Our Scientists

The Arboretum is home to diverse nitrogen-fixing legume species originating from around the world. Alaina Bisson will sample the root nodules from 100 trees with known origins in the Arboretum. She will sequence and identify the nitrogen-fixing rhizobia bacterial communities associated with these trees and determine if the location of origin impacts the community composition.

Andrea Berardi is a research associate in the Hopkins Lab broadly interested in the processes of adaptation and speciation, with a particular focus on the role floral color in creating reproductive barriers. She is currently working on a project to understand the evolution of red flower color in North American Silene species, specifically whether access to hummingbird pollinators and/or polyploidy events played the biggest roles.

Anna Feller was a Swiss National Science Foundation postdoctoral fellow in the Hopkins lab. She focuses on understanding the processes and mechanisms that generate and maintain biological diversity and how species evolve and persist. In the Hopkins lab, she is studying reproductive isolation and gene flow between several closely related lineages of Phlox flowers that all occur in geographic proximity.

Cecilia Prada Cordero is a postdoctoral fellow in the Taylor lab. Ceci focuses on the influence of abiotic and biotic factors on tree species composition, distribution, and biogeochemical processes, with a specific emphasis on filling research gaps in soil-plant-fungi interactions in tropical forests.

Austin Garner was a graduate student in the Hopkins lab studying speciation in Phlox.

Winter presents significant challenges to long lived perennial species, and in particular, to the reproductive buds that form before winter. Trees have developed different strategies for surviving winter and ensuring reproductive success. Camilo Villouta focuses on understanding the tradeoff between different survival strategies that trees employ with successful reproduction in the spring. This work will add insight to how climate change may impact temperate woody species. Camilo is an assistant professor at the University of Rhode Island.

As a research assistant in the Friedman lab, Ellie Mendelson contributed to a variety of projects related to plant evolution and morphology. For her undergraduate thesis, Ellie studied the fruit developmental network in early diverging angiosperms Austrobaileya scandens and Illicium floridanum with the Ambrose Lab at the New York Botanical Garden.

Lauren Church was a research assistant in the Taylor lab, and helped with sample processing, data analysis, as well as field work (her favorite part). Lauren completed her undergraduate thesis in the Taylor lab looking at the impacts of fertilizer treatments on soil bacterial communities, plant health and soil nutrients. Her research interests include global change biology, environmental justice, and human-environmental interactions.

Lindsay McCulloch was a NOAA Climate and Global Change postdoctoral fellow working in the Taylor lab. Lindsay’s work focuses on the role plant-microbial symbioses play in the biogeochemical cycling and function of tropical forests, and how these processes may affect global carbon and nutrient cycling.

Megan Wilcots received her PhD in Ecology from the University of Minnesota – Twin Cities and her BA in Environmental Biology with a focus on Ecology and Evolution from Columbia University. Her research experience has spanned from the tropics to the poles, with a focus on how global change affects carbon uptake of ecosystems. Her dissertation research focused on how nitrogen deposition affects plant community composition and ecosystem carbon storage in Minnesota grasslands. She also works in the Arctic, understanding how nutrient release from permafrost thaw may restructure Arctic ecosystems.

Megan is the first Global Change Postdoctoral Fellow from the Arnold Arboretum, a position she holds jointly with the Harvard University Center for the Environment (HUCE) as an Environmental Fellow. As a Fellow, Megan works with Professor Ben Taylor to study how Arctic heatwaves alter nitrogen fixation and carbon uptake. Megan is now an Applied Climate Scientist for The Nature Conservancy and a Visiting Scholar of the Arnold Arboretum.

Hannah Adler, undergraduate student, Harvard College, Taylor Lab
Spencer Carter, undergraduate student, Harvard College, Hopkins Lab
Nick Daley, undergraduate student, Harvard College, Taylor Lab
Isabel Eddy, undergraduate student, Harvard College, Taylor Lab
Joseph Fadule, undergraduate student, Harvard College, Taylor Lab
Jake Greer, undergraduate student, Harvard College, Hopkins Lab
Andrew Ford, undergraduate student, Harvard College, Hopkins Lab
Sabrina Freidus, undergraduate student, Harvard College, Hopkins Lab
Kim Hartung, undergraduate student, Harvard College, Taylor Lab
Peyton Jones, undergraduate student, Harvard College, Hopkins Lab
Dorina Kodeanu, undergraduate student, Harvard College, Hopkins Lab
Catherine Mailly, undergraduate student, Harvard College, Hopkins Lab

Iñaki Hormaza is a Research Professor at IHSM la Mayora in Spain. As a Fulbright Scholar in 2022, he visited the Arboretum to study fruit development in the paw paw. Earlier visits focused on flower and fruit development in the Rosaceae collection.

Alexandria Pete is a PhD Student in the OEB department. She did research rotations in the Friedman and Kramer Labs.

Angie Diana was a research assistant in the Hopkins Lab.

Antonio Serrato-Capuchina was a postdoctoral fellow in the Hopkins Lab interested in leveraging naturally hybridizing species complexes to uncover patterns in the development of reproductive isolation and better understand the evolution of species. Currently he is at Boston University.

Ben Goulet-Scott was a PhD Candidate in the Hopkins Lab. Ben is interested in adaptation and speciation in Phlox. Ben is now the higher education & lab coordinator at the Harvard Forest.

A MEME Student in the Hopkins Lab, Bushra Shahid aimed to investigate whether there is a shift towards earlier and more autonomous selfing in sympatric populations of Phlox cuspidata compared to allopatric populations, constant with reinforcement favoring traits that reduce hybridization in sympatry.

Cristina Ferrer Blanco was a PhD student at the IHSM La Mayora in Spain. She studys reproductive biology of an early divergent angiosperm, Asimina triloba (Pawpaw), mainly focused on its incompatibility system.

Daniel Buonaiuto was a PhD candidate in the Wolkovich and Holbrook Labs. He is interested in how plant communities are responding to global change, and how these responses are affecting the composition and function of North American ecosystems.

Jacob Suissa was a PhD Candidate in the Friedman Lab. He is an evolutionary biologist focusing on Ferns and Lycophytes. He takes a broad scale macroevolutionary approach as well as a small scale physiological approach to answer interesting questions about fern evolution.

Marwa Abdelal is a Co-Op Student from Northeastern University that worked in the Hopkins Lab.

Overwintering of leaf buds is a common strategy thought to allow plants to adapt to periodically stressful environments. Morgan Moeglein developed a comparative framework for understanding fundamental questions of the timing and mechanisms of leaf preformation in buds, its contribution to seasonal growth, and the conservation of these strategies using closely related species in the Arboretum’s living collections. Morgan is an assistant professor at Norwich University and a Visiting Scholar of the Arnold Arboretum.

Wendy Clement, a Visiting Scholar at the Arnold Arboretum and a Associate Professor at the College of New Jersey, studied floral traits using the living collections of Lonicera (honeysuckles) at the Arnold Arboretum. She is interested in using trait data, such as color, morphology, rewards, and floral scent to describe the evolutionary history of floral form in Lonicera and identify potential instances of shifts in pollination syndrome.

Wenying Liao was a Postdoctoral fellow in the Taylor Lab. Wenying combines statistical and theoretical modeling, greenhouse work, and policy analysis to study the global nitrogen cycle, focusing on the understanding of symbiotic nitrogen fixation in natural forests and the sustainable management of nitrogen use in agricultural landscapes.

A plant ecophysiologist, Jake Grossman has a strong interest in forest ecosystems and trees.  Jake examined drought vulnerability and water use strategies in maples (Acer spp). Combining field and greenhouse experiments, he analyzed the potential effects of climate change on the Arboretum’s collections. Jake is an assistant professor at St. Olaf College in the Biology and Environmental Studies departments.

• Grossman JJ*. 2023. Phenological physiology: seasonal patterns of plant stress tolerance in a changing climate. New Phytologist 237: 1
• Grossman JJ*. 2021. Evidence of constrained divergence and conservatism in climatic niches of the temperate Maples (Acer L.). Forests 12(5): 535. Abstract
• Kovaleski AP*, Grossman JJ*. 2021. Standardization of electrolyte leakage data and a novel liquid nitrogen control improve measurements of cold hardiness in woody tissue. Plant Methods 17: 53. (APK and JJG contributed equally) Abstract

Elizabeth Spriggs is an evolutionary biologist with a passion for plant conservation. Her research focused on the chestnuts and ashes (Castanea and Fraxinus) – iconic, but severely threatened, North American trees. Using phylogeography and genomics, she examined genetic diversity and population structure in relation to disease with an eye towards identifying individuals of conservation value. Currently, Beth is as a data scientist at Amazon Robotics.

• Spriggs EL*, Fertakos ME. 2021. Evolution of Castanea in North America: restriction-site-associated DNA sequencing and ecological modeling reveal a history of radiation, range shifts, and disease. American Journal of Botany 108: 1692-704. Abstract

Al Kovaleski is a plant physiologist interested in understanding how woody plants adapt to freezing stresses during winter. Al examined cold hardiness, chilling response, and resumption of growth to recalibrate phenological models of budbreak in diverse tree species in the Arboretum. Al is an assistant professor at the University of Wisconsin, Madison.

• Kovaleski AP*. 2022. Woody species do not differ in dormancy progression: Differences in time to budbreak due to forcing and cold hardiness. Proceedings of the National Academy of Sciences 119: e2112250119. Abstract
• Kovaleski AP*, Grossman JJ*. 2021. Standardization of electrolyte leakage data and a novel liquid nitrogen control improve measurements of cold hardiness in woody tissue. Plant Methods 17: 53. (APK and JJG contributed equally) Abstract

Caio Guilherme Pereira is a postdoctoral fellow at MIT and a visiting fellow at the Arnold Arboretum. Caio aims to understand the molecular mechanisms of plant-environment interaction and discover how this interaction plays a role in the underlying growth pattern, composition and diversity of the plants.

Cat Chamberlain was a PhD student in the Wolkovich and Holbrook Labs. She is interested in understanding how anthropogenic climate change affects plant communities and plant phenology.

As a research assistant in the Hopkins Lab, Charlie Hale contributed to a variety of projects which combine field and greenhouse experiments with genomic analyses to study mechanisms of speciation in plants. Currently, he is a graduate student at Cornell University.

Kristel Schoonderwoerd was a PhD student in the Friedman Lab. Interested in many facets of evolutionary botany, she studied the diverse strategies temperate tree species use to overwinter embryonic leaves in resting buds and expand these leaves in the spring.

Samridhi Chaturvedi was a postdoctoral fellow in the Hopkins Lab. With an interest in the genomic basis of adaptation and speciation, she aimed to understand the genomic patterns of hybridization and introgression in Phlox species.

Steve is developing a new framework to consider nutrient use efficiency (NUE) in plants beyond the traditional methods focused on vegetative tissues. He will measure the carbon and nitrogen costs of reproduction in samaras, a type of fruit. Samaras are green during seed development, suggesting active photosynthesis, but tend to lose their pigments as seeds mature. He will assess whether carbon acquisition and nutrient recycling during reproduction are large enough to influence whole plant NUE.

Amelia Keyser-Gibson, Research Assistant, Friedman Lab and Weld Hill Labs, studied the reproductive development of conifers, as well as various other plant morphological questions.

Barry Logan in collaboration with Dave Des Marais, examined divergent host spruce responses to parasitic dwarf mistletoe infection in the Arboretum. Barry is a Professor and Associate Dean of Bowdoin College and was a Visiting Scholar of the Arnold Arboretum of Harvard University.

A plant ecophysiologist, Jake Grossman has a strong interest in forest ecosystems and trees.  Jake examined drought vulnerability and water use strategies in maples (Acer spp). Combining field and greenhouse experiments, he analyzed the potential effects of climate change on the Arboretum’s collections. Jake is an assistant professor at St. Olaf College in the Biology and Environmental Studies departments.

• Grossman JJ*. 2023. Phenological physiology: seasonal patterns of plant stress tolerance in a changing climate. New Phytologist 237: 1
• Grossman JJ*. 2021. Evidence of constrained divergence and conservatism in climatic niches of the temperate Maples (Acer L.). Forests 12(5): 535. Abstract
• Kovaleski AP*, Grossman JJ*. 2021. Standardization of electrolyte leakage data and a novel liquid nitrogen control improve measurements of cold hardiness in woody tissue. Plant Methods 17: 53. (APK and JJG contributed equally) Abstract

As environmental engineer with interests in plant biology, Jie Yun is focused on solving practical environmental problems through the interdisciplinary research. She was a PhD student at MIT and Visiting Fellow of the Arnold Arboretum working in the Des Marais Lab.

Natalia is interested in understanding the evolution of flower and fruit development and the morphological changes driving diversification of flowering plants. At the Arboretum, she will focus on fruit diversity by comparing morphological and anatomical features and transcriptomic data of members of the Rubiaceae with distinct fruit types.

• Suárez-Baron H, Alzate JF, Ambrose BA, Pelaz S, González F, Pabón-Mora N. 2023. Comparative morphoanatomy and transcriptomic analyses reveal key factors controlling floral trichome development in Aristolochia (Aristolochiaceae). Journal of Experimental Botany74(21):6588–6607. Abstract

Rebecca Povilus, Postdoctoral Fellow, MIT and Visiting Fellow, Arnold Arboretum of Harvard University, is interested in the idea that molecular resources are important tools for connecting how changes at the gene and genome level affect developmental processes. She focuses on how evolutionary changes during the development of the egg-producing structure could give rise to the wide array of egg-sac morphologies in angiosperms.

Wayne Daly graduated from Trinity College Dublin in 2016 with an MSc in biodiversity and conservation. He completed a study on geoxylic suffrutices, and a dissertation on salt marsh ecology and plant community compositions. As an intern in the Wolkovich Lab, he will learn more about the time effects and pressures on plants and plant phenology from various environmental factors and anthropogenic activities.

Kasia Zieminska aims to understand how tree anatomy impacts function. By focusing on diverse species in the Arboretum’s living collections, she will examine the relationship between diversity in anatomical structure and water storage mechanisms and how this relationship influences plant biodiversity and ecological strategies. Kasia is a research fellow at Western Sydney University, Australia.

• Ziemińska K*. 2023. The role of imperforate tracheary elements and narrow vessels in wood capacitance of angiosperm trees. IAWA Journal 1(aop):1–14. Abstract
• Ziemińska K*, Rosa E, Gleason SM, Holbrook NM. Wood day capacitance is related to water content, wood density, and anatomy across 30 temperate tree species. Plant Cell Environ. 43: 3048– 3067.

Examining 25 species of basal angiosperms in the Arboretum’s living collections, Adam will measure physiological traits associated with water balance to examine the trade-offs between water transport, water storage, and the ability to maintain turgid and showy flowers.

Elizabeth Spriggs is an evolutionary biologist with a passion for plant conservation. Her research focused on the chestnuts and ashes (Castanea and Fraxinus) – iconic, but severely threatened, North American trees. Using phylogeography and genomics, she examined genetic diversity and population structure in relation to disease with an eye towards identifying individuals of conservation value. Currently, Beth is as a data scientist at Amazon Robotics.

• Spriggs EL*, Fertakos ME. 2021. Evolution of Castanea in North America: restriction-site-associated DNA sequencing and ecological modeling reveal a history of radiation, range shifts, and disease. American Journal of Botany 108: 1692-704. Abstract

In the Hopkins Lab, Franchesco Molina investigated how the genes involved in meiosis are locally adapted to different temperatures in Arabidopsis arenosa. Francheso was a PhD Student and Fellow of the Arnold Arboretum

In Aristolochia (dutchman’s pipe), the trichomes (hairs) found on flowers are important for attracting and retaining flies for pollination. Harold focuses on the genetic mechanisms underlying trichome development in this non-model plant.

• Suárez-Baron H, Alzate JF, Ambrose BA, Pelaz S, González F, Pabón-Mora N. 2023. Comparative morphoanatomy and transcriptomic analyses reveal key factors controlling floral trichome development in Aristolochia (Aristolochiaceae). Journal of Experimental Botany74(21):6588–6607. Abstract

As part of the Erasmus Mundus Master Program in Evolutionary Biology, Henry North conducted research in the Hopkins Lab for 6 months. Henry focused on the genetic mechanisms of pollination in Phlox.

Julia Marrs was a PhD Candidate at Boston University and Visiting Felllow of the Arnold Arboretum of Harvard University. Julia’s interests include terrestrial carbon cycling and remote sensing of vegetation. She investigated the link between the solar-induced chlorophyll fluorescence signal measured by tower and satellite platforms and plant physiological processes occurring at the leaf level.

As a research assistant in the Friedman Lab, Laura Clerx studied early evolutionary thought, with a focus on biologists (especially botanists) who made contributions to evolutionary theory, both prior to and concurrent with Charles Darwin.

Matt Farnitano was a research assistant in the Hopkins Lab. Starting Fall 2019, Matt is a graduate student at the University of Georgia.

Shayla Salzman was a PhD Candidate in OEB and Fellow of the Arnold Arboretum. In the Hopkins and the Pierce Labs, Shayla focused on Cycads and their weevil pollinators and how scent variation leads to the species-specific mutualisms.

Diana Bernal was a visiting fellow in the Hopkins Lab. She investigated the developmental mechanisms underlying variation of the reproductive mode in the Brachiaria.

Federico Roda is interested in understanding the functional mechanisms of environmental adaptation in plants. As postdoctoral fellow in the Hopkins Lab, Federico investigated the molecular basis of the evolution of reproductive isolation in the genus Phlox.

Heather Briggs was a postdoctoral researcher in the Hopkins Lab. She focused on understanding pollination behavior of Battus philenor on Texas Phlox.

Isabelle Chuine is CNRS research director at the Centre d’Ecologie Fonctionnelle & Evolutive in Montpellier, France. As a Bullard Fellow, her project tackled the ongoing challenge of providing robust forecasts of climate change impacts on forest trees phenology. She tested key hypotheses on the regulation of cell seasonal activity using a series of experiments combining ecophysiology and biotracing methods.

Building on her work as a Putnam fellow, Jessica Savage will examine a diverse set of species in the Arboretum’s living collections to see how the anatomical diversity of phloem, the part of the vascular system responsible for sugar transport, may impact patterns of vegetative and reproductive growth.

• Savage JA, Kiecker T, McMann N, Park D, Rothendler M, Mosher K. 2022. Leaf out time correlates with wood anatomy across large geographic scales and within local communities. New Phytologist 235: 953-64. Abstract

Juan M. Losada was a postdoctoral fellow in the Friedman, Holbrook and Leslie Labs. He is interested in the biochemical communication events between the male and female during pollination and fertilization. He focused on the evolution of the nourishing behavior of the perisperm and endosperm.

Kasia Zieminska aims to understand how tree anatomy impacts function. By focusing on diverse species in the Arboretum’s living collections, she will examine the relationship between diversity in anatomical structure and water storage mechanisms and how this relationship influences plant biodiversity and ecological strategies. Kasia is a research fellow at Western Sydney University, Australia.

• Ziemińska K*. 2023. The role of imperforate tracheary elements and narrow vessels in wood capacitance of angiosperm trees. IAWA Journal 1(aop):1–14. Abstract
• Ziemińska K*, Rosa E, Gleason SM, Holbrook NM. Wood day capacitance is related to water content, wood density, and anatomy across 30 temperate tree species. Plant Cell Environ. 43: 3048– 3067.

Marjorie Lundgren is a plant ecophysiologist. As a postdoctoral fellow at MIT and Arboretum Visiting Fellow, she focused on deconstructing the components of perenniality with an aim to inform crop improvement strategy.

Morgan Moeglein, a graduate student in the Edwards Lab at Yale University, studied the environmental and genetic factors governing leaf shape in the genus Viburnum utilizing the living collection of the Arnold Arboretum.

As a research associate in the Hopkins Lab, Sevan Suni investigated both the ecological factors and underlying genetic mechanisms that contribute to adaptation and speciation in Phlox populations. She is now an assistant professor at the University of San Francisco.

Callin Switzer was a PhD Candidate in the Hopkins Lab. He is investigating bumblebee buzz pollination to understand how bees buzz and why there is variation in buzzing. After the Arboretum, Callin was a postdoctoral fellow in the eScience Institute at the University of Washington.

Research associate and principal investigator Cam Webb studies the evolution and ecology of tropical plants, and is experimenting with new informatics and capacity-building approaches to plant inventory and taxonomy. Currently, Cam is collaborating with co-PI Sarah Mathews on a National Science Foundation funded project that focuses on the ecology, biogeography, and biodiversity informatics of trees in Indonesian forests.

The research of David Des Marais, Senior Fellow, focuses on how plants interact with the environment and the variation in these interactions between species. Understanding how plants adapt to the local environment can increase our ability to conserve plant populations. Dave is now an assistant professor at MIT.

Elizabeth Wolkovich is interested in how communities assemble and disassemble in light of global changes. The Wolkovich lab focuses on testing and understanding underlying mechanisms using both theoretical techniques and field experiments to study how current and future plant communities are shaped.

Ignacio Morales-Castilla was a research associate working in the the Wolkovich Lab. His research focused on the role of historical and evolutionary processes on current diversity patterns. He is interested in better understanding and predicting species and ecosystem vulnerability in a context of Global Change.

Jack Smith was a Harvard undergraduate studying Environmental Science and Public Policy. Jack worked in the Friedman lab exploring plant morphology and development.

Johan Arango earned his bachelor’s degree in Agroindustrial Engineering. He is currently pursuing a Master’s Degree in Sustainability and joined the Wolkovich Lab in the Fall of 2016. He was drawn to the lab because he is very interested in the effect that climate variation has on plants. He is very interested in societies’ reliance on plants and how a growing global population along with expanding markets will pose challenges and opportunities to achieve sustainability, especially in food systems.

Jonathan Davies is an Associate Professor at McGill University in Canada. His work broadly addresses questions related to the distribution of biodiversity and the challenges posed to its conservation through recent changes to the environment.

As part of the Aronia breeding program, Jonathan Mahoney is investigating the mating systems and compatibility issues of intergeneric hybridization between Aronia and related taxa.

• Mahoney JD, Brand MH. 2021. Pre- and postzygotic barriers associated with intergeneric hybridization between Aronia melanocarpa (Michx.) Elliott x Pyrus communis L. and ×Sorbaronia dippelii (Zabel) CK Schneid. x Pyrus communis. HortScience 56(2): 177-184. Abstract

Li is interested in the role of hybridization on species diversification.  As part of his Hu Award, Li will spend one year at the Arboretum to examine hybridization in Sorbus.

• Li M, Ohi-Toma T, Gao Y-D, Xu B, Zhu Z-M, Ju W-B, Gao X-F. 2017. Molecular phylogenetics and historical biogeography of Sorbus sensu stricto (Rosaceae). Molecular Phylogenetics and Evolution 111: 76-86.

Rebecca Povilus was a PhD candidate in the Friedman Lab. She is interested in the idea that molecular resources are important tools for connecting how changes at the gene and genome level affect developmental processes. She focused on how evolutionary changes during the development of the egg-producing structure could give rise to the wide array of egg-sac morphologies in angiosperms.

As a NSF post-doctoral fellow in Cynthia Weinig’s lab at the University of Wyoming, Rob Baker is investigating the relationship between anatomical features and water use efficiency in diverse cultivars of Brassica rapa.

The research of Chase Mason is focused on the evolution of leaf physical and chemical defenses in relation to the leaf economics spectrum (LES), habit, and species’ source climate across woody genera. LES relates the initial investment of carbon during leaf development with the net carbon gain of that leaf. Chase is an assistant professor at the University of British Columbia, Okanagan.

• De La Pascua DR, Smith‐Winterscheidt C, Dowell JA, Goolsby EW, Mason CM*. 2020. Evolutionary trade‐offs in the chemical defense of floral and fruit tissues across genus Cornus. Appl Plant Sci. 107(9):1260–73.
• Mason CM*, LaScaleia MC, De La Pascua DR, Monroe JG, Goolsby EW. 2020. Learning from dynamic traits: Seasonal shifts yield insights into ecophysiological trade-offs across scales from macroevolutionary to intraindividual. Int J Plant Sci. 181: 88-102.

Dan Flynn was a research associate in the Wolkovich Lab. He is interested in understanding the processes in which plant communities assemble and disassemble and how this will influence the ability of ecosystems to adapt to global climate change.

Elisabeth Forrestel was a postdoctoral fellow in the Wolkovich Lab. The focus of her research was to understand how an important economic crop, wine grapes, respond to climate change. She will study their responses both in the field and after manipulating their environment in growth chamber studies.

Eric Goolsby is a post-doctoral researcher at Edwards Lab at Brown University. His research focuses on developing methods to examine the evolution of phenotypic responses to abiotic stress. The Arboretum collections allowed him to test his methods in a wide range of species.

Grace Yu, a research assistant in the Friedman Lab, was involved in projects studying angiosperm (flowering plant) reproductive and fertilization biology and embryology.

Jehane Samaha was a lab technician in the Wolkovich Lab. She examined functional traits and phenology of trees out in the field, in the lab, and in the greenhouse to understand how communities respond to global climate change.

Jessica Savage is interested in understanding how seasonal changes in vascular activity influence flowering and carbon allocation. Specifically she compared xylem and phloem anatomy, physiology and function in precocious flowering species (those that flower before the leaves emerge) with related species that flower later in the season. Jessica is an associate professor at the University of Minnesota, Duluth.

• Savage JA*. 2019. A temporal shift in resource allocation facilitates flowering before leaf out and spring vessel maturation in precocious species. American Journal of Botany 106(1):113–22.
• Savage JA*, Beecher SD, Clerx L, Gersony JT, Knoblauch J, Losada JM, Jensen KH, Knoblauch M, Holbrook NM. 2017. Maintenance of carbohydrate transport in tall trees. Nature Plants 3: 965-972

Rubén Sancho was a PhD student at the University of Zaragosa in Spain. He worked with Dave Des Marais to sequence the transcriptome of multiple Spanish species of Brachypodium, an important model grass species.

A lab technician in the Wolkovich Lab, Tim Savas was involved in research focusing on community ecology in light of global climate change.

Using members of the Arboretum’s Rosaceae collection, Jorge will compare ovule morphology from the earliest stages to maturity as well as the expression pattern of a gene thought to be important in ovule development.

• Losada JM, Hormaza JI, Lora J. 2017. Pollen–pistil interaction in pawpaw (Asimina triloba), the northernmost species of the mainly tropical family Annonaceae. American Journal of Botany 104:1891–1903

Grey Monroe was a Ph.D. student at Colorado State University, Fort Collins that worked in the Des Marais Lab. Grey was awarded an Eden grant to come to the Arnold Arboretum for his research.

A PhD candidate at the National University of Colombia, Marcela Serna is interested in understanding the role reproductive biology plays in the response of Magnolia to climate change to aid conservation efforts.

Stuart Graham is a master’s student in the Erasmus Mundus Master Program in Evolutionary Biology. In the Hopkins Lab, he examined the behavior of pollinators that visit two sister species of Texas wildflower – Phlox drummondii and P. cuspidata.

Ailene Ettinger focused on predicting the response and sensitivity of plants to a changing climate. By examining diverse trees growing in a common environment, she can identify functional traits that are important for success outside their historical conditions. Ailene is currently a quantitative ecologist at The Nature Conservancy.

• Wolkovich EM, Chamberlain CJ, Buonaiuto DM, Ettinger AK, Morales-Castilla I. 2022. Integrating experiments to predict interactive cue effects on spring phenology with warming. New Phytologist 235: 1719-1728. Abstract
• Ettinger AK*, Buonaiuto DM, Chamberlain CJ, Morales-Castilla I, Wolkovich EM. 2021. Spatial and temporal shifts in photoperiod with climate change. New Phytologist 230: 462-474. Abstract
• Ettinger AK*, Chamberlain CJ, Morales-Castilla I, Buonaiuto DM, Flynn DFB, Savas T, Samaha JA, Wolkovich EM. 2020. Winter temperatures predominate in spring phenological responses to warming. Nature Climate Change.
• Ettinger AK*, Gee S, Wolkovich EM. Phenological sequences: how early-season events define those that follow. American Journal of Botany. 105: 1-1010(12):1137–42.

Andrew will perform RNA sequencing (RNA-seq) on cambium and wood forming tissues of diverse trees in the Arboretum. Potentially important regulatory genes expressed in these tissues will be identified and analyzed as a first step to understanding the evolution of woody growth.

Utilizing the conifer collection, Guangyou Hao studied the differences in the structural, physiological, and mechanical properties of water transport and xylem hydraulics between evergreen and deciduous conifers (which shed their leaves). Guangyou is a professor at the Institute of Applied Ecology at the Chinese Academy of Sciences.

• Hao G-Y*, Lucero ME, Sanderson SC, Zacharias EH, Holbrook NM. 2013. Polyploidy enhances the occupation of heterogeneous environments through hydraulic related trade-offs in Atriplex canescens (Chenopodiaceae). New Phytologist 197: 970–8.
• Hao G-Y*, Wang A-Y, Sack L, Goldstein G, Cao K-F. 2013. Is hemiepiphytism an adaptation to high irradiance? Testing seedling responses to light levels and drought in hemiepiphytic and non-hemiepiphytic Ficus. Physiologia Plantarum 148: 74-86.
• Hao G-Y*, Wheeler JK, Holbrook NM, Goldstein G. 2013. Investigating xylem embolism formation, refilling and water storage in tree trunks using frequency domain reflectometry. Journal of Experimental Botany 64: 2321-2332.

A recent graduate from the University of Connecticut, Kate Morozova was a Research Assistant in the Friedman Lab. One project that she was involved with was to examine the surface structure of Ginkgo biloba using scanning electron microscopy.

Utilizing the Arboretum’s Malus collection, Ling will conduct research to improve the databases and knowledge of ornamental crabapples as a Registration Authority. Her database will focus on the flowers of Malus to improve the understanding of flowering time.

Rosanne focuses on ectomycorrhizal fungi that are present on roots of trees in well-spaced habitats like the Arboretum. She plans to sequence, identify and compare the fungal partners on the roots of Oak trees present at the Arboretum with those at the Harvest Forest. Matching funds for this award was generously provided by the Harvard Forest.

• Healy RA, Zurier H, Bonito G, Smith ME, Pfister DH. 2016. Mycorrhizal detection of native and non-native truffles in a historic arboretum and the discovery of a new North American species, Tuber arnoldianum sp. nov. Mycorrhiza 26: 781-792.
• Leicht-Young SA, Healy R, Del Tredici P. 2016. Observation of mycorrhizal colonization in roots in natural populations of Celastrus orbiculatus Thunb. The Journal of the Torrey Botanical Society 143: 322-324.
• Shao D, Tang S, Healy RA, Imerman PM, Schrunk DE, Rumbeiha WK. 2016. A novel orellanine containing mushroom Cortinarius armillatus. Toxicon 114: 65-74.

Ursula King is a PhD student at the University of Connecticut, interested in the evolution of aquatic plants. Specifically, she is developing molecular markers to explore the population dynamics and reproductive biology of Najas flexilis (Hydrocharitaceae), a monoecious, freshwater annual, in which pollination is entirely underwater. As a visiting fellow in the Friedman Lab, Ursula learned techniques to observe ovule development in this species.

A visiting scholar in the Friedman Lab, Biao Jin, Associate Professor at Yangzhou University, is interested in exploring the evolution of reproductive biology from gymosperms to angiosperms.

The research interests of Cary Pirone lay primarily in understanding how chemical signals mediate biological phenomena. As a Putnam Fellow, she explored the complexities of pollination drops (ovular secretions) of several conifer species and ginkgo using biochemical and anatomical approaches. Cary is a scientist at the US Food and Drug Administration.

• Prior N, Little SA, Boyes I, Griffith P, Husby C, Pirone-Davies C*, Stevenson DW, Tomlinson PB, von Aderkas P. 2019. Complex reproductive secretions occur in all extant gymnosperm lineages: a proteomic survey of gymnosperm pollination drops. Plant Reprod. 32: 153-166.
• Nepi M, Little S, Guarnieri M, Nocentini D, Prior N, Gill J, Barry Tomlinson P, Ickert-Bond SM, Pirone C*, Pacini E, von Aderkas P. 2017. Phylogenetic and functional signals in gymnosperm ovular secretions. Annals of Botany 120: 923-936.
• Pirone-Davies C*, Prior N, Von Aderkas P, Smith D, Hardie D, Friedman WE, Mathews S. 2016. Insights from the pollination drop proteome and the ovule transcriptome of Cephalotaxus at the time of pollination drop production. Annuals of Botany 117: 973-984.
• Prior N, Little SA, Pirone C*, Gill JE, Smith D, Han J, Hardie  D, O’Leary SJB, Wagner RE, Cross T, Coulter A, Borchers C, Olafson RW, and von Aderkas P. 2013. Application of proteomics to the study of pollination drops. Applications in Plant Science 1: 1300008.

Using members of the Arboretum’s Rosaceae collection, Jorge will compare ovule morphology from the earliest stages to maturity as well as the expression pattern of a gene thought to be important in ovule development.

• Losada JM, Hormaza JI, Lora J. 2017. Pollen–pistil interaction in pawpaw (Asimina triloba), the northernmost species of the mainly tropical family Annonaceae. American Journal of Botany 104:1891–1903

Julien Bachelier was a postdoctoral fellow in the Friedman Lab. His work focuses on the evolution of seed plants, particularly in the origin of flowering plants and the evolutionary development of flower and carpel. Julien’s thesis investigations compared the structure and development of flowers in closely related families such the Anacardiaceae and the Burseraceae.

Sarah Mathews was a Sargent Fellow and principal investigator at the Arnold Arboretum. She is interested in plant phylogenetics and in the question of how changes in light-sensing systems have influenced the ability of plants to survive and diversify. The Mathews Lab uses phylogenetic, genetic, and comparative physiological approaches to explore the links between molecular and functional evolution in the phytochrome photoreceptor family.

The research of Stacey Leicht Young examined the ecological and reproductive strategies required for lianas (woody vines) to be successful in its environment utilizing the Arboretum’s Leventritt Shrub and Vine Garden. Stacey is a project scientist at RK&K (Rummel, Klepper & Kahl, LLP) in Baltimore, Maryland.

• Leicht-Young SA*, Healy R, Del Tredici P. 2016. Observation of mycorrhizal colonization in roots in natural populations of Celastrus orbiculatus Thunb. The Journal of the Torrey Botanical Society 143: 322-324.

A PhD Candidate at the University of Melbourne in Australia, Stephanie Conway is interested in the role of the shoot apical meristem in the evolution of shoot architecture. As a visiting fellow in the Friedman Lab, she focused on shoot apical meristems utilizing the extensive collection of gymnosperms at the Arboretum.

Stuart Davies is the director of the Center for Tropical Forest Science at the Smithsonian Tropical Research Institute. He is interested in the ecology and evolution of tropical rainforests. Using a global network of large-scale long-term forest monitoring plots, he is investigating how environmental variation and change affect the diversity and dynamics of forests.

Iñaki Hormaza is a Research Professor at IHSM la Mayora in Spain. As a Fulbright Scholar in 2022, he visited the Arboretum to study fruit development in the paw paw. Earlier visits focused on flower and fruit development in the Rosaceae collection.

From the University of Melbourne, Australia, the research of Denise Johnstone focuses on the physiological mechanisms involved in drought response in urban trees. As a visiting scholar in the Zwieniecki Lab, she examined xylem physiology during drought stress.

Elizabeth Ryan is an undergraduate student at Brown University working with Dov Sax. As an Arboretum Visiting Fellow, she worked with Michael Dosmann to research plant distributions in the face of climate change.

Erica Fadon is a PhD student in the Herrero Lab at the Pomology Department of the Aula Dei Experimental Station–CSIC, Spain. Using the Arboretum’s living collection, Erica closely examined the development of sweet cherry flowers (Prunus avium) in order to determine which stage the flowers undergo winter dormancy.

The research of Francesca Secchi, a postdoctoral researcher in the Zwieniecki Lab, aims at understanding the principles of the biological function of vascular systems in plants. Her current research is focused on embolism formation and refilling using molecular, physiological, and biophysical approaches.

Hugh is interested in examining the evolutionary relationships of species within genera. By comparing chromosome numbers, he seeks to clarify the relationships between diploid and polyploid species. Previous visits to the Arnold Arboretum and the Harvard University Herbaria led to the publication of monographs on genera Betula and Sorbus.

Juan M. Losada is a graduate student in the Pomology Department of the Aula Dei Experimental Station–CSIC, Spain. He is interested in the events between pollination and fertilization, primarily the role of arabinogalactan proteins in pollen-pistil interactions in Malus. During his stay at the Arboretum, he worked with Ned Friedman to expand his dissertation studies to include Magnolia and Stewartia.

Kang Min Ngo is a research assistant for the CTFS. Based in Singapore, she is interested in understanding the role of forests in a changing climate, particularly through carbon sequestration.

Arnold Arboretum Sargent Fellow Maciej Zwieniecki addresses the structure, surface chemistry, and mechanical properties of the network of fluid conduits in plants. The Zwieniecki Lab studies the specialized cells that distribute water, solutes, and energy over long distances, as well as how the terminal exchange surfaces (roots and leaves) interface with the environment.

The research of Noeline Morrissey, a master’s student in the Friedman Lab, focused on trichome morphology and development. Comparing the multiple forms of trichomes in hops (Humulus lupulus) and related genera should shed light on the evolution of these highly specialized structures.

Brian Morgan focuses on the use of geographic information systems (GIS) technology as a management and decision-making tool for public gardens. Brian created a GIS for the Arnold Arboretum based on the ArcGIS Public Garden Data Model, and a web-based application for performing collections research. Brian is the executive director of the Alliance for Public Gardens GIS.

David Kenfack is the coordinator for the Center for Tropical Forest Science-Smithsonian Institution Global Earth Observatory (CTFS–SIGEO) Africa Program. His primary interests are the use of plant systematics to explore species limits and exploring the ecological processes that explain tropical forest dynamics in Africa.

Working in the Friedman Lab with Julien Bachelier, the focus is on the comparative morphology of female gametophytes in diverse conifers in an effort to shed light on the evolution of female gametophyte development

Erin Kurten was a postdoctoral fellow working with Stuart Davies and CTFS-AA. Erin’s work focuses on tropical plant community ecology and the interactions which underlie community assembly processes and biogeographic patterns. With CTFS, Erin investigated how tree species adapt their phenology in response to drought stress in the seasonally-dry tropical forests of Southeast Asia.

Iñaki Hormaza is a Research Professor at IHSM la Mayora in Spain. As a Fulbright Scholar in 2022, he visited the Arboretum to study fruit development in the paw paw. Earlier visits focused on flower and fruit development in the Rosaceae collection.

As a graduate in the Diggle Lab at the University of Colorado, Rob focused on the evolution of shoot architecture by examining the molecular developmental pathways within and among populations, where genetic divergence, adaptation, and speciation occur. Specifically, he examined natural variation in shoot architecture patterning in Mimulus gattatus.

Conservation of threatened plant species is of great interest to Abby Hird. As the conservation director for Botanic Gardens Conservation International–United States (BGCI-US), she collaborates with the Arnold Arboretum to implement the recommendations of the North American Collections Assessment. The goal is to preserve threatened taxa and increase genetic diversity by preserving wild-collected plants at the Arboretum and other botanical gardens.

As a Putnam Fellow, Jennifer Winther established a research program on the developmental genetic mechanisms underlying male and female identity in the reproductive structures (cones) of gymnosperms. Now an assistant professor in biology at Grand Valley State University, Michigan, she continues this research with her undergraduate students.

Richard Primack is a professor of biology at Boston University. The Putnam Fellowship enabled Richard to evaluate the effects of climate change on plants and animals at the Arnold Arboretum and Concord. It also fostered an ongoing collaboration with Harvard Professor Chuck Davis to focus on how the evolutionary relationships between species play a role in adaptation to climate changes.

As a Putnam Fellow, Eric Hsu investigated the Arboretum’s Acer (maple) and Stewartia collections to build a case for their designation as national collections by the American Public Garden Association. Eric is currently the Plant Information Coordinator at Chanticleer Gardens. 

Nina Theis, in collaboration with Arboretum taxonomist Jianhua Li and Michael Donoghue at Yale, used molecular phylogenetics to investigate the evolution of fragrance in Lonicera (honeysuckle) and Syringa (lilac) as a Putnam Fellow. Nina continues to study the ecology of fragrance production in her current role a professor of biology at Elms College in Chicopee, Massachusetts.

Tim Brodribb studied the Arboretum’s extensive conifer collection for his Putnam Fellowship, comparing the evolutionary trends of leaf structure and function for Southern and Northern Hemisphere species. Currently, he is a professor at the University of Tasmania, Australia, investigating the deep time evolution of veins and photosynthesis in leaves.

As Putnam Fellow, Sonali Saha collaborated with Harvard Professor Noel Michele Holbrook in investigations of the physiological properties of bamboo species. She is currently a senior biologist at the Institute for Regional Conservation in Miami and an adjunct professor of biology at Miami Dade College.

Lawren Sack studied hydraulic conductance and structure of tree leaves as a Putnam Fellow. Now he is a professor of plant physiology and ecology at UCLA, and a faculty affiliate for UCLA’s Center for Tropical Research. His research continues to focus on leaf and whole plant water transport, as well as the ecology and physiology of plant species coexistence, the evolution of diversity of leaves, forest dynamics and ecohydrology, and conservation physiology.

Sonia Uyterhoeven is the head of horticulture at Greenwood Gardens in New Jersey. As a Putnam Fellow, she evaluated the Arboretum’s IUCN plants (International Union for Conservation of Nature).

As a Putnam Fellow, Michael Dosmann studied the taxonomy of katsura trees (Cercidiphyllum), the reproductive biology of a rare monkshood, the efficacy of plant exploration efforts, and helped coordinate plant selection and sequence for the Leventritt Shrub and Vine Garden. Michael returned to the Arboretum in 2007 and is now the keeper of living collections where he guides the Arboretum’s stewardship and development of its collection of temperate woody species. His work explores new strategies and tactics aimed at improving collections management and enhancing the use of Arboretum collections for research. Additionally, he conducts research on the physiological ecology of woody plants and participates in floristic efforts through domestic and foreign plant exploration.

Youngdong Kim was awarded a Putnam Fellowship to reconstruct the phylogeny of the genus Berberis (barberry) to resolve the evolutionary relationships among its Asian and North American species. Youngdong is currently a professor of biology at Hallym University in South Korea.

Putnam Fellow Donglin Zhang employed morphological and genetic approaches to study the origins of tree lilacs and a new Chamaecyparis (Atlantic whitecedar) cultivar, ‘Quiana’. He is a professor at the University of Georgia. His research focuses on conservation and the utilization of germplasm of ornamental plants.

As Putnam Fellow, Jianhua Li studied the phylogenetic relationships of witch hazels (Hamamelis) and studied the classification of tree lilacs (Syringa) with Arboretum propagator Jack Alexander. After his fellowship, Jianhua served a senior research scientist at the Arboretum until 2009. Jianhua is a professor at Hope College.

Katherine Gould Mathews first worked with Arnold Arboretum scientists as a curatorial assistant at the Harvard University Herbaria. As a Fellow, she studied the phylogenetics of the eastern North American/eastern Asian disjunct genus Triosteum (Caprifoliaceae). Katherine is currently an associate professor of biology at Western Carolina University, where her research focuses on the evolutionary history of southern Appalachian plant species.

During her appointment as a Putnam Fellow, Keiko Satoh worked on the E. H. Wilson archival collection, particularly researching his plant introductions and their distribution by the Arboretum. Her focus on the distribution of Metasequoia (dawn redwood) culminated in an article for Arnoldia on the global travels of the plant initiated by the Arboretum in the late 1940s.

As Putnam Fellow, Jinshuang Ma studied the natural history and worldwide cultivation of Metasquoia glyptostroboides (dawn redwood), a species originally distributed worldwide by the Arnold Arboretum. Since 2001, Jinshuang has worked as a research taxonomist at the Brooklyn Botanic Garden. His research career has centered on conservation biology, the flora of Asia, and taxonomic advances.

As a Putnam Fellow, Kim Tripp used the living collections to examine the physiology of plant adaptability and propagation in a range of exotic and native taxa, including established historic accessions, newly collected specimens, and rarely cultivated species. After serving as director at the New York Botanical Garden, she turned to a new career in osteopathic medicine.

David Ackerly initiated his postdoctoral work on the evolution of the genus Acer (maple). As a professor at the University of California, Berkeley, David is still utilizing data he collected during his Putnam Fellowship and including the maples in new studies on the evolution of woody plants. His research focuses on trait-based community ecology, niche and trait evolution, and climate change.

As a Putnam Fellow, Jun Wen utilized cutting-edge analyses and newly developed molecular tools to examine the biogeographic distribution of plants in eastern Asia and eastern North America. As a research scientist and chair of botany at the Smithsonian Institution, her research program has successfully incorporated classical field explorations, modern DNA molecular tools, and advanced theories of phylogenetics and biogeography.

Michael Dirr, currently Professor Emeritus at the University of Georgia, came to the Arboretum as a Putnam Fellow during a sabbatical from his work as a faculty member of the University of Georgia. Of the fellowship, Michael states that it “was a springboard to the worldwide panoply of woody plants. I spent my days in the remarkable living collection, a herbarium that blankets the world, and a library where a researcher’s queries are always answered. What more could a plantsman ask?”

The Putnam Fellowship gave Elizabeth Kellogg the opportunity to learn and apply new genetic techniques to solve contemporary research questions. Currently, she is a Robert E. King Distinguished Investigator of the Donald Danforth Plant Science Center, a member of the National Academy of Sciences, and an Associate of the Arnold Arboretum of Harvard University. Her research includes explorations of the molecular machinery that control plant shape and structure and investigations of plant morphology and variation exhibited by closely related plants.

As a Fellow, Richard Schulhof developed the first comprehensive plan for the Arboretum collections and landscape, and was hired thereafter as the Arboretum’s director of public programs. After serving as director of Descanso Gardens in his native Southern California, Richard was lured back to the Arboretum as the deputy director. Recently retired, Richard served as the chief executive officer at Los Angeles County Arboretum and Botanic Garden between 2009-2023.

To relate the complexity of leaf shape to ecological and evolutionary factors, Jessica Gurevitch, collected and analyzed a large number of maple leaves from the Arboretum’s living collections. The Putnam Fellowship gave her the freedom to explore new research directions toward statistical applications in plant population and community ecology. Jessica is a professor at the State University of New York in Stony Brook