Eileen Helmer, PhD

Treesearch Publications

• Nafiseh Haghtalab, Tamara Heartsill Scalley, Tana E. Wood, J. Aaron Hogan, Humfredo Marcano-Vega, Thomas Brandeis, Thomas Ruzycki, Eileen Helmer. 2026. Multi-Resolution Mapping of Aboveground Biomass and Change in Puerto Rico’s Forests with Remote Sensing and Machine Learning
• Holly L. Munro, Christopher W. W. Woodall, William R. L. Anderegg, Colin M. Beier, Bronson P. Bullock, Kendall DeLyser, David D. Diaz, Bianca N.I. Eskelson, Margaret E. K. Evans, Jeff W. Atkins, John D. Foppert, Bryan C. Foster, Thomas R. Fox, Jereme M. Frank, Robert E. Froese, George C. Gaines, Peter Gould, Temesgen Hailemariam, Edie Sonne Hall, Katherine A. A. Heckman, Eileen Helmer, J. Aaron Hogan, Coeli Hoover, Stephen M. Kinane, David W. MacFarlane, Lara T. Murray, Gregory Paradis, Krishna P. Poudel, Stephen P. Prisley, James L. Rakestraw, Hector Restrepo, Ajay Sharma, John D. Shaw, Erin Smith-Mateja, Curtis L. VanderSchaaf, Can Vatandaslar, Aaron R. Weiskittel, Sheng-I. Yang. 2025. Challenges and Strategic Recommendations for Enhancing Quantification and Projection of Forest Carbon Dynamics
• Don Faber-Langendoen, David A. Keith, Javier Loidi, Eileen Helmer, Wolfgang Willner, Gonzalo Navarro, John Hunter, Changcheng Liu, Reginald T. Guuroh, Patricio Pliscoff. 2025. Advancing the EcoVeg approach as a terrestrial ecosystemtypology: From global biomes to local plant communities
• Eileen Helmer, N.R. Goodwin, V. Gond, C.M. Souza, G.P. Asner. 2025. Remote Sensing Handbook Volume IV - Characterizing tropical forests with multispectral imagery. Chapter 1
• German Vargas G., Humfredo Marcano-Vega, Tom Ruzycki, Tana E. Wood, William R. L. Anderegg, Jennifer S. Powers, Eileen Helmer. 2025. Aridity and forest age mediate landscape scale patterns of tropical forest resistance to cyclonic storms
• Sheng-I Yang, Thomas Brandeis, Eileen Helmer, Humfredo Marcano-Vega. 2025. Predicting species-specific diameter growth rate for Caribbean trees using mixed-effects extreme gradient boosting
• J. Aaron Hogan, Jeremy W. Lichstein, Eileen Helmer, Matthew E. Craig, Evan Fricke, Viola Henrich, Steven A. Kannenberg, Charles D. Koven, Kees Klein Goldewjik, David M. Lapola, Yue Li, Yadvinder Malhi, John Quinn, Stephanie Roe, Cesar Terrer, Emilio Vilanova, Anthony P. Walker, Kai Zhu, Erle C. Ellis. 2024. Anthromes and forest carbon responses to global change
• Joseph M. Wunderle Jr., Michael Akresh, Dave Currie, Javier E. Mercado, Eileen Helmer, David Ewert. 2024. Factors influencing home range size and overlap in nonbreeding Kirtland’s Warblers on Eleuthera, The Bahamas
• Genie M. Fleming, Joseph M. Wunderle Jr., Jennifer D. White, David Currie, Eileen Helmer, David N. Ewert. 2024. Winter dry season reproductive phenology in Bahamian dry forest and implications for conservation
• Eileen Helmer, Shannon Kay, Humfredo Marcano-Vega, Jennifer S. Powers, Tana E. Wood, Xiaolin Zhu, David Gwenzi, Thomas S. Ruzycki. 2023. Multiscale predictors of small tree survival across a heterogeneous tropical landscape
• Sheng-I Yang, Thomas Brandeis, Eileen Helmer, Michael P. Oatham, Tamara Heartsill Scalley, Humfredo Marcano-Vega. 2022. Characterizing height-diameter relationships for Caribbean trees using mixed-effects random forest algorithm
• Sebastián Martinuzzi, Bruce D. Cook, Eileen Helmer, Michael Keller, Dexter H. Locke, Humfredo Marcano-Vega, María Uriarte, Douglas C. Morton. 2022. Patterns and controls on island‐wide aboveground biomass accumulation in second‐growth forests of Puerto Rico
• Xiaolin Zhu, Eileen Helmer, David Gwenzi, Melissa Collin, Sean Fleming, Jiaqi Tian, Humfredo Marcano-Vega, Elvia J. Meléndez-Ackerman, Jess K. Zimmerman. 2021. Characterization of Dry-Season Phenology in Tropical Forests by Reconstructing Cloud-Free Landsat Time Series
• Shuai Xu, Xiaolin Zhu, Eileen Helmer, Xiaoyue Tan, Jiaqi Tian, Xuehong Chen. 2021. The damage of urban vegetation from super typhoon is associated with landscape factors: Evidence from Sentinel-2 imagery
• Meng Liu, Wei Yang, Xiaolin Zhu, Jin Chen, Xuehong Chen, Linqing Yang, Eileen Helmer. 2019. An Improved Flexible Spatiotemporal DAta Fusion (IFSDAF) method for producing high spatiotemporal resolution normalized difference vegetation index time series
• Eileen Helmer, E. A. Gerson, Scott Baggett, Benjamin Bird, Thomas S. Ruzycki, Shannon M. Voggesser. 2019. Neotropical cloud forests and páramo to contract and dry from declines in cloud immersion and frost
• Nathan W. Cooper, David N. Ewert, Joseph M. Wunderle Jr., Eileen Helmer, Peter P. Marra. 2019. Revising the wintering distribution and habitat use of the Kirtland’s warbler using playback surveys, citizen scientists, and geolocators
• Eileen Helmer, Thomas Ruzycki, Barry T. (Ty) Wilson, Kirk Sherrill, Michael Lefsky, Humfredo Marcano-Vega, Thomas Brandeis, Heather Erickson, Bonnie Ruefenacht. 2018. Tropical Deforestation and Recolonization by Exotic and Native Trees: Spatial Patterns of Tropical Forest Biomass, Functional Groups, and Species Counts and Links to Stand Age, Geoclimate, and Sustainability Goals
• Xiaolin Zhu, Eileen Helmer, Jin Chen, Desheng Liu. 2018. An Automatic System for Reconstructing High-Quality Seasonal Landsat Time-Series
• Jake Rice, Cristiana Simão Seixas, María Elena Zaccagnini, Mauricio BedoyaGaitán, Natalia Valderrama, Christopher B. Anderson, Mary T. K. Arroyo, Mercedes Bustamante, Jeannine Cavender-Bares, Antonio Diaz-de-Leon, Siobhan Fennessy, Jaime Ricardo García Márquez, Keisha Garcia, Eileen Helmer, Bernal Herrera, Brian Klatt, Jean P. Ometo, Vanesa Rodríguez Osuna, Fabio R. Scarano, Steven Schill, Juliana Sampaio Farinaci. 2018. Summary for policymakers of the regional assessment report on biodiversity and ecosystem services for the Americas of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services
• Mercedes Bustamante, Eileen Helmer, Steven Schill, Jayne Belnap, Laura K. Brown, Ernesto Brugnoli, Jana E. Compton, Richard H. Coupe, Marcello Hernández-Blanco, Forest Isbell, Julie Lockwood, Juan Pablo Lozoya Ascárate., David McGuire, Anibal Pauchard, Ramon Pichs-Madruga, Ricardo Ribeiro Rodrigues, Gerardo Arturo Sanchez- Azofeifa, Alvaro Soutullo, Avelino Suarez, Elizabeth Troutt. 2018. Chapter 4: Direct and indirect drivers of change in biodiversity and nature’s contributions to people
• Xiaolin Zhu, Eileen Helmer. 2018. An automatic method for screening clouds and cloud shadows in optical satellite image time series in cloudy regions
• E. Medina, E. Cuevas, H. Marcano-Vega, E. Meléndez-Ackerman, Eileen Helmer. 2017. Biogeochemical Relationships of a Subtropical Dry Forest on Karst
• David Gwenzi, Eileen Helmer, Xiaolin Zhu, Michael Lefsky, Humfredo Marcano-Vega. 2017. Predictions of Tropical Forest Biomass and Biomass Growth Based on Stand Height or Canopy Area Are Improved by Landsat-Scale Phenology across Puerto Rico and the U.S. Virgin Islands
• K. Banda-R, A. Delgado-Salinas, K. G. Dexter, R. Linares-Palomino, A. Oliveira-Filho, D. Prado, M. Pullan, C. Quintana, R. Riina, G. M. Rodriguez M., J. Weintritt, P. Acevedo-Rodriguez, J. Adarve, E. Alvarez, A. Aranguren B., J. C. Arteaga, G. Aymard, A. Castano, N. Ceballos-Mago, A. Cogollo, H. Cuadros, F. Delgado, W. Devia, H. Duenas, L. Fajardo, A. Fernandez, M. A. Fernandez, J. Franklin, E. H. Freid, L. A. Galetti, R. Gonto, R. Gonzalez-M., R. Graveson, Eileen Helmer, A. Idarraga, R. Lopez, H. Marcano-Vega, O. G. Martinez, H. M. Maturo, M. McDonald, K. McLaren, O. Melo, F. Mijares, V. Mogni, D. Molina, N. d. P. Moreno, J. M. Nassar, D. M. Neves, L. J. Oakley, M. Oatham, A. R. Olvera-Luna, F. F. Pezzini, O. J. R. Dominguez, M. E. Rios, O. Rivera, N. Rodriguez, A. Rojas, T. Sarkinen, R. Sanchez, M. Smith, C. Vargas, B. Villanueva, R. T. Pennington. 2016. Plant diversity patterns in neotropical dry forests and their conservation implications
• D. Faber-Langendoen, T. Keeler-Wolf, D. Meidinger, C. Josse, A. Weakley, D. Tart, G. Navarro, B. Hoagland, S. Ponomarenko, G. Fults, Eileen Helmer. 2016. Classification and description of world formation types
• Xiaolin Zhu, Eileen Helmer, Feng Gao, Desheng Liu, Jin Chen, Michael A. Lefsky. 2016. A flexible spatiotemporal method for fusing satellite images with different resolutions
• Eileen Helmer, Nicholas R. Goodwin, Valery Gond, Carlos M. Souza, Jr., Gregory P. Asner. 2015. Characterizing tropical forests with multispectral imagery
• G. M. Fleming, Joseph M. Wunderle Jr., D. N. Ewert, Joseph J. O'Brien, Eileen Helmer. 2015. Functional attributes of two subtropical shrubs and implications for the distribution and management of endangered bird habitat
• E. Medina, Eileen Helmer, E. Melendez-Ackerman, Humfredo Marcano-Vega. 2014. Natural vegetation groups and canopy chemical markers in a dry subtropical forest on calcareous substrate: the vegetation of Mona Island, Puerto Rico
• Robert Kennedy, Serge Andrefouet, Warren B. Cohen, Cristina Gomez, Patrick Griffiths, Martin Hais, Sean P. Healey, Eileen Helmer, Patrick Hostert, Mitchell B. Lyons, Garrett W. Meigs, Dirk Pflugmacher, Stuart R. Phinn, Scott Powell, Peter Scarth, Susmita Sen, Todd A. Schroeder, Annemarie Schneider, Ruth Sonnenschein, James E. Vogelmann, Michael A. Wulder, Zhe Zhu. 2014. Bringing an ecological view of change to Landsat-based remote sensing
• Eileen Helmer, H.E. Erickson, Thomas Brandeis, Ariel Lugo. 2014. Controls on fallen leaf chemistry and forest floor element masses in native and novel forests across a tropical island
• S. Martinuzzi, Ariel Lugo, Thomas Brandeis, Eileen Helmer. 2013. Case study: Geographic distribution and level of novelty of Puerto Rican forests
• Ariel Lugo, Eileen Helmer, E. Santiago Valentín. 2012. Caribbean landscapes and their biodiversity
• D. Faber-Langendoen, T. Keeler-Wolf, D. Meidinger, C. Josse, A. Weakley, D. Tart, G. Navarro, B. Hoagland, S. Ponomarenko, J.-P. Saucier, G. Fults, Eileen Helmer. 2012. Classification and description of world formation types. Part. I (Introduction)
• D. Faber-Langendoen, T. Keeler-Wolf, D. Meidinger, C. Josse, A. Weakley, D. Tart, G. Navarro, B. Hoagland, S. Ponomarenko, J.P. Saucier, G. Fults, Eileen Helmer. 2012. Classification and description of world formation types. Part II (Description of formation types)
• Thomas Brandeis, Elvia J. Meléndez-Ackerman, Eileen Helmer. 2012. Forest vegetation cover assessment on Mona Island, Puerto Rico
• Thomas S. Ruzycki, Jay Benner, Shannon M. Voggesser, Barbara P. Scobie, Eileen Helmer, Courtenay Park, David W. Fanning, Seepersad Ramnarine. 2012. Detailed maps of tropical forest types are within reach: forest tree communities for Trinidad and Tobago mapped with multiseason Landsat and multiseason fine-resolution imagery
• Claire C. Larkin, Charles Kwit, Joseph M. Wunderle Jr., Eileen Helmer, M. Henry H. Stevens, Montara T.K. Roberts, David N. Ewert. 2011. Disturbance type and plant succesional communities in Bahamian dry forests
• Eileen Helmer. 2010. Radiometric normalization
• Joseph M. Wunderle Jr., Dave Currie, Eileen Helmer, David N. Ewert, Jennifer D. White, Thomas S. Ruzycki, Bernard Parresol, Charles Kwit. 2010. Kirtland’s warblers in anthropogenically disturbed early-successional habitats on Eleuthera, The Bahamas
• Eileen Helmer, Thomas S. Ruzycki, Joseph M. Wunderle Jr., Shannon Vogesser, Bonnie Ruefenacht, Charles Kwit, Thomas Brandeis, David N. Ewert. 2010. Mapping tropical dry forest height, foliage height profiles and disturbance type and age with a time series of cloud-cleared Landsat and ALI image mosaics to characterize avian habitat
• Eileen Helmer, M. A. Lefsky, D. A. Roberts. 2009. Biomass accumulation rates of Amazonian secondary forest and biomass of old-growth forests from Landsat time series and the Geoscience Laser Altimeter System
• Thomas Brandeis, Eileen Helmer, Humfredo Marcano-Vega, Ariel Lugo. 2009. Climate shapes the novel plant communities that form after deforestation in Puerto Rico and the U.S. Virgin Islands
• Thomas Brandeis, Eileen Helmer, Humfredo Marcano-Vega, Ariel Lugo. 2009. Climate shapes the novel plant communities that form after deforestion in Puerto Rico and the U.S. Virgin Islands
• Todd Kennaway, Eileen Helmer, Michael Lefsky, Thomas Brandeis, Kirk Sherrill. 2009. Mapping land cover and estimating forest structure using satellite imagery and coarse resolution lidar in the Virgin Islands
• Jock A. Blackard, M. V. Finco, Eileen Helmer, G. R. Holden, M. L. Hoppus, D.M. Jacobs, Tonya Lister, Gretchen Moisen, Mark D. D. Nelson, Rachel Riemann, B. Ruefenacht, D. Salajanu, D. L. Weyermann, K. C. Winterberger, T. J. Brandeis, Ray L. Czaplewski, Ronald E. McRoberts, Paul L. Patterson, Ronald Tymcio. 2008. Mapping U.S. forest biomass using nationwide forest inventory data and moderate resolution information
• Eileen Helmer, T.A. Kennaway, D.H. Pedreros, M.L. Clark, Humfredo Marcano-Vega, L.L. Tieszen, S.R. Schill, C.M.S. Carrington. 2008. Land cover and forest formation distributions for St. Kitts, Nevis, St. Eustatius, Grenada and Barbados from decision tree classification of cloud-cleared satellite imagery. Caribbean Journal of Science. 44(2):175-198.
• T.A. Kennaway, Eileen Helmer, M.A. Lefsky, Thomas Brandeis, K.R. Sherill. 2008. Mapping land cover and estimating forest structure using satellite imagery and coarse resolution lidar in the Virgin Islands
• B. Ruefenacht, M.V. Finco, Mark D. D. Nelson, Ray L. Czaplewski, Eileen Helmer, J. A. Blackard, Geoffrey R. Holden, Andrew J. Lister, Dumitru Salajanu, Dale Weyermann, Ken Winterberger. 2008. Conterminous U.S. and Alaska Forest Type Mapping Using Forest Inventory and Analysis Data
• CURTIS E. WOODCOCK, RICHARD ALLEN, MARTHA ANDERSON, ALAN BELWARD, ROBERT BINDSCHADLER, Warren B. Cohen, FENG GAO, SAMUEL N. GOWARD, DENNIS HELDER, Eileen Helmer, RAMA NEMANI, LAZAROS OREOPOULOS, JOHN SCHOTT, PRASAD S. THENKABAIL, ERIC F. VERMOTE, JAMES VOGELMANN, MICHAEL A. WYNNE WULDER. 2008. Free Access to Landsat Imagery.
• Eileen Helmer, Thomas Brandeis, Ariel Lugo, Todd Kennaway. 2008. Factors influencing spatial pattern in tropical forest clearance and stand age: Implications for carbon storage and species diversity.
• Ariel Lugo, Eileen Helmer, Abel Vale. 2007. La conservacion y vulnerabilidad a la urbanizacion del karso puertorriqueño
• Thomas Brandeis, Eileen Helmer, Sonja Oswalt. 2007. The status of Puerto Rico's forests, 2003
• Thomas Brandeis, Eileen Helmer, Sonja Oswalt. 2007. El Estado de los Bosques de Puerto Rico, 2003
• Eileen Helmer. 2007. A comparison of radiometric normalization methods when filling cloud gaps in Lansat imagery.
• Todd Kennaway, Eileen Helmer. 2007. The Forest Types and Ages Cleared for Land Development in Puerto Rico.
• A.E. Lugo, E. Medina, J. Carlos Trejo Torres, Eileen Helmer. 2006. Botanical and ecological basis for the resilience of Antillean dry forests
• Eileen Helmer, M. A. Lefsky. 2006. Forest Canopy Heights in Amazon River Basin Forests as Estimated with the Geoscience Laser Altimeter System (GLAS)
• Eileen Helmer, M. A. Lefsky. 2006. Forest Canopy Heights in Amazon River Basin Forests as Estimated with the Geoscience Laser Altimeter System (GLAS)
• Eileen Helmer, B. Ruefenacht. 2005. Cloud-Free Satellite Image Mosaics with Regression Trees and Histogram Matching.
• Eileen Helmer. 2004. Forest conservation and land development in Puerto Rico.
• Ariel Lugo, Eileen Helmer. 2004. Emerging forests on abandoned land: Puerto Rico’s new forests
• H. Ricardo Grau, T. Mitchell Aide, Jess K. Zimmerman, John R. Thomlinson, Eileen Helmer, Xioming Zou. 2003. The Ecological Consequences of Socioeconomic and Land-Use Changes in Postagriculture Puerto Rico
• J. Danilo Chinea, Eileen Helmer. 2003. Diversity and composition of tropical secondary forests recovering from large-scale clearing: results from the 1990 inventory in Puerto Rico
• CHRISTOPHER DALY, Eileen Helmer, Maya Quinones. 2003. Mapping the Climate of Puerto Rico, Vieques and Culebra.
• Eileen Helmer, Olga Ramos, T. DEL M. LÓPEZ, Maya Quinones, W. DIAZ. 2002. Mapping the Forest Type and Land Cover of Puerto Rico, a Component of the Caribbean Biodiversity Hotspot
• Ariel Lugo, Leopoldo Miranda Castro, Abel Vale, Tania del Mar López, Enrique Hernández Prieto, Andrés García Martinó, Alberto R. Puente Rolón, Adrianne G. Tossas, Donald A. McFarlane, Tom Miller, Armando Rodríguez, Joyce Lundberg, John Thomlinson, José Colón, Johannes H. Schellekens, Olga Ramos, Eileen Helmer. 2001. Puerto Rican Karst-A Vital Resource

Data and Tools

• Dataset
  

  Puerto Rico, Vieques and Culebra land cover and forest formations circa 2000

  https://research.fs.usda.gov/iitf/products/dataandtools/puerto-rico-vieques-and-culebra-land-cover-and-forest-formations-circa
• Dataset
  

  Historical maps of land use in Puerto Rico in 1951

  https://research.fs.usda.gov/iitf/products/dataandtools/historical-maps-land-use-puerto-rico-1951
• Dataset
  

  Leaf mass per area for 105 tree species in Puerto Rico

  https://research.fs.usda.gov/iitf/products/dataandtools/leaf-mass-area-105-tree-species-puerto-rico

• Project
  

  Forest's Response to Hurricanes

  https://research.fs.usda.gov/iitf/projects/forest-responses-hurricanes
  Station

  International Institute of Tropical Forestry
• Program
  

  Forest Inventory and Analysis Puerto Rico and U.S. Virgin Islands

  https://research.fs.usda.gov/iitf/programs/fia
  Station

  International Institute of Tropical Forestry

• Oregon State University, Ph.D., Forest Ecology, 1998
• University of Minnesota, M.S.C.E., Environmental Engineering and Sciences, 1987
• University of Illinois, B.S., Ecology, Ethology and Evolution, 1984