MICHELLE A. EVANS-WHITE, Ph.D., Assistant Professor,
Research Interests and Current Projects
I am an ecologist specializing in
freshwater ecosystems. Much of my research
examines how ecological stressors, such as pollution, alter species patterns
and interactions in these freshwater ecosystems. I am particularly interested in how changes
in community structure may translate into changes in ecosystem function. I use a variety of approaches to address
questions including laboratory, greenhouse, and field experiments. Most of my research has focused on stream
algal and macroinvertebrate (insects, crustaceans, and mollusks) communities.
Consequences of reduced
water quality in streams
A majority of streams and lakes in the
Forecasting
biodiversity and ecosystem function
Many climate change models predict altered precipitation
amounts and frequencies that could ultimately affect stream hydrology and
organic matter and nutrient inputs and cycling.
My current research examines whether community structure and ecosystem
process responses to altered flooding and drying frequencies depend on land use
and land cover within watersheds. These
relationships can then be linked to climate model predictions to forecast
future changes in stream structure and function.
Ecological
stoichiometry
Ecological stoichiometry
examines the consequences of mass balance of energy and elements in ecological
interactions. Elemental requirements for
tissue production differ among animals because of differing body plans
(example: bones versus a chitin
exoskeleton) and life history traits (example: short- versus long-lived
animals; complete metamorphosis). Within
ecological interactions, elemental imbalances exist between consumers and their
food resources. For example, the carbon:nitrogen (C:N) or C:phosphorus
(C:P) ratio of primary consumers is often lower than that of their food
resources (algae or detritus), which results in more C and less N and P than
they need to build tissue. This sort of
imbalance could lead to N or P limitation of consumers and may drive community
patterns in ecosystems across nutrient gradients (bottom-up effects). Ecological stoichiometry
may also be used to examine the role of animals in elemental cycles (top-down
effects). Stoichiometry
theory invades many aspects of my current research. For example, I am interested in whether
nutrient enrichment of streams and food resources may alter community stoichiometry by selecting for species with high nutrient
demands. In addition, I am interested in
how contaminants may alter the stoichiometry of
community interactions.
Ecotoxicology
Although contaminant effects on individual species
dominate many contaminant risk assessments, anthropogenic contaminants have the
ability to alter community and ecosystem processes. In previous research, colleagues and I have
examined effects of new “green” chemicals (ionic liquids) on
community interactions and the effects of genetically-modified crops on
agricultural stream consumers and food webs.
I continue to be interested in how contaminants may affect stream
communities and ecosystem processes.
Mentoring
Clay Prater
(Masters, Biology)
Nicki Jensen (Undergraduate,
Biology)
Phillip Bumpers
(Undergraduate, Biology)
Mckinley Case
(Undergraduate, Biology)
Autumn Allison
(Undergraduate, Biology)
Erin Scarbrough (Undergraduate, Biology)
Teaching
Spring 2009: Special Topics in Zoology: Biogeochemistry
and Global Change (BIOL 4933: MWF at 2:30)
Recent
publications:
Evans-White, M.A. and G.A. Lamberti.
2009. Direct and indirect effects of a
potential aquatic contaminant on grazer algae interactions. Environmental
Toxicology and Chemistry 28: 418-426
Griffiths, N.A., J.L. Tank, T.V. Royer, E.J. Rosi-Marshall, M.R. Whiles, C.P. Chambers, T.C. Frauendorf, and M.A. Evans-White. In press. Rapid breakdown of maize detritus in agricultural
streams. Ecological Applications.
Bengtson, J.R., M.A.
Evans-White, and K.B. Gido. 2008.
Effects of grazing minnows and crayfish on stream ecosystem structure
and function. Journal of the North American Benthological
Society 27:772-782
Rosi-Marhsall, E.J., J.L.
Tank, M.R. Whiles, T.V. Royer, M. Evans-White, C. Chambers, N.A. Griffiths, J. Pokelsek, and M.L. Stephan. 2007. Toxins in transgenic crop
byproducts may affect headwater stream ecosystems. Proceedings
of the
Evans-White, M.A. and G.A. Lamberti.
2006. Stoichiometry
of consumer-driven nutrient recycling across nutrient regimes in streams. Ecology
Letters 9:1186-1197.
Evans-White, M.A. and G.A. Lamberti.
2005. Grazer species effects on epilithon nutrient composition. Freshwater
Biology 50:1786-1799.
Evans-White, M.A., G.A. Lamberti.
2005. Regional and taxonomic patterns in
benthic macroinvertebrate elemental composition in streams. Freshwater
Biology 50:1786-1799.
Frost, P.C., M.A. Evans-White, Z.V. Finkel,
T.C. Jensen, and V. Maztek. 2005.
Are you what you eat?
Physiological constraints on organismal stoichiometry in an elementally imbalanced world. Oikos 109:18-28.
Bernot, R.J., M.A. Brueseke, M.A. Evans-White, and G.A. Lamberti. 2005.
Acute and chronic toxicity of imidazolium-based
ionic liquids on Daphnia magna. Environmental Toxicology and Chemistry
24:87-92.
Bobeldyk, A.M., J.M. Bossenbroek, M.A. Evans-White, D.M. Lodge, and G.A. Lamberti. 2005.
Secondary spread of zebra mussels (Dreissena polymorpha) in coupled lake-stream systems. Ecoscience 12:
339-346.
Curriculum
vitae
Back to Department of Biological
Sciences at The University of Arkansas
Email me: mevanswh@uark.edu
More information on opportunities for Graduate Study in
Biological Sciences at UA
More information on the Ecology and Evolution Group
in Biological Sciences at UA
Last updated 9/14/2005