Multi-scale predictions of massive conifer mortality due to chronic temperature rise

  • An Addendum to this article was published on 26 October 2016


Global temperature rise and extremes accompanying drought threaten forests1,2 and their associated climatic feedbacks3,4. Our ability to accurately simulate drought-induced forest impacts remains highly uncertain5,6 in part owing to our failure to integrate physiological measurements, regional-scale models, and dynamic global vegetation models (DGVMs). Here we show consistent predictions of widespread mortality of needleleaf evergreen trees (NET) within Southwest USA by 2100 using state-of-the-art models evaluated against empirical data sets. Experimentally, dominant Southwest USA NET species died when they fell below predawn water potential (Ψpd) thresholds (April–August mean) beyond which photosynthesis, hydraulic and stomatal conductance, and carbohydrate availability approached zero. The evaluated regional models accurately predicted NET Ψpd, and 91% of predictions (10 out of 11) exceeded mortality thresholds within the twenty-first century due to temperature rise. The independent DGVMs predicted ≥50% loss of Northern Hemisphere NET by 2100, consistent with the NET findings for Southwest USA. Notably, the global models underestimated future mortality within Southwest USA, highlighting that predictions of future mortality within global models may be underestimates. Taken together, the validated regional predictions and the global simulations predict widespread conifer loss in coming decades under projected global warming.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Observations and theoretical drivers of increasing conifer mortality.
Figure 2: Predawn Ψ measurements are strongly correlated with the mechanisms of mortality6.
Figure 3: Predictions of climate and forest mortality for Southwestern USA to AD 2100.
Figure 4: Dynamic global vegetation models predictions of NET percentage losses between 2000 and 2100.

Change history

  • 07 October 2016

    This Letter has an addendum associated with it, for details see pdf.


  1. 1

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

    Article  Google Scholar 

  2. 2

    Peng, S. et al. A drought-induced pervasive increase in tree mortality across Canada’s boreal forest. Nature Clim. Change 1, 467–471 (2011).

    Article  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  Google Scholar 

  4. 4

    Maness, H., Kushner, P. J. & Fung, I. Summertime climate response to mountain pine beetle disturbance in British Columbia. Nature Geosci. 6, 65–70 (2012).

    Article  Google Scholar 

  5. 5

    Friedlingstein, P. et al. Uncertainties in CMIP5 climate projections due to carbon cycle feedbacks. J. Clim. 27, 511–526 (2014).

    Article  Google Scholar 

  6. 6

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

    Article  Google Scholar 

  7. 7

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

    CAS  Article  Google Scholar 

  8. 8

    Phillips, O. L. et al. Drought sensitivity of the Amazon rainforest. Science 323, 1344–1347 (2009).

    CAS  Article  Google Scholar 

  9. 9

    Reichstein, M. et al. Climate extremes and the carbon cycle. Nature 500, 287–295 (2013).

    CAS  Article  Google Scholar 

  10. 10

    Kurz, W. A. et al. Mountain pine beetle and forest carbon feedback to climate change. Nature 452, 987–990 (2008).

    CAS  Article  Google Scholar 

  11. 11

    Plaut, J. et al. Hydraulic limits preceding mortality in a piñon-juniper woodland under experimental drought. Plant Cell Environ. 35, 1601–1617 (2012).

    Article  Google Scholar 

  12. 12

    Cowan, I. R. & Givnish, T. J. On the Economy of Plant Form and Function 133–170 (Cambridge Univ. Press, 1986).

    Google Scholar 

  13. 13

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

    CAS  Article  Google Scholar 

  14. 14

    Mitchell, P. J. et al. Drought response strategies define the relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality. New Phytol. 197, 862–872 (2013).

    CAS  Article  Google Scholar 

  15. 15

    Poyatos, R. et al. Drought induced defoliation and long periods of near zero gas exchange play a key role in accentuating metabolic decline of Scots pine. New Phytol. 200, 388–401 (2013).

    CAS  Article  Google Scholar 

  16. 16

    Sevanto, S. et al. How do trees die? A test of the hydraulic failure and carbon starvation hypotheses. Plant Cell Environ. 37, 153–161 (2013).

    Article  Google Scholar 

  17. 17

    McDowell, N. & Allen, C. Darcy’s law predicts widespread forest loss due to climate warming. Nature Clim. Change 5, 669–672 (2015).

    Article  Google Scholar 

  18. 18

    Martínez-Vilalta, J. et al. A new look at water transport regulation in plants. New Phytol. 204, 105–115 (2014).

    Article  Google Scholar 

  19. 19

    Whitehead, D. & Jarvis, P. G. in Water Deficits and Growth Vol. 6 (ed. Kozlowski, T. T.) 49–152 (Academic, 1981).

    Google Scholar 

  20. 20

    Williams, A. P. 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 

  21. 21

    Gaylord, M. L. et al. Drought predisposes piñon-juniper woodlands. New Phytol. 198, 567–568 (2012).

    Article  Google Scholar 

  22. 22

    McDowell, N. G. et al. Mechanisms of plant survival and mortality during drought: Why do some plants survive while others succumb? New Phytol. 178, 719–739 (2008).

    Article  Google Scholar 

  23. 23

    Breshears, D. D. et al. Tree die-off in response to global-change-type drought: Mortality insights from a decade of plant water potential measurements. Front. Ecol. Environ. 7, 185–189 (2009).

    Article  Google Scholar 

  24. 24

    Jiang, X. et al. Projected future changes in vegetation in western North America in the 21st century. J. Clim. 26, 3671–3687 (2013).

    Article  Google Scholar 

  25. 25

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

    CAS  Article  Google Scholar 

  26. 26

    Gerald, A. et al. The WCRP CMIP3 multimodel dataset: A new era in climate change research. Bull. Am. Meteorol. Soc. 88, 1383–1394 (2007).

    Article  Google Scholar 

  27. 27

    Rauscher, S. A., Kucharski, F. & Enfield, D. B. The role of regional SST warming variations in the drying of meso-America in future climate projections. J. Clim. 24, 2003–2016 (2011).

    Article  Google Scholar 

  28. 28

    Allen, C. D., Breshears, D. D. & McDowell, N. G. On underestimation of global vulnerability to tree mortality and forest die-off from hotter drought in the Anthropocene. Ecosphere 6, 129 (2015).

    Article  Google Scholar 

  29. 29

    Carnicer, J. et al. Widespread crown condition decline, food web disruption, and amplified tree mortality with increased climate change-type drought. Proc. Natl Acad. Sci. USA 108, 1474–1478 (2011).

    CAS  Article  Google Scholar 

  30. 30

    Koven, C. D. Boreal carbon loss due to poleward shift in low-carbon ecosystems. Nature Geosci. 6, 452–456 (2013).

    CAS  Article  Google Scholar 

  31. 31

    Settele, J. et al. in Climate Change 2014: Impacts, Adaptation, and Vulnerability (eds Field, C. B. et al.) 271–359 (IPCC, Cambridge Univ. Press, 2014).

    Google Scholar 

Download references


This work was financially supported by the Department of Energy, Office of Science, by Los Alamos National Lab’s Lab Directed Research and Development programme, by NSF-EAR-0724958 and NSF-EF-1340624, and also by ANR-13-AGRO-MACACC, and NSF-IOS-1549959, by the Department of Agriculture AFRI-NIFA programme, by the U.S.G.S. Climate and Land Use Program, and by a National Science Foundation grant to the University of New Mexico for Long Term Ecological Research.

Author information




N.G.M. and W.T.P. designed the experiment. A.P.W., C.X., D.S.M., J.O., J.C.D., R.A.F., X.J., J.D.M., S.A.R. and C.K. performed model simulations. N.G.M. performed measurements. L.T.D., S.S., R.P., J.L., J.P. and N.G.M. collected measurements. All authors contributed to the writing of the paper.

Corresponding author

Correspondence to N. G. McDowell.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

McDowell, N., Williams, A., Xu, C. et al. Multi-scale predictions of massive conifer mortality due to chronic temperature rise. Nature Clim Change 6, 295–300 (2016).

Download citation

Further reading