Research in the Leege Lab
Research in the Leege Lab
Georgia Southern University
Department of Biology
My research focuses on conservation and restoration ecology with regards to plant population and community ecology and threats to biodiversity in a variety of ecosystems. In particular, I am interested in the ecology of rare and invasive plants and how they interact to influence each others' population dynamics. My students and I use field and greenhouse observations and experiments to answer questions about the role of herbivores, fire, invasive species and climate change in regulating plant population and community dynamics. My research is based primarily in the southeastern U.S. I have some openings in my lab for graduate students at the masters level and for undergraduate research projects that address these or similar questions.
Coastal Sand Dune Restoration
Tybee Island is home to Georgia’s most visited beach, but it has increasingly felt the effects of climate change and sea level rise. For years, Tybee has nourished its beaches with dredged sand, and in 2020 Tybee constructed an entirely new dune system. With funding from the Georgia DNR and in partnership with Tybee Island, we are conducting a study both to monitor the success of these new dunes and to determine best practices in coastal dune restoration. The new dune was planted with native dune vegetation, and we implemented experimental treatments to assess the effects of plating density and community assemblage on dune movement (erosion/accretion). We are collecting data on plant growth in order to determine correlations with dune movement, and we plan to create a monitoring protocol documenting the most important measurements to take when determining the success of a dune restoration. These protocols will be of use to volunteers on Tybee for this project, as well as to coastal managers along the Southeastern Atlantic Coast. Additionally, this research will provide insight into the best planting practices to build a sustainable dune. We will learn which plants and in which densities most successfully trap sand to continue building dunes, and what planting options are most cost effective.
Funding Georgia Department of Natural Resources Coastal Resources Division Coastal Incentive Grant (subaward through the City of Tybee Island), University of Georgia Marine Extension and Sea Grant Research Traineeship, Georgia Southern College of Science and Mathematics Academic Excellence, Georgia Southern Institute for Coastal Plain Science Summer Research Assistantship, Georgia Southern Office of Research Undergraduate Summer Funding
Students who have worked on this project
Graduate Students: Travis William, Shannon Matzke
Undergraduates: Maxine Hauser, Alexandra Findlay (Honor's student) volunteers from Fall 2020/Spring 2021 BIOL3535 Botany class
Learn more about our Coastal Dune Restoration Research and view all news, publications and presentations here.
Wetland Restoration and Management
Southeastern wetlands provide critical ecosystem services in regulating flooding, removing pollutants, trapping sediment, and providing essential habitat for a wide diversity of organisms. Despite their importance, wetlands are threatened by changing hydrology and the introduction of invasive species, potentially impacting their ecosystem function. My students and I are studying the effects and management of a variety of invasive species including Chinese privet and Japanese stiltgrass, in a local, residential wetland in an effort to determine their impact and ultimately restore the site to full ecological function.
Students who have worked on this project
Undergraduates: Trevor Woodyard, Josie Richards (honors student), Dahja Wright, Michaella (Valkenaar) Ivey
Publications
Presentations
"Response of invasive Japanese stiltgrass (Microstegium vimineum) and its associated plant community to management treatments in a residential wetland.” Lissa Leege, Dahja Wright and Josie Richards. Oral Presentation, 84th Annual Meeting of the Association of Southeastern Biologists. Winston Salem, NC
"What are the impacts of deer browsing and Japanese stiltgrass (Microstegium vimineum) on native sapling growth in a residential wetland in southeastern Georgia?” Josie Richard and Lissa Leege. Poster Presentation, 84th Annual Meeting of the Association of Southeastern Biologists. Winston Salem, NC
“Privet Removal Increases Cover, but not Native Herb-Layer Richness in a Georgia Wetland.” Michaella Valkenaar and Lissa Leege. Oral Presentation, 82nd Annual Meeting of the Association of Southeastern Biologists (virtual).
Threats to Endangered Plants of Georgia
Relict trillium adult, subadult, and juvenile. Photo taken by Christopher Heckel.
Invasive Vine and Deer Herbivory Effects on to Endangered Trillium reliquum
With the Trillium system, we ask the question, how do populations of endangered species respond to threats by invasive plants and deer? With funding from the Department of Natural Resources, we constructed deer exclosures and removed Lonicera japonica (Japanese honeysuckle, an invasive vine) from multiple sites across the range of trillium in Georgia and have monitored population and community dynamics. Our work has shown that trillium populations are rapidly declining in the presence of invasive kudzu, and while invasive honeysuckle has decreased trillium carrying capacity, trillium populations are stable where they co-occur with Japanese honeysuckle. Deer are responsible for life stage regression and increased trillium dormancy, which over time may decrease trillium populations.
Funding
Georgia Department of Natural Resources, Sigma Xi (2), Garden Club of America: Catherine Beattie Fellowship (2), Marie Mellinger Grant, Georgia Southern University: COST Academic Excellence (2), Student Faculty Research Award, COST COUR, etc.
Students who have worked on this project
Graduate students: Christopher Heckel, Jacob Thompson
Undergraduates: D. Josh Parris, T. Lance Fulghum, Tabitha Williford
Publications
Thompson, Jacob and Lissa Leege. 2011. A field study of seed germination in the endangered Trillium reliquum Freeman (Trilliaceae). Plant Species Biology 26: 111-115.
Leege, Lissa, Jacob Thompson, and Darren Parris. 2010. The response of rare and common trilliums (Trillium reliquum, T. cuneatum and T. maculatum) to deer herbivory and invasive honeysuckle removal. Castanea 75(4): 433-443.
Heckel, Christopher and L.M. Leege. 2007. Life history and reproductive biology of the endangered Trillium reliquum. Plant Ecology 189(1): 49-57.
Presentations
April 2012. “Measuring Long-Term Effects of Deer Herbivory on the Rare Plant, Trillium reliquum using matrix models.” Fulghum, Thomas L; Leege, Lissa M; and Thompson, Jacob. Poster presentation, Association of Southeastern Biologists, Annual Meeting, Athens, GA.
March 2006. "The impacts of white-tailed deer herbivory and Lonicera japonica on the population dynamics of Trillium reliquum." Jacob S. Thompson* and L.M. Leege. at Georgia Academy of Science Annual Meeting at Georgia Perimeter College, Lawrence, GA. Best graduate student paper in Biological Sciences.
August 2004. "The effects of invasive vine encroachment on the population dynamics of an endangered herb." Newsworthy and Late-breaking contributed paper with Christopher D. Heckel. Ecological Society of America Annual Meeting. Portland, OR.
March 2004. "Impacts of exotic invasive vines on a population of the endangered Trillium reliquum." Contributed paper with Christopher D. Heckel. Georgia Academy of Science Annual Meeting. Berry College, GA. Best graduate student paper in Biological Sciences.
November 2003. "Impacts of exotic invasive vines on a population of the endangered Trillium reliquum." Poster presentation with Christopher D. Heckel. Invasive Plants in Natural and Managed Systems: Linking Science and Management and 7th International Conference on the Ecology and Management of Alien Plant Invasions, Fort Lauderdale, FL.
Fire Ecology and Management of the Endangered Trillium persistens
Trillium persistens is an endangered perennial herb that is restricted to a 4 mile radius in the Tallulah - Tugaloo River system of Georgia and South Carolina. The species occurs in a variety of habitat types, including the Table Mountain pine system. The Table Mountain pine requires fire for regeneration, and the DNR has conducted several controlled burns in the areas where Trillium persistens co-occurs with Table Mountain Pine.
With DNR funding, the Leege lab has been monitoring populations of T. persistens to determine population response to fire, to develop population projection models to predict future population size, and to document the natural history of the species. Our experimental work has shown that trillium populations are not negatively affected by fire. Recruitment of seedlings is highly variable across years and sites, and dormancy is a common phenomenon, and hence is important in developing projection models.
Presentations
April 2012. “The effects of fire and dormancy on population dynamics of endangered Trillium persistens.” Tabitha N. Williford, Lissa M. Leege and Cassandra M. Plank. Oral presentation, Association of Southeastern Biologists, Annual Meeting, Athens, GA.
April 2010 "The effects of prescribed burning and population fragmentation on the demography of the federally endangered herb, Trillium persistens, and its community." Cassandra M. Plank and Lissa M. Leege at Georgia Academy of Science Annual Meeting in Columbus, GA. Best graduate student paper in Biological Sciences.
March 2010 “Reproductive biology of the endangered herb Trillium persistens in natural conditions.” Poster presentation with Chase H. Patrick and Lissa M. Leege. at Georgia Academy of Science Annual Meeting in Columbus, GA.
Persistent trillium adults, subadults (3 leaves, no flower), and juvenile (single leaf) marked with aluminum tags. Photo by Tabitha Williford.
Funding
Georgia Department of Natural Resources, Marie Mellinger Grant
Students who have worked on this project
Graduate students: Cassandra Plank, Kevin Kirby
Undergraduates: Sara Fletcher, Laura Gover, Aaron Murphy, Joseph Nasworthy, Justin Norris, Chase Patrick, Dylan Walls, Tabitha Williford (Senior Honors Thesis)
Publications
Plank, C.M. 2011. Investigation of the demography of the federally endangered herb, Trillium persistens across its range and within a fire-dependent habitat. Tipularia pp. 26-32.
Hairy rattleweed adult with many flowering stems (photo credit Alan Cressler)
Threats to Endangered Baptisia arachnifera
Hairy rattleweed (Baptisia arachnifera) occurs in only two counties in the world - in Wayne and Brantley Counties in southeast Georgia's coastal plain. The legume is highly endangered due to habitat loss (conversion to timber land). It also loses a good share of its seed crop each year to a natural seed predator.
We have documented a more than 80% reduction in population size on sites managed for timber, whereas powerline cuts and sites that have not been harvested and replanted in > 30 years maintain relatively stable populations. Only one tract of land on which this species occurs receives formal protection (from The Nature Conservancy and the Department of Natural Resources).
With funding from the Department of Natural Resources and US Fish and Wildlife, we have monitored its population dynamics on timber land and in the one protected site to better understand its natural history and to determine the effects of fire, herbicides, and natural and human caused threats to the population.
Funding
Georgia Department of Natural Resources (3 contracts), US Fish and Wildlife.
Students who have worked on this project
Graduate Students: Ruth Ann Steinbrecher, Timothy Estep Jacob Thompson, Amy Squire (UGA), D. Josh Parris
Publications
Durden, L.A., T.J. Estep and L.M. Leege. 2011. Uresiphita reversalis (Crambidae, Pyraustinae) larval herbivory on the state and federally endangered hairy rattleweed, Baptisia arachnifera, in Georgia. Southern Lepidopterists’ News 33: 96-98.
Presentations
October 2013. "Micronutrient Requirements and Timber Management Effects on Endangered Baptisia arachnifera" Ruth Ann Steinbrecher, Subhrajit Saha, Lissa Leege and Chiao-Ying Chou. Poster presentation, Society of American Foresters, National Congress, Charleston, SC. Ruth Ann Steinbrecher and Subhrajit Saha.
March 2011. “Factors relating to germination and seedling success in Baptisia arachnifera” Timothy J. Estep, Lissa M. Leege, and John Pascarella. Georgia Academy of Science Annual Meeting in Gainesville, GA.
April 2009. “Response of an endangered coastal plain legume (Baptisia arachnifera) to prescribed fire. Lissa M. Leege. Association of Southeastern Biologists, Annual Meeting, Birmingham, AL. Winner of North Carolina Botanical Garden Award for best paper.
Plant Herbivore Interactions
Redbay mortality 8 months following initial symptoms of Laurel Wilt Disease. Photo by A. Mayfield , Florida DACS Division of Forestry
Effects of Laurel Wilt Disease on Redbay-Dominated Plant Communities
In 2003, significant mortality of redbay trees (Persea borbonia) was noted along the Georgia coast. Redbay mortality was soon linked to the rapidly- spreading Laurel Wilt Disease, brought to the United States with the accidental introduction of the redbay ambrosia beetle, Xyleborus glabratus, which carries a fungus, Raffaelea lauricola, that causes Laurel Wilt Disease. A single entry hole into a redbay tree by an infected X. glabratus is enough to kill a tree in three weeks.
The Leege lab has documented the impact of Laurel Wilt Disease on plant communities by comparing infested with uninfested plant communities in the lower and upper Coastal Plain of Georgia. We found that even the smallest redbay size category stems are killed in infested plant communities, and species such as sweetbay and loblolly bay are of higher importance in infested sites than control sites.
Funding
Georgia Native Plant Society
Students who have worked on this project
Graduate students: Kimberly Spiegel
Undergraduate students: Juliette Jordan, Monique Copeland, Wendy Wilson
Publications
Spiegel, Kimberly S. and Lissa M. Leege. 2013. Impacts of laurel wilt disease on redbay (Persea borbonia) population structure and forest communities in the coastal plain of Georgia, USA. Biological Invasions 15(11): 2467-2487.
Presentations
August 2010. “Impacts of Laurel Wilt Disease on Redbay (Persea borbonia) Population Structure and Forest Communities in the Coastal Plain of Georgia, USA.” Kimberly S. Spiegel and Lissa M. Leege, at Botanical Society of America Meeting in Providence, RI.
April 2010. “Plant community response to Laurel Wilt Disease.” Poster presentation with Kimberly Spiegel, Association of Southeastern Biologists, Annual Meeting, Birmingham, AL.
March 2009. “Aliens in a new land: how do Asian ambrosia beetles (Xyleborus glabratus) find their host?” Poster presentation with Juliette T. Jordan, L.M. Leege, Norman Schmidt and Amanda Hollebone. Georgia Academy of Science Annual Meeting, Atlanta, GA.
February 2009. “Host Chemistry and Redbay Ambrosia Beetle Attraction.” Savannah, GA. Laurel Wilt Disease Conference – Forest Health Monitoring Working Group Meeting.
Interactions between the redbay tree (Persea borbonia) and its psyllid leaf galler (Trioza magnoliae)
The leaves of redbay trees are commonly infested with galls that are produced in response to the jumping plant louse, Trioza magnoliae. In my lab, we are interested in the fitness cost of the galls to this evergreen tree. We are also investigating patterns of gall distribution in sites of varying resource availability.
In collaboration with Dr. Norman Schmidt of GSU's Department of Chemistry, we have also quantified levels of defensive chemicals in redbay.
We have conducted field work on this system at George L. Smith State Park, Herty Preserve on the GSU campus, and on three of Georgia's barrier islands.
Students who have worked on this project
Charlie Bridges, Leonard Brown, Ben Churcher, April Edwards, Susan George, Elaine Giles, R. Brooke Hastings, Christine Mayo (Department of Chemistry), BJ Newell, Julie Powell
Publications
Leege, Lissa M. 2006. The relationship between psyllid leaf galls and redbay (Persea borbonia) fitness traits in sun and shade. Plant Ecology 84(2): 203-212.
Presentations
Leege, L.M. and R. B. Hastings. 2002. Biological constraints to reproductive success in populations of coastal and inland redbay (Persea borbonia). Georgia Journal of Science 60(1).
Leege, L.M. and C. Bridges. 2000. The Distribution of Galls on Redbay Leaves in Sand Dune and Maritime Forest Habitats: is Life Really Better at the Beach? Georgia Journal of Science 58 (1): 49.
Spring 2005 "The concentration of essential oils of redbay (Persea borbonia) with respect to seasonal changes." Poster presentation with Sara Calvarese and Norman E. Schmidt at 37th Annual Southeast Regional American Chemical Society Undergraduate Research Conference, Mississippi State University.
Cakile edentula in fruit and flower on the shore of Lake Huron, MI.
(Photograph by F. D'Arcangelo)
Effect of herbivory across ontogeny of sea rocket (Cakile edentula), a dune annual
With the sea rocket system, I ask the question, how do plants in nitrogen-poor environments allocate their resources to growth, reproduction and defense in order to optimize their fitness? In my lab, we are investigating resource allocation across the life cycle as well as fitness effects of herbivory at different stages of the plant's life. We are also doing comparative work between Great Lakes and Georgia barrier island Cakile edentula populations.
Sea rockets produce glucosinolates, a class of compounds that are not used in primary metabolism and are thought to serve a defensive function for plants in the mustard family. Glucosinolates are responsible for the "hot" taste in radishes and mustard. We are quantifying these compounds and determine how plant allocation to this type of chemical defense varies across the life of a plant.
Funding
GSU
Students who have worked on this project
Emily Bankard (Michigan State University), Dourinina Beal, Karen Brown , Brent Ginn, Daisy Kangeter
Presentations/Publications
July 2004 "When should a plant defend or grow? Herbivory and glucosinolate concentrations through the life of a beach annual, Cakile edentula". Contributed paper with DH Kangeter, BT Ginn, and KR Brown. Ecological Society of America Annual Meeting. Portland, OR.
Brown, K.R., B.T. Ginn, L.M. Leege. 2001. Effects of Herbivore Damage on Growth and Reproduction in Cakile edentula. Georgia Journal of Science 59(1):25.
Wild horses on Cumberland beach.
Feral horse effects on plant communities at Cumberland Island
A growing wild horse population (more than 200 individuals) lives on Cumberland Island. The horses graze on the island in the salt marsh and in the sand dunes as well as in pasture land. This grazing and trampling may be altering the structure and composition of plant communities in these habitats.
1999-2002, we worked with the park service to monitor feral horse impacts to these communities and are interested in determining the ability of a large, non-native herbivore to alter plant community structure.
Funding
National Park Service Challenge Cost Share Grant
Georgia Southern University
Students who have worked on this project
Master's student: Peter Dolan
Undergraduates: Quiana Manning, LaChieka Miller, Trey Yearwood
Presentations/Publications
Dolan, P and L.M. Leege. 2002. Feral horses in dune and saltmarsh habitats on Cumberland Island. Georgia Journal of Science 60(1).
Dolan, P. and L.M. Leege. 2001. Feral Horse Impacts on the Saltmarsh of Cumberland Island. Georgia Journal of Science 59(1):51.