John Brewer

Professor of Biology

• Faculty
• Instructor

• Email:

  jbrewer@olemiss.edu

• Office Location:

  412 Shoemaker

• Phone:

  662-915-1077

• Website:

  John S. Brewer

Dr. Brewer is an ecologist who studies the effects of disturbance, primarily fire, on plant communities.

Research Interests

Dr. Brewer's research focuses on the effects of disturbances and resources on the structure and dynamics of plant populations and communities. He uses responses of plants to “measure” the impacts of disturbances and resources 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 him is the ecological role of fire.

Some of his current research includes:

1. the effects of fire and competition on the maintenance of plant species diversity
2. the community-level consequences of morphological plasticity in common and endangered plants
3. the effect of fire suppression in the 20th century and ecological restoration on the structure of coastal plain forest and savanna communities
4. invasive species

Publications

78.Arrington-Thomas, A.L.* and J.S. Brewer. 2023.

Graminification and reversal of mesophication in a restored oak woodland

Ecological Restoration 41 (2-3) 109-118.

Modern fire exclusion in upland oak- and oak-pine-dominated forests has resulted in reduced flammability of surface fuels as a result of the replacement of flammable fuels of oaks and associated vegetation by less flammable fuels produced by mesophytic trees. Some consequences of such “mesophication” include reductions in herb diversity, C4 grasses, and oak regeneration. We tested two hypotheses of the effects of C4 grasses and tree leaf litter on fuel consumption in the field in restored and unrestored oak woodlands: 1) the presence of C4 grasses increases fuel consumption by a late growing-season prescribed fire (“graminification”), and 2) removing tree leaf fuels reduces fuel consumption by a late growing-season fire to a greater extent in areas lacking substantial, slow-to-dry mesophyte tree leaf litter (mesophication reversal). Consistent with graminification, removing C4 grasses in a restored oak woodland reduced fuel consumption, and fuel consumption was greater following tree leaf litter removal in restored woodland plots containing C4 grasses than in areas that had not been restored and that lacked such grasses. Consistent with mesophication reversal, removing tree leaf fuels reduced fuel consumption to a greater extent in areas where tree leaf litter was dominated by pyrophytic oaks than in an untreated area with a significant amount of mesophyte tree leaf litter. We conclude that mesophication can be reversed at early stages of restoration by thinning mesophytic trees and opening the canopy. Increases in C4 grasses (graminification) at late stages of restoration further increase flammability.

77. Brewer, J. S. 2023. Mechanisms of fire-maintained plant species diversity in species-rich wet pine savannas. Ecosphere 14:e4387.

76. Holloway, J. C., and J. S. Brewer. 2022. Growth and tissue nutrient responses of adults of Sarracenia alata to prey exclusion, nutrient addition, and neighbor reduction. American Journal of Botany 109: 2006–2017.

75. Glitzenstein, J.S., J.S. Brewer, R.E. Masters, J.M. Varner, and J.K. Hiers. 2021 Fire ecology and fire management of southeastern Coastal Plain pine ecosystems. In: C. Greenburg, B. Collins (eds). Fire Ecology and Management: Past, Present, and Future of U.S. Forested Ecosystems. Pp. 63-104.

74.  Brewer JS, Paniw M, Ojeda F (2021) Plant behavior and coexistence: stem elongation of the carnivorous subshrub Drosophyllum lusitanicum within xerophytic shrub canopies. Plant Ecol 222:1197–1208.

73. Alexander, Heather D., Courtney Siegert, J. Stephen Brewer, Jesse K. Kreye, Marcus A. Lashley, Jennifer K. McDaniel, Alison K. Paulson, Heidi J. Renninger, J. Morgan Varner. 2021.^. Mesophication of oak landscapes: evidence, knowledge gaps, and future research. BioScience, biaa169.

Full Publication List>>