Kelly (Machalek) Major's Research Area
Under the broad umbrella of “physiological ecology”, research in my lab has focused on photosynthetic physiology, physiological compensation, and mechanisms of stress tolerance in algal and plant model systems. We are particularly interested in:
- algal and plant responses to abiotic and/or biotic environmental pressures,
- the underlying mechanisms associated with these responses (e.g., physiological compensation), and
- how the ability to respond to environmental change [or the lack thereof] relates to the ecology of these organisms and long-term native plant community resilience.
Invasive Plant Physiology and Ecology
The loss of biodiversity, as a result of biological invasion, is second only to habitat destruction. Although scientists are working hard to identify the factors that contribute to the success of non-native plants, the reality is that very little is understood about how biology and environmental conditions interact to facilitate invasive species. Floristic surveys conducted across coastal Alabama indicate that high concentrations of non-native plants occur in the central-most portions of Mobile and Baldwin Counties, and border the Mobile-Tensaw Delta (MTD). Such survey data, together with those gathered from our ongoing studies of plant communities of the Mobile-Tensaw watershed, are being used to determine to what extent non-native species have impacted southern Alabama and how best to predict the occurrence of notable plant pests for the purposes of eradication, maintenance of biodiversity, and management of threatened natural resources.
Using these baseline data, we have formulated hypothesis-driven research regarding the physiological ecology of native and non-native plants, the influence of environmental change on plant competitive outcomes, and implications for the long-term survival of native [often endemic] communities and maintenance of ecosystem integrity. Our current research is focused on the effects of nitrogen availability on native and non-native aquatic plant performance and, in turn, its influence on the relationship between nitrogen and carbon metabolism. This research has the potential for real-world application with respect to our understanding of interspecific plant interactions, resource competition, and evolutionary fitness in the face of rising CO2 levels and climate change.
Impacts of Disturbance on Plant Community Resilience and Biodiversity in the Mobile-Tensaw Delta
The Mobile-Tensaw Delta (MTD) is a sensitive, integrated system where terrestrial, freshwater, and coastal communities converge into a transition zone, characterized by high productivity and biological diversity, making it ecologically, economically, and recreationally important to the Gulf region. This “ecotonal bridge” is also subject to anthropogenic and natural disturbances that include: eutrophication, development, industrial pollution – including the DWH oil spill, tropical storms, drought, and flooding events. Because measurable changes occur as a function of time, space, and intensity, the MTD is ideal for testing hypotheses about how disturbance and habitat degradation influence natural communities and, therefore, food web dynamics.
By adopting a collaborative, multi-scaled approach, we are addressing the complexities and broader impacts of environmental degradation, habitat loss, and disturbance in the MTD. Results from this and other ongoing studies will contribute to our understanding of the underlying mechanisms of resilience and susceptibility to stress (phase shifts and biological invasion), and the importance of the terrestrial-aquatic interface. Ultimately, we hope these data will guide important decisions regarding community conservation and resource management in the Delta.
Lafabrie, C., Major, K.M., Major, C.S. & Cebrian, J. 2013. Trace metal contamination of the aquatic plant Hydrilla verticillata and associated sediment in a coastal Alabama creek (Gulf of Mexico-USA). Marine Pollution Bulletin. 68: 147-151.
Lafabrie, C., Major, K.M., Major, C.S., Miller, M.M. & Cebrian, J. 2011. Comparison of morphology and photo-physiology with metal/metalloid bioaccumulation in Vallisneria neotropicalis. Journal of Hazardous Materials. 191: 356-365.
Miller (Mintz), M.M., Phipps, S., Major, C.S. & Major, K.M. 2011. Non-point source (NPS) nutrient pollution and its influences on submerged aquatic plant community structure and biological invasion in the Weeks Bay National Estuarine Research Reserve (WBNERR). Estuaries and Coasts. 34: 1182–1193.
Lafabrie, C., Major, K.M. Major, C.S. & Cebrian, J. 2010. Arsenic and mercury bioaccumulation in the aquatic plant, Vallisneria neotropicalis. Chemosphere. 82: 1393-1400.
Plutchak, R., Major, K.M., Cebrian, J., Foster, C.D., Miller, M-E.C., Anton, A., Sheehan, K.L., Heck, Jr., K.L. & Powers, S. 2010. The impact of oyster reef restoration on nutrient dynamics and primary productivity in tidal marsh creeks of the North Central Gulf of Mexico. Estuaries and Coasts. 33: 1355-1364.
Martin, D.L., Boone, E., Caldwell, M.M., Major, K.M. & Boettcher, A.A. 2009. Liquid culture and growth quantification of the seagrass pathogen, Labyrinthula sp. Mycologia. 101(5): 632-635.
Cebrian, J., Foster, C.D., , Plutchak, R., Sheehan, K., Miller, M-E, Anton, A., Major, K.M., Heck, K.L., Jr. & Powers, S.P. 2007. The impact of Hurricane Ivan on the primary productivity and metabolism of marsh tidal creeks. Aquatic Ecology. 41(2): 391-404.
Major, K.M., Kirkwood, A.E., Major, C.S., McCreadie, J.W. & Henley, W.J. 2005. In situ studies of algal biomass in relation to physicochemical characteristics of the Salt Plains National Wildlife Refuge, Oklahoma, USA. Saline Systems. 1: 11.
Current Graduate Students
Molly Miller, Ph.D. candidate (Co-mentor: Tim Sherman)
Brian McPherson, M.S. candidate
Jeffrey Zabolotney, M.S. candidate (Co-mentor: Tim Sherman)
Previous Graduate Students
Charles Stapleton, Ph.D. (2013)
Amanda Ecker, M.S. (2012)
Molly Mintz Miller, M.S. (2010)
Katherine VanDeven, M.S. (2010)
Suzanne Sweetser, M.S. (2008)
Rochelle Plutchak, M.S. (2007)