Directory

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 Advisory / Steering Committee:

The role of the committee is to provide guidance on the strategic directions of the center, prioritization of research themes, and staffing. The committee is comprised of members representing diverse groups associated with ecology and management of Hawaii's forests. Many of the committee members are active collaborators on Tropical HTIRC research and extension projects.

Name

Title, Institution

Steve Bergfeld
Hawai‘i Island Branch Manager, Hawaiʻi DLNR Division of Forestry and Wildlife
Daniel Bowman
State Forester, USDA Natural Resources Conservation Service, Pacific Islands Area
Kualiʻi Camara
Department of Hawaiian Home Lands
Phil Cannon
Forest Pathologist, USDA Forest Service, Pacific Southwest Region
Susan Cordell
Director, Institute of Pacific Islands Forestry, USDA Forest Service, Pacific Southwest Research Station
Nicklos Dudley
Forester and Maunawili Experiment Station Manager, Hawaiʻi Agriculture Research Center
J.B. Friday
Extension Forester, University of Hawaiʻi at Mānoa
Christian Giardina
Director, Institute of Pacific Islands Forestry, USDA Forest Service
Matthew Ginzel
HTIRC Director, Entomology and Forestry and Natural Resources, Purdue University
Jennifer Grimm
Forest Management Specialist, Hawaiʻi DLNR Division of Forestry and Wildlife
Neil Hannahs
Paniolo Tonewoods
Robert Hauff
State Protection Forester, Hawaiʻi DLNR Division of Forestry and Wildlife
Greg Hendrickson
General Manager, Kealakekua Mountain Reserve
Travis Idol
Professor of Tropical Forestry and Agroforestry, University of Hawaiʻi Mānoa
Zachary Judd
Forestry Manager, Parker Ranch
Nicholas Koch
Paniolo Tonewoods
Creighton M. Litton
Professor of Ecosystem Ecology, University of Hawai‘i at Mānoa
Zhao Ma
Interim Department Head, Forestry and Natural Resources, Purdue University
Robert K. Masuda
Senior Advisor, Forestry and Natural Resources, Purdue University
Irene Sprecher
Forest Solutions, Inc.

Tropical HTIRC Graduate Students, Staff, and Affiliate Scientists

Erin Bell

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

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

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

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

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

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

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

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

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

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

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.

Tropical HTIRC Graduate Student Alumni and Past Staff

Achyut Adhikari

Achyut is a MS student at the University of Hawai‘i, studying biology of koa reproduction and vegetative propagation, to help overcome koa wilt.

Lilian Ayala

Lilian was an MS student at Purdue University, studying genetic variation in cold tolerance, survival, and growth of high-elevation koa.

Gaoussou Diarra

Gaoussou completed his Ph.D. at the University of Hawai‘i in 2015, studying seedling nutrition.

Aziz Ebrahimi

Aziz Embrahimi, a post-doctoral fellow at Purdue University, is studying forest-climate interactions, cold tolerance genes in koa, and phylogenomics of Juglans species. His focus lies in landscape genomics, phylogeny, and tree species evolution.

Erin Hickey

Erin completed her M.S. at the University of Hawai‘i in 2016, studying vegetative propagation.

Faith Inman

Faith was Tropical HTIRC project coordinator and Research / Extension Faculty with University of Hawai‘i from 2013-2016.

Bradley Kaufmann

Bradley completed his M.S. at the University of Hawai‘i in 2016, studying nursery systems. He was then Tropical HTIRC project coordinator and propagation specialist until 2018.

Oriana Krauss

Oriana completed her M.S. at Purdue University of Hawai‘i in 2014, studying tree improvement. She was a Tropical HTIRC research associate and University of Hawai‘i Junior Extension Agent until 2016.

Shaneka Lawson

Shaneka is a Research Plant Physiologist with the USDA Forest Service, Northern Research Station, studying genetic variation among koa populations and genes regulating the formation of figured wood.

Bob Masuda

Bob was a Tropical HTIRC senior advisor from 2010-2017.

Charles Michler

Charles was a USDA Forest Service Northern Research Station Project Leader and the first Tropical HTIRC director.

Quinn Moon

Quinn Moon is a senior Global Environmental Science and biology student at the University of Hawai‘i at Mānoa. For the past few years, he has helped on a number of research projects including the early establishment of ‘iliahi with endemic host species and studying the symbiotic nutrient transfer between koa and ‘iliahi. In 2022, Quinn traveled to Hawai‘i Island to assist Emily Thyroff in both greenhouse and field experiments. Quinn is planning to begin a PhD studying the ecology and evolution of plant-fungal interactions.

Juan Oliet

Juan was a visiting professor with Tropical HTIRC during 2014-2015, studying ecophysiology of forest restoration. He is a Professor at the Technological University of Madrid, Spain.

Indira Paudel

Indira is a post-doctoral scientist at Purdue University, studying adaptiveness of koa populations to resource availability.

Kyle Rose

Kyle completed his Ph.D. at Purdue University in 2017, studying the adaptive role of heteroblasty in koa.

Kylle Roy

Kylle Roy is a PhD candidate at Purdue University in the Department of Forestry and Natural Resources. Kylle is studying the chemical ecology of beetles, fungi, and ʻōhiʻa trees in association with Rapid ʻŌhiʻa Death (ROD).

Anna Sugiyama

Anna was a post-doctoral scientist at Purdue University, studying use of intraspecific variation to predict seedling performance in koa.

Emily Thyroff

Emily Thyroff is a a post-doctoral fellow at Purdue University, studying tropical dry forest restoration with regeneration of endemic Santalum species, known as ‘iliahi or Hawaiian sandalwood.

Adel Youkhana

Adel is a post-doctoral scientist at the University of Hawai‘i, studying clonal propagation of koa.