Staff

Science & Conservation

Scientific Staff

The NTBG Science and Conservation programs are led by dedicated science staff across several gardens and departments working together to fulfil NTBG’s mission and key strategic priorities.

Dr. Tiffany Knight

– Director of Science and Conservation

As Director of Science and Conservation for the National Tropical Botanical Garden, Tiffany oversees the strategic development of science and conservation at the Juliet Rice Wichman Botanical Research Center (BRC) at NTBG’s headquarters on Kauai. Tiffany came to NTBG in 2024 from a position as Professor and Head of Department of Species Interaction Ecology in Leipzig, Germany where she continues to have an affiliation. Following her PhD from the University of Pittsburgh, Tiffany held positions and adjunct appointments at the University of Florida, the National Center for Ecological Analysis and Synthesis, Washington University in St. Louis, the Missouri Botanical Garden, and Chicago Botanic Garden. Tiffany is passionate about ecological research and new technologies that can be directly applied to conservation and restoration of plant biodiversity.

Contact: tknight@ntbg.org

Katie Magoun

– Executive Assistant

As Executive Assistant Katie supports the Director, oversees the Botanical Research Center, serves as a point of contact for internal and external stakeholders, visitors and students, and manages higher level and ad hoc projects and accounting. Katie joined NTBG in 2022 bringing 12 years of experience as Executive Assistant to the Head of Island School.

Contact: kmagoun@ntbg.org

Dr. David H. Lorence

– Senior Research Botanist

Dr. David Lorence occupies the B. Evans Chair of Botany and came to the National Tropical Botanical Garden in 1987. Research specialties are systematic studies of tropical plants, floristics, and invasive plant species. His systematic research focuses on Pacific and neotropical members of the large and diverse Rubiaceae family, which includes coffee, quinine, and gardenias. He also studies Pacific island pteridophytes and the Monimiaceae family of the Malagasy region. David leads NTBG’s publication of regional Pacific Floras, including publication of the Flora of Marquesas Islands in 2020 and Flora of Samoa in 2022. He currently leads the work for a Flora of Micronesia.

Contact: dlorence@ntbg.org
Google Scholar Profile

Timothy W. Flynn

– Herbarium Curator

Tim is Curator of the Herbarium (PTBG) at the National Tropical Botanical Garden. He has been working at NTBG since 1981. In addition to managing the herbarium he has also participated in fieldwork in Hawaiʻi, Samoa, Tonga, Niue, the Cook Islands, Kosrae, Pohnpei, Palau, Australia, New Caledonia, and Ecuador, and currently has a particular interest in contributing to understudied bryophytes.

Contact: tflynn@ntbg.org

Dr. Seana K. Walsh

– Conservation Scientist and Curator of Living Collections

In her dual position as Conservation Scientist and Curator of Living Collections of the National Tropical Botanical Garden, Seana leads the organization’s efforts to implement the Hawaiʻi Strategy for Plant Conservation and oversees the conservation and development of NTBG’s living collections, working closely with the Plant Records Manager to ensure well documented and curated collections. She earned a M.S. in Botany from the University of Hawaiʻi at Mānoa in 2015 and a Ph.D. from the University of Copenhagen in 2023 focused on science-based conservation management of threatened Hawaiian plants.

Contact: swalsh@ntbg.org
Google Scholar Profile
Twitter: @Walsh_Seana

Kevin Houck

– Plant Records Manager

As Plant Records Manager for the National Tropical Botanical Garden since 2017, Kevin Houck oversees the gardens Plant Records Office and work closely with the Curator of Living Collections to ensure the gardens collections are well documented and curated. Kevin holds a BSc from University of Colorado, majoring in Psychology and Environmental, Population and Organismic Biology, and is currently undertaking a Master of Science degree in Library and Information Science from the University of Hawaii.

Contact: plantrecords@ntbg.org

Kenneth R. Wood

– Senior Research Biologist

Ken’s research focuses on the study and conservation of Pacific Island floras. His essential responsibilities include organizing and conducting botanical field surveys with a specialty in accessing rough terrain habitats. Other aspects of his research include: mapping the distribution and abundance of rare Pacific island plants (phytogeography); collecting herbarium specimens for scientific study, collecting seeds, spores, and cuttings for conservation, and DNA material for genetic sequencing; publishing conservation status data and new species descriptions; and contributing to conservation biology research and educational outreach through national and international scientific collaboration.

Contact: kwood@ntbg.org
ResearchGate Profile

Dr. Dustin Wolkis

– Scientific Curator of Seed Conservation

As Scientific Curator of Seed Conservation, Dustin manages NTBG’s Seed Bank and Laboratory and specialize in ex situ seed conservation biology with an emphasis on seed and pollen storage behavior, seed longevity and aging kinetics, seed borne pathogen abatement, and seed dormancy and dormancy alleviation of native Hawaiian plant species of conservation importance. His research aims to understand how seeds respond to desiccation and subfreezing temperatures, identifying regeneration intervals, and determining optimal seed propagation techniques. Dustin holds an MSc in Plant Biology and Conservation from Arizona State University and a PhD degree from 2023 from the University of Copenhagen, Denmark, focused on seed conservation biology in the Hawaiian flora.

Contact: dwolkis@ntbg.org
Google Scholar Profile

Dr. Ben Nyberg

– GIS and Drone Program Coordinator

Ben is a GIS and drone specialist working on the application of cutting-edge technology in plant conservation. He has a PhD from the Natural History Museum of Denmark, University of Copenhagen in Botany and MSc degree in GIS (Geographic Information System) from Penn State University. At NTBG he is responsible for management of organization-wide phytogeography data and GIS modeling, contributing data to NTBGs research and conservation work, as well as to over 400 NTBG led IUCN Red List assessments. Ben leads NTBGʻs innovative drone program which helps botanists globally with the survey of hard to access terrain. His work has had a significant impact on the conservation of a number of critically endangered plants and has led to the discovery of several new species.

Contact: bnyberg@ntbg.org
Google Scholar Profile
Twitter: @BenBotanical

Dr. Uma Nagendra

– Conservation Operations Manager and Ecologist, Limahuli Garden

Dr. Uma Nagendra is the Conservation Operations Manager and Ecologist, at NTBG’s Limahuli Garden and Preserve on Kaua’i, where she is responsible for leading biocultural conservation projects within the 1,000-acre Limahuli Preserve. Uma has a PhD in disturbance ecology from the University of Georgia from 2017. Uma’s research interests span many aspects of applied ecological conservation. Overall, work at Limahuli aims to find appropriate management strategies for ecological and cultural resilience while connecting modern science to traditional ecological practice and knowledge.

Contact: unagendra@ntbg.org

Dr. Michael Opgenorth

– Director of Kahanu Garden and Preserve, Hāna, Maui

Michael “Mike” Opgenorth has been the Director of NTBG’s Kahanu Garden and Preserve in Hāna, Maui, since 2015. Mike earned his undergraduate degree in Business Management with a minor in Plant Production/Plant Management from the University of Hawai’i at Mānoa. He later achieved his Ph.D. in Horticultural Science from the Natural History Museum of Denmark, University of Copenhagen. Mike’s research focuses on plants of the Pacific, particularly rare and culturally significant species. Using an interdisciplinary approach, his work investigates documentation of plant diversity, human relationships to plants, and their cultivation.

Contact: mopgenorth@ntbg.org

Noel Dickinson

– Manager of Breadfruit Institute

A small farmer, born and raised on Kauaʻi, Noel Dickinson is passionate about rural food security and sustainable, diversified agriculture as a means of achieving it. As Coordinator for the Breadfruit Institute, Noel Dickinson is responsible for institute operations, conservation, horticulture, research, and outreach activities including the establishment and management of the Regenerative Organic Breadfruit Agroforestry (ROBA) demonstration at McBryde Garden. Noel attended the University of Hawaiʻi at Hilo where she earned a BS in Horticulture with specialization in Tropical Plant Science and Agroecology, as well as Plant Tissue Culture certification. In addition to her responsibilities as the institute’s Coordinator, Noel is currently pursuing a PhD from the University of Copenhagen, Denmark, focusing on the improvement of conservation, curation, and management of collections of heritage crops and their wild relatives within botanical gardens -specifically Artocarpus.

Contact: ndickinson@ntbg.org

Amanda Vernon

– Science and Conservation Assistant

Amanda is the Science and Conservation Assistant at the National Tropical Botanical Garden. She has contributed to a range of projects within the herbarium, including her role as a technician for the Marquesas Flora website—a collaborative project between NTBG and the Smithsonian Institution— and as an assistant for the herbarium collections as part of joint National Science Foundation (NSF) grant to digitize regional Pacific herbaria. Currently, she is contributing to efforts to digitize NTBG’s bryophyte and lichen collections and is working with the herbarium curator to develop a field guide to the common mosses of the Hawaiian Islands. She holds an MS in Botany from the University of Hawaiʻi at Mānoa.

Contact: avernon@ntbg.org

Dr. Susan Fawcett

– Postdoctoral Researcher

Fawcett is currently a Postdoctoral Researcher at the National Tropical Botanical Garden, where she studies the diversity and evolution of the native Hawaiian flora, with ongoing projects focused on Pritchardia, Geniostoma, Lysimachia, the Hawaiian Silversword lineage and ferns.

She is also a Research Botanist at the University and Jepson Herbaria at UC Berkeley and a National Geographic Explorer. Research and fieldwork has taken her to Latin America and the Pacific, recently collecting ferns and documenting biodiversity in Jamaica, the Dominican Republic, Puerto Rico and Fiji. Her doctoral research at the University of Vermont was focused on the evolution of ferns, resulting in a phylogenomic study and taxonomic revision of the Thelypteridaceae.

She grew up in Petoskey, Michigan, and graduated from the University of Michigan with a BFA and BGS in 2005, and from Northern Michigan University with an MS in 2012. Her masters research focused on the flora and ecology of a neotropical savanna in the Caribbean of Honduras, and she is presently on faculty at the University of Michigan Biological Station, where she teaches botany and botanical illustration.

Contact: sfawcett@ntbg.org

Jena Osmani

– Seed Bank and Laboratory Technician

Jena supports the conservation of Hawaiʻi’s rare and endangered flora as Seed Bank and Laboratory Technician. She helps steward a vital collection of over 18 million seeds, conducting seed, pollen, and fern spore research to ensure these collections remain viable for restoration efforts. She completed her Master’s of Science in Environmental Horticulture at the University of Florida in 2023, where she collaborated with small-scale farmers to research regional seed production practices and post-harvest drying treatments in culturally important crop and ecologically significant wild species. Jena is inspired by the role seeds play in preserving both biodiversity and the stories of the landscapes they come from.

Contact: josmani@ntbg.org

Research Associates

Dr. Ruth Aguraiuja
Native Hawaiian Ferns

Dr. Ruth Aguraiuja’s main research interest is to learn about different life strategies, biology and ecology of endangered native fern species. The ultimate goal is to apply this knowledge for prevention of their extinction, improvement of the condition of extant populations, and restoration of populations in the sites where suitable habitat conditions are still available. Read more »

It involves different aspects of the research: in situ monitoring of the distribution, condition and population dynamics, thus gathering information for further application of different restoration methods (population reinforcement, reintroduction, assisted colonization); ex situ propagation and study on species specific details of reproductive biology, development in younger life stages and critical factors that may affect their survival in natural habitats. Simultaneous conduct and combination of both gives the best results in preserving the species, and botanical gardens have a crucial role in propagating plants for conservation and restoration.

Dr. Bruce Baldwin
Vascular Plant Systematics

Dr. Bruce Baldwin’s research in collaboration with others at NTBG seeks to improve understanding of the origins, evolutionary diversification, and modern diversity of the Hawaiian flora, especially the endemic silversword alliance (Argyroxiphium, Dubautia, Wilkesia; Asteraceae) and their mainland relatives, with special attention to conservation biology. Read more »

Recent progress toward these goals has included a phylogenomic study involving hundreds of nuclear genes and extensive sampling of species throughout the silversword alliance and the greater taxonomic tribe to which they belong, the Madieae. Continuing analyses of those data have been providing more detailed and nuanced perspectives on the evolutionary and biogeographic history of the silversword alliance and the ecological radiation of these iconic Hawaiian plants throughout the islands. Conservation goals of Bruce’s collaborative research at NTBG continue to include description of newly recognized species that need protection, and assisted germination and other reproductive assistance toward critically endangered endemic Hawaiian members of the sunflower family (Asteraceae or Compositae).

Dr. Michael Balick
Economic Botany, Ethnobotany

Dr. Michael Balick has studied the relationship between plants, people and culture, the field known as ethnobotany, and floristics, the study of botanical diversity within a specific region for more than four decades. Most of his research is in remote regions of the tropics, where he works with Indigenous cultures to document plant diversity, knowledge of its traditional utilization and evaluation of the potential of botanical resources, particularly medicinal plants, for broader application and use. Read more »

His most recent scientific research projects, in collaboration with colleagues from NTBG, focuses on Micronesia, on the islands of Pohnpei, Kosrae, Palau and surrounding remote atolls, and Melanesia, in the Republic of Vanuatu, in the southern islands of the archipelago known as Tafea Province. In both Micronesia and Melanesia, he and his colleagues document the diversity, local use and management of plant resources in support of biocultural conservation. Dr. Balick has authored over 200 scientific papers in peer-reviewed journals, and authored, co- authored or edited 32 scientific and general interest books and monographs. Recent books include the two volume Ethnobotany of Palau: Plants, People and Island Culture coauthored with Ann Hillmann Kitalong, in collaboration with David H. Lorence, and the forthcoming Plants, People and Culture of Tafea Province, Vanuatu. He received his B.Sc. from the University of Delaware and his A.M, and Ph.D. from Harvard University. He has been at the New York Botanical Garden since 1980.

Dr. John Game
Hawaiian Pteridophytes

John Game grew up in England but has lived in Berkeley, California since 1978. As a retired molecular geneticist, formerly employed by the Lawrence Berkeley National Laboratory, and currently an unpaid Research Associate at the University of California Herbarium (UC) at Berkeley and at NTBG he works on documenting Pacific Island plants and collecting specimens, especially ferns and bryophytes; donating several hundred specimens to PTBG, UC and other herbaria. Read more »

Currently studying ferns and lycophytes of Fiji and have published papers with others documenting these groups on Taveuni and Rotuma, as well as bryophytes of the Cook Islands and mosses of Kauaʻi. Dr. Game is working on a paper documenting the ferns of Fiji’s Lau Islands and has published many plant photographs in books, magazines, and on the Internet. Dr. Game has a photograph album of Hawaiian pteridophytes on Flickr and another album of Hawaiian bryophytes. Interested in ex situ conservation of Pacific Island plants, Dr. Game is an active member and supporter of the Hawaiʻi branch of the Nature Conservancy as well as NTBG. In California he is on the Board of Calflora, a non-profit organization that provides detailed on-line information about Californian plants. Also, a past Board member of the California Native Plant Society.

Dr. Elliot Gardner
Science and Conservation, Breadfruit

Elliot Gardner is an Assistant Professor of Biology at Case Western Reserve University and was previously a postdoctoral fellow at the International Center for Tropical Botany at The Kampong. His research focuses on the systematics and chemical ecology of flowering plants, especially in the Moraceae. Read more »

He has collaborated with NTBG on Artocarpus (breadfruit and relatives) research for nearly a decade, investigating the phylogenetics and pollination of the genus together with fellow NTBG Research Associate Dr. Nyree Zerega. More recently, he has begun investigating the floral volatile chemistry of Hawaiian Hibiscus and Kadua together with NTBG scientist Dr. Seana Walsh.

Dr. Michael Kiehn
Island Floras and Cytotaxonomy

Dr. Michael Kiehn’s current and future research work in collaboration with the NTBG will focus on three main topics. First, chromosome studies on plant species native or introduced to the Hawaiian Islands. Second, studies on the speciation, radiation, life history, and conservation of native Hawaiian species. Third, studies on the speciation, radiation, life history, and conservation of taxa occurring on islands, e.g., from the genera Coprosma (Rubiaceae) and Cyrtandra (Gesneriaceae). Read more »

For all these topics, the living plants cultivated at the NTBG and the seed bank collections of the NTBG offer a wealth of taxa worth being studied. In addition, the herbarium PTBG, and the experience and knowledge of the NTBG staff with the flora of Hawaii, the Pacific, with seed biology and the Rubiaceae are likely to be very supportive for the planned studies.

Dr. Jean-Yves Meyer
Pacific Biodiversity Conservation

Jean-Yves will facilitate the work of NTBG to document the vascular flora (flowering plants and ferns) and non-vascular flora (bryophytes) of French Polynesia and other South Pacific islands, and assist their botanists in the field.

Dr. Nina Rønsted
Biocultural Conservation, Plant Collections

Nina Rønsted’s collaboration with NTBG focuses on the role of botanical gardens in saving endangered Pacific oceanic island plants through raising awareness, conservation horticulture, and maintaining genetically representative living conservation collections of threatened species. Read more »

Current examples include a review with Ben Nyberg of global collections of island flora in botanical gardens and to what extent they are contributing to conservation science of these endangered ecosystems. With Seana Walsh and a shared PhD student Sverre Schou, we conduct a conservation genetic study of Lebronnecia kokiodes endemic to the Marquesas Islands. Dr. Rønstedsupervises Noel Dickinson in her ongoing PhD project on curating conservation collections and sustainable agroforestry of Artocarpus altilis in Hawaiʻi. She is also a proud NTBG Fellow.

Mr. James Shevock
Hawaiian Bryophytes

Bryophyte inventory activities across the Pacific Basin is the focus of James Shevock’s bryological research. The southern Philippines and Taiwan are current expedition priorities for the past decade. Read more »

An ongoing interest in the bryoflora of Hawaiʻi since this is the easternmost outpost for many bryophyte genera in Asia. James’ goal is to continue field exploration in Kauaʻi in collaboration with botanists at NTBG. In 2024 James led a workshop at NTBG on bryophytes and mosses.

Dr. Stephen Weller
Breeding Systems, Restoration Ecology

Dr. Stephen Weller is interested in the evolution of reproductive systems in Schiedea (Caryophyllaceae), one of the largest endemic plant genera in the Hawaiian Islands. This interest is shared with Ann K. Sakai, and together they have worked with many scientists, including those at NTBG and the Smithsonian Institution. Read more »

Most recently, in collaboration with Warren Wagner (Smithsonian Institution) and NTBG staff members Ben Nyberg and Ken Wood on the description of a new species of Schiedea that was discovered by a drone. Seeds provided by NTBG were grown at UC Irvine and provided information used to describe the species. Another interest is in the phylogenetic relationships among Schiedea species and have worked on this project with Norman Wickett and Krissa Skogen (University of Vienna), Michael Moore (Oberlin College), Angela McDonnell (St. Cloud University), and Warren Wagner. A topic of special interest has been the role of hybridization in the transfer of male sterility alleles across species boundaries relative to de novo evolution of separate sexes in this lineage.

Dr. Kawika Winter
Biocultural Conservation

For the past few years, Dr. Kawika Winter has had a multi-faceted research project in Hāʻena (Kauaʻi) that was designed to test our theories relating to “ecomimicry in Indigenous resource management” (Winter et al. 2020) with empirical data. This project, which was collaboratively developed with Lei Wann (NTBG Director, Limahuli Garden and Preserve) and other lineal descendants who are members of Hui Makaʻāinana o Makana, is aimed at better understanding Indigenous stewardship practices by unlocking the ecological foundations of the Kānaka ʻŌiwi (Native Hawaiian) concept of ʻāina momona (sustainable resource abundance). Read more »

One major line of research is to test a hypothesis about sunlight being a driver of ʻoʻopu (native stream goby) abundance. Another major line of research is to quantify the impacts of the Indigenous practice of imu (fish house) construction on the abundance of fishes in the nearshore reefs. The results of this research will inform the biocultural restoration efforts that Hāʻena is well-known for. In addition to that research project, Kawika mentors graduate students who are conducting botanical research into various native plants that are found in Limahuli Preserve.