Tim W. Stewart

515-294-1644, Fax 515-294-7874
twstewar@iastate.edu
http://www.public.iastate.edu/~twstewar/

B.A. Biology, Ithaca College, 1989
M.S. Biology, SUNY Brockport, 1993

Teaching

General Ecology, Natural History of Iowa Vertebrates, Ecology of Freshwater Invertebrates

Research

My primary research focus involves use of aquatic invertebrate population and community attributes (e.g., densities, biomass, diversity, taxonomic composition) to assess ecosystem health.  Most current projects are intended to evaluate impacts of intensive agriculture and urbanization on water and habitat quality in wetlands, streams and rivers, and lakes.  By quantifying spatial and temporal variation in biological components of ecosystems, we provide evidence of adverse environmental impacts that guide pollution abatement efforts, water and habitat quality management, ecosystem restoration strategies, and conservation of rare or ecologically/economically important species.

Publications

Stewart, T.W, and Downing, J.  2008.  Macroinvertebrate communities and environmental conditions in recently constructed wetlands.  Wetlands 28:141-150.

Litvan, M.E., Stewart, T.W., Pierce, C.L., and Larson, C.J.  2007.  Local effects of grade control structures on the macroinvertebrate assemblage of an agriculturally-impacted stream.  River Research and Applications 24: 218-233.

Stewart, T.W.  2007.  Measuring animal movements in a natural ecosystem: a mark-recapture investigation using stream-dwelling snails.  American Biology Teacher 69(1). http://www.nabt.org/sites/S1/File/pdf/069-01-0028.pdf

Stewart, T.W.  2006.  The freshwater gastropods of Iowa (1821-1998): taxonomic composition, geographic distributions, and conservation concerns.  American Malacological Bulletin 21:59-75.

Stewart, T.W.  2006.  Observing and quantifying predator-avoidance behavior: habitat shifts in snails threatened by shell-crushing predators.  Teaching Issues and Experiments in Ecology, Volume 4.  Ecological Society of America. http://tiee.ecoed.net/vol/v4/experiments/habitat_shifts/abstract.html

Stewart, T.W., and Dillon, R.T. Jr.  2004.  Composition and geographic distribution of Virginia’s freshwater gastropod fauna: a review using historical records.  American Malacological Bulletin 19:79-91.

Stewart, T.W., Shumaker, T.L., and Radzio, T.A.  2003.  Linear and nonlinear effects of habitat structure on composition and abundance in the macroinvertebrate community of a large river.  American Midland Naturalist 149:293-305.

Stewart, T.W., and Embrey, T.R.  2003.  Demonstrating that habitat structure facilitates coexistence of predator and prey: a laboratory experiment using goldfish and invertebrates.  American Biology Teacher 65:292-297