Department of Environment and
About our research
is the study of how traits of living
things both affect and are affected
by the availability and quality of
water. Our research focuses on
understanding these traits by
studying mechanisms of vegetative
stress responses to environmental
dynamics, such as drought, elevated
temperature, and nutrient
limitation. A key activity of our
research involves the development of
novel biophysical models that
assimilate physical and
physiological observations to
identify emergent traits of plants
that are difficult to quantify
Our work is predominantly
on forests and crops. We are
specifically combining canopy
physiology with soil-plant
hydraulics to understand the
mechanisms of drought- and
biotic-related mortality of trees.
By integrating these mechanisms with
hydrologic processes we can better
understand why some trees survive
drought and biotic attack by tapping
into sources of water subsidy. For
crops we are acquiring predictive
understanding of productivity rates
in response to novel drought, heat,
and nutrient stresses. This work is
facilitated by new modeling
frameworks that combine biophysical
modeling, genomics, and hierarchical
Our research addresses many
important issues facing society,
including severe and prolonged
droughts that promote widespread
forest mortality, increase pressure
on water resources, and stress food
AGU Editor's Vox:
What's in a name?
products: Drought-related tree
Tai, X., D.S. Mackay, J.S. Sperry, P.
Brooks, W.R.L. Anderegg, L.B.
Flanagan, S.B. Rood, and C. Hopkinson.
2018. Distributed plant hydraulic and
hydrological modeling to understand
the susceptibility of riparian
woodland trees to drought-induced
mortality. Water Resources
J.-C. Domec, Z.C. Berry, A.M.
Schwantes, D.R. Woodruff, K.A.
McCulloh, H.W. Polley, R. Wortemann,
J.J. Swenson, D.S. Mackay, N.G.
McDowell, and R.B. Jackson. 2018.
Co-occurring woody species have
diverse hydraulic strategies and
mortality rates during an extreme
drought. Plant, Cell and
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:
McDowell, N.G., A.P. Williams, C. Xu,
W.T. Pockman, L.T. Dickman, S.
Sevanto, R. Rangle, J. Limousin, J.
Plaut, D.S. Mackay, J. Ogee, J.C.
Domec, C.D. Allen, R.A. Fisher, X.
Jiang, J.D. Muss, D.D. Breshears, S.A.
Rauscher, and C. Koven. 2016.
Multi-scale predictions of massive
conifer mortaility due to chronic
temperature rise. Nature Climate
Change, 6, 295-300,
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,
products: Ecophysiological function
Mackay, D.S., P.R. Savoy, C.
Grossiord, X. Tai, J.R. Pleban, D.R.
Wang, N.G. McDowell, H.D. Adams, and
J.S. Sperry. In Press. Conifers depend
on established roots during drought:
results from a coupled model of carbon
allocation and hydraulics. New
Wang, D.R., C.R. Guadagno, X. Mao,
D.S. Mackay, J.R. Pleban, R.L. Baker,
C. Weinig, J.-L. Jannink, and B.E.
Ewers. 2019. A framework for
modeling in plants. Journal of
70(9), 2561-2574, doi:
Pleban, J.R., D.S. Mackay, B.E. Ewers,
T.L. Aston, and C. Weinig.2018.
Phenotypic trait identification using
a multimodel Bayesian method: a case
study using photosynthesis in Brassica
rapa genotypes. Frontiers in
Plant Science, 8, 448, doi:
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,
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:
> Integrating plant hydraulics with
climate and hydrology to understand
and predict responses to climate
> A systems analysis of plant
growth promotion by the rhizosphere
(see Project web site)
> Predicting genotypic variation in
growth and yield under abiotic stress
through biophysical process modeling
> Improving hydrologic
representation in earth systems
(see Hydrologic Process
education and research:
of Environment and
in Evolution, Ecology, &
National Center for Geographic
Information and Analysis (NCGIA)
Interdisciplinary Exchange (ERIE)
Universities for the Advancement
of Hydrologic Science (CUAHSI)
Hills Critical Zone Observatory
Carbon Program (NACP)