Faculty Profile

Stephen Brewer
Professor of Biology
Phone Number: (662)915-1077
Email: jbrewer@olemiss.edu
http://home.olemiss.edu/~jbrewer/

Key Words: Fire Ecology, Biodiversity, Historical/Restoration Ecology, Barrier Islands, Salt Marshes, Invasive Species

Research Description: My research focuses on the effects of disturbances and resources on the structure and dynamics of plant populations and communities. I use responses of plants to "measure" the impacts of disturbances and resource additions and their relevance to the conservation and restoration of threatened or degraded plant communities in the southeastern coastal plain of the United States. Of particular interest to me is the ecological role of fire. Some of my current and past research includes:

  1. the effects of fire and competition on the maintenance of plant species diversity in pitcher plant bogs (Competition and Savanna Biodiversity),
  2. the community-level consequences of morphological plasticity in common and endangered plants (Plasticity, Adaptation to Fire, Carnivorous Plants),
  3. the effect of fire suppression in the 20th century on the structure of coastal plain forest and savanna communities (Historical and Restoration Ecology),
  4. salt marsh ecology (Salt Marsh Ecology), and
  5. invasive species (Invasive Species).

Honors Theses:

Rodriguez Castillo, Karina (2021) Responses of the Carnivorous Pink Spoonleaf Sundew (Drosera capillaris) to Nitrogen Addition, Phosphorus Addition, and Simulated Fire (full text)

Patterson, Amanda Lyn (2011) "The Effects of Burning and Thinning on the Amount of Carbon in Aboveground Leaf Litter and Live Vegetation in Fire-Suppresed Oak Forests"

Available Research Projects:

Why carnivorous plants rarely occur in nutrient rich wetlands

Project Description: This project will test the hypothesis that carnivorous plants are missing from nutrient-rich wetlands because they lack adequate airspace tissue within their limited root systems to tolerate the extremely low oxygen levels in nutrient-rich wetland soils. The classic hypothesis to explain why carnivory is beneficial, which originated with Charles Darwin, is that carnivory is an adaptation for tolerating nutrient-poor soils. We are challenging this hypothesis and are examining an alternative hypothesis: carnivory is an adaptation for obtaining nutrients while avoiding soil hypoxia in mildly hypoxic substrates. The evidence so far in support includes carnivorous plants being more strongly associated with wetlands (with oxygen-deprived soils) than with nutrient-poor soils. Carnivorous plants also have shallow roots with little or now airpace tissue (a common adaptation that non-carnivorous plants use to tolerate low oxygen soils). Carnivorous plants are nonetheless largely absent from nutrient-rich wetlands. We hypothesize that this is because the soils in these habitats have more hypoxic soils than nutrient-poor wetlands, and that even the production of shallow roots makes carnivorous plants intolerant of such conditions, unless there is adequate airspace tissue in these roots, because hypoxia is severe throughout the soil profile in nutrient-rich wetlands.

Desired Student Qualifications: The needs to be able to tolerate unpleasant field conditions (humidity, heat, bugs) and needs to have had some familiarity with ecology and botany, preferably having had General Ecology and/or Botany. BISC 162 is a non-negotiable requirement.

Project Timeline: Field work later this fall (October or November). Lab work afterwards into the spring semester.

Duties of Student Researcher: This project will require some field work and some laboratory work. Later this fall the student travel with Brewer and his graduate student, Matt Abbott, to collect wetland plants from a nutrient-rich tidal freshwater marsh on the Pascagoula River and from a nutrient-poor wet savanna. These plants will be brought back to the lab to have their roots washed and examined for airspace tissue to test the hypothesis that carnivorous plants are missing from nutrient-rich wetlands because they lack adequate airspace tissue within their limited root systems to tolerate the extremely low oxygen levels in nutrient-rich wetland soils. The student will use pycnometer to compare how much airspace tissue is in plants at the nutrient-rich site versus in those at the nutrient-poor site. We predict that non-carnivorous plants at the nutrient-rich site will have deeper roots and more airspace tissue than will non-carnivorous plants at the nutrient-poor wetland.

Last Updated on 2015-09-30 06:40:42