Department of Geography and
Graduate Program in Ecology, Evolution & Behavior
Changes in temperature and precipitation extremes are enhancing severe droughts, mortaility of forests, and increasing pressure on water resources for growing food. We seek mechanistic understanding of these dynamics by looking through the lens of plant hydraulics, which describes water flow from the soil to the atmosphere through plant xylem, and is a control over for nutrient, carbon, and energy exchanges. In addition, we are using genomics to refine our mechanistic understanding of plant responses to environmental change. We combine empiricism, mathematical models, and data analytics. One product of our research is the Terrestrial Regional Ecosystem Exchange Simulator (TREES, see Mackay et al 2015 Water Resources Research), a biophysical model of plant hydraulics, carbon and nitrogen dynamics, and hydrology.
Representative products: Integrated hydrology and plant traits
Millar, D., B.E. Ewers, D.S. Mackay, S.D. Peckham, D. Reed, and A. Sekoni. 2017. Improving ecosystem-scale modeling of evapotranspiration using ecological mechanisms that account for compensatory responses following disturbance. Water Resources Research, 53, 7853-7868, doi:10.1002/2017WR020823.
Tai, X.., D.S. Mackay, W.R.L. Anderegg, J.S. Sperry, and P.D. Brooks. 2017. Plant hydraulics improves and topography mediates prediction of aspen mortality in southwestern U.S. New Phytologist, 213(1), 113-127. DOI: 10.111/nph.14098.
Mackay, D.S., D.E. Roberts, B.E. Ewers, J.S. Sperry, N.G. McDowell, and W.T. Pockman. 2015. Interdependence of chronic hydraulic dysfunction and canopy processes can improve integrated models of tree response to drought. Water Resources Research, 51(8), 6156-6176, doi:10.1002/2015WR017244.
McDowell, N.G., R.A. Fisher, C. Xu, J.C. Domec, T. Holtta, D.S. Mackay, J.S. Sperry, A. Boutz, L. Dickman, N. Gehres, J.M. Limousin, A. Macalady, J. Martinez-Vilalta, M. Mencuccini, J.A. Plaut, J. Ogee, R.E. Pangle, D.P. Rasse, M.G. Ryan, S. Sevanto, R.H. Waring, A.P. Williams, E.A. Yepez, and W.T. Pockman. 2013. Tansley Review: Evaluating theories of drought-induced vegetation mortality using a multi-model-experiment framework. New Phytologist, 200, 304-321.
D.S., B.E. Ewers, B.D. Cook, and K.J. Davis. 2007.
drivers of evapotranspiration in a shrub wetland and an upland
forest in northern Wisconsin, Water Resources Research,
43, W03442, doi:10.1029/2006WR005149.
Representative products: Canopy structure and function
Savoy, P. and D.S. Mackay. 2015. Modeling the seasonal dynamics of leaf area index based on environmental constraints to canopy development. Agricultural and Forest Meteorology, 200, 46-56.
Mackay, D.S., B.E. Ewers, M.M. Loranty, E.L. Kruger, and S. Samanta. 2012. Bayesian analysis of canopy transpiration models: A test of posterior parameter means against measurements. Journal of Hydrology, 432-433, 75-83, doi: 10.1016/j.hydrol.2012.02.019.
Mackay, D.S., B.E. Ewers, M.M. Loranty, and E.L. Kruger. 2010. On the representativeness of plot size and location for scaling transpiration from trees to a stand. Journal of Geophysical Research - Biogeosciences, 115, G02016, doi:1029/2009JG001092.
Loranty, M.M., D.S. Mackay, B.E. Ewers, E. Traver, and E.L. Kruger, 2010. Competition for light between individual trees lowers reference canopy stomatal conductance: results from a model. Journal of Geophysical Research - Biogeosciences, 115, G04019, doi:10.1029/2010JG001377.
Mackay, D.S., D.E. Ahl, B.E. Ewers, S.T.
Gower, S.N. Burrows, S. Samanta, and K.J. Davis. 2002. Effects
of forest composition on estimates of evapotranspiration in a
northern Wisconsin forest. Global Change Biology,
Current research projects:
> Integrating plant hydraulics with climate and hydrology to understand and predict responses to climate change
> A systems analysis of plant growth promotion by the rhizosphere microbiome
(see Project web site)
> Predicting genotypic variation in growth and yield under abiotic stress through biophysical process modeling
> Improving hydrologic representation in earth systems modeling
(see Hydrologic Process Team)
Relevant education and research:
Graduate Program in Evolution, Ecology, & Behavior
Center for Geographic Information and Analysis (NCGIA)
Ecosystem Restoration through Interdisciplinary Exchange (ERIE)
Consortium of Universities for the Advancement of Hydrologic Science (CUAHSI)
Ecosystem-Atmosphere Study (ChEAS)
Susquehanna Shale Hills Critical Zone Observatory (SSHCZO)
American Carbon Program (NACP)
Web of Science ID
Google Scholar Profile