Gerardo Avalos, Ph.D.


Center Director


Costa Rica


B.S. in Biology
University of Costa Rica

M.S. in Tropical Ecology and Conservation
University of Missouri-St. Louis (MO, USA)

Ph.D. in Tropical Ecology and Conservation (Ecophysiology)
University of Missouri-St. Louis (MO, USA)


SFS 4910/4920 Directed Research
(The School for Field Studies)

SFS 2050 Language, Culture and Society of Costa Rica
(The School for Field Studies)

Multivariate Statistics, Natural History of Costa Rica, Ecology of Palms
Associate Professor (University of Costa Rica)

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Faculty Profile

Gerardo Avalos holds a Ph.D. and an M.S. in plant physiological ecology and conservation from the University of Missouri at St. Louis. After obtaining his B.Sc. in Biology at the University of Costa Rica, Gerardo began his graduate studies at the University of Colorado at Boulder, and then he transferred to the University of Missouri – St. Louis, where he investigated the physiological ecology of lianas and using a construction crane to reach the canopy working with the Smithsonian Tropical Research Institute in Panama. His dissertation examined the light acclimation of tropical lianas to temporal and spatial changes in light availability at the surface the forest canopy. His current research interests include the biomechanics of tropical palms, the impact of illegal extraction on the population biology of palms, the effects of habitat fragmentation on species conservation of local and migratory birds, the functional ecology of hummingbirds, and the dynamics of carbon sequestration. After serving for 6 years as the Center for Sustainable Development Studies resident ecologist, Gerardo became the Center Director in 2007. He is aslo associated with the University of Costa Rica where he teaches Botany, Natural History, and Multivariate Statistics.

Academics & Research

Areas of Expertise

  • Carbon sequestration
  • Functional ecology of hummingbirds
  • Multivariate statistics
  • Palm allometry
  • Physiological ecology of tropical plants
  • Plant biomechanics
  • Tropical ecology and conservation

Professional Affiliations

  • Member, Association for Tropical Biology and Conservation (ATBC)
  • Member, Society for Economic Botany
  • Member, Botantical Societry of America
  • Member, Editorial Board of Oecologia (Ecophysiology section)

Research Interests

I am interested in the physiological adaptations of tropical plants to spatial and temporal changes in the availability of light, especially the characters that are responsible for the expression of plasticity at the extremes of the light gradient in a tropical forest: the understory and the canopy. In my PhD dissertation I explored the physiological ecology of canopy lianas and their adaptation to light gradients working 50 m above the ground form the top of a construction crane located in a jungle in Panama. Currently, I am doing research on the biomechanics of tropical palms to understand the limits to height increases and the strategies of leaf display in plants that only have primary growth.

These interests led to research projects looking at the dynamics of the extraction of non-timber forest products coming from palms, such as heart of palm. I have explored the ecological consequences of palm extraction, as well as the social and cultural interface determining extraction preferences. I also have studied the effects of fragmentation of roads on neotropical birds, especially understory insectivores, implementing plant ecology techniques (hemispherical photographs) to describe habitat structure and to predict habitat quality for many understory insectivore species. Finally, I have studied the temporal cycles of tropical aquatic macroinvertebrates and their utility as biological indicators. In all these research areas I apply the latest multivariate statistics techniques to understand the interactions among multiple variables across space and time.

Research Projects

This project uses an 8-year database on the diversity and distribution of aquatic macroinvertebrates across 6 sites in Costa Rica, two of them located within Braulio Carrillo National Park. The streams in this project included pristine sites located at similar elevation but with different structure and different sources of impacts. We implement different bioindication indices, and expanded the data base for Río Santa Clara in Guápiles. I have found stability in Order composition at the local level, but great dynamism across temporal scales, justifying the idea of maintaining long-term monitoring programs to detect temporal changes in the structure of bioindicator Orders.


Manuscripts in the works looking at changes across space and time over 8 years, and at the use of hierarchical diversity at the Order and Family level to track changes in the structure of macroinvertebrate bioindicators.

This project monitors the growth of seedlings of the palm Euterpe precatoria in response to canopy changes measured with hemispherical photos. Euterpe precatoriaconcentrates the bulk of illegal extraction of heart of palm from national parks. Seedlings of E. precatoria were planted in 2005 in two forest fragments in the Caribbean lowlands of Costa Rica. Sets of photographs are analyzed and correlated with seeling growth. Canopy changes at both field sites have been very stable, and that most seedlings experienced negative growth and increased mortality. We are now monitoring E. precatoria palms growing in the open. In addition, seedlings of Geonoma edulis (another extracted species are being grown in the greenhouse of the University of Costa Rica, and will soon be planted in Braulio Carrillo National Park to start a different monitoring study).


Manuscripts are the works looking at shade tolerance in Euterpe precatoriaand Geonoma edulis.

Grants and Awards

Keynote speaker to the International Palm Society meeting in San Jose, Costa Rica, May 2008.


Select Publications

Salguero-Hernández, G. & G. Avalos. (2019). Report of bird captures in the páramo of Cerro Buena Vista, Costa Rica. Zeledonia 23(1): 55-59.
Chacón-Madrigal, E., Avalos, G., Hofhansl, F., Coronado, I., Ferrufino, L., MacVean, A. & D. Rodríguez. (2019). Biological invasions by plants in continental Central America. Chapter 9 in: Global Plant Invasions, Springer Verlag.
Avalos, G. (2018). Still searching the rich coast: Biodiversity of Costa Rica, numbers, processes, patterns, and challenges. Chapter 7 in Pullaiah, T. (editor). Global Biodiversity, 4. CRC Press, Florida, USA.
Cambronero, M., G. Avalos & C. Alvarez-Vergnani. (2018). Carbon accumulation in seven neotropical palm species from different forest strata. Palms, 62(1).
Kandlikar, G., Vaz, M., Kriebel, R., Vargas, G., Michelangeli, F., Cordero, R., Almeda, F., Avalos, G., Fetcher, N., Kraft, N. (2018). Contrasting patterns of taxonomic, phylogenetic and functional variation along a Costa Rican altitudinal gradient in the plant family Melastomataceae. Journal of Tropical Ecology, 34(3). (pp 204-208).
Avalos, G., A. Häger, E. Arévalo, M. Little, & K. Goodall. (2017). El Centro de Estudios sobre Desarrollo Sostenible, un modelo de educación en el extranjero con una huella positiva en Costa Rica. Ambientico 264. (pp 4-12).
Cambronero, M., G. Avalos & C. Alvarez-Vergnani. (2017). Variation in carbon fraction in seven neotropical palm species of different forest strata. Palms.
Hager, A. & G. Avalos. (2017). Does functional diversity determine carbon storage in an altered tropical landscape? Oecologia.
Ley, J.M. & G. Avalos. 2016. American Journal of Botany (in rev).
Avalos, G. 2016. p. 17-38 In: S. Molina & Rojas, C. (eds). The Paradigm of Forests and the Survival of the Fittest. CRC Press, Florida, USA.
Goldstein, G., L. S. Santiago, P.I. Campanello, G. Avalos, Y.J. Zhang & M. Villagra. 2016. In: Tropical Tree Physiology: Adaptations and Responses in a Changing Environment, Springer International, Editors: Guillermo Goldstein, Louis S Santiago, pp.319-336
Avalos, G. & S. S. Mulkey. 2014. Am. J. Bot. 101(12). doi: 10.3732/ajb.1400127
Fernández-Otárola, M. & G. Avalos. 2014. Am. J. Bot. 101 (6): 1023-1028. doi:10.3732/ajb.1400089
Sánchez, N.V., L.E. Vargas-Castro, G. Avalos & F. Paniagua. 2014. Journal of Field Ornithology 85(4): 347-354.
Celis, G. & G. Avalos. 2013. Revista de Biología Tropical 61(4): 1859-1868.
Avalos, G., M. Fernández-Otárola & J.T. Engeln. 2013. Revista de Biología Tropical 61(3): 1415-1424.
Sylvester, O., G. Avalos & N. Cháves-Fernández. 2012. Palms 56(4): 190-201.
Avalos, G., A. Soto & W. Alfaro. 2012. Revista de Biología Tropical 60(1): 65-73.
Vargas, LE, Sánchez, NV & G Avalos. 2011. Journal of Tropical Ecology 27:65–72.
Avalos, G. & O. Sylvester. 2010. 24(5): 969-974. Included in the special issue of TREES on Empirism and Modeling in 2014.


Kandlikar, G., Carita-Vaz, M., Kriebel, R. Vargas, G., Michelangeli, F. Cordero, R., Almeda, F., Avalos, G., Fetcher, N., & Kraft N. J. B. 2015. 100TH Annual Meeting of the Ecological Society of America, Baltimore, Maryland.
Hager, A. & G. Avalos. 2015. Conference: 21st Annual Conference, International Society of Tropical Foresters - Conserving biodiversity across multiple use landscapes through strategic governance and land-use planning, Yale School of Forestry and Environmental Studies, New Haven, Connecticut.
Avalos, G., G. Lee & A. Soto. 2013. Proceedings of the Association for Tropical Biology and Conservation, San José, Costa Rica, June 2013.
Avalos, G. and G. Lee. 2012. III Congress of Ornithology, Costa Rica. San José.
Sylvester, O. and G. Avalos. 2009. Meeting of the Latinamerican Network of Botany, San Jose, Costa Rica, November 2009.
San Ramon, Costa Rica, July 2008.
May 2008. The conference versed on the Functional Ecology of Palms in Costa Rica.
In the annual reunion of the Association for Tropical Ecology and Conservation in Michoacán, Mexico, July 2007.
M.G. Gei and G. Avalos. 2006. IX latinamerican Interntional Symposium of Botany, Santo Domingo, Domenic Republic, May 2006.
Avalos, G. & M. Mauricio Fernandez. 2005. Congress of Conservation and Wildlife Management, 21 to 25 February 2005, Universidad Nacional, Heredia, Costa Rica.
Avalos, G. & E. Bermúdez. 2005. Congress of Conservation and Wildlife Management, 21 to 25 February 2005, Universidad Nacional, Heredia, Costa Rica.
Avalos, G. 2003. IV Congreso Nacional de Biología Clodomiro Picado, San José Costa Rica.
Avalos, G., A. Soto, J. Veenstra, T. Smith and C. Keller. 2002. Proceedings of the Association for Tropical Biology, Panama city, Panama, June 2002.
Avalos, G. 1998. VII Congreso Latinoamericano de Botanica: Diversity and Conservation of plant resources in Latin America. Mexico DF, Mexico, in October 1998.
Avalos, G. & S.S. Mulkey. 1997. Tropical Diversity: Origins, maintenance and conservation. Symposium and Annual Meeting. Association for Tropical Biology and OTS, Costa Rica San Jose June 1997.