Staff Profile
Photo for Sean McMahon, Forest Ecologist


My lab is focused on understanding how tree demography--the growth, survival, and recruitment of individual stems--is driven by physiological and environmental processes.  We also study how demographic dynamics drive large-scale patterns of forest structure, function, and diversity.  Much of our work evolves from using extant data from both the Smithsonian's ForestGEO network, FIA, remote sensing data sets, and extensive research of Geoffrey Parker, a colleague and forest ecologist at the Smithsonian Environmental Research Center, where we are based.  We also explore these questions by collecting new data whenever possible.  If a research focus is on forest dynamics, there is no limit to the kinds of projects we want to weave into our team.  

I am the Temperate Program Coordinator for the Smithsonian Institution's CTFS-ForestGEO network.   There are currently 17 temperate plots in the program in North America and Europe, with a number of other partner plots in China.  My responsibilities for the network involve facilitating synthetic science, assisting network partners in research, data-collection, and data vetting, storage and curation.  I also work to expand the network into new biomes, with unique flora, distrubance histories, and new partner institutions to promote fundamental research to build a global understanding of forest dynamics.   



  • Merow, Cory, Latimer, Andrew M., Wilson, Adam M., McMahon, Sean M., Rebelo, Anthony G. and Silander, John A., Jr. (2014). On using integral projection models to generate demographically driven predictions of species' distributions: development and validation using sparse data. Ecography, 37 (12) , 1167-1183.
  • Merow, Cory, Smith, Mathew J., Edwards, Thomas C., Guisan, Antoine, McMahon, Sean M., Normand, Signe, Thuiller, Wilfried, Wüest, Rafael O., Zimmermann, Niklaus E. and Elith, Jane. (2014). What do we gain from simplicity versus complexity in species distribution models?. Ecography, 37 (12) , 1267-1281.
  • Réjou-Méchain, M., Muller-Landau, Helene C., Detto, Matteo, Thomas, S. C., Le Toan, T., Saatchi, S. S., Barreto-Silva, J., Bourg, N. A., Bunyavejchewin, S., Butt, N., Brockelman, W. Y., Cao, M., Cárdenas, D., Chiang, J. M., Chuyong, G. B., Clay, K., Condit, Richard S., Dattaraja, H. S., Davies, Stuart James, Duque, A., Esufali, S., Ewango, C., Fernando, R. H. S., Fletcher, C. D., Gunatilleke, I. A. U. N., et al. (2014). Local spatial structure of forest biomass and its consequences for remote sensing of carbon stocks. Biogeosciences Discussions, 11 (4) , 5711-5742.
  • Chisholm, Ryan A., Muller-Landau, Helene C., Abdul Rahman, Kassim, Bebber, Daniel P., Bin, Yue, Bohlman, Stephanie A., Bourg, Norman A., Brinks, Joshua, Bunyavejchewin, Sarayudh, Butt, Nathalie, Cao, Honglin, Cao, Min, Cárdenas, Dairon, Chang, Li-Wan, Chiang, Jyh-Min, Chuyong, George, Condit, Richard S., Dattaraja, Handanakere S., Davies, Stuart, Duque, Alvaro, Fletcher, Christine, Gunatilleke, Nimal, Gunatilleke, Savitri, Hao, Zhanqing, Harrison, Rhett D., et al. (2013). Scale-dependent relationships between tree species richness and ecosystem function in forests . Journal of Ecology, 101 (5) , 1214-1224.
  • Metcalf, C. Jessica E., McMahon, Sean M., Salguero-Gómez, Roberto and Jongejans, Eelke. (2013). IPMpack: an R package for integral projection models. Methods in Ecology and Evolution, 4 (2) , 195-200.
  • Stark, Scott C., Leitold, Veronika, Wu, Jin L., Hunter, Maria O., de Castilho, Carolina V., Costa, Flávia R. C., McMahon, Sean M., Parker, Geoffrey G., Shimabukuro, Mô, Lefsky, Michael A., Keller, Michael, Alves, Luciana F., Schietti, Juliana, Shimabukuro, Yosio Edemir, Brandão, Diego O., Woodcock, Tara K., Higuchi, Niro, de Camargo, Plinio B., de Oliveira, Raimundo C. and Saleska, Scott R. (2012). Amazon forest carbon dynamics predicted by profiles of canopy leaf area and light environment. Ecology Letters, 15 (12) , 1406-1414.
  • McMahon, Sean M., Harrison, Sandy P., Armbruster, W. Scott, Bartlein, Patrick J., Beale, Colin M., Edwards, Mary E., Kattge, Jens, Midgley, Guy, Morin, Xavier and Prentice, I. Colin. (2011). Improving assessment and modelling of climate change impacts on global terrestrial biodiversity. Trends in Ecology & Evolution, 26 (5) , 249-259.
  • McMahon, Sean M., Metcalf, Charlotte J. E. and Woodall, Christopher W. (2011). High-Dimensional Coexistence of Temperate Tree Species: Functional Traits, Demographic Rates, Life-History Stages, and Their Physical Context . PLoS ONE, 6 (1) , e16253.
  • Salk, Carl F. and McMahon, Sean M. (2011). Ecological and environmental factors constrain sprouting ability in tropical trees . Oecologia, 166 (2) , 485-492.
  • Canning-Clode, João, Maloney, Kelly O., McMahon, Sean M. and Wahl, Martin. (2010). Expanded view of the local-regional richness relationship by incorporating functional richness and time: a large-scale perspective . Global Ecology and Biogeography, 19 (6) , 875-885.
  • Clark, James S., Bell, David, Chu, Chengjin, Courbaud, Benoit, Dietze, Michael, Hersh, Michelle, HilleRisLambers, Janneke, Ibáñez, Inés, LaDeau, Shannon, McMahon, Sean M., Metcalf, Jessica, Mohan, Jacqueline, Moran, Emily, Pangle, Luke, Pearson, Scott, Salk, Carl, Shen, Zehao, Valle, Denis and Wyckoff, Peter. (2010). High-dimensional coexistence based on individual variation: a synthesis of evidence. Ecological Monographs, 80 (4) , 569-608.
  • McMahon, Sean M., Parker, Geoffrey G. and Miller, Dawn R. (2010). Evidence for a recent increase in forest growth . Proceedings of the National Academy of Sciences of the United States of America, 107 (8) , 3611-3615.
  • McMahon, Sean M., Parker, Geoffrey G. and Miller, Dawn R. (2010). Reply to Foster et al.: Using a forest to measure trees: Determining which vital rates are responding to climate change . Proceedings of the National Academy of Sciences of the United States of America, 107 (21) , E88-E89; E88-E89.
  • McMahon, Sean M., Dietze, Michael,C., Hersh, Michelle,H., Moran, Emily V. and Clark, James S. (2009). A Predictive Framework to Understand Forest Responses to Global Change. Annals of the New York Academy of Sciences, 1162 , 221-236.
  • Metcalf, C. Jessica E., McMahon, Sean M. and Clark, James S. (2009). Overcoming data sparseness and parametric constraints in modeling of tree mortality: a new nonparametric Bayesian model. Canadian Journal of Forest Research-Revue Canadienne De Recherche Forestiere, 39 (9) , 1677-1687.