Meet Our People

Students, Staff, & Research Fellows

Douglass F. Jacobs

Director, Tropical Hardwood Tree Improvement and Regeneration Center (Tropical HTIRC)

Douglass F. Jacobs is the Fred M. van Eck Professor of Forest Biology in the Department of Forestry and Natural Resources at Purdue University and Affiliate Graduate Faculty in the Department of Natural Resources and Environmental Management at the University of Hawai‘i at Mānoa. He studies the ecology and physiology of forest regeneration. He began working in Hawai‘i in 2003, co-instructing a course on forestry nursery systems to Pacific Island managers, which led to the publication of the Tropical Nursery Manual (USDA Forest Service Agriculture Handbook 732). He was based in Hilo during 2016, where he was a Visiting Professor at University of Hawai‘i at Mānoa and the USDA Forest Service Institute of Pacific Islands Forestry. As Director of Tropical HTIRC, he leads an integrated research and extension program to promote the restoration of native Hawaiian forest tree species.

Tropical HTIRC Graduate Students, Staff, and Affiliate Scientists

Erin Bell

PhD Student at Purdue University
Research

Erin Bell is a PhD student with the Department of Forestry and Natural Resources at Purdue University. She earned her undergraduate degree in Biology from Carroll College in 2014 and her master’s degree from Miami University in 2020. Prior to enrollment at Purdue, she gained experience in ecological research in Idaho and Montana with the US Forest Service before moving to work in the diverse ecosystems of Hawai’i. Working with Maui Forest Bird Recovery Project and their partners since 2019, she developed a passion for native plants and the unique relationships they hold with Hawai’i’s forest birds. Erin is interested in pursuing research that explores forest restoration techniques that benefit native birds, land managers, and plant biodiversity to inform and influence management decisions.

Owen Burney

Professor at New Mexico State University
Research

Owen is an Professor at New Mexico State University. He is leading projects related to thinning of juvenile stands of koa, grafting of koa, ‘iliahi restoration, and collaborating on other initiatives.

Solomon Champion

PhD Candidate, University of Hawai‘i at Mānoa
Research

Solomon Champion is a PhD candidate in the Botany Department at the University of Hawai‘i at Mānoa, studying the genetics of native Hawaiian tree species. Solomon’s interests are in genomics, phylogenetics, and evolution. He is using population genetics to elucidate population structure within the Hawaiian sandalwoods as a whole and to identify hybrid individuals. Solomon is using physiological and genomic methods to characterize genotypic variation at the individual and population levels. He hopes this research helps answer practical questions about phenotypic plasticity, local adaptation and hybridization within ‘iliahi.

Kelly French

PhD student at Purdue University
Research

Kelly French is a PhD student at Purdue University, Department of Forestry and Natural Resources. Kelly earned her BA in Biology from Colgate University in 2015 and worked for four years in human genetics while spending most weekends working on her family’s 450-acre Tree Farm in Maine. This drove her to return to school to study forestry, and in 2021 she graduated with her MS in Forest Resources from the University of Maine where she studied tree ecophysiology. During her PhD, Kelly is especially interested in investigating tree water and carbon relations in ‘iliahi and various host species, while developing adaptive management strategies to minimize drought stress. She plans to use physiological parameters to inform longer-term species growth responses, and is interested in how macroclimate, microclimate, and elevation influence these responses.

Simon Landhäusser

Professor at University of Alberta
Research

Simon Landhäusser is a Professor at University of Alberta. He is collaborating in projects on ‘iliahi physiology and host plant interactions, koa propagation and planting, and the role of carbon reserves for disease resistance in ʻōhiʻa

Asa McCurdy

PhD Student
Research

Asa McCurdy is a PhD student with the Department of Forestry and Natural Resources at Purdue University. He earned his undergraduate degree in Plant Sciences and Technology from the University of Missouri-Columbia in 2020 and his master’s degree in Botany and Plant Pathology from Purdue University in 2023. Asa’s PhD project focuses on the link between nonstructural carbohydrate (NSC) and chemical defense dynamics of ʻōhiʻa trees to predict their resistance to Rapid ʻŌhiʻa Death, a destructive fungal pathogen complex. Asa is collecting samples from mature ʻōhiʻa trees to quantify NSC reserves and chemical defenses throughout the year and using this foundational knowledge to inform subsequent field and greenhouse trials. While Asa’s thesis will focus on NSC dynamics, collaboration with members of the Trowbridge Lab at the University of Wisconsin-Madison will elucidate defense compound dynamics. Asa aims to use these NSC and chemical defense compound data to inform decision making for ROD mangement and mitigation stratgeies.

Rebekah Ohara

PhD Candidate at Purdue University
Research

Rebekah Ohara completed her PhD in the Department Forestry and Natural Resources at Purdue University during 2024, focusing on the pathways and opportunities for community-managed forests in Hawai‘i. She is the President and CEO for the Akaka Foundation for Tropical Forests, a nonprofit organization with a vision of vibrant forest communities alive with the voices of Hawai‘i from one generation to the next. Rebekah received her B.A. in Anthropology in 2009 from Humboldt State University (HSU), and in 2013 she completed her M.A. in Social Science at HSU’s Environment and Community Program, focusing on the social and ecological considerations of tropical forest conservation in Ecuador. Rebekah previously served as a Teacher’s Assistant and Field Guide for HSU’s Primate Field School at the Organization for Tropical Studies in Costa Rica.

Celso Oliveira

Research Scientist in the Department of Forestry and Wildlife Ecology at the University of Wisconsin-Madison
Research

Celso Oliveira is a research scientist in the Department of Forestry and Wildlife Ecology at the University of Wisconsin-Madison. He earned his undergraduate degree from the University of São Paulo and completed his PhD in Chemistry in 2021 from the University of Nevada-Reno under the mentorship of Prof. Christopher Jeffrey. Celso has dedicated his early academic career to exploring the use of spectroscopy tools, particularly Nuclear Magnetic Resonance, for the study of plant secondary metabolism and its implications in ecological interactions. Throughout his student years, he worked extensively on the isolation and characterization of novel compounds from tropical plant species of the genus Piper and Peperomia. Working with Prof. Amy Trowbridge during his appointment at Wisconsin, Celso has been involved in an NSF-BII project to study aspen chemical defenses against the invasive spongy moth and fungal canker disease. Now returning to a tropical ecosystem, he is participating in a collaborative project to identify chemical and physiological traits implicated in ʻōhiʻa resistance to ROD.

Tawn Speetjens

PhD Student at Purdue University
Research

Tawn Speetjens is a third year PhD student at Purdue University in the Department of Forestry and Natural Resources (FNR). He was born and raised in Honokaʻa on the Big Island of Hawaiʻi, and graduated from the University of Hawaiʻi, Hilo in 2009 with a BS in Biology, and from Purdue University in December 2022 with a MS from the Department of Forestry and Natural Resources. He has worked throughout Hawaiʻi’s diverse ecosystems with highlights which include working for the USFWS on Laysan Island in the northwestern Hawaiian Islands, banding forest birds at the Hakalau National Wildlife refuge, and conducting watershed management with the Kohala Watershed Partnership. He also worked as a forester and nursery manager for the Hāloa ʻĀina Reforestation Project where he was introduced to the unique challenges of growing Hawaiian sandalwood species (ʻiliahi). Tawn has a passion for growing Hawaiʻi’s native plants and is interested in ecological restoration and commercial production of ʻiliahi and native Hawaiian natural resources. He led development of a S. paniculatum propagation protocol that was published in Tree Planters Notes in 2021. His MS research examined the effects of fertilizers and host pairing on nursery production and field establishment of S. paniculatum and he published the first chapter of his thesis in the journal Forests in 2023. Tawn continues to work with S. paniculatum in his PhD research as he explores the physiological mechanisms that underlie the ʻiliahi-host connection.

Aaron Wehrman

MEM Student, University of Hawai‘i at Mānoa
Research

Aaron Wehrman completed his MEM (Masters in Environmental Management) degree in 2024 at the University of Hawai‘i at Mānoa. He was born and raised on Oahu and graduated from the University of Hawai‘i at Hilo with a BS in Environmental Science in 2022. Aaron started his undergraduate work in Marine Science but made a transition to applied terrestrial ecology. He worked with Dr. JB Friday, Dr. Travis Idol, and the Department of Hawaiian Home Lands on an Acacia koa reforestation project on Mauna Kea, studying the effectiveness of reforesting koa in a gorse dominated landscape. Aaron is extremely grateful to the Hau‘oli Mau Loa foundation for funding his education and research.

Pandu Wirabuana

PhD Student at Purdue University
Research

Pandu Wirabuana is a PhD candidate at the UH Mānoa. He received his BS and MS from Universitas Gadjah Mada, Indonesia. Pandu has worked for 10 years in Indonesian tropical forests before starting his PhD program. He has experience working on mangrove restoration and plantation forest management with eucalyptus and albizia. Pandu has a strong background in forest growth and yield. He started his PhD program in 2022, working with Dr. Travis Idol as his supervisor. His research focuses on mixed stand management between ʻiliahi and host species in Hawaiian tropical dry forests, specifically addressing the balance of competition, facilitation, and parasitisim between ʻiliahi-host at the stand level. Pandu is writing his dissertation and planning his final defense for 2025. His dissertation committee is comprised of Drs. Travis Idol, Douglass Jacobs, JB Friday, Michael Saunders, and Kasey Barton.