ASU SoLS Faculty: Thomas H. Nash III

Dr. Nash came to Arizona State University in 1971 after completing M.S. and Ph.D. degrees at Rutgers University. Three times he has been an Alexander von Humboldt Scholar, conducting research for two years at the Universities of Würzburg and Kiel and Max Planck Institute for Chemistry in Mainz in Germany and a Fulbright Scholar at The University of Graz in Austria. He is past-president of the American Bryological and Lichenological Society, past-secretary for the International Association of Lichenology and is currently a fellow in the Arizona-Nevada Academy of Science. He is the curator of the Arizona State University Lichen Herbarium.

Two broad themes dominate our research: 1) studies on the effects of air pollution on plants, and 2) studies on the biology of lichens, symbiotic organisms that dominate over 10% of terrestrial North America. Insofar as lichens are excellent indicators of air pollution, the two themes overlap. Interest in air pollution also includes studies on vascular plants, which were investigated at the community level around Arizona's copper smelters. For a while we also conducted tree-ring studies because they provide a unique record of long-term pollution responses. A smelting area in British Columbia with a well-documented pollution record provided a model system for these studies, which included modelling dose-response relationships for SO₂. With lichens numerous field studies have been made around pollution sources, such as factories and in Los Angeles and Mexico City. In addition, we have conducted many controlled fumigation studies with the principal gaseous air pollutants studying basic response mechanisms to gaseous pollutants by lichens.

Lichenological studies cover a range of topics: basic physiology, ecophysiology, population and community ecology, and systematics. Field studies on photosynthesis, respiration and nitrogen fixation have been conducted in Alaska, Arizona, and California. Lichens provide a model system for studying photosynthesis because confounding stomatal dependency does not occur. We have studied lichen photosynthesis dependencies on CO₂ and O₂ concentrations, light intensity, temperature, and external water potential. Physiological studies have included cold and salt stress investigations. In the future we will improve our biochemical and biophysical understanding of lichen gas exchange relationships. In the ecology area we have conducted a canopy manipulation study to determine the role of epiphytic lichens in ecosystem functioning with an emphasis on mineral cycling in an oak-lichen woodland. In this ecosystem, studies we have on-going collaboration with the Biogeochemistry section of The Max Planck Institute for Chemistry in Mainz, Germany. Systematic studies include a revision of the South American Xanthoparmeliae and a long-term investigation of the lichen flora of the Sonoran Desert region involving collaborative studies with 80 international scientists. The latter studies are supported by one of the largest lichen herbaria in North America. Volume I & II are published and Vol. III, the last one, is nearing completion .

Nash III, T.H., B.D. Ryan, P. Diederich, C. Gries and F. Bungartz (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol. II. (pp. 776 - covering over 100 genera of lichens and over 50 genera of lichenicolous fungi and together over 800 species). Lichen Unlimited: Tempe, AZ.

Nash III, T.H., B.D. Ryan, C. Gries and F. Bungartz (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol. I. (pp. 532 - covering over 140 genera and almost 600 species). Lichen Unlimited: Tempe, AZ.

Nash III, T.H. (ed.) 1996. Lichen Biology. Cambridge: Cambridge University Press.

Selected Journal Publications | CV (PDF)

Bungartz, F., Elix, J.A. and Nash III, T.H. 2004 [2005]. The genus Buellia sensu lato in the greater Sonoran Desert region: saxicolous species with one-septate ascospores containing xanthones. Bryologist 107: 459-479.

Nash III, T.H., Elix, J.A. and Herrera-Campos, M.A. 2004. Preliminary treatment of Xanthoparmelia for Mexico . Symb. Bot. Ups. 34: 239-326.

Bungartz, F., Garvie, L.A.J. and Nash III, T.H. 2004. Anatomy of the endolithic Sonoran Desert lichen Verrucaria rubrocincta Breuss: implications for biodeterioration and biomineralization. Lichenologist 36: 55-73.

Nash III, T.H., Gries, C., Zschau, T., Getty, S., Ameron, Y., and Zambrano, A. 2003. Historical patterns of metal atmospheric deposition to the epilithic lichen Xanthoparmelia in Maricopa County, Arizona, U.S.A. Journal of Physics IV (France) 107: 921-924.

Zschau, T., Getty, S., Gries, C., Ameron, Y., Zambrano, A. and Nash III, T.H. 2003. Spatial and temporal deposition patterns in Maricopa County, Arizona, to lichens. Environmental Pollution 125: 21-30.

Nash III, T.H. and Gries, C. 2002. Lichens as bioindicators of sulfur dioxide. Symbiosis 33: 1-21.

Zambrano, A., Nash III, T.H. and Herrera-Campos, M.A.. 2002. Lichens and air pollution in the forests surrounding Mexico City. Pp. 283-297. In: Fenn, M.E., de Bauer, L.I. and Hernndez-Tejeda, T. (eds.) Urban Air Pollution and Forests. Resources at Risk in the Mexico City Air Basin. Berlin: Springer Verlag.

Nash III, T.H., Gries, C. and G. Rambold, G. 2002. Lichen Floras: Past and Future for North America. Bryologist 105: 635-640.

Hafellner, J., Triebel, D., Ryan, B.D., and Nash III, T.H. 2002. On lichenicolous fungi from North America II. Mycotaxon. 84: 293 - 329.

Davis, W.C., Gries, C. and Nash III, T.H. 2002. The influence of temperature on the weight and net photosynthesis of the aquatic lichen Peltigera hydrothyria over long periods of time. Bibliotheca Lichenologica 83: 233-242.

Schoeninger, R., Gries, C. and Nash III, T.H. 2002. Herbarium databases: creation and maintenance. Bibliotheca Lichenologica. 82: 291-299.

Herrera-Campos, M.A., Nash III, T.H. and Zambrano, A. 2001. A revision of the Usnea fragilescens group for Mexico. Bryologist 104: 235-259.

Nash III, T.H., Thomas, M., Hoober, J.K., Gries, C. and Zheng, S.-X. 2001. Free amino acids in lichens and their symbionts. Bibliotheca Lichenologica. 78: 313-319.

Kuhn, U., Wolf, A., Gries, C., Nash III, T.H. and Kesselmeier, J. 2000. Field measurements on the exchange of carbonyl sulfide between lichens and the atmosphere. Atmospheric Environment 34: 4867-4878.

Zambrano, A. and Nash III, T.H. 2000. Lichen responses to short-term transplantation in Desierto de los Leones, Mexico City. Environmental Pollution 107: 407-412.

Davis, WC, C Gries, and TH Nash III. (2000). The ecophysiological response of the aquatic lichen Hydrothyria venosa to nitrate in terms of weight and photosynthesis over long periods of time. Bibliotheca Lichenologica 75:201-208.

Lumbsch, HT, TH Nash III, and MI Messuti. (1999). Pertusaria species with hyaline ascospores in southwestern North America (Pertusariales, Accomycotina). Bryologist 102:215-239.

Zambrano, A., Nash III, T.H. and Gries, C. 1999. Physiological effects of the Mexico City atmosphere on lichen transplants on oaks. Journal of Environmental Quality 28: 1548-1555.

Moberg, R, and TH Nash III. (1999). The genus Heterodermia in the Sonoran Desert area. Bryologist 102:1-14.

Herrera-Campos, MA, P Clerc, and TH Nash III. (1999). Pendulous species of Usneae from the temperate forests in Mexico. Bryologist 101:303-329.

Gries, C, M-J Sainz, J Romagni, S Goldsmith, U Kuhn, J. Kesselmeier, and TH Nash III. (1997). The uptake of gaseous sulfur dioxide in lichens. New Phytologist 135:595-602.

Knops, JMH, TH Nash III, and WH Schlesinger. (1996). The influence of epiphytic lichens on the nutrient cycling of an oak woodland. Ecological Mongr 66(2):159-179.

Gries, C, TH Nash III, and J Kesselmeier. (1994). Exchange of reduced sulfur gases between lichens and the atmosphere. Biogeochemistry 13:1-15.