Board of Directors 2020

Member Directors


Elizabeth Braker

Professor of Biology, Occidental College

  • B.A. Colorado College 1977
  • Ph.D. U.C. Berkeley 1986

I am thrilled to have this opportunity to serve the Organization for Tropical Studies (OTS) as the interim CEO. I have been involved with OTS for over 30 years:

As a graduate student, I had the opportunity to take our flagship course: Tropical Biology: An Ecological Approach in 1979. For my Ph.D. research, I studied plant-insect interactions at La Selva, with fellowship support from the Noyes Foundation.

As an educator, I have led graduate courses, been a visiting faculty member on OTS undergraduate and graduate courses, and led Occidental students to study tropical biology at OTS field stations.

As a scientist, I work at La Selva on several projects, including a collaboration with colleagues from Occidental and Universidad Nacional in Costa Rica. We are studying how the growth and survival of one of the most common trees in this forest is affected by rainfall, feeding by insects, and symbiotic bacteria.

  • Board of Directors (2006-2012 and 2016-present)
  • Nominating Committee (2015-2018)
  • Education Committee (2002-2017)
  • Vice-Chair for Education from 2006-2012
  • La Selva Advisory Committee, Science Committee
  • 2005 Strategic Planning Committee-Education

As the OTS community considers how the organization will grow and thrive into its next half-century, we must preserve the resources at the core of our organization: our research stations, our world-class educational programs, and the people that are committed to them. I am ready to contribute to the creative thinking, hard work, and dedication needed to help OTS evolve and deepen its commitment to enhancing education about, and research in, the tropical world.

For more information about the future of OTS and how you can help, please contact me at elizabeth.braker@tropicalstudies.org or contact Jim Boyle, Vice President Philanthropy at james.boyle@tropicalstudies.org or at 360.920.6302. Thank you!


Susan Cordell

Director, Institute of Pacific Islands Forestry

  • M.S. University of Hawai’i 1996
  • Ph.D. University of Hawai’i 1999

I am a research ecologist with the U.S. Forest Service’s Institute of Pacific Islands Forestry, based in Hilo, Hawai.

I carry out research based on my expertise in plant ecophysiology. Ecophysiology looks at the structure and functions of plants to better understand their tolerance to change and their ability to adapt in new locations or situations.

When people think about Hawai’i, they usually think about lush tropical rainforests. And we definitely have those here, but I do a lot of my research in tropical dry forests, which are some of the rarest, most specialized ecosystems in the world.

Tropical dry forests are facing insurmountable threats from a lot of invasive plants, particularly grasses brought in from various parts of the world. It might sound strange to think of grass as a threat, but here it is. Not only do they crowd out native plants, but these grasses are very flammable, so they’ve now brought wildfire into an ecosystem that wasn’t designed to be burned. With every fire, more native plants are destroyed, and they’re replaced by these fire-adapted intruders.

These research themes represent an articulation of future Institute research and our vision to continue developing next generation understanding of landscape change, testing of conservation based tools, facilitating the production of knowledge to improve the ecological condition of native ecosystems of the Pacific, enhance the sustainability of resource use in our region, and maintain the quality of life for those in our Pacific community. Institute Scientists have identified research themes as representing the frontiers of natural resources science and management in Hawai‘i and the US Affiliated Pacific, but also frontiers in tropical ecology and natural resources science broadly.

  • USDA Forest Service Institutional Representative, 2006-present.
  • Member Director, Board of Directors
  • Las Cruces Advisory Committee
  • Board of Directors Executive Committee.

Kyle Harms

Professor of Biological Sciences, Louisiana State University

  • Ph.D. Princeton University – 1997

Kyle is a Professor of Biological Sciences at Louisiana State University (LSU), where he teaches undergraduate courses in conservation biology and ecology, as well as graduate courses in community ecology. His principal research interests are the ecological and evolutionary processes that give rise to and maintain patterns in high-diversity plant communities, especially tropical forests and sub-tropical pine savannas. He grew up in rural Iowa, but has since worked in the field, with colleagues, and with data sets from all five tropical continents. A seven-month field season in Chile as an undergraduate helped orient him toward graduate school and a dissertation project in Latin America. He earned a Ph.D. at Princeton University by completing a research project on Barro Colorado Island (Panama), and then enjoyed tropically-oriented, post-doctoral stints at the Smithsonian Tropical Research Institute, University of California at Santa Barbara, and Cornell University, before accepting his faculty position at LSU.

  • Advanced Comparative Neotropical Ecology (Four Forests) Course (2001)
  • OTS Courses Resource Person (1998-present, occasionally)
  • Panel Judge for OTS Student Paper of the Year (2014-2016)
  • OTS Science Committee (2009-2014)
  • Member Director, OTS Board of Directors (2018-present)
  • LSU Institutional Representative (LSU is a permanent member institution)

André Kessler

Professor of Biology, Cornell University

  • M.A. University of Würzburg, Germany 1998
  • Ph.D. Max Plank Institute for Chemical Ecology/University of Jena, Germany 2002

As undergraduate and graduate student I had the first exposure to tropical environments when studying insect biodiversity in Bornean primary and secondary rainforests.

I have co-led an OTS graduate specialty course on “Plant Animal Interactions in the Tropics” at La Selva and have been visiting faculty on OTS graduate courses.

I am a chemical ecologist research focuses on the mechanisms, ecological consequences and the evolution of plant induced responses to herbivore damage. Conceptually, I study plant secondary metabolism as a vehicle of information transfer. Chemical information can mediate complex interactions from the molecular and cell to the whole plant and community level. As a consequence, my research includes studying chemical elicitation of plant responses, plant chemistry-mediated alterations in insect population and community dynamics, plant-plant communication, plant-pollinator interactions and plant defense mechanisms against herbivores. Moreover, we put a particular emphasis on studying the ecological functions and evolution of plant metabolic responses and chemical information transfer in the plants’ native habitats. With more recent projects my group tries to apply some of the chemical ecology principles found in native systems to control insect pests in agricultural systems. My research includes a number of different study systems in New York, Utah, Peru, Costa Rica, Colombia and Kenya.

  • Board of Directors (2015-2019 and 2019-present)
  • Governance/HR Committee (2018-present)
  • Education Committee (2018-present)
  • Finance Committee (2018-present)
  • Interim Chair of Governance/HR Committee (2020)
  • Assembly of Delegates for Cornell (2012-present)

Erin Kuprewicz

Assistant Research Professor & Vertebrate Collections Manager, Department of Ecology and Evolutionary Biology, University of Connecticut

  • B.S. University of California Santa Barbara, 2003
  • Ph.D. University of Miami

Erin is a tropical ecologist who studies plant-animal interactions and how they scale up to affect forest communities in a changing world. Her research programs in Costa Rica and México examine how terrestrial mammal granivores facilitate (via seed dispersal) or prevent (via seed predation) plant range expansions to outpace upslope ecosystem shifts expected as the climate rapidly warms. In the Madre de Dios region of Perú, she investigates how hunting of terrestrial seed dispersers affects carbon storage in adult trees via disruptions in seed-to-seedling transitions. Erin is especially interested in using field experiments to understand how seed-eating animals interact with seeds and seedlings spanning suites of traits and how flexible ecological interactions affect plant survival and spread in biodiverse ecosystems. She is based at the University of Connecticut (the first OTS Lifetime Member Institution!) where she is an Assistant Research Professor (2016-present) and Vertebrate Collections Manager (2019-present). Erin has over 15 years of experience conducting research, leading field courses, and building conservation capacity in the Neotropics. Her close, sustained connections with numerous tropically-oriented organizations (including OTS, ATBC, Smithsonian), long-term research programs spanning three countries in tropical America, and her passion for mentorship of early career scientists (e.g., coordinating and serving as resource faculty on many OTS fundamentals courses in Costa Rica, founding the ATBC Student and Early Career Scientist Chapter) provide her with the experience she needs to serve as an effective Member Director on the OTS Board of Directors. Erin’s tropical connections, creativity, enthusiasm, and experience within and outside of OTS put her in a unique position to further OTS’ mission as a leader in transformative tropical science research and education.

  • Board of Directors (2020-present)
  • Award Committee Chair (2018-present) OTS Kimberly G. Smith Outstanding Student Paper Award.
  • Reviewer (2012-present) OTS Kimberly G. Smith Outstanding Student Paper Award
  • Institutional Representative, University of Connecticut (2016-present)
  • La Selva Advisory Committee
  • Ad hoc reviewer, OTS graduate student grants
  • Coordinator of graduate courses (Tropical Biology: An Ecological Approach) in 2011, 2012, and 2013.
Gabriel Macaya

Gabriel Macaya

Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica

  • Diploma of Specific Studies in Biochemistry, Université Paris, 1972
  • Ph.D. Université Paris, 1977

Gabriel Macaya has studied the conformation of DNA, the organization of the genome of eukaryotes and the interaction of the Ag + ion with DNA. In addition, he has worked in molecular biology and virology, and developed methodologies to fractionate DNA using cesium salt gradients. He is the principal investigator of the projects “Bipolar Endophenotypes in Population Isolations” and “Mapping of Genes of Susceptibility to Alcoholism”, both in his position at the Center for Research in Cellular and Molecular Biology, of the University of Costa Rica.

He has held the positions of Vice Chancellor for Research at the University of Costa Rica (1981 to 1988), Rector of the University of Costa Rica (1996 to 2004), Director and researcher of the Center for Research in Cellular and Molecular Biology at the University of Costa Rica (1992 to 1996), Science and Technology Strategy Project Consultant at the CR-USA Foundation (2005), President of the National Academy of Sciences (2006-2014), and Vice President of the Executive Committee of the 21st Century Strategy (2007).

In addition, he is a member of the Costa Rican Society of Biochemistry and Molecular Biology, member since 1987 and President (2020-2025) of the Board of Directors of the Omar Dengo Foundation. For 10 years he was a member of the Scientific Council of the Stazione Zoologica Anton Dohrn, Naples, Italy. He received the National Prize for Science “Clodomiro Picado Twight” in 1977, as well as the following awards: “Knight of the Order of Academic Palms”, awarded by the Government of France, “Doctor of Humane Letters”, awarded by the New York State University, 1998 and “Officer of the Order of the Legion of Honor”, granted by the French government on May 29, 2002.

  • Has been involved with OTS since before the bridge
  • Worked with the Clarks on the trees project
  • Helped negotiate the UCR – OTS relationship
  • Permanent member of the Board of Visitors
  • Institutional Representative for University of Costa Rica
  • Stakeholder Director, 2018-present

Nathan Muchhala

Assistant Professor, Department of Biology; University of Missouri – St. Louis

  • Ph.D. University of Miami, USA;
  • B.A. Earlham College, USA

Nathan Muchhala is an Associate Professor of Biology at the University of Missouri – St. Louis (UMSL), where he teaches undergraduate courses in ecology, as well as graduate courses in evolution and systematics. His research centers around the evolution of plant-pollinator interactions, with a particular focus on plants pollinated by bats and hummingbirds, and he has conducted fieldwork in multiple countries in the Neotropics such as Ecuador, Colombia, Costa Rica, and Bolivia. He uses various approaches including molecular phylogenetics, population genetics, and field experiments to explore questions such as how specialization evolves, what the ecological and evolutionary consequences of competition for pollination are, and how pollinators affect plant speciation. He earned his Ph.D. at the University of Miami, during which he spent three years living and working in Ecuador, and then did postdoctoral stints at the University of Toronto and the University of Nebraska – Lincoln. He is currently serving as the Director of Graduate Studies for UMSL’s Biology Department.

Nathan became a huge fan and proponent of OTS ever since he participated in a Tropical Ecology field course in the summer of 2001.

  • Board of Directors (2020-present)
  • Institutional Representative, University of Missouri, St. Louis (2014-present)
  • OTS resource person, 2015 and 2017.

Oscar J. Rocha

Associate Professor, Kent State University

  • B.A. Universidad de Costa Rica 1980, 1981
  • M.Sc. Universidad de Costa Rica 1985
  • Ph.D. Penn State University, 1990

I started my long-term association with OTS in 1981, when I visited La Selva as a student for the first time. I served as Station Manager at La Selva from 1984-1985. The position changed to Assistant Director during my tenure.

As a graduate student, I served as a Teaching Assistant for Tropical Biology: An Ecological Approach in 1986.

As an educator, I have led undergraduate courses from Penn State University, Iowa State University, and Kent State University to La Selva, Las Cruces, and Palo Verde. I have been a visiting faculty member on graduate courses.

The goal of my work is to study genetic variation in natural populations of plants and animals using molecular markers. I am interested in understanding how ecological factors, such the reproductive biology, and human disturbances, affect the distribution of genetic variation. This information is useful for establishing conservation strategies for these populations.

My work in tropical dry forests focuses on the impact of synchronization of flowering phenology on pollination, fruit set, and gene movement among closely related tropical dry forest trees. It is my interest to study the variation in the floral display at three levels. First, I make comparisons between species that differ in the duration and synchronization of their flowering season. Second, I examine the variation within species during the reproductive season, as the density of flowering individuals changes. Third, I study the consequences of flowering out of synchrony. Pollination, fruit set, and gene movement depending on the responses of pollinators to the differences in floral displays.

  • Board of Directors
  • Nominating Committee
  • Vice President of Costa Rican Institution
  • Costa Rican Institution Committee
  • La Selva Advisory Committee, Science Committee

Chelsea Ward

Professor of Biology and Environmental Science, Auburn University at Montgomery

  • B.S. Florida Institute of Technology, 1998
  • Ph.D. Auburn University – 2005

Chelsea is the Chair of the Department of Biology and Environmental Science where she has been faculty since 2005. Her research focuses on latitudinal gradients in immunology and stress physiology in anurans, primarily focusing on changes in the environment affect these physiological processes. As faculty, her primary focus involves teaching and learning how to engage today’s science students in novel ways.

Her relationship with OTS began when she helped a fellow graduate student with his field season at La Selva looking at vertical habitat use of anurans. She then returned to start a project of her own the next year, Latitudinal Gradients in Stress Physiology, a Physiological Explanation of the Jimmy Buffet Effect. As new faculty she was the first in her college to bring students to La Selva and negotiated Auburn’s life time membership not long after. Currently, she works to increase underrepresented students in study abroad and STEM programs.

  • Auburn University Institutional Representative, 2007 to present
  • Science Committee 2017 to present
  • Member Director, Board of Directors 2018 to present
  • Education Committee 2018 to present, Chair 2019 to present
  • Executive Committee 2019 to present
  • Secretary to the Board, 2019 to present

Stakeholder Directors


P. Bryan Heidorn

Professor of Information Science, University of Arizona

  • B.S. University of Pittsburgh, Psychobiology 1979
  • Ph.D. University of Pittsburgh 1997

I work in a field called biodiversity informatics on such topics as using natural language processing to extract plant features form text, electronic keys, mining of museum specimen metadata and use of genomics and environment to predict phenotypic expression.

I also work on scientific data policy sometimes with OTS. My current research includes use of machine learning to predict phenotype from genetics and environmental variables. https://genophenoenvo.github.io/. I was a professor for 10 years at the University of Illinois. I then served two years as a program director in the NSF Division of Biological Infrastructure, and I arrived at the University of Arizona 10 years ago and was the founding director of the School of Information. I served on the OTS Informatics committee for 8 years. He served on the Board of Trustees for the JRS Biodiversity Foundation for seven years as a chair of the grants committee, vice president and president. JRS has an activist board that fosters research and infrastructure for the dissemination of biodiversity information particularly in Africa.

  • Board of Directors
  • Audit Committee (2019-present)
  • Communication Committee (2019)
  • Science Committee

David Knell

CEO TelNG and Owner of Breckinridge Pour House

  • M.A. Cambridge University

David Knell, CEO of TelNG, is a forward thinking technologist who appreciates that some people are caught in a time warp. TeING was founded a decade ago in England, before relocating to Breckenridge. The telecom company is courting the diminishing fax transmission market with their newest product FaxJack. Essentially the FaxJack apparatus contains software to make packet transmission reliable by adding delay, he said. By adding a three second delay dropped data is avoided.

In addition to TeING, David owns the bar and restaurant BoLD with his wife Marina’s. The menu at is founded on recipes from Marina’s grandmother’s Greek recipes and features local Colorado ingredients whenever possible.

  • Stakeholder Director
  • OTS Board of Directors (2019- present)

George Middendorf

Professor of Biology, Howard University

  • A.B. Dartmouth College 1973
  • M.A. Hunter College, City University of New York 1975
  • Ph.D. University of Tennessee – Knoxville 1979

My association with the Organization for Tropical Studies began over a decade ago when I was asked to serve as the university representative. It has continued since then and I consider it to be a great honor to be asked to serve as the Chair of the OTS Board of Trustees.

Unlike many others on the Board, I did not take an OTS course during my undergraduate and graduate years, although I have conducted REU mentor workshops at La Selva and Las Cruces. My research career has involved fieldwork at research stations in the deserts and tropics. For over four decades, I’ve conducted behavioral and ecological studies of lizards at the Southwestern Research Station of the American Museum of Natural History. In addition, I’ve worked on the behavior of mantis shrimp at the Smithsonian Tropical Research Institution in Panama and more recently, on the population demographics of sloths in Suriname.

While most of my teaching has focused in classrooms—ecology, animal behavior and science & public policy, an interdisciplinary course, I’ve also taught field courses in Arizona, New Mexico, Bolivia, Panama, Peru, and Suriname. Because of my position at Howard University, an HBCU, I have been involved in efforts to increase minority representation in the environmental fields—serving on NSF’s Committee on Equal Opportunities in Science and Engineering and chair of ESA’s Environmental Justice Section. I’ve also served on ESA’s Committee on Diversity and Education and currently chair ESA’s 4DEE (Four-Dimensional Ecology Education) Subcommittee that developed and is now implementing this ESA-endorsed curricular framework.

  • Howard University Representative (2009-)
  • Member, Advisory Committee for Academic Diversity (2009-2014)
  • Chair, Advisory Committee for Academic Diversity (2014-2018)
  • Chair, Governance and Human Resources Committee (2018-2019)
  • Member, OTS Board of Directors (2014- present)
  • Interim Chair, OTS Board of Directors (2019-2020)
  • Chair, OTS Board of Directors (2020-present)

Muriel Poston

Professor of Environmental Analysis, Pitzer College

  • M.S. University of California, Los Angeles
  • Ph.D. University of California, Los Angeles
  • J.D. University of Maryland-Baltimore

Dr. Poston currently a professor in the Environmental Analysis program at Pitzer College and previously served as Dean of the Faculty/Vice President for Academic Affairs from 2012-15. In addition, she served as the Division Director for the Division of Biological Infrastructure in the Biological Sciences Directorate (2016-19) and as Division Director in the Human Resource Division in the Education and Human Resources Directorate (2011-12) at the National Science Foundation. From 2005-2011, she also served as Dean of Faculty and Professor of Biology at Skidmore College. She is a plant systematist whose research has focused on the phylogenetics of Loasaceae. Throughout her career, she has worked to support efforts to broaden the participation of underrepresented students and faculty in science, technology, engineering and mathematics (STEM) disciplines, and sought to enhance the capacity and infrastructure of STEM facilities. She spent over twenty years as a professor in the Department of Biology/Botany at Howard, where she focused on undergraduate education, served as curator of the university herbarium, and worked on the development of an environmental science program. Dr. Poston previously served as a program director and deputy division director in the Biological Sciences Directorate at the National Science Foundation (NSF) where she was responsible for programs to enhance infrastructure for biological research collections, research instrumentation, and field station facilities. She has served as the Chair of the congressionally mandated Committee on Equal Opportunities in Science and Engineering and the NSF Advisory Committee for the Biological Sciences Directorate. She has also served as a member of the Advisory Committee for Project Kaleidoscope, and as a member of the National Academy of Sciences, National Research Council Board of Life Sciences. She is a Fellow by the American Association for the Advancement of Science, and is currently a member of the Board of Directors of the American Institute of Biological Sciences.

  • Member Director, Board of Directors
  • Participant in Faculty Lead courses using OTS field stations
  • OTS alum

John Tobin-de la Puente

Professor of Practice of Corporate Sustainability, Cornell University

  • Ph.D. Harvard University, Organismic and Evolutionary Biology
  • J.D. Harvard University
  • B.S. University of California at Los Angeles, Biology

Professor John Tobin-de la Puente is a professor of practice at the Charles H. Dyson School of Applied Economics and Management. He is an environmental biologist and attorney by training. He has over two decades of private sector experience, having practiced corporate law and worked in the international finance industry for most of his career. His recent work focuses on corporate sustainability, including the management of environmental, social, and reputational risks; stakeholder engagement and communications; business ethics; sustainability strategy; and, development of financial products and services that aim to address broad societal challenges. In addition, he has substantial leadership and governance experience in not-for-profit entities at the board level, particularly in the areas of environment, science, and education.

  • Stakeholder Director (2020-present)
  • Board of Directors (2005-2014)
  • Chair of Audit Committee
  • Secretary of the Board

Álvaro Umaña Quesada

Treasurer and Chair of Audit Committee CATIE

  • Research and Development Division, CATIE (Centro Agronómico Tropical de Investigación y Enseñanza)
  • M.S. Stanford University, M.S. Penn State University
  • Ph.D. Stanford University

Alvaro Umaña Quesada, Ph.D., is Senior Research Fellow at the Tropical Agronomic Center for Research and Higher Education (CATIE) in Turrialba, Costa Rica, and he is recognized as a leader in policy formulation and in environmental economics.

Umaña was Costa Rica’s first Minister of Energy and Environment, under Arias’ first administration, from 1986 to 1990. In this role, he expanded and regionalized the system of protected areas, created new financial mechanisms, developed a unique system of incentives known today as “payment for ecosystem services,” and promoted the creation of the National Biodiversity Institute. He also designed and developed a master’s program in Sustainable Development and led it for a decade at INCAE, Central America’s School of Business and Management. In ten years, over 120 students from 20 countries have graduated and the program continues to thrive.

Umaña is the author of numerous publications and books, including: The World Bank Inspection Panel: The First Four Years and Financing for Sustainable Development and Point West: The Political History of the Guanacaste National Park Project. International awards that he has received include the President’s Public Service Award from the Nature Conservancy in 1988, a Special Achievement Award from the National Wildlife Federation in 1989, and an honorary doctorate in Law from Williams College for his work on payment for ecosystem services.

Umaña has been a board member of the United Nations Educational, Scientific, and Cultural Organzation (UNESCO), the Rockefeller Foundation, the World Resources Institute, and the Stockholm Environment Institute. He also has been a member of the Goldman Environmental.

  • Stakeholder Director, OTS Board of Directors (2018- present)
  • Interim Treasurer and Chair of Audit Committee (2019- present)

Terry Vogt

Managing Director, Terra Global Capital LLC

  • A.B. Harvard University
  • MBA University of Colorado, Boulder

Terry Vogt grew up in Mexico, but has spent much of his life in Brazil, first as a Peace Corps volunteer in Northeast Brazil, then as head of Wells Fargo’s Brazil office, followed by fifteen years as a partner in a Rio-based investment group. He went further afield in Latin America when he spent three years in Costa Rica as Chief Operating Officer of the Inter-American Institute for Cooperation on Agriculture — IICA — an international organization dealing with agriculture and sustainable rural development throughout the hemisphere. He finished his career as Director of Sustainable Conservation Finance for the Gordon & Betty Moore Foundation.

He is the past Chairman of the Board of Global Footprint Network and served as Member of the Board of CATIE, the Central American graduate school of agriculture. In 1996 Fernando Henrique Cardoso, President of Brazil, decorated Mr. Vogt with the Order of Rio Branco for his services promoting trade and investment for Brazil. He has an undergraduate degree in Latin American History from Harvard and a Masters in Operations Research from the University of Colorado.

  • Stakeholder Director (2020-present)
  • Member, Board of Visitors