2019).

    CAS  Article  ADS  Google Scholar 

  18. 18.

    David, T. S. et al. Water-use strategies in two co-occurring Mediterranean evergreen oaks: surviving the summer drought. Tree Physiol. 27, 793–803 (2007).

    CAS  Article  Google Scholar 

  19. 19.

    Zencich, S. J., Froend, R. H., Turner, J. V. & Gailitis, V. Influence of groundwater depth on the seasonal sources of water accessed by Banksia tree species on a shallow, sandy coastal aquifer. Oecologia 131, 8–19 (2002).

    Article  ADS  Google Scholar 

  20. 20.

    Naumburg, E., Mata-Gonzalez, R., Hunter, R. G. & Martin, D. W. Phreatophytic vegetation and groundwater fluctuations: a review of current research and application of ecosystem response modeling with an emphasis on Great Basin vegetation. Environ. Manage. 35, 726–740 (2005).

    Article  Google Scholar 

  21. 21.

    Snyder, K. A. & Williams, D. G. Water sources used by riparian trees varies among stream types on the San Pedro River, Arizona. Agric. For. Meteorol. 105, 227–240 (2000).

    Article  ADS  Google Scholar 

  22. 22.

    Kottek, M., Grieser, J., Beck, C., Rudolf, B. & Rubel, F. World map of the Köppen–Geiger climate classification updated. Meteorol. Zeitschrift 15, 259–263 (2006).

    Article  ADS  Google Scholar 

  23. 23.

    Eleringer J. R. & Dawson T. Water uptake by plants: perspectives from stable isotope composition. Plant Cell Environ. 1073–1082 (1992).

  24. 24.

    Dawson, T. E., Mambelli, S., Plamboeck, A. H., Templer, P. H. & Tu, K. P. Stable isotopes in plant ecology. Annu. Rev. Ecol. Syst. 33, 507–559 (2002).

    Article  Google Scholar 

  25. 25.

    Rothfuss, Y. & Javaux, M. Reviews and syntheses: isotopic approaches to quantify root water uptake: a review and comparison of methods. Biogeosciences 14, 2199–2224 (2017).

    CAS  Article  ADS  Google Scholar 

  26. 26.

    Orlowski, N. et al. Inter-laboratory comparison of cryogenic water extraction systems for stable isotope analysis of soil water. Hydrol. Earth Syst. Sci. 22, 3619–3637 (2018).

    CAS  Article  ADS  Google Scholar 

  27. 27.

    Chen, Y. et al. Stem water cryogenic extraction biases estimation in deuterium isotope composition of plant source water. Proc. Natl Acad. Sci. USA 117, 33345–33350 (2021).

    Article  ADS  Google Scholar 

  28. 28.

    Pastorello, G., Trotta, C., Canfora, E. & Al., E. The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data. Sci. Data 7, 225 (2020).

    Article  Google Scholar 

  29. 29.

    Zhao, Y. & Wang, L. Plant water use strategy in response to spatial and temporal variation in precipitation patterns in China: a stable isotope analysis. Forests 9, 1–21 (2018).

    Google Scholar 

  30. 30.

    Miguez-Macho, G. & Fan, Y. The role of groundwater in the Amazon water cycle: 2. Influence on seasonal soil moisture and evapotranspiration. J. Geophys. Res. Atmos. 117, (2012).

  31. 31.

    Poulter, B. et al. Contribution of semi-arid ecosystems to interannual variability of the global carbon cycle. Nature 509, 600–603 (2014).

    CAS  Article  ADS  Google Scholar 

  32. 32.

    Ahlstrom, A. et al. The dominant role of semi-arid ecosystems in the trend and variability of the land CO2 sink. Science 348, 895–899 (2015).

    Article  ADS  Google Scholar 

Download references


This work was supported by grants from the European Commission Seventh Framework Programme (EartH2Observe 603608) to G.M.-M. and grants from the US National Science Foundation (NSF-EAR-825813 and AGS-1852707) to Y.F. All computation was performed at CESGA (Centro de Supercomputación de Galicia) Supercomputer Center at the Universidade de Santiago de Compostela in Galicia, Spain. We thank FLUXNET and the GRDC and their contributors worldwide for providing ET and river flow observations for model validations.

Author information




G.M.-M. performed model simulations and analyses. Y.F. compiled and analysed isotope estimates. Y.F. and G.M.-M. wrote the manuscript.

Corresponding authors

Correspondence to Gonzalo Miguez-Macho or Ying Fan.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature thanks Adrià Barbeta, Timothy Brodribb, Youri Rothfuss, Ruud Van der Ent and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 Isotope-based estimates of fractional contribution to plant xylem water.

(a) Source-2 and (b) Source-3+4 (undistinguished isotopically) during dry periods (best sampled). Where species are sampled at the same location (dots overlapping), the highest is displayed on the top.

Extended Data Table 1 Modelled fractional contribution from the four water sources to monthly transpiration as global and hemispheric average
Extended Data Table 2 Modelled fractional contribution of four water sources to monthly transpiration for the 12 climatic types represented in the model, ranked by annual plant uptake of total past precipitation (Source-2+3+4, bold font)
Extended Data Table 3 Modelled plant water source by drainage positions, for low, seasonal and perennial water stress groups
Extended Data Table 4 Isotope-based estimate of vegetation use of past precipitation (past P) (as % xylem water) averaged over each climatic water stress class, with propagated error in parentheses
Extended Data Table 5 Isotope-based estimates of dry period vegetation use of past precipitation along drainage gradient, with propagated error in parentheses
Extended Data Table 6 Isotope-based estimates of dry season vegetation use of past precipitation for eight growth forms with >10 observations, with propagated error term in parentheses; they are loosely ranked by the total plant use of past precipitation (orange)
Extended Data Table 7 Isotope-based estimates of dry season vegetation use of past precipitation for the 10 best sampled genera

Supplementary information

Supplementary Information

This file contains Supplementary Information Sections 1–4, including Supplementary Figs. 1–11, Supplementary Tables 1–4 and Supplementary References. See contents page for full details.

Reporting Summary

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Miguez-Macho, G., Fan, Y. Spatiotemporal origin of soil water taken up by vegetation. Nature 598, 624–628 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing