Sean McMahon

Ecologist-Temperate forest program coordinator

Smithsonian Institution Global Earth Observatory
Smithsonian Environmental Research Center

P.O. Box 28, Edgewater, MD 21307-0028
Ph. (443) 482-2262,  e-mail: mcmahons@si.edu

Education

Positions

January, 2011 – present. SIGEO Forest Ecologist and Temperate Program Coordinator. 

March, 2009 – December, 2010.  Center for Tropical Forest Science at the Smithsonian Tropical Research Institute and Smithsonian Environmental Research Center.  Post-doctoral Fellow. 

2006-2009. Duke University. Post-doctoral researcher with James S. Clark.  Nicholas School of the Environment. 

Published Articles

J-R. Makana, C. N. Ewango, S. M. McMahon, S. C. Thomas, T. B. Hart, R. Condit. (in press). Trends of forest change in monodominant and mixed Central African old-growth.  Journal of Tropical Ecology.

McMahon, S. M., Harrison, S. P., Armbruster, W. S., Bartlein, P.J., Beale, C, Edwards, M. E., Kattge, J, Midgley, G, Morin, X, and Prentice, I C. 2011. Improving assessments of climate-change impacts on global biodiversity. TRENDS IN ECOLOGY \& EVOLUTION, 26(5), 249-259. doi:10.1016/j.tree.2011.02.012.

McMahon, S. M, C.J.E. Metcalf, and C. Woodall. 2011. High-dimensional coexistence of temperate tree species: functional traits, demographic rates, life- history stages, and their physical context.  PLoS ONE. 6(1): e16253. DOI: 10.1371/journal.pone.0016253.t002

Salk, C. F. and S. M. McMahon. 2010. Trait-environment interactions explain sprouting patterns in tropical tree species. OECOLOGIA. Volume 166, Number 2, 485-492, DOI: 10.1007/s00442-010-1850-7. 

McMahon, S. M., Parker, G. G., Miller, D. R. 2010. Evidence for a recent increase in forest growth. Proceedings of the National Academy of Sciences. 107:3611–3615.

McMahon, S. M., Parker, G. G., Miller, D. 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. 107(21):E88-E89. 

Canning-Clode, J., Maloney, K. O., McMahon, S. M. and Wahl, M. 2010. . Expanded view on the local-regional richness relationship by incorporating functional richness and time-a large scale perspective. Global Ecology and Biogeography. 

Clark, James S., D. Bell, C. Chu, B. Courbaud, M. Dietze, M. Hersh, J. HilleRisLambers, I. Ibáñez, S. LaDeau, S. M. McMahon, J. Metcalf, J. Mohan, E. Moran, L. Pangle, S. Pearson, C. Salk, Z. Shen, D. Valle, P. Wyckoff. 2010. High dimensional coexistence based on individual variation: a synthesis of evidence. Ecological Monographs. 

Metcalf, C.J.E., McMahon, S.M., and  Clark, J.S. 2009. Modeling tree mortality as a non-parametric function of diameter and growth, with prior weights on mortality of large trees. Canad. J. Forest. Res. 39: 1677–1687.

McMahon, S. M., M. C. Dietze, M. H. Hersh, E. V. Moran, and J. S. Clark. 2009. A predictive framework to understand forest responses to global change. The Year in Ecology and Conservation Biology. Annals of the New York Academy of Sciences. 1162: 221–236.

McMahon, S. M. and C. J. E. Metcalf. 2008. Transient sensitivities of non-indigenous shrub species indicate complicated invasion dynamics. Biological invasions. 10(6): 833-846.

Thompson, S., G. Katul, and S. M. McMahon. 2008. Dispersal strategy confines spatial organization of biomass in arid and semi-arid ecosystems. Water Resources Research.

Loarie, S. R., B. E. Carter, K. Hayhoe, S. M. McMahon, R. Moe, C. A. Knight, D. D. Ackerly. 2008. Climate Change and the Future of California's Endemic Flora. PLoS ONE 3(6).

McMahon, S. M. and J. M. Diez. 2007. Scales of association: hierarchical linear models and the measurement of ecological systems. Ecology Letters. 10(6):437-452.

McMahon, S. M. 2005. Quantifying the community: using Bayesian Learning Networks to find structure and conduct inference in invasions biology. Biological Invasions 7(5):833-844.

Starzomski, B.M., B. J. Cardinale, J.A. Dunne, M. J. Hillery, C.A. Holt, M. A. Krawchuk, M., Lage, S. M. McMahon, and M. C. Melnychuk. 2004. Contemporary visions of progress in ecology, and thoughts for the future. Ecology and Society. 9(1).

McMahon, S. M. and M. W. Cadotte. 2002. Complexity and Conservation: an ecological perspective. Bioscience 52:460-461.

Vazquez, D. P., S. M. McMahon, N. Z. Muth, and M. D. Collins. 2002. Review of The Unified Neutral Theory of Biodiversity and Biogeography by Stephen P. Hubbell. Journal of Experimental Marine Biology and Ecology 269(2):249-250.

McMahon, S. M., K. H. Miller, and J. Drake. 2001. Networking tips for social scientists and ecologists. Science 293:1604-1605.

Books

Cadotte, M. W., McMahon, S. M., and Fukami, T. 2006. Conceptual Ecology and Invasions Biology: reciprocal approaches to nature. Springer-Verlag. Dordrecht, The Netherlands.

Book chapters

Clark, J. S. and D. Bell, M. Dietze, M. Hersh, I. Ibanez, S. LaDeau, S. M. McMahon, J. Metcalf, E. Moran, L. Pangle, and M. Wolosin. Models for demography of plant populations. To appear in Handbook of Bayesian Analysis, edited by Tony OHagan and Mike West.

McMahon, S. M., M. W. Cadotte, and T. Fukami, 2006. Tracking the tractable: using invasions to guide the exploration of conceptual ecology In: M.W. Cadotte, S. M. McMahon and T Fukami (eds.). Conceptual Ecology and Invasions Biology: reciprocal approaches to nature. Springer-Verlag Academic Academic Press. Dordrecht, The Netherlands.

Cadotte, M. W., S. M., McMahon, and T. Fukami 2006. Linking spatially dependent processes in invasions. In: In: M.W. Cadotte, S. M. McMahon and T Fukami (eds.). Conceptual Ecology and Invasions Biology: reciprocal approaches to nature. Springer-Verlag. Dordrecht, The Netherlands.

Invited Presentations

McMahon, S. M. Changing forests in a changing world. June, 2010. Nicolet National Forest Breeding Bird Survey, Wisconsin, US.

McMahon, S. M. Scaling from trees to the forest and back: inferring changes in temperate forests. April, 2010. Department of Biology Ecolunch speaker the University of Pennsylvania.

McMahon, S. M. Combining chronosequence and census data shows recent accelerated growth of temperate forest stands. February, 2010. Smithsonian Tropical Research Institute. Panama City, Panama.

McMahon, S. M., J. S. Clark. Movement of forest species. September, 2009. Workshop on biodiversity and climate change. Kew Gardens, London, England.

McMahon, S. M. Structured variance and the coexistence of forest tree species. December, 2008. Invited lecture at the Ecole Normale Superieure, Paris, France.

McMahon, S. M. The future of forests: statistical and computational challenges of predicting large-scale biological systems. October, 2008. Math-Biology Series. Appalachian State University, Boone, NC.

McMahon, S. M., J. Metcalf, and J. Drake. December, 2006. The collision of systems: shifting the conceptual framework of invasion biology. Biology, Ecology and Management of World's Worst Plant Invasive Species. University of Delhi, India.

McMahon, S. M. June, 2004. Using machine learning to learn nature: Bayesian learning networks and inference in invasions biology. Conference on Computational and Mathematical Population Dynamics. Trento, Italy.

McMahon, S. M. 2003. Gaps, herbs, and insects: community structure in an old-growth southern Appalachian forest. Evolution and Behavior Seminars, Knoxville, TN.

Groups and Invited Workshops

Forest biodiversity working group. Part of the Research Coordination Network (NSF funded) grant on ecological forecasting and data assimilation. 

Research Coordination Network (NSF funded) workshop on Ecological forecasting and data assimilation. NEON, Inc. Boulder, CO, July 2110. 

CTFS database workshop. February, 2010. Bradley University. Peoria Illinois. 

Workshop on Biodiversity and Climate Change. Royal Botanic Gardens, Kew, UK. September 2009. Organized by QUEST. September 2009.

Alpine summer school: Interaction and coevolution of climate and the biosphere. Valsavarenche, Italy. June, 2008. 

Workshop on ‘Advanced prediction of biome boundary shifts in regional and global dynamic vegetation models.’ JAMSTEC Institute. Yokohama, Japan. March, 2008. 

NSF workshop on Data-Model Assimilation. Norman, OK. October, 2007. 

McMahon, S. M. and J. S. Clark. Modeling the trees for the forest: a computer simulation of a terrestrial ecosystem. A course for the Terrestrial Modeling component of the Statistical and Applied Mathematical Sciences Institute (SAMSI). Education and Outreach Program. Research Triangle, NC. March, 2007. 

A brief introduction to Bayesian statistics (short course with computer lab). Max Plank Institute of Demographic Research. Rostock, Germany. October 2006.  

Computation

Programming languages: R, C++, SQL, Unix, MatLab, Python, SAS.

Applications expertise: MS Office, JMP, Adobe Photoshop, Adobe Illustrator, Adobe GoLive, DreamWeaver. 

Currently developing two R packages: ‘Canopy’ to analyze and display ground-based LiDAR acquisition; ‘TreeIPM’ to develop integral projection models for forest data (CTFS database).