Biology faculty profile

David Janos

Associate Professor

166A Cox Science Center, Dept. of Biology
1301 Memorial Drive, Coral Gables, FL 33124

phone (305) 284-6300
fax (305) 284-3039
laboratory website

Education and Professional Experience

B.S., Carleton College, 1969
M.S., University of Michigan, 1971
Ph.D., University of Michigan, 1975
Smithsonian Tropical Research Institute,Postdoctoral Work, 1976-1979
Harvard University, Postdoctoral Work, 1994-1995

Grants and Awards

National Institute of General Medical Sciences (M.S. Gaines with D.P. Janos): “Initiative for minority students: bridges to the baccalaureate.” $648,000; 2005-2008
National Science Foundation (L. Sternberg with M. Gaines, G. Goldstein, D. Janos, and F. Miralles-Wilhelm): “Acquisition of two isotope ratio mass spectrometers.” $252,130; 2004-2005
National Science Foundation, Integrative Plant Biology (to D.P. Janos): “Plant iron nutrition in calcareous soils: are arbuscular mycorrhizas a help or a hindrance?” $242,391; 2003-2006
Innovative Projects/Technology Renewal, Offices of the Provost and Dean, University of Miami, and a matching gift from Dr. Edward Dauer (to D.P. Janos, with L. Sternberg and S. Schultz): “Biological tissue analysis equipment for undergraduate laboratories.” $100,000; 1998-2000
Florida State Legislature Special Appropriations for Tropical Fruit Research, Florida Department of Agriculture and Consumer Services (to B. Schaffer, with D.P. Janos, J. Crane, and M. Schroeder): “An investigation of the dependence and responsiveness of young lychee trees to mycorrhizal fungi.” $8,600; 1998
Florida State Legislature Special Appropriations for Tropical Fruit Research, Florida Department of Agriculture and Consumer Services (to B. Schaffer, with D.P. Janos): “Improving growth and nutrient uptake of young Lychee trees with beneficial (mycorrhizae) fungi.” $8,200; 1997
Cooperative Research Centre for the Sustainable Development of Tropical Savannas (to D.P. Janos): “Proposal to visit the CRC for Tropical Savannas.” AUS$12,300; 1997

Areas of Focus

Evolutionary biology
Tropical biology
Conservation and restoration biology

Research Interests

My research concerns the evolutionary, physiological ecology of root symbioses, especially mycorrhizas. These fungus-root mutualisms are pervasive among plants in natural ecosystems, and especially in the notoriously mineral nutrient-poor soils of the tropics, are indispensable for mineral nutrient uptake by a majority of plant species. Mycorrhizas can be important for successful restoration of degraded tropical lands, and might have promise for low-input, sustainable agriculture. My work takes two major foci: 1) factors influencing whether or not mycorrhizas form, and 2) once appropriate mycorrhizas do form, what are the consequences for host survival and growth. Within these foci, my research and publications have spanned alpha taxonomy of glomeromycotan fungi to rodent dispersal of those fungi, and defining dependence and responsiveness of plants to mycorrhizas through consequences of those attributes for plant succession, competition, community composition, and biodiversity.

Teaching Interests

I am most interested in fostering students’ experiential learning (i.e., “learning by doing”). I incorporate this philosophy in My three most frequently offered courses: “Howard Hughes Medical Institute (HHMI) Introductory Biology Laboratory” (BIL 151), “Tropical Field Biology” (BIL 335), and “Biology of Fungi” (BIL 527). In the HHMI laboratory, freshmen students are provided an opportunity to conduct research, instead of pursuing prescribed, “cookbook” exercises. Tropical Field Biology lectures develop two main topics: 1) a primer of tropical biology (from climate and soils to plant-animal interactions and biodiversity) especially as pertains to an elevation gradient on the Atlantic slope of Costa Rica; and 2) how to survive an eight-day backpacking hike in cloud forest and rain forest along that elevation gradient. The classroom preparation is followed by a chance to put all the lecture information into practice during a ten-day trip to Costa Rica during spring recess. Biology of Fungi couples lectures with two laboratory classes each week, but instead of the labs illustrating the lectures, work undertaken in the laboratory such as identifying fungi isolated from natural sources, rationalizes supporting, explanatory lectures. Additionally, together with Mike Gaines, I convene a graduate seminar course “Research Design by Progressive Synthesis” (BIL 675), that applies a process for conceptualizing research to each participant’s own research study.

Publications

Schroeder, M.S. and D.P. Janos. 2005. Plant growth, phosphorus nutrition, and root morphological responses to arbuscular mycorrhizas, phosphorus fertilization, and intraspecific density. Mycorrhiza 15:203-216.
Schroeder, M.S. and D.P. Janos. 2004. Phosphorus and intraspecific density alter plant responses to arbuscular mycorrhizas. Plant and Soil 264:335-348.
Aristizábal, C., E.L. Rivera, and D.P. Janos. 2004. Arbuscular mycorrhizal fungi colonize decomposing leaves of Myrica parvifolia, M. pubescens and Paepalanthus sp. Mycorrhiza 14:221-228.
Janos, D.P., M.S. Schroeder, B. Schaffer, and J.H. Crane. 2001. Inoculation with arbuscular mycorrhizal fungi enhances growth of Litchi chinensis Sonn. trees after propagation by air-layering. Plant and Soil 233:85-94.\
Janos, D.P., and C.L. Cain. 1998. Mycorrhiza in review. Mycorrhiza 7:331-333.
Torti, S.D., P.D. Coley, and D.P. Janos. 1997. Vesicular-arbuscular mycorrhizae in two tropical monodominant trees. Journal of Tropical Ecology 13:623-629.
Bakarr, M.I., and D.P. Janos. 1996. Mycorrhizal associations of tropical legume trees in Sierra Leone, West Africa. Forest Ecology and Management 89:89-92.
Janos, D.P., C.T. Sahley, and L.H. Emmons. 1995. Rodent dispersal of vesicular-arbuscular mycorrhizal fungi in Amazonian Peru. Ecology 76:1852-1858.
Fischer, C.R., D.P. Janos, D.A. Perry, R.G. Linderman, and P.Sollins. 1994. Mycorrhiza inoculum potentials in tropical secondary succession. Biotropica 26:369-377.
Janos, D.P. 1993. Vesicular-arbuscular mycorrhizae of epiphytes. Mycorrhiza 4:1-4.
Maffia, B. R., N.M. Nadkarni, and D.P. Janos. 1993. Vesicular-arbuscular mycorrhizae of epiphytic and terrestrial Piperaceae under field and greenhouse conditions. Mycorrhiza 4:5-9.
Janos, D.P. and J.M. Trappe. 1982. Two new Acaulospora species from tropical America. Mycotaxon 15:515-522.
Janos, D.P. 1980. Mycorrhizae influence tropical succession. Biotropica 12 (Supplement): 56-64.
Janos, D.P. 1980. Vesicular-arbuscular mycorrhizae affect lowland tropical rain forest plant growth. Ecology 61:151-162.
Garwood, N.C., D.P. Janos, and N. Brokaw. 1979. Earthquake-caused landslides: a major disturbance to tropical forests. Science 205:997-999.
Janos, D.P. 1977. Vesicular-arbuscular mycorrhizae affect the growth of Bactris gasipaes. Principes 21:12-18.
Janzen, D.H., G.A. Miller, J. Hackforth-Jones, C.M. Pond, K. Hooper, and D.P. Janos. 1976. Two Costa Rican bat-generated seed shadows of Andira inermis (Leguminosae). Ecology 57:1068-1075.
Gentry, J.L. and D. Janos. 1974. A preliminary generic key and geographic checklist of the Boraginaceae in Central America and Panama. Phytologia 27:445-455.

Books and monographs:
Committee on Selected Biological Problems in the Humid Tropics. 1982. Ecological Aspects of Development in the Humid Tropics. National Academy of Sciences, Washington, D.C. 297 pp.
Janos, D.P. 1975. Vesicular-arbuscular Mycorrhizal Fungi and Plant Growth in a Costa Rican Lowland Rainforest. Doctoral dissertation, The University of Michigan, Ann Arbor. 172 pp.
Simpson, D.R. and D.P. Janos. 1974. Punch Card Key to the Families of Dicotyledons of the Western Hemisphere South of the United States. Field Museum of Natural History, Chicago, Illinois. 63 cards and 15 pages text.