Michael E. Day

Associate Research Professor of Physiology and Ecophysiology
122 Nutting Hall

Degree: Ph.D. University of Maine 2000School of Forest Resources

Research Interests and Current Projects: In overview, my research interests are broad and include ontogenetic regulation, environmental regulation of physiological processes, climate change and paleoecology. I see these as very exciting times in plant physiology. As a discipline, we now have the tools and knowledge base to begin linking ecophysiological processes from the molecular-genomic level, through organismal levels, to the ecosystem and biome levels. This integration also permits researchers to advance beyond the concept of plants as collections of mechanistic processes, to understanding plant ecophysiology in its proper complexity.

Ontogeny of woody plants is among my long-term research interests. For the past two decades, I have investigated life-stage development using red spruce as a model species. This has included the longest running reciprocal grafting experiments that have provided insight into the complex interactions of age, size and environment. I am currently investigating the interaction between plant growth regulators (phytohormones) and plant size on physiology, anatomy and branching structure.

Environmental influences on plants overlaps with my other ecophysiological and paleoecological interests and includes diverse studies on water, temperature, atmospheric humidity, and light effects with a focus on organismal integration and influence on plant growth and development.

Functional ecology of unique maritime ecosystems is an interdisciplinary effort to understand how physiological ecology and ecosystem processes are related to oceanic proximity using the unique natural system produced by abruptly changing thermal gradients along the coast of the Gulf of Maine.

Selected Publications:

Day, M.E., and M.S. Greenwood. 2011. Regulation of ontogeny in temperate conifers. Pp. 91-120 In F.C. Meinzer, T. Dawson and B. Lachenbruch, eds. Size- and age-related changes in tree structure and function. Volume in Springer Tree Physiology Series, Springer-Verlag, NY

Greenwood, M.S., M.E. Day and J. Schatz. 2010. Separating the effects of tree size and meristem maturation on shoot development of grafted scions of red spruce (Picea rubens Sarg). Tree Physiology 30:459-468.

Bethers, S., M. E. Day, G. B. Wiersma, I. J. Fernandez and A. Elvir. 2009. Effects of chronically, elevated nitrogen and sulfur deposition at BBWM on sugar maple saplings: nutrition, growth, and photosynthetic physiology. Forest Ecology and Management 258:895-902.

Day, M., I. Fernandez, G. Jacobson and R. Jagels. 2009. Forests composition. Pp. 26-29 In J.L. Jacobson, I.V. Fernandez, P.A. Mayewski and C.V. Schmitt, eds. Maine’s climate future: an initial assessment. University of Maine, Orono, Maine.

Greenwood, M.S., M.E. Day and G.P. Berlyn. 2009. Regulation of foliar plasticity in conifers: developmental and environmental factors. Journal of Sustainable Forestry 28: 48-62.

Greenwood, M.S., M.H. Ward, M.E. Day, S.A. Adams, and B.J. Bond. 2007. Age-related trends in red spruce foliar plasticity in relation to declining productivity. Tree Physiology 28:255-232.

Bond, B.J., N. Czarnomski, C. Cooper, M.E. Day and M. S. Greenwood. 2006. Developmental decline in height growth in Douglas-fir. Tree Physiology 27:441-453.

Day, M.E., J.L. Schedlbauer, W.H. Livingston, M.S. Greenwood, A.S. White, and J.C. Brissette. 2005. Influence of seedbed light environment, and elevated night temperature on growth and carbon allocation in pitch pine (Pinus rigida) and jack pine (Pinus banksiana) seedlings. Forest Ecology and Management 205:59-71.

Elvir, J.A., G.B. Wiersma, M.E. Day, M.S. Greenwood, and I.J. Fernandez. 2006. Effects of enhanced nitrogen deposition on foliar chemistry and physiological processes of forest trees at the Bear Brook Watershed in Maine. Forest Ecology and Management 221:207-214.

Equiza, M.A., M.E. Day, R. Jagels and Xiaochun Li. 2006. Photosynthetic down-regulation in the conifer Metasequoia glyptostroboides growing under continuous light: the significance of carbohydrate sinks and paleo-ecophysiological implications. Canadian Journal of Botany 84: 1453-1461.

Equiza, M.A., M.E. Day, and R. Jagels. 2006. Physiological responses of three deciduous conifers (Metasequoia glyptostroboides, Taxodium distichum, and Larix laricina) to a continuous-light environment: adaptive implications for the early-Tertiary polar summer. Tree Physiology 26: 353-364.

Jagels,R. and M.E. Day. 2004. The adaptive physiology of Metasequoia to Eocene high-latitude environments. In Hemsley, A.and I. Poole. (eds.) The evolution of plant physiology p.405-429. Elsevier, Oxford.

Day M.E., M.S. Greenwood, C. Diaz-Sala. 2002. Age- and size-related trends in woody plant shoot development: regulatory pathways and evidence for genetic control. Tree Physiology 22:507-513.

Fraver, S., R.G. Wagner, and M.E. Day. 2002. Dynamics of down woody debris following gap harvesting in the Acadian forest of central Maine, U.S.A.. Canadian Journal of Forest Research 32:2094 2105.

Greenwood, M.S., W.H. Livingston, M.E. Day, A.S. White, and J.C. Brissette. 2002. Contrasting modes of survival by jack and pitch pine at a common range limit. Canadian Journal of Forest Research 32:1662-1674

Day, M.E. 2000. Influence of temperature and leaf-to-air vapor pressure deficit on net photosynthesis and stomatal conductance in red spruce (Picea rubens). Tree Physiology 20:47-53.