Dr. Susan E. Crow is an Associate Professor of Soil Ecology and Biogeochemistry in the Natural Resources and Environmental Management Department within the College of Tropical Agriculture and Human Resources and an affiliate of the Water Resources Research Center at the University of Hawaii Manoa.  She studies the natural carbon cycle and human impacts on the soil environment and serves on the state Greenhouse Gas Sequestration Task Force (formerly Carbon Farming Task Force) and the North American Carbon Program, Carbon Cycle Science Interagency Working Group: Science Leadership Group member. Susan is an Associate Editor for the journal Biogeochemistry and belongs to the American Geophysical Union, Soil Science Society of America, Soil and Water Conservation Society, and International Soil Carbon Network.


Christine Tallamy Glazer – Christine Tallamy Glazer is lab manager of the Soil Ecology and Biogeochemistry lab. She received her MS in Marine Science, with a concentration in Marine Biology/Biochemistry, from the University of Delaware.  Upon her arrival on Oahu in 2004, she conducted biogeochemical research utilizing stable isotopes to trace microbial nutrient cycles in recirculating aquaculture systems as a research associate at the Oceanic Institute. After two years at the Oceanic Institute, she taught high school math and science for three years, then returned to the lab as an analyst for the Biogeochemical Stable Isotope Facility at the University of Hawaii. Christine was recently certified as a Community Emergency Response Team member.  She enjoys snorkeling, hiking, swimming, and spending time with her husband and two young children.

Dr. Johanie Rivera-Zayas (Postdoctoral Fellow) – Johanie focuses on soil nitrogen dynamics, soil microbial interactions, and greenhouse gas emissions. Her field experience encompasses soil, plant, and GHG dynamics in tropical, subtropical, and temperate systems. Among multiple roles, Johanie leads the U.S. Climate Alliance funded project: On the path to carbon neutrality: a Hawaii carbon land use opportunity assessment. The project goal is to maximize landscape-scale sequestration rates, through collaborations with stakeholders, resource managers, and local communities to develop a land-use classification map optimized for climate mitigation at the State of Hawai ́i scale. Johanie will lead a co-production process that collaboratively identifies and prioritizes: 1) high-quality lands for climate-smart food production systems, 2) underutilized lands for climate-smart agroforestry, reforestation, forestry practices, 3) recently abandoned lands for rehabilitating soil health, 4) managed watershed forests, and 5) engages and honors the diverse conditions that shape land-use decision making in Hawai’i.

Current Students:


Elaine Vizka (Ph.D.) – My research aims to investigate the soil health status across the Hawaiian Islands, optimize soil health metrics for Hawaii by discerning which metrics are critical factors across its diverse landscapes, and understand which management practices are environmentally and economically viable for farmers. Sustainably managing soils while maintaining productivity in Hawaii is particularly challenging due to their diverse nature and use. Healthy soil is of the utmost importance as it can protect Hawaii’s limited resources, enhance ecosystem services, and mitigate climate change.

I received my B.S. in Environmental Biosciences and B.A. in Geoscience from University of Iowa. As an undergraduate, I worked on several research and outreach projects including planning an urban agriculture area, assessing sand quality, and researching a species of diatom found in saturated soils. I continued my academic career at Iowa State University and received two M.S. degrees in Soil Science and Environmental Science with a certificate in Geographical Information Sciences (GIS). My Master’s thesis investigated how soil health varied with differing management systems across landscapes in Iowa. I worked towards optimizing soil health metrics in Iowa by measuring how responsive metrics were to management differences, the quantity of soil samples needed to detect differences in soil health between management practices, and where on the landscape these differences were most easily observed.

I dedicate my home life to scuba diving, hiking, gardening, dancing, yoga, and my pets.

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Alexis Stubbs (M.E.M.) – I was born in Lake Tahoe, CA and raised on the westside of Hawai’i Island. Over the recent years of my adult life, I have strengthened my relationship with nature through that of Hawaiian thinking, gifting me the means to steward the ‘āina. I have grown to recognize that the health of the people is a direct reflection of the health of the environment and therefore the compromised immunity of our planet and steady rise of human ailments are likely relative. Through my undergraduate education in Plant Science and Agroecology at the University of Hawaii at Hilo, I learned that the salubrity of the environment begins within the soil and therefore soil fertility is an integral component of human existence. I have grown passionate about deconstructing the conventional agriculture methodologies that have consequently degraded soil conditions and have taken on the next part of my educational journey to further learn, study and analyze the ways in which people can play a role in soil remediation through regenerative practices. I am stoked to be a part of the Crow Lab to which will serve as the primary catalyst for me to accomplish my graduate study goals! I will be studying waste sustainability through anaerobic digestion and determining its potential to remediate soil and produce a reliable source of renewable energy.

Ryan Ueunten (M.E.M.) – Aloha! My name is Ryan Ueunten and I am from Kalihi, O’ahu. In 2016, I graduated at UH Mānoa with a B.S. in Global Environmental Science (Dept. of Oceanography). Currently, I am a student in the Master’s of Environmental Management program (Dept. of Natural Resources and Environmental Management), and my interest is in restoring indigenous agricultural systems in Hawai‘i. Throughout my life, I’ve been lucky enough to work in lo‘i systems (flooded taro patches) and learn from many dedicated people who are growing kalo (taro) in Hawai‘i. Many of these people, who are kūpuna, farmers, educators, community members, parents, and students, greatly inspire me to pursue an academic career in revitalizing important traditional foods and practices.

At present, I am researching soil remediation of lo‘i systems. I hope to learn the most effective and cost efficient ways of remediating lo‘i soils contaminated with heavy metals, so that ultimately we can reclaim spaces for kalo cultivation in Hawai‘i. Mahalo!

Karen Moran Rivera (Ph.D.) I am from El Salvador and I began my studies at Zamorano University (Honduras), a top agricultural university in Latin America. I came to the U.S. as a visiting scholar to work in Dr. Stuart Grandy’s lab at the University of New Hampshire, where I went to received her M.S. in 2020. As a Masters student, I built a bio-economic model that aims to understand how soil organic matter building and N leaching varies with variation in the impacts of cover crops, and how this will impact future yields and the farmer economy.  Today, as a Ph.D. student in Natural Resources and Environmental Management at the University of Hawai’i, my research focuses on understanding soil organic matter dynamics and the economic benefit of carbon sequestration in tropical lands. Helping smallholding farmers to become more resilient and productive is my long-term goal.


Valerie M. Fajotina is a student, currently enrolled in Leeward Community College Associate in Science (AS) Sustainable Agriculture program. Her inspiration Helping children use nature to learn to be free and safe individuals, empowered by their thoughts, check out The Keiki Paʻaini Project, LLC. In addition to being a student, Valerie is a mother, avid learner, entrepreneur, Veteran, contributor @bad_motherfarmer. Featured in GoFarm Hawaii Home Gardening Basics Episode 1. Military experience provided her with data collection and complex, “system of systems thinking” experience that may be applied creative and productively to soil health and agriculture in Hawaii. Valerie’s combination of on-farm and data science experience allows her to uniquely contribute to the development of a privacy policy and data input features for our research group’s web-based Hawaii Soil Health Tool.  For her internship, she will simultaneously refine features for the tool that make it both accessible to farmers currently participating in soil health trials and protected to ensure all our users’ privacy.

Martin A. Sampson Benavides is a Visiting Scholar and recent B.S. graduate of the Panamerican Agricultural University, Zamorano, Honduras. His inspiration is helping farmers in Nicaragua be sustainable and efficient and to achieve that a strong background in soil science is needed, which does not stop in the field. Martin’s experience is mostly in the field and he wants to complement that knowledge with laboratory experience and learn more about the science behind soil health. Martin is primarily providing much needed assistance in the lab analyzing a back-log of soil health samples in preparation for a wave (maybe tsunami is better wording) of samples expected starting in the summer. In addition to his previous experience as an intern, researcher, and farm production supervisor, the laboratory experience will help him be as holistic as possible for his future career goals that may include running a laboratory himself.

Lab Alumni

Jon Wells (Ph.D.) – Jon aimed to improve the sustainability of bioenergy systems through efficient conversion and carbon economy. His dissertation was titled “Understanding carbon in large-scale agricultural production systems for bioenergy in the tropics: selecting soils, feedstocks, and conversion pathways”. Dr. Wells will join Dr. Yiqi Luo’s research group as a postdoctoral researcher at Northern Arizona University in 2021.

Daniel Richardson (M.S.) – Originally from Oahu, Dan earned a B.S. from the NREM Department at the University of Hawaii at Manoa and his research interests are soil microbiology, soil health, and the how soils can relate to global sustainability. Dan enjoys surfing, hiking, and digging holes.

Casey McGrath (M.S.) – For her M.S. Thesis, Casey established an innovative deep soil warming field experiment at the Lyon Arboretum in Hawaii and measured ecosystem carbon flux for one year of heating.  Unlike any deep soil warming experiment to date, there was no significant respiration response to augmented soil temperatures past the surface layer. Multimodal analysis confirmed the hypothesis that high concentrations of amorphous minerals were the primary driver of the lack of respiration response, followed by high relative soil moisture and low bacterial richness. Casey graduated in Fall 2019 with her M.S. from University of Hawaii Manoa and a manuscript is nearly complete describing the findings. After graduating, amid the COVID-19 pandemic, Casey moved onto a Post Masters Research Associate – Environmental Data Analyst position at the Department of Energy’s Pacific Northwest National Laboratory in Richland, WA.  


Hannah Hubanks – M.S. 2019 NREM. “Towards a Hawaii soil health index: Identifying sensitive and practical indicators of change across land use and soil diversity.” Hannah’s thesis was an epic tour of the diversity in soils, land use, and management across the islands to determine the range of soil parameters that define a healthy soil in Hawaii.  Her work resulted in a manageable, practical, and sensitive list of potential indicators of soil health across productive systems to develop into a soil health index. Hannah currently works as a soil health specialist for Oahu Resource Conservation and Development.


Mathilde Duvallet (intern) – visiting student of ecology and engineering from AgroParis Tech; originally from Normandy, France, Mathilde conducted her international internship requirement in the Crow Lab.  She assisted in the connection of deep soil heating probes through a complex electrical network which creates heat within the deep soil profile using heating cable and installation of the novel temperature sensor network. The temperature network includes wiring the sensors to multiplexors to a data logger in order to collect temperature data. In addition, she assisted in the collection of soil cores, analysis of the microbial communities at the study sit and soil gas flux sampling.


Mika Sebastian (intern) –   Mika  conducted surveys of local producers on Oahu and Maui and photo documenting their stories about their land, crops, and what soil health means to each individual.  A resulting web-based story board will help communicate the need for healthy soils for landscape resilience and thriving communities.


Genelle Watkins – M.S. 2018 NREM. Interests in conservation and sustainability took Genelle to Pemba Island in East Africa where she worked with local communities to develop a strategy to conserve and restore mangrove forests to help maintain livelihoods. Her passion for sustainability and hope to better this planet through citizen science research that directly involves people and communities to make a positive global impact will take her far.  After graduating, Genelle worked for Hawaii Green Growth developing content for the Aloha+ Challenge Dashboard.


Kaelin Sylva B.S. 2018 NREM  Kaelin completed her internship assisting with field site planning, maintenance, and characterization for the deep soil warming project at the Lyon Arboretum and transitioned to research assistant, making everything run a little smoother for all of us in the Crow lab.


Annika Little B.S. 2017 NREM Annika conducted her NREM internship in the Crow Lab and completed independent research on the distribution of biochar in soil aggregates in a zero-tillage perennial grass system. After graduating, she worked for the U.S. Army Medical Command in the Forensic Toxicology Drug Testing Laboratory and a Specimen Controller.


Steven Leone 2017 Steven worked with the Crow Lab throughout 2017 to help convert an overgrown jungle patch into a Deep Soil Warming field site for a long term, manipulative experiment to test the effect of warmer soil on ecosystem processes and carbon biogeochemistry.  He developed the temperature sensor network for the field site at the Lyon Arboretum and this website.

Adel Youkhana 2011-2016 Postdoctoral Researcher, Junior Researcher “Water and carbon footprint and plant parameters of biofuel production on the HC&S sugarcane lands on Maui, Hawaii”.

Lauren Deem M.S. 2016 NREM “Mechanistic understanding of improvements in yield and sustainability of biochar-amended soil”.  Currently a Crop and Soil Scientist at Kuo Testing Labs, Othello, Washington.

Jabez Meulemans M.S. 2016 NREM “Systems approach to assessing the environmental and economic sustainability of food and fuel crops with biochar soil amendment”. After graduating, he became the Environmental Services Coordinator for Jefferson Country in Colorado (Denver area) tackling sustainability issues through renewable energy initiatives and water/energy efficiency and conservation projects.

Konni Biegert Institute of Soil Science and Land Evaluation, University of Hohenheim, Germany, M.S. 2015 “Biochar effects on greenhouse gas emission from two Hawaiian arable soils”.

Olivia Schubert Technician 2015-2016

Nancy Parker Technician 2015-2016

Michelle Lazaro M.S. 2015 NREM Recipient of the 2013 Hau‘oli Mau Loa Foundation Graduate Fellowship in NREM, “Optimization of baseline soil carbon stock assessment across the Hawaiian Islands”.  Presidential Management Fellow (STEM) at the U.S. Forest Service, Pacific Northwest Research Station, Portland, OR.  After graduating, Michelle became a Natural Resource Specialist, Inventory Reporting and Mapping Team, Resource Monitoring and Assessment Program at the same station.

Whitney Ray M.S. 2015 NREM “Greenhouse gas emission balance of biofuel feedstock for potential carbon trading”.  After graduating, she became a Manager, Impact-Directed Environmental Accounts at National Fish and Wildlife Foundation, San Francisco, CA.

Hironao Yamazaki M.S. 2013 NREM “Alteration in soil carbon pools following land use and management change for bioenergy feedstock production”.

Meghan Pawlowski (Lind) M. S. NREM 2013 “Greenhouse gas flux and fine root dynamics of sugarcane and Napier grass under deficit irrigation”.  Previously, an Environmental Specialist V for the Texas Department of Transportation. Currently an Ecologist/Project Manager for Cox-McLain Environmental Consulting, Inc., Austin, Texas.

Mataia Reeves M.S. 2012 “The potential carbon sequestration of Eucalyptus grandis in conjunction with its use as a biofuel feedstock”.  After graduating, she became a Research Associate at Pioneer Hi-Bred, Waimea, HI.

Yudai Sumiyoshi M.S. 2012 “Belowground carbon cycle of Napier and Guinea grasses grown for sustainable biofuel feedstock production”, degree awarded December 2012.  Awarded “Best NREM Master’s Student Presentation” at the 2011 CTAHR Student Research Symposium. Awarded “2011 Outstanding Student Paper Award” from the Biogeosciences Section of the American Geophysical Union.

Undergraduate Lab Research Assistants Alumni:

Katherine Hiu · Maxim Irion · Sebastian Sievert · Winter Lim · Jeremiah Hasley · Derek Risch · Kimber Troumbley · Eryn Opie · Sean Reseigh · Davis Turner · Nathan Hunter · Erika Mizokuchi · Mark Miller · Heather Kikkawa