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MSU NSF C-RUI
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C-RUI Faculty C-RUI Students C-RUI Publications C-RUI Presentations Other Links
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William Spencer Associate Professor Ph.D. 1992 University of Michigan Dr. Spencer currently has two main research emphases. One is the biology of aquatic/wetland plants, and the other is wetland ecology. Dr. Spencer has NSF (KYEPSCoR) funding to study the environmental control of gene expression in Hydrilla verticillata, and also has NSF (C-RUI) funding to study the ecology of mudflat vegetation on Kentucky Lake. He has just finished several wetland related projects. One project identified the source water for an endangered wetland, another determined the effect of land-use activity upon the ability of a wetland to remove nitrate in surface water, and another evaluated the effect of sedimentation upon wetland plant communities. Dr. Spencer has also recently finished a stream related project where the diversity of benthic algae in a forested versus agricultural watershed was compared. He has just begun a project with Dr. Haluk Chetin (Geosciences) on a NASA funded project using hyper-spectral remote sensing to plant ecology. C-RUI Research Water level manipulation on Kentucky Lake profoundly affects the distribution of vegetation along an elevation gradient. Plant communities change from a River Birch/Sycamore forest community at the uppermost reach of the gradient to a Buttonbush/Swamp Hibiscus community mid-way along the gradient. The lower reaches of the gradient support an expansive emergent annual plant community during low water (fall, winter, early spring) and a sparse submersed plant community during high water (late spring, summer, early fall). The lower reaches of the gradient are highly disturbed environments where predictable and recurrent annual flooding exerts a strong abiotic force on vegetation distribution. The middle reaches of the gradient are not disturbed, but the hydric (water-logged) soils create an extremely stressful anaerobic root zone that must be tolerated by the perennial shrubs and herbs. The upper reaches of the gradient are not disturbed by flooding, nor do they contain an anaerobic root zone. But, given the availability of water and the relatively nutrient rich soils competition for both above- and below-ground resources likely occurs. The occurrence of disturbance-, stress-, and competition-controlled habitats along the elevation gradient provides excellent field conditions for studying the effects of disturbance, stress and compeition upon the evolution of life history patterns in plants, and the importance of these three factors in structuring plant communities. Students may study a range of topics extending from life history evolution to the physiological response of plants to disturbance, stress, or competition. Experiments can be conducted in the field or in our newly acquired glasshouse mesocosm facility (Spencer, WE et al. 1998). Publications: Spencer, W.E. Population density-dependent plant physiology. Am. J. of Botany. in revision. Lickvar, R and W Spencer. Distribution of winter annual vegetation across environmental gradients within a Mojave Desert playa. Madrono. 45: 231-238. (1998) Spencer, W E, et al. Optimum temperature for carbon assimilation in Kentucky Lake follows seasonal change inambient temperature. Archiv fur Hydrobiologie 141:389-401. (1998) Rundle, J and W Spencer. Status, problems and future projections for the Obion Creek floodplain, Hickman Co., KY. Sixth Symposium on The Natural History of the Cumberland River Valley. (1998) Spencer, W., Wetzel, R.G. and Teeri, J. Photosynthetic phenotype plasticity and the role of phosphoenolpyruvate carboxylase in Hydrilla verticillata. Plant Science 118:1-9. (1996) Spencer, W., Teeri, J. and Wetzel, R.G. Acclimation of photosynthetic phenotype to environmental heterogeneity. Ecology 75:301-314. (1994) Spencer, W. and Wetzel, R.G. Acclimation of photosynthesis and dark respiration of a submersed angiosperm beneath the ice in a temperate lake. Plant Physiology 101:985-991. (1993) Beer, S., Spencer, W. and Bowes, G. Bicarbonate use and evidence for a carbon concentrating process in the mat-forming cyanophyte Lyngbya birgei G.M. Smith. Aquatic Botany 42:159-171. (1992) Bowes, G., Spencer, W., and Beer, S. Ecophysiological considerations in the weed potential of Lyngbya. In: Proceedings of the European Weed Research Society, Eighth Symposium on Aquatic Weeds. (1990) Beer, S., Spencer, W., Holbrook, G. and Bowes, G. Gas exchange and carbon fixation properties of the mat-forming cyanophyte Lyngbya birgei G.M. Smith. Aquatic Botany 38:221-230. (1990) Published abstracts: Bethel, M., Chetin, H., and Spencer, W. Use of vegetative stress to indicate elevated levels of toxic metals in soil as determined by spectral reflectance measurements. Second International Conference on Geospatial Information in Agriculture and Forestry, Orlando, FL, 10-12 January 2000. Spencer, W. and Jevans, H. The photosynthetic ecology of the rare white-water stream macrophyte Podostemum ceratophyllum. Seventh Symposium on The Natural History of the Cumberland River Valley. (1999) Spencer. W. The effect of watershed characteristics upon stream benthic algae communities in western Kentucky. Seventh Symposium on The Natural History of the Cumberland River Valley. (1999) Susilawati, E., Harris, K.L., Ferguson, Johnston, T. and Spencer, W. Environmental control of gene expression in the submersed aquatic weed Hydrilla verticillata. Seventh Symposium on The Natural History of the Cumberland River Valley. (1999) Bottom, J., Rundle and Spencer, W. Long-term monitoring of vegetation and sedimentation patterns in the Obion Creek , KY floodplain. Seventh Symposium on The Natural History of the Cumberland River Valley. (1999) Spencer, W. Density-dependent physiological plasticity in aquatic plants. Sixth Symposium on The Natural History of the Cumberland River Valley. (1997) Spencer, W., Delaney, S., Rice, G., Johnston, K., Seither, R., and White, D.S. Optimum temperature for photosynthetic assimilation in Kentucky Lake follows seasonal change in ambient temperature. Sixth Symposium on The Natural History of the Cumberland River Valley. (1997) Rundle, J. and Spencer. W. The effect of land-use activity on denitrification potential of wetland soils. Sixth Symposium on The Natural History of the Cumberland River Valley. (1997) Spencer, W., Wetzel, R.G. and Teeri, J. Ecological significance of C4-like photosynthesis in Hydrilla. International Symposium on the Biology and Management of Aquatic Plants. July 12-16, Daytona Beach, FL. (1992) Spencer, W., Teeri, J., and Weztel, R.G. Phenotypic variation in photosynthetic pathway: Patterns in Hydrilla physiology within environmental gradients. Ecology s72:256. (1991) Spencer, W. and Wetzel, R.G. Seasonal differences in gas exchange, phosphorus and RuBP concentrations, and RuBISCO activity in a northern submersed aquatic angiosperm. Plant Physiology s93:126. (1990) Reiskind, J.B., Rowland-Bamford, A.J., Spencer, W., Beer, S., Schweder, M., Bowes, G., and Davis, J.S. Inorganic carbon acquisition in tropical marine macroalgae. Plant Physiology s93:56. (1990)
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