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Soil Microfungal Collections

For an updated database see www.moldsforyou.org

Education

B.S., University of Nebraska, 1953.
M.S., Ph.D. University of Wisconsin, Madison, 1956 .
Ph.D., University of Wisconsin, Madison,1960.

Professional Experience

Professor Emerita, Botany                        1989-present    University of Wyoming
Professor, Botany                                       1976-1989         University of Wyoming
Visiting Professor, Bacteriology               1976-1977         U. Wisconsin
Associate Professor, Botany                    1968-1976         University of Wyoming
Assistant Professor, Botany                     1963-1968         University of Wyoming
Post-doctoral Project Associate              1960-1963         U. Wisconsin
Research Assistant/Teaching Asst.       1954-1960         U. Wisconsin
Public School Teacher, Sciences            1953-1954         Ralston, Nebraska

Research Emphasis

Dr. Christensen's research program in mycology has focused primarily on fungal ecology and the contributions of fungi to ecosystem functioning. Working with students, she has conducted quantitative analyses of soil microfungal communities in forests, deserts, and grasslands of the Rocky Mountains and, more recently, of long-term ecological research sites in North America. Her approach is to characterize fungal communities in terms of species diversity, community structure, and species composition. The global patterning of ecologically sensitive assemblages of fungal species has been of special interest.

Since the mid-1960s, Dr. Christensen and her students have described 15 new species of molds and have monographed three sections in the genus Aspergillus. Under the terms of recent contracts with two major drug companies, she submitted 3000 microfungal cultures submitted for product screening in 1989-93. Currently, she is working on the systematics and ecology of Penicillium species in soil.

Work on mycorrhizae in the UW Botany Department began in the 1970s. Recent studies have involved differentiating ecotypes in vescicular- arbuscular mycorrhizal fungi, primarily on the basis of specific effects on host plant physiology.

Representative Publications

• Christensen, M. 1981. Species diversity and dominance in fungal communities. Pages 201-232 in D.T. Wicklow and G.C. Carroll (eds). The fungal community: its organization and role in the ecosystem. Marcel Dekker, New York.
• Christensen, M. 1981. A synoptic key and evaluation of species in the Aspergillus flavus group. Mycologia 73:1056-1084.
• Christensen, M. and D.E Tuthill. 1986. Aspergillus: an overview. Pages 195-209 in R.A. Samson and J.L Pitt (eds). Advances in Penicillium and Aspergillus Systematics. Plenum Press, London.
• Christensen, M. 1989. A view of fungal ecology. Mycologia 81: 1-19.
• Stahl, P.D. and M. Christensen. 1991. Population variation in the mycorrhizal fungus Glomus mosseae: Breadths of environmental tolerence. Mycol. Res. 95: 300-307.
• Christensen, M., S.L. Miller and D. Tuthill. 1994. Color standards: a review and evaluation in relation to Penicillium taxonomy. Mycol. Res. 98: 635-644.
• States, J.S. and M. Christensen. 2001. Fungi associated with biological soil crusts in desert grasslands of Utah and Wyoming. Mycologia, 93(3):432-439
• Christensen, M., J.C. Frisvad and D. Tuthill. 1999. Penicillium species diversity in soil and some taxonomic and ecological notes. In:  R.A. Samson and J.I. Pitt(Editors). Penicillium and Aspergillus Systematics. (Accepted, July 1997)
• Christensen, M., J.C. Frisvad and D. Tuthill. 1999. Penicillium Miczynskii and related species. Mycol. Res. 103: 527-541.
• Tuthill, Dorothy E., Jens C. Frisvad, and Martha Christensen. 2001. Systematics of Penicillium simplicissimum based on rDNA sequences, morphology and secondary metabolites. Mycologia, 93(2): 298-308