Tad Day is a plant ecologist who studies factors that control plant performance, plant litter decomposition and carbon cycling. While much of his past work investigated these questions in Antarctic tundra, the main aim of his present work is to unravel the mechanisms involved in plant litter decomposition in the Sonoran Desert. These mechanisms are poorly understood, limiting the ability of biogeochemists to accurately predict and model this important pathway of the carbon cycle in deserts.
While microbes appear to play a dominant role in litter decomposition in many ecosystems, direct breakdown of litter by sunlight (photodegradation) appears particularly important in deserts. Day's research examines how the optical, anatomical and chemical properties of leaf litter influence decomposition by environmental drivers such as sunlight, and biotic drivers such as microbes.
Guénon R, Day TA, Velazco-Ayuso S, Gros R. 2017. Mixing of Aleppo pine and Holm oak litter increases biochemical diversity and alleviates N limitations of microbial activity. Soil Biology and Biochemistry 105:216-226.
Day TA, Guénon R, Ruhland CT. 2015. Photodegradation of plant litter in the Sonoran Desert varies by litter type and age. Soil Biology and Biochemistry 89:109-122.
Elmendorf SC, Henry GH, Hollister RD, Björk RG, Bjorkman AD, Callaghan TV, Collier LS, Cooper EJ, Cornelissen JHC, Day TA, et al. 2012. Global assessment of experimental climate warming on tundra vegetation: heterogeneity over space and time. Ecology Letters 15: 164-175.
Elmendorf SC, Henry GH, Hollister RD, Björk RG, Boulanger-Lapointe N, Cooper EJ, Cornelissen JHC, Day TA, et al. 2012. Plot-scale evidence of tundra vegetation change and links to recent summer warming.Nature Climate Change 2:453-457.
Strauss SL, Day TA, Garcia-Pichel F. 2012.Nitrogen cycling in desert biological soil crusts across biogeographic regions in the Southwestern United States.Biogeochemistry 108:171-182.
Strauss SL, Garcia-Pichel F, Day TA. 2012. Soil microbial carbon and nitrogen transformations at a glacial foreland on Anvers Island, Antarctic Peninsula. Polar Biology 35:1459-1471.
Day TA, Zhang ET, Ruhland CT. 2007. Exposure to solar UV-B radiation accelerates mass and lignin loss of Larreatridentata litter in the Sonoran Desert. Plant Ecology 193:185-194.
Krna, MA, Thomas Day & CT Ruhland. Effects of neighboring plants on the growth and reproduction of Deschampsia antarctica in Antarctic tundra. Polar Biology (2009).
SL Strauss, CT Ruhland & Thomas Day. Trends in soil characteristics along a recently deglaciated foreland on Anvers Island, Antarctic Peninsula. Polar Biology (2009).
Day TA, CT Ruhland, SL Strauss, J-H Park, ML Kreig, MA Krna & DM Bryant. Response of plants and the dominant microarthropod, Cryptopygus antarcticus, to warming and contrasting precipitation regimes in Antarctic tundra. Global Change Biology (2009).
Day TA, CT Ruhland, CT, FS Xiong. Warming increases aboveground biomass and C stocks in vascular-plant dominated Antarctic tundra. Global Change Biology (2008).
Day TA, Zhang ET, Ruhland CT. 2007. Exposure to solar UV-B radiation accelerates mass and lignin loss of Larreatridentata litter in the Sonoran Desert. Plant Ecology 193:185-194.
J Park, Day TA. Temperature response of CO2 exchange and dissolved organic carbon release in a maritime Antarctic tundra ecosystem. Polar Biology (2007).
J Park, Day TA, S Strauss, C Ruhland. Biogeochemical pools and fluxes of carbon and nitrogen in a maritime tundra near penguin colonies along the Antarctic Peninsula. Polar Biology (2007).
L Morse, S Faeth, Thomas Day. Neotyphodium interactions with a native grass are driven by endophyte haplotype. Functional Ecology (2007).
Patrick Neale, Walter Helbing, Thomas Day. Symposium in print: UV effects in aquatic and terrestrial environments. Photochemistry and Photobiology (2007).
Strauss, Sarah, Ruhland, Christopher, Garcia-Pichel, Ferran, Day, Thomas. Microbial colonization in a recently exposed glacial foreland of the Antarctic Peninsula. Proceedings of the International Symposium on Environmental Biogeochemistry, Taupo, New Zealand (2007).
Morse, L, Faeth, Stanley, Day, Thomas. Neotyphodium interactions with a native grass are. New Zealand Grassland Association (2007).
Park, J-H, Day, Thomas. Temperature response and acclimation of the carbon cycle in a maritime Antarctic tundra ecosystem. (2006).
C Ruhland, F Xiong, W Clark, Thomas Day. The influence of ultraviolet-B radiation on growth, hydroxycinnamic acids and flavonoids of Deschampsia antarctica during springtime ozone depletion in Antarctica. Photochemistry and Photobiology (2005).
E Mueller, Thomas Day. The effect of urban ground cover on microclimate, growth and leaf gas exchange of oleander in Phoenix, Arizona. International Journal of Biometeorology (2005).
C Ruhland, F Xiong, W Clark, Thomas Day. The influence of solar ultraviolet-B radiation on hydroxycinnamic acids, flavonoids and growth of Deschampsia antarctica during springtime ozone depletion in Antarctica. Photochemistry and Photobiology (2004).
C Ruhland, F Xiong, W Clark, Thomas Day. The influence of solar ultraviolet-B radiation on hydroxycinnamic acids, flavonoids and growth of Deschampsia antarctica during springtime ozone depletion in Antarctica. Plant Ecology (2004).
G Johnson, Thomas Day. Localization and identification of UV-induced blue fluorophores in Sorghum bicolor leaves. Physiologia Plantarum (2004).
R Coleman, Thomas Day. Plant responses to contrasting levels of sub-ambient solar UV-B: testing the saturation hypothesis. Physiologia Plantarum (2004).
R Coleman, Thomas Day. Response of cotton and sorghum to several levels of subambient solar UV-B radiation: a test of the saturation hypothesis. Physiologia Plantarum (2004).
E Wentz, P Gober, R Balling, Thomas Day. Spatial patterns and determinants of winter atmospheric carbon dioxide concentrations in an urban environment. Annals of the Association of American Geographers (2002).
F Xiong, C Ruhland, Thomas Day. Effect of springtime ultraviolet-B radiation on growth of Colobanthus quitensis at Palmer Station, Antarctica. Global Change Biology (2002).
G Johnson, Thomas Day. Enhancement of photosynthesis in Sorghum bicolor by ultraviolet radiation. Physiologia Plantarum (2002).
L Morse, S Faeth, Thomas Day. Effect of Neotyphodium endophyte infection on growth and leaf gas exchange of Arizona fescue under contrasting water availability regimes. Environmental and Experimental Botany (2002).
P Convey, PJ Pugh, C Jackson, A Murray, C Ruhland, F Xiong, Thomas Day. Response of Antarctic terrestrial microarthropods to long-term climate manipulations. Ecology (2002).
Thomas Day, P Neale. Effects of UV-B radiation on terrestrial and aquatic primary producers. Annual Review of Ecology and Systematics (2002).
C Ruhland, Thomas Day. Size and longevity of seedbanks in Antarctica and the influence of ultraviolet-B radiation on survivorship, growth and pigment concentrations of Colobanthus quitensis seedlings. Environmental and Experimental Botany (2001).
F Xiong, Thomas Day. Effect of solar ultraviolet-B radiation during springtime ozone depletion on photosynthesis and biomass production of Antarctic vascular plants. Plant Physiology (2001).
S Mantha, G Johnson, Thomas Day. Evidence from action and fluorescence spectra that UV-induced violet-blue-green fluorescence enhances leaf photosynthesis. Photochemistry and Photobiology (2001).
Thomas Day. Multiple trophic levels in UV-B assessments - completing the ecosystem. New Phytologist (2001).
Thomas Day, C Ruhland, F Xiong. Influence of solar ultraviolet-B radiation on Antarctic terrestrial plants: results from a 4-year field study. Journal of Photochemistry and Photobiology B: Biology (2001).
Thomas Day, P Gober, F Xiong, E Wentz. Temporal patterns in near-surface CO2 concentrations over contrasting vegetation types in the Phoenix metropolitan area. Agricultural and Forest Meteorology (2001).
. . Ecosystems, evolution and ultraviolet radiation (2001).
Johnson, G, Mantha, S, Day, Thomas. Photosynthetic significance of UV-induced blue fluorescence in foliage. (2001).
C Ruhland, Thomas Day. Effects of ultraviolet-B radiation on leaf elongation, production and phenylpropanoid concentrations of Deschampsia antarctica and Colobanthus quitensis in Antarctica. Physiologia Plantarum (2000).
F Xiong, E Mueller, Thomas Day. Photosynthetic and respiratory acclimation and growth response of Antarctic vascular plants to contrasting temperature regimes. American Journal of Botany (2000).
G Johnson, S Mantha, Thomas Day. A spectofluorometric survey of UV-induced blue-green fluorescence in foliage of 35 species. Journal of Plant Physiology (2000).
Day, Thomas, Ruhland, C, Xiong, F. Photosynthetic and respiratory response of Antarctic vascular plants to warming: linking carbon assimilation to growth. (2000).
Johnson, G, Mantha, S, Day, Thomas. Prevalence and photosynthetic significance of UV-induced blue-green fluorescence in foliage. (2000).
Research Activity
Day,Thomas*, Garcia-Pichel,Ferran. Collaborative Research: Photodegradation in deserts: litter optical and structural considerations. NSF-BIO-DEB(5/1/2013 - 4/30/2017).
Day,Thomas*, Klopatek,Jeffrey M. RESPONSE OF TERRESTRIAL ECOSYSTEMS ALONG THE ANTARCTIC PENINSULA TO A CHANGING CLIMATE. NSF-OPP(9/1/2003 - 8/31/2007).
Faeth,Stanley H*, Day,Thomas. SHIFTING COSTS AND BENEFITS OF SYSTEMATIC ENDOPHYTE INTERACTIONS WITH NATIVE GRASS HOSTS. NSF-BIO(3/15/2002 - 8/31/2007).
Balling,Robert C*, Day,Thomas, Fernando,H J S, Gober,Patricia, Hogan,Timothy D, Klopatek,Jeffrey M, Wentz,Elizabeth Ann. DYNAMICS OF AN URBAN CARBON DIOXIDE DOME. NSF-BIO(5/1/1999 - 4/30/2003).
Faeth,Stanley H*, Day,Thomas. THE ROLE OF FUNGAL ENDOPHYTES IN SEMI-ARID FOREST GRASSLAND COMMUNITIES. NSF-BIO(1/1/1998 - 2/28/2002).
Day,Thomas*. IMPACTS OF CLIMATE CHANGE ON ANTARTIC WASCULAR PLANTS: WARMING AND UV-B RADIATION1. NSF-OPP(9/1/1997 - 9/30/2001).
Day,Thomas*, Clark,William Dennis. UV AUTOFLOURESCENCE IN LEAVES. USDA(7/1/1997 - 6/30/2001).
Day,Thomas*. ASSESSING UV-BCONSTRAINTS ON PHOTOSYNTHETIC CAPACITY: LINKING LEAF STRUCTURES TO FUNCTION. USDA(6/1/1996 - 5/31/1997).
Elmendorf S, Henry G, et al including Day TA (one of 20 coauthors as part of the Tundra Vegetation Change Group). Assessments of recent tundra change based on repeated vegetation surveys. 2010 Fall Meeting, AGU (American Geophysical Union), San Francisco, CA (Dec 2010).
Krna MA, Day TA, Ruhland CT. Effects of climate manipulations on the production and decomposition of Antarctic vascular plants. Annual Meeting of the New Zealand Ecological Society. University of Otago, Dunedin, New Zealand (Oct 2010).
Krna MA, Ruhland CT, Park JY, Strauss SA, Day TA. Effects of warming and increased precipitation on terrestrial Antarctic tundra d13C and d15N isotopic signatures. Annual Meeting of the Ecological Society of America, Pittsburgh, PA (Aug 2010).
Maisah AK, Confair RD, Day TA. Is the sensitivity of Antarctic plants to solar UV-B exposure related to unique environmental conditions in Antarctica?. 17th Annual SOLS Undergraduate Research Poster Symposium, ASU (Mar 2010).
Day TA, Ruhland CT. Effectiveness of different wavebands of solar radiation on litter decomposition in the Sonoran Desert. Annual Meeting of the Ecological Society of America, Albuquerque, NM (Aug 2009).
Strauss SL, Garcia-Pichel F, Day TA. Microbial colonization in recently exposed glacial forelands of the Antarctic Peninsula. Annual Meeting of the Ecological Society of America, Albuquerque, NM (Aug 2009).
Ruhland CT, Krna MT, Strauss SL, Day TA. Effects of supplementary warming and precipitation on decomposition of Antarctic vascular plant litter. Annual Meeting of the Ecological Society of America, Albuquerque, NM (Aug 2009).
Strauss SL, Garcia-Pichel F, Day TA. Microbial colonization of a glacial foreland along the coast of the Antarctic Peninsula. American Society for Microbiology. Arizona/Southern Nevada Meeting, University of Arizona, Tucson (Mar 2009).
Ruhland CT, Day Thomas. Hydroxycinnamic acids in the epidermis of Antarctic vascular plants may convey increased tolerance against ultraviolet-B radiation during ozone depletion events. Ferulate ‘08: An international conference on hydroxycinnamates and related plant phenolics (Jul 2008).
SL Strauss, CT Ruhland, F Garcia-Pichel, Thomas A Day. Microbial colonization in recently exposed glacial forelands of the Antarctic Peninsula. Amercian Society of Microbiology, Arizona-Nevada Branch Meeting, Tempe, AZ (Apr 2008).
Daddacha, W, Ruhland, C, Krna, M, Strauss, S, Day, Thomas, Secott, T. Comparison of Microbial Plant Litter Degradation Potential in Transitional and Established Antarctic Peninsula Vascular Plant Ecosystems. Annual Northcentral US Meeting of the American Society for Microbiology (Oct 2006).
Day, Thomas, Ruhland, C, Bryant, D, Strauss, S, Krna, M. Effects of warming and supplemental precipitation on CO2 flux, nutrient cycling, and primary production in Antarctic tundra. Annual Meeting of the Ecological Society of America (Aug 2006).
Krna, M, Day, Thomas, Ruhland, C. Effects of neighboring plants on growth and reproduction of Deschampsia antarctica in Antarctic tundra. Annual Meeting of the Ecological Society of America (Aug 2006).
Morse, L, Faeth, S, Day, Thomas. Neotyphodium interactions with a native grass are driven by endophyte haplotype. Annual Meeting of the Ecological Society of America (Aug 2006).
Bryant, D, Strauss, S, Thomey, M, Ruhland, C, Day, Thomas. C:N:P stoichiometry of Antarctic tundra microcosms under increased temperature, precipitation, and soil glucose addition. Annual Meeting of the Ecological Society of America (Aug 2006).
Ruhland, C, Strauss, S, Day, Thomas. Effects of supplemental warming and precipitation on growth and reproduction on Antarctic vascular plants. Annual Meeting of the Ecological Society of America (Aug 2006).
Strauss, S, Ruhland, C, Secott, T, Day, Thomas. Soil development and nutrient cycling during early succession of glacial forelands along the Antarctic Peninsula. Annual Meeting of the Ecological Society of America (Aug 2006).
Neale, Patrick, Helbing, Walter, Day, Thomas. UV effects in Aquatic and Terrestrial Environments. Symposium at the Annual Meeting of the American Society for Photobiology (Jun 2006).
Day, Thomas, Ruhland, C. Effects of warming and supplemental precipitation on productivity and C storage of tundra along the Antarctic Peninsula. IXth SCAR (Scientific Committee on Antarctic Research) Biology Symposium (Jul 2005).
Day, Thomas. Impact of warming on plant perfomance and carbon cycling in tundra ecosystems along the Antarctic Peninsula. Photosynthesis Center Seminar Series, ASU (Apr 2005).
Day, Thomas, Bryant, D, Strauss, S, Thomey, M, Secott, T, Ruhland, C. Effect of climate manipulations on vascular-plant dominated tundra along the Antarctic Peninsula. Synthesis of Soil Biodiversity and Ecosystem Functioning in Anarctica NSF workshop (Apr 2005).
Ruhland, C, Day, Thomas. Effects of enhanced UV-B radiation during springtime ozone depletion on growth and phenylpropanoid chemistry of Antarctic hairgrass (Deschampsia antarctica). Annual Meeting of the American Society of Photobiology (ASP) (Jul 2004).
Morse, L, Day, Thomas, Faeth, S. Effect of host genotype and Neotyphodium endophyte on growth, leaf gas exchange, leaf rolling and stomatal density of Arizona fescue under contrasting water availability regimes. 5th International Symposium on Neotyphodium/Grass Interactions (May 2004).
Morse, L, Faeth, S, Day, Thomas. Effect of Neotyphodium infection and genotype on growth and gas exchange of Arizona fescue under contrasting water availability. 5th International Symposium on Neotyphodium/Grass Interactions
Day, Thomas. Effects of climate change on photosynthesis, growth and reproduction of Antarctic vascular plants. Fourth Conference on Biochemistry, Ecophysiology and Population Biology of Alpine & Polar Plants
Kolander, T, Krna, M, Day, Thomas, Ruhland, C, Secott, T. Preliminary characterization of microbial succession in an early transitional ecosystem on the Antarctic Peninsula. American Society of Microbiology - Midwest Region
Krieg, Michelle, Day, Thomas. Climate change impacts on terrestrial arthropod fauna in Antarctic tundra. 16th Annual NASA/Arizona Space Grant Symposium of Undergraduate Researc
Krieg, Michelle, Day, Thomas. Effects of climate change on terrestrial arthropod fauna in tundra on the Antarctic Peninsula. 14th Annual SOLS Undergraduate Research Poster Symposium
Strauss, Sarah, Ruhland, Christopher, Garcia-Pichel, Ferran, Day, Thomas. Microbial colonization in a recently exposed glacial foreland of the Antarctic Peninsula. International Symposium on Environmental Biogeochemistry
Day, Thomas. Influence of enhanced UV-B radiation due to ozone depletion on productivity, growth, photosynthesis, and DNA damage in terrestrial plants along the Antarctic Peninsula. Second General Assembly of SPARC (Stratospheric Processes and their Role in Climate), World Climate Research Programme
Day, Thomas, Mueller, E, Xiong, F, Balling, R. Temporal patterns in near-surface CO2 concentrations in the Phoenix urban CO2 dome over contrasting vegetation types. Third Symposium on the Urban Environment, American Meteorological Society
Coleman, R, Day, Thomas. Plant responses to four levels of sub ambient UV B radiation: investigating the saturation hypothesis. Annual Meeting of the Ecological Society of America
Day, Thomas, Ruhland, C, Xiong, F. Four years of warming enhances biomass and seed production, and litter accumulation in Antarctic tundra. Annual Meeting of the Ecological Society of America
Johnson, G, Day, Thomas. Significance and localization of ultraviolet-induced blue fluorescence in foliage. Annual Meeting of the Ecological Society of America
Morse, L, Day, Thomas, Faeth, S. Effect of Neotyphodium infection on growth and leaf gas exchange of Arizona fescue under contrasting water availability. Annual Meeting of the Ecological Society of America
Ruhland, C, Xiong, F, Clark, W, Day, Thomas. The effects of solar UV B on growth and phenylpropanoids of Deschampsia antarctica. Annual Meeting of the Ecological Society of America
Day, Thomas, Zhang, E, Ruhland, C. Exposure to solar UV-B radiation accelerates mass and lignin loss of Larrea tridentata litter in the Sonoran Desert. Annual Meeting of the American Society for Photobiology
Service
Arizona Science Olympiad State Tournament, Event Supervisor (2017-present)
Chilean National Commission for Science and Technology Research (CONICYT), Ad hoc proposal reviewer (2014 - Present)
Outreach to K-12 science classes., Advisor (2014 - Present)
American Association for the Advancement of Science (AAAS), Reviewer (2014 - Present)
