Vegetation-Fire FeedbacksPositive feedbacks between vegetation and fire play a key role in the dynamics of savanna-forest boundaries. We are particularly interested in understanding how plant traits and climate mediate the intensity of this feedback.
Plant adaptations to fireWe have been using comparative approaches to understand the origin and ecology of savanna trees and shrubs. We are particularly interested in understanding how natural selection has shaped their morphology, physiology, and ecology in ways that define the unique properties of savanna ecosystems.
Miconia pohliana, a savanna tree species Miconia cuspidata, a forest tree species
Check out our publications about fire ecology
Grady, J.M. & Hoffmann, W.A. (2012) Caught in a fire trap: Recurring fire creates stable size equilibria in woody resprouters. Ecology, 93:2052-2060.
Hoffmann, W.A., Jaconis,S.Y, Geiger, E.L., Gotsch, S.G., Franco, A.C. (2012) Fuels or microclimate? Understanding the drivers of fire feedbacks at savanna-forest boundaries. Austral Ecology, 37:634-643.
Hoffmann, W.A., Geiger, E.L., Gotsch, S., Rossatto, D.R., Silva, L.C.R., Lau, O.L., Haridasan, M., & Franco, A.C. (2012) Ecological thresholds at the savanna-forest boundary: How plant traits, resources and fire govern the distribution of tropical biomes. Ecology Letters, 15:759-768.
Wall W.A., Hoffmann W.A., Wentworth T.R., Gray J.B. & Hohmann M.G. (2012) Demographic effects of fire on two endemic plant species in the longleaf pine-wiregrass ecosystem. Plant Ecology, 213: 1093-1104.
Ratnam, J., Bond, W.J., Fensham, R.J., Hoffmann, W.A., Archibald, S., Lehmann, C.E.R., Andersen, M.T., Higgins,S.I., Sankaran, M. (2011) When is a "forest" a savanna, and why does it matter? Global Ecology and Biogeography, 20:653-660.
Lehmann, C.E.R.. Archibald, S.,Hoffmann, W.A. and Bond, W.J. (2011) Deciphering the distribution of the savanna biome. New Phytologist, 19: 197-209.
Geiger, E.L., Gotsch, S.G., do Vale, G.D., Haridasan, M., Franco, A.C., & Hoffmann, W.A. (2011) Distinct roles of savanna and forest tree species in regeneration following fire suppression in a Brazilian savanna. Journal of Vegetation Science, 22:312-321.
Marchin, R.M., Bhandari, R.K., Wall, W.A., Hohmann, M.G., Gray, J.B., Hoffmann, W.A. (2009) Are rare species less shade tolerant than common species in fire-prone environments? A test with seven Amorpha (Fabaceae) species. Plant Ecology, 205:249–260.
Hoffmann, W.A., R. Adasme, M. Haridasan, M. Carvalho, E. L. Geiger, M. A. B. Pereira, S. G. Gotsch, and A. C. Franco (2009). Tree topkill, not mortality, governs the dynamics of alternate stable states at savanna-forest boundaries under frequent fire in central Brazil. Ecology 90:1326-1337.
Hoffmann, W.A., B. Orthen, and P.K.V. Nascimento. 2003. Comparative fire ecology of tropical savanna and forest trees. Functional Ecology, 17: 720-726
Hoffmann, W.A., W. Schroeder and R.B. Jackson. 2003. Regional feedbacks among climate, fire, and tropical deforestation. Journal of Geophysical Research - Atmospheres, 108, DOI: 2003JD003494.
Hoffmann, W.A. and O.T. Solbrig. 2003. The role of topkill in the differential response of savanna woody species to fire. Forest Ecology and Management, 180:273-286.
Hoffmann, W.A. and A.C. Franco. 2003. Comparative growth analysis of tropical savanna and forest trees using phylogenetically-independent contrasts. Journal of Ecology, 91: 475-484.
Hoffmann, W. A., W. Schroeder, and R. B. Jackson. 2002. Positive feedbacks of fire, climate, and vegetation change and the conversion of tropical savannas. Geophysical Research Letters, 15: doi: 10.1029/2002GL015424
Hoffmann, W.A. 2002. Direct and indirect effects of fire on radial growth of cerrado savanna trees. Journal of Tropical Ecology 18:137-142.
Hoffmann, W.A., F.A. Bazzaz, N.J. Chatterton, P. Harrison, and R.B. Jackson. 2000. Elevated CO2 enhances resprouting of a tropical savanna tree. Oecologia, 123(3) 312-317.
Hoffmann, W. A. 2000. Post-establishment seedling success of savanna and forest species in the Brazilian Cerrado. Biotropica, 32(1):62-69
Hoffmann, W. A. 1999. Fire and population dynamics of woody plants in a Neotropical savanna: matrix model predictions. Ecology 80:1354-1369.
Hoffmann, W. A. 1998. Post-burn reproduction of woody plants in a Neotropical savanna: the relative importance of sexual and vegetative reproduction. Journal of Applied Ecology 35:422-433.
Hoffmann, W. A. 1996. The effects of cover and fire on seedling establishment in a neotropical savanna. Journal of Ecology. 84:383-393