Tropical ecology, ecophysiology, and global change
My research focuses primarily on understanding how fire, drought, and other factors control tree success and vegetation structure in savannas and forests of North and South America, with particular attention to the Cerrado region of central Brazil and longleaf pine ecosystems of southeastern U.S. To understand these factors from both functional and evolutionary perspectives, my work involves multiple approaches, including ecophysiology, phylogenetic analyses, controlled experiments, demographic studies, and modeling.
Lehmann, C. E., Anderson, T. M., Sankaran, M., Higgins, S. I., Archibald, S., Hoffmann, W. A., … & Bond, W. J. (2014). Savanna Vegetation-Fire-Climate Relationships Differ Among Continents. Science, 343:548-552.
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.
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., Marchin, R., Abit, P., and Lau, O.L. (2011) Hydraulic failure and tree dieback are associated with high wood density in a temperate forest under extreme drought. Global Change Biology, 8: 2731-2742.
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.
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.
Giambelluca, T.W., Scholz, F.G., Bucci, S.J., Meinzer, F.C., Goldstein, G., Hoffmann, W.A., Franco, A.C., Buchert, M.P. (2009) Evapotranspiration and energy balance of Brazilian savannas with contrasting tree density. Agricultural and Forest Meteorology,149:1365-1376.
Rossatto, D.R., Hoffmann, W.A., Franco, A.C. (2009) Differences in growth patterns between co-occurring forest and savanna species affect the forest-savanna boundary. Functional Ecology, 23: 689-698.
Hao, G.-Y. Hoffmann, W.A. Scholz, F.G. Bucci, S.J. Meinzer, F.C. Franco, A.C. Cao, K.-F. Goldstein, G. (2008) Stem and leaf hydraulics of congeneric tree species from adjacent tropical savanna and forest ecosystems. Oecologia, 155:405-415.
Hoffmann, W.A., Orthen, B. and Franco, A.C. 2004. Constraints to seedling success of savanna and forest trees across the savanna-forest boundary. Oecologia,140:252-260.
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., 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. and R.B. Jackson. 2000. Vegetation-climate feedbacks in the conversion of tropical savanna to grassland. Journal of Climate, 13:1593-1602.