Current Research

I’m currently exploring the responses of multiple species and multiple genotypes within species to their environment. Responses I’m evaluating include: phenology (timing of budburst and growth), as well as germination, flowering and plant growth. I develop models that can be used to predict plant responses to current or future climates. I also study the responses of many species to silvicultural practices, such as variable density thinning or species mixtures, or to factors such as bole or root damage, which may affect tree survival and growth.

Research Interests

• How do plants respond to their environment?
• What are the physiological triggers involved in starting or stopping plant growth?
• How can we use that information to make better management decisions?

Past Research

I have developed models to predict the timing of budburst and tree growth during the year, as well as biology and management of Douglas-fir (valued for wood production), Oregon white oak (threatened system), alder and poplar (biomass production), and other tree species including cedars, pines, hemlock, and true firs. I have also looked at the effects of overstory stand conditions on tree growth and understory responses and the effects of a wide range of harvesting practices on short- and long-term site productivity.

Why This Research is Important

My research provides information to managers about species (and genotype) responses to environment and silvicultural practices through scientific publications describing the results from studies, general publications, and models to predict tree or stand responses. These models are important because it is not possible to collect information on the possible treatments or conditions that might occur on specific sites; thus, responses are modeled or predicted. The information I developed on Oregon white oak communities and packaged for small private landowners is important because most of the white oak is on private land, and there is a narrow biological time window to implement the treatments required for restoring these systems. Information I develop on plant responses to their environment should assist managers in making decisions on selecting species and genotypes for planting and in managing for specific objectives

Education

• University of Washington, Ph.D. Tree Physiology and Soils 1983
• SUNY College of Environmental Science and Forestry, M.S. Silviculture 1975
• SUNY College of Environmental Science and Forestry, B.A. Forest Botany 1973

Featured Publications & Products

• Harrington, Constance A.; St. Clair, Brad. 2017. The Douglas-fir seed-source movement trial yields early results.
• Ford, Kevin R.; Harrington, Constance A.; St. Clair, J. Bradley. 2017. Photoperiod cues and patterns of genetic variation limit phenological responses to climate change in warm parts of species range: Modeling diameter-growth cessation in coast Douglas-fir.
• Ford, Kevin ; Harrington, Connie; Bansal, Sheel; Gould, Peter J.; St. Clair, Brad. 2016. Will changes in phenology track climate change A study of growth initiation timing in coast Douglas-fir.
• Harrington, Connie; Ford, Kevin ; St. Clair, Brad. 2016. Phenology of Pacific Northwest tree species.
• Harrington, Connie; Gould, Peter J.; St. Clair, Brad. 2010. Modeling the effects of winter environment on dormancy release of Douglas-fir.
• Comfort, Emily J.; Roberts, Scott D.; Harrington, Constance A. 2010. Midcanopy growth following thinning in young-growth conifer forests on the Olympic Peninsula, western Washington.
• Devine, Warren D.; Harrington, Constance A.; DeBell, Dean S. 2010. Intra-annual growth and mortality of four Populus clones in pure and mixed plantings.
• Ares, Adrian; Harrington, Constance A; Terry, Thomas A.; Kraft, Joseph M. 2009. Vegetation control effects on untreated wood, crude cellulose and holocellulose 𗉝C of early and latewood in 3- to 5-year-old rings of Douglas-fir.
• Harrington, Constance A.; Devine, Warren D. 2011. Stand development following precommercial thinning and fertilization treatments in a western redcedar (Thuja plicata) dominated forest.
• Devine, Warren D.; Harrington, Constance A. 2010. Planting native oak in the Pacific Northwest.

Publications

• Strunk, Jacob L.; Harrington, Constance A.; Brodie, Leslie C.; Prevéy, Janet S. 2020. Seeing the forest below the trees: occurrences of shrubs in the Pacific Northwest.
• McDaniel, Josh ; Prevey, Janet S.; Harrington, Connie ; St. Clair, Brad . 2019. Nature and Nurture: Genetics and Climate Influence the Timing of Flowering in Trees.
• Mazza, Rhonda ; Harrington, Connie ; St. Clair, Brad ; Ford, Kevin . 2018. Done for the season: How do Douglas-fir know when to stop growing.
• Prevéy, Janet S.; Harrington, Constance A. 2018. Effectiveness of winter temperatures for satisfying chilling requirements for reproductive budburst of red alder (Alnus rubra).
• Jones, Dryw ; Harrington, Constance ; Marshall, David . 2018. Modeling wound-closure response over time in Douglas-fir trees.
• Jones, Dryw ; Harrington, Constance ; Marshall, David . 2018. Survival, and growth response of Douglas-fir trees to increasing levels of bole, root, and crown damage.
• Prevey, Janet S.; Harrington, Constance A.; St. Clair, J. Bradley. 2018. The timing of flowering in Douglas-fir is determined by cool-season temperatures and genetic variation.
• Willis, John L.; Roberts, Scott D.; Harrington, Constance A. 2018. Variable density thinning promotes variable structural responses 14 years after treatment in the Pacific Northwest.
• Harrington, Constance A.; Holub, Scott M.; Bauer, Cici; Steel, E. Ashley. 2017. The distribution of tree roots in Douglas-fir forests in the Pacific Northwest in relation to depth, space, coarse organic matter and mineral fragments..
• Wilhelmi, Nicholas P.; Shaw, David C.; Harrington, Constance A.; St. Clair, John Bradley; Ganio, Lisa M. 2017. Climate of seed source affects susceptibility of coastal Douglas-fir to foliage diseases.
• Curtis, Robert O.; Harrington, Constance A.; Brodie, Leslie C. 2017. Stand development 18 years after gap creation in a uniform Douglas-fir plantation.
• Curtis, Robert O.; Bansal, Sheel; Harrington, Constance A. 2016. Relation of initial spacing and relative stand density indices to stand characteristics in a Douglas-fir plantation spacing trial.
• Watts, Andrea; Harrington, Connie; Gould, Peter. 2016. Rise and shine: How do northwest trees know when winter is over.
• Bansal, Sheel; Harrington, Connie; St. Clair, Brad. 2016. Tolerance to multiple climate stressors: a case study of Douglas-fir drought and cold hardiness.
• Harrington, Constance A.; Carlson, William C. 2015. Morphology and accumulation of epicuticular wax on needles of Douglas-fir (Pseudotsuga menziesii var. menziesii).
• Watts, Andrea; Bansal, Sheel; Harrington, Connie; St. Clair, Brad. 2015. Predicting Douglas-fir's response to a warming climate.
• Burner, D. M.; Brauer, D. K.; Snider, J. L.; Harrington, C. A.; Moore, P. A. 2014. Phenological responses of juvenile pecan and white oak on an upland site.
• Devine, Warren D.; Footen, Paul W.; Harrison, Robert B.; Terry, Thomas A.; Harrington, Constance A.; Holub, Scott M.; Gould, Peter J. 2013. Estimating tree biomass, carbon, and nitrogen in two vegetation control treatments in an 11-year-old Douglas-fir plantation on a highly productive site.
• Gould, Peter J.; Harrington, Connie. 2013. Making the little things count: modeling the development of understory trees in complex stands.
• Devine, Warren D.; Harrington, Constance A. 2013. Restoration release of overtopped Oregon white oak increases 10-year growth and acorn production.
• Gould, Peter J.; Harrington, Constance A.; St. Clair, J. Bradley. 2012. Growth phenology of coast Douglas-fir seed sources planted in diverse environments.
• O'Callaghan, Joan; Brodie, Leslie; Harrington, Constance; Gould, Peter; Devine, Warren. 2012. Remember redcedar! An overlooked species reveals its potential.
• Devine, Warren D.; Harrington, Constance. 2011. Factors affecting diurnal stem contraction in young Douglas-fir.
• Gould, Peter J.; Harrington, Constance A.; Devine, Warren D. 2011. Growth of Oregon white oak (Quercus garryana).
• Devine, Warren D.; Harrington, Constance A.; Kraft, Joseph M. 2010. Acorn storage alternatives tested on Oregon white oak.
• Brodie, Leslie C.; Harrington, Constance A. 2010. Response of Western redcedar to release and fertilization in a mixed-species stand.
• Parks, Noreen; Harrington, Connie; St. Clair, Brad; Gould,  Peter. . 2010. The future of spring bud burst: looking at the possibilities.
• Harrington, Timothy B., Ph.D..; Harrington, Constance A.; DeBell, Dean S. 2009. Effects of planting spacing and site quality on 25-year growth and mortality relationships of Douglas-fir (Pseudotsuga menziesii var menziesii)..
• Harrington, Constance A.; Schuette, William. 2009. Evaluating sites for planting hardwoods in the Pacific Northwest.
• Southworth, Dariene; Carrington, Elizabeth M.; Frank, Jonathan L.; Gould, Peter; Harrington, Connie A.; Devine, Warren D. 2009. Mycorrhizas on nursery and field seedlings of Quercus garryana.
• Devine, Warren D.; Harrington, Constance A. 2009. Relationships among foliar phenology, radial growth rate, and xylem density in a young Douglas-fir plantation.
• Gould, Peter J.; Harrington, Constance A. 2009. Root morphology and growth of bare-root seedlings of Oregon white oak.
• Peter, David H.; Harrington, Constance. 2009. Six years of plant community development after clearcut harvesting in western Washington.
• Peter, David H.; Harrington, Constance A. 2009. Synchronicity and geographic variation in Oregon white oak acorn production in the Pacific Northwest.
• Cline, Morris G.; Bhave, Neela; Harrington, Constance A. 2009. The possible roles of nutrient deprivation and auxin repression in apical control.
• Erickson, Heather E.; Harrington, Constance A.; Marshall, David D. 2009. Tree growth at stand and individual scales in two dual-species mixture experiments in southern Washington State, USA.
• Devine, Warren D.; Harrington, Constance A.; Peter, David H. 2007. Oak woodland restoration: understory response to removal of encroaching conifers..
• Brodie, Leslie C.; Harrington, Constance A. 2006. Response of young red alder to pruning.
• Harrington, Constance A.; Buermeyer, Karl R.; Brodie, Leslie C.; Wender, Bryan W. 2002. Factors influencing growth and flowering of understory plants in conifer stands in Western Washington.
• Harrington, Constance A.; Kern, Christel C. 2002. Will Garry oak respond to release from overtopping conifers.

Research Highlights

Highlight	Title	Year
PNW-2018-92	Climate of seed source affects susceptibility of Douglas-fir to foliage diseases Douglas-fir at higher elevations and in more continental conditions in the Pacific Northwest could experience more foliar diseases as local envi ...	2018
PNW-2011-08	Oregon white oak regeneration enhanced through proper seed and seedling management Planting Native Oak in the Pacific Northwest is the first comprehensive study of Oregon white oak planting technique. Without post-planting man ...	2011
PNW-2016-218	The Douglas-fir Seed-Source Movement Trial Sheds Light on Responses of Adaptive Traits to Changing Climates This multi-site Forest Service study, encompassing a range of climate and soil conditions, is providing some very specific results on tree growt ...	2016
PNW-2018-114	Thinning to create gaps in forest canopy increases structural variability in conifer plantations Two studies provide scientific basis for stand treatments designed to accelerate bio- and structural diversity in uniform conifer stands in west ...	2018
PNW-2018-7	Timing of flowering in Douglas-fir is determined by cool-season temperatures and genetic variation New model predicts Douglas-fir flowering to within an average of 5 days of observed flowering date. Warmer temperatures in the future will likel ...	2018
PNW-2013-108	Tree Adaptation to Future Climates Involves Multiple Aspects Genetic variation in growth phenology is a potentially important resource for mitigating some of the effects of climate change. Variation in dia ...	2013