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Janet L. Mayfield

Janet L. Mayfield

– President and Chief Executive Officer

Janet Mayfield is the President and Chief Executive Officer at National Tropical Botanical Garden (NTBG). Janet leads five geographically distinct botanical gardens whose combined mission is to enrich life by perpetuating tropical plants, ecosystems, and cultural heritage.

Having lived on Kauaʻi for over 36 years, she has a deep appreciation for the community, the culture, and the environment. She was raised on a farm in Eastern Washington and recognizes the complexity of creating sustainable food sources and the challenges of maintaining environmentally responsible agriculture.

Janet holds a BS in Accounting from Arizona State University and began her career with NTBG as Controller in 1997. From 2003-2018 she served as Chief Financial Officer and Chief Operating Officer. Janet assumed the role of Chief Executive Officer and Director in 2019 and successfully led the organization through the pandemic and helped to ensure a thriving, sustainable future for the organization. She is currently guiding the NTBG leadership team through the creation and implementation of a new 2023 – 2027 five-year strategic plan.

In addition to her role with NTBG, Janet has extensive experience in the management and finances of other non-profit organizations and continues to serve on community boards and advisory committees.

Tami Rollins

Tami Rollins

– Chief Financial Officer

Tami is a CPA whose career has focused on accounting, finance, and taxes. She has a Bachelor of Business Administration from Florida Atlantic University and has lived and worked on Kauai since 1987. Her experience ranges from working 20 years in public accounting with an emphasis on tax and non-profit audits and another 12 years working in the for-profit corporate world before joining the NTBG team in 2014 as the Controller. In 2019 she took over as CFO when Janet Mayfield became the CEO. Ms. Rollins also has served on many non-profit boards over the years.

Dr. Nina Rønsted

Dr. Nina Rønsted

– Director of Science and Conservation

As Director of Science and Conservation for the National Tropical Botanical Garden, Nina oversees the strategic development of science and conservation at the Juliet Rice Wichman Botanical Research Center (BRC) at NTBG’s headquarters on Kauai. Nina came to NTBG in 2019 from a position as Professor and Curator of vascular plants and Director of Science at the Natural History Museum of Denmark, University of Copenhagen, where she continues to be adjunct professor. She is also affiliated with the EECB graduate specialization at the University of Hawaii at Manoa. Following her PhD from the University of Copenhagen, Nina held research fellowships at the Royal Botanic Gardens Kew in the UK and the University of Minnesota. Nina’s research is interdisciplinary and centered on the origin, distribution and conservation of plant diversity and the relationship between people and plants including the role of botanical gardens and collections.

Tobias Koehler

Tobias Koehler

– Director of South Shore Gardens (McBryde and Allerton)

Tobias Koehler joined NTBG’s staff in February 2016 as director of its gardens on the South Shore of Kaua’i. A member of NTBG’s senior management team, he is responsible for the activities within the McBryde and Allerton Gardens, including horticultural care and visitor program, as well as facilities upkeep for these gardens and NTBG’s adjacent headquarters campus.

Mr. Koehler spent nearly a decade in the private sector as an environmental planner, project manager, and operations manager. In addition to his extensive experience in the for-profit world, he has a strong background in non-profit management as well as in marketing, business development, business process improvement, budgeting, financial management, resource management, and contracting.

After completing an undergraduate degree in biology from the University of California at Berkeley and conducting botanical research in Panama and French Polynesia, Mr. Koehler relocated to Hawai’i and earned a Master’s degree in botany and one in business administration.

Lei Wann

Lei Wann

– Director of Limahuli Garden & Preserve

Since January 2020, Lei Wann has been the Director of Limahuli Garden and Preserve. Her ancestral ties to Limahuli and passion to care for Ha‘ena has created a deep connection that shines strongly in her leadership. She is able to share knowledge of the past while bringing in modern research.

Lei Wann went to school at the University of Waikato, UH of Hilo, and UH of Manoa with degrees in Anthropology, Pacific Island Studies, and Elementary Education. She began her career in conservation, then spent many years in education leading and developing aina based curriculum for keiki at Kawaikini NCPCS and Kamehameha Schools. Currently, she is carrying on her kuleana at Limahuli Garden and Preserve by teaching and perpetuating the biocultural traditions of Ha‘ena.

Michael Opgenorth

Michael Opgenorth

– Director of Kahanu Garden and Preserve

Mr. Michael “Mike” Opgenorth came to NTBG in February 2015 with a wide set of skills. In addition to his lifelong background in horticulture, Mr. Opgengorth holds a bachelor’s degree in business administration. He also earned an academic minor in Plant Production/Plant Management from the College of Tropical Agriculture and Human Resources at the University of Hawai’i.

Prior to joining the NTBG team as director of the organization’s Maui garden, Mr. Opgenorth served in numerous capacities at the Hawai’i Department of Agriculture where he worked with a wide range of stakeholders at all levels in Hawai’i’s agriculture community. In his spare time, he works as a tropical plant advisor for a garden lifestyle application, identifying plants from all over the tropical world as well as plant diseases and plant pests.

Heather George

Heather George

– Director of Philanthropy

Heather George joined NTBG as Director of Philanthropy in March 2019. Ms. George has over 20 years of experience working with environmental non-profit organizations as a fundraiser and event coordinator. She is passionate about environmental conservation, science-based resource protection, and communicating the importance of the natural world. Prior to NTBG, Ms. George served as Grants Manager for Waterkeeper Alliance. Previously based in Southern California, she is a graduate of UCLA and has lived on Kauai since 2014.

David Bryant

David Bryant

– Director of Communications

David is passionate about bringing people and plants together. He served as the Director of Education & Engagement for the California Native Plant Society (CNPS) where he led public programs and campaigns to foster transformative change for people-plant relationships. He led statewide campaigns to build awareness and action for pivotal environmental issues in California, including wildfire, plant poaching, native plant horticulture, and Indigenous stewardship.

Before CNPS, David served as the Director of Visitor Experience at California Botanic Garden. He led the implementation of the first interpretive master plan, oversaw a robust communications calendar, brought the retail nursery online, steered large-scale public events and led the rebranding of the organization. David is continually indebted to mentors from California and Baja California Native communities who have guided his commitment and passion for plant advocacy. David received his BFA from the Rhode Island School of Design and began his career with a formative internship at the Harvard Museum of Natural History, where he got to bring together his love of art and environmental communications.

Dr. Brian Sidoti

Dr. Brian Sidoti

– Director of The Kampong

Brian has nearly two decades of experience working at multiple botanical gardens and various museum settings. Most recently, he was at Fairchild Tropical Botanic Garden, where he co-led The Fairchild Challenge through program development, fundraising and marketing. He previously taught at State College of Florida, Manatee-Sarasota and co-led its Biotechnology Outreach Program. Brian received his Ph.D. in Botany from the University of Wisconsin- Madison, where he studied the evolutionary history and conservation genetics of the Caribbean Basin cardinal airplant. Brian also has his M.S. in Biology through Florida International University and Fairchild’s graduate program. As an FIU alumnus, he is excited by the collaborative opportunities between The Kampong and the International Center for Tropical Botany. Brian volunteered in The Peace Corps in Nicaragua as a Community Environment Promoter after receiving his B.A. in Biology at Colby College.

As Director, he is thrilled to provide leadership and direction to The Kampong – a living botanical garden and museum. He is excited to lead the team in connecting people to plants through enriching experiences focused on discovery, education, horticulture and scientific research.

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