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Tree mortality predicted from drought-induced vascular damage


The projected responses of forest ecosystems to warming and drying associated with twenty-first-century climate change vary widely from resiliency to widespread tree mortality1,2,3. Current vegetation models lack the ability to account for mortality of overstorey trees during extreme drought owing to uncertainties in mechanisms and thresholds causing mortality4,5. Here we assess the causes of tree mortality, using field measurements of branch hydraulic conductivity during ongoing mortality in Populus tremuloides in the southwestern United States and a detailed plant hydraulics model. We identify a lethal plant water stress threshold that corresponds with a loss of vascular transport capacity from air entry into the xylem. We then use this hydraulic-based threshold to simulate forest dieback during historical drought, and compare predictions against three independent mortality data sets. The hydraulic threshold predicted with 75% accuracy regional patterns of tree mortality as found in field plots and mortality maps derived from Landsat imagery. In a high-emissions scenario, climate models project that drought stress will exceed the observed mortality threshold in the southwestern United States by the 2050s. Our approach provides a powerful and tractable way of incorporating tree mortality into vegetation models to resolve uncertainty over the fate of forest ecosystems in a changing climate.

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Figure 1: Hydrologic model simulations.
Figure 2: Plant hydraulic threshold in relation to water deficit.
Figure 3: Hindcast maps of forest mortality.
Figure 4: Future trajectories of drought stress.


  1. Cox, P. M. et al. Amazonian forest dieback under climate-carbon cycle projections for the 21st century. Theor. Appl. Clim. 78, 137–156 (2004).

    Article  Google Scholar 

  2. Scholze, M., Knorr, W., Arnell, N. W. & Prentice, I. C. A climate-change risk analysis for world ecosystems. Proc. Natl Acad. Sci. USA 103, 13116–13120 (2006).

    Article  Google Scholar 

  3. Huntingford, C. et al. Simulated resilience of tropical rainforests to CO2-induced climate change. Nature Geosci. 6, 268–273 (2013).

    Article  Google Scholar 

  4. McDowell, N. G. et al. The interdependence of mechanisms underlying climate-driven vegetation mortality. Trends Ecol. Evol. 26, 523–532 (2011).

    Article  Google Scholar 

  5. Powell, T. L. et al. Confronting model predictions of carbon fluxes with measurements of Amazon forests subjected to experimental drought. New Phytol. 200, 350–365 (2013).

    Article  Google Scholar 

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

    Article  Google Scholar 

  7. Keenan, T. F. et al. Increase in forest water-use efficiency as atmospheric carbon dioxide concentrations rise. Nature 499, 324–327 (2013).

    Article  Google Scholar 

  8. Allen, C. D. et al. A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests. Forest Ecol. Manage. 259, 660–684 (2010).

    Article  Google Scholar 

  9. Stocker, T. F. et al. (eds) Climate Change 2013: The Physical Science Basis (IPCC, Cambridge Univ. Press, 2013).

  10. Ponce-Campos, G. E. et al. Ecosystem resilience despite large-scale altered hydroclimatic conditions. Nature 494, 349–352 (2013).

    Article  Google Scholar 

  11. Zhao, M. & Running, S. W. Drought-induced reduction in global terrestrial net primary production from 2000 through 2009. Science 329, 940–943 (2010).

    Article  Google Scholar 

  12. Ma, Z. et al. Regional drought-induced reduction in the biomass carbon sink of Canada’s boreal forests. Proc. Natl Acad. Sci. USA 109, 2423–2427 (2012).

    Article  Google Scholar 

  13. Phillips, O. L. et al. Drought-mortality relationships for tropical forests. New Phytol. 187, 631–646 (2010).

    Article  Google Scholar 

  14. van Mantgem, P. J. et al. Widespread increase of tree mortality rates in the Western United States. Science 323, 521–524 (2009).

    Article  Google Scholar 

  15. Friend, A. D. et al. Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO2 . Proc. Natl Acad. Sci. USA 11, 3280–3285 (2014).

    Article  Google Scholar 

  16. Anderegg, W. R. L., Berry, J. A. & Field, C. B. Linking definitions, mechanisms, and modeling of drought-induced tree death. Trends Plant Sci. 17, 693–700 (2012).

    Article  Google Scholar 

  17. Sala, A., Piper, F. & Hoch, G. Physiological mechanisms of drought-induced tree mortality are far from being resolved. New Phytol. 186, 274–281 (2010).

    Article  Google Scholar 

  18. Hoffmann, W. A., Marchin, R. M., Abit, P. & Lau, O. L. Hydraulic failure and tree dieback are associated with high wood density in a temperate forest under extreme drought. Glob. Change Biol. 17, 2731–2742 (2011).

    Article  Google Scholar 

  19. Urli, M. et al. Xylem embolism threshold for catastrophic hydraulic failure in angiosperm trees. Tree Phys. 33, 672–683 (2013).

    Article  Google Scholar 

  20. Anderegg, W. R. L. et al. Drought’s legacy: multiyear hydraulic deterioration underlies widespread aspen forest die-off and portends increased future risk. Glob. Change Biol. 19, 1188–1196 (2013).

    Article  Google Scholar 

  21. Sperry, J. S., Adler, F. R., Campbell, G. S. & Comstock, J. P. Limitation of plant water use by rhizosphere and xylem conductance: Results from a model. Plant Cell Environ. 21, 347–359 (1998).

    Article  Google Scholar 

  22. Flint, L. E., Flint, A. L., Thorne, J. H. & Boynton, R. Fine-scale hydrologic modeling for regional landscape applications: The California Basin Characterization Model development and performance. Ecol. Process. 2, 1–21 (2013).

    Article  Google Scholar 

  23. Rehfeldt, G. E., Ferguson, D. E. & Crookston, N. L. Aspen, climate, and sudden decline in western USA. Forest Ecol. Manage. 258, 2353–2364 (2009).

    Article  Google Scholar 

  24. Stephenson, N. Actual evapotranspiration and deficit: Biologically meaningful correlates of vegetation distribution across spatial scales. J. Biogeogr. 25, 855–870 (1998).

    Article  Google Scholar 

  25. Muggeo, V. M. Estimating regression models with unknown break-points. Stat. Med. 22, 3055–3071 (2003).

    Article  Google Scholar 

  26. McDowell, N. G. et al. Evaluating theories of drought-induced vegetation mortality using a multimodel—experiment framework. New Phytol. 200, 304–321 (2013).

    Article  Google Scholar 

  27. Park Williams, A. et al. Temperature as a potent driver of regional forest drought stress and tree mortality. Nature Clim. Change 3, 292–297 (2013).

    Article  Google Scholar 

  28. Choat, B. et al. Global convergence in the vulnerability of forests to drought. Nature 491, 752–755 (2012).

    Article  Google Scholar 

  29. Sperry, J. S., Donnelly, J. R. & Tyree, M. T. A method for measuring hydraulic conductivity and embolism in xylem. Plant Cell Environ. 11, 35–40 (1988).

    Article  Google Scholar 

  30. Huang, C-Y. & Anderegg, W. R. L. Large drought-induced aboveground live biomass losses in southern Rocky Mountain aspen forests. Glob. Change Biol. 18, 1016–1027 (2012).

    Article  Google Scholar 

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W.R.L.A. thanks the NSF DDIG grant for research funding and equipment. W.R.L.A. was supported in part by the NOAA Climate and Global Change Postdoctoral Fellowship program and an award from the Department of Energy (DOE) Office of Science Graduate Fellowship Program (DOE SCGF). C-y.H. was sponsored by the Ministry of Science and Technology of Taiwan and National Taiwan University. F.W.D. was supported in part by the National Science Foundation Macrosystems Biology Program, NSF no. EF-1065864. J.A.B. and C.B.F. were supported by the Carnegie Institution for Science. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modelling groups (listed in Methods of this paper) for producing and making available their model output. For CMIP the US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals.

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W.R.L.A., J.A.B. and C.B.F. conceived the experiment. W.R.L.A. collected the data and W.R.L.A. and A.F. ran the models. C-y.H., L.F., F.W.D. and J.S.S. contributed new analytic tools. W.R.L.A. wrote the paper with all authors adding revisions.

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Correspondence to William R. L. Anderegg.

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Anderegg, W., Flint, A., Huang, Cy. et al. Tree mortality predicted from drought-induced vascular damage. Nature Geosci 8, 367–371 (2015).

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