Senior Scientists

PEA’s senior scientists span a variety of disciplines with the depth of experience.

Michael G. Andreu, Ph.D.

Forest Ecology & Management, Agro-Forestry, Bio-energy

Michael Andreu has been practicing forestry for over 20 years. He has worked with forests issues in the US, Central America and West Africa. He has extensive experience as a consulting land manager on properties throughout the US South and has worked with land management agencies including The Nature Conservancy, US Department of Defense, International Paper Company, and numerous private landowners (institutional and individuals). He currently has a faculty appointment as an Associate Professor of Forest Systems at the University of Florida School of Forest Resources and Conservation and is the Co-coordinator of the Tampa Bay Watershed Forest Working Group and the UF Program for Tropical Ecology and Conservation Science. Michael Andreu has numerous peer reviewed scientific publications and is a co-author of the book Forests and Society: Sustainability and life cycles of forests in human landscapes.  Dr. Andreu is a professor of forest systems and extension specialist at the University of Florida, Gainesville. He holds a Ph.D. from the University of Washington (Silviculture & Forest Protection), a MF from Duke University School of the Environment (Forest Resource Management) and a BA from The University of the South (Sewanee) in Natural Resources. Dr. Andreu speaks English (native), and French (working).

Olga Barbosa, Ph.D.

Ecosystem Services, Agroecology, Vinecology

Olga Barbosa is interested in the relationship between humans and the environment from an ecological perspective. Her research has been continuously centered around the effects of habitat fragmentation on both species (beetles and birds) and ecosystem functions (water and nitrogen cycling). She has conducted this work across Chile, specifically in Fray Jorge National Park, a fragmented cloud forest immersed in a semi desert area, and more recently in semi-pristine areas that transition into highly dynamic and human dominated ecosystems such as cities and agricultural ecosystems. She is active in engaging the wine industry on the conservation of Chilean Mediterranean Ecosystems. The conservation of this habitat is important not only for wineries that depend on the provision of ecosystem services that sustain production and wine quality, but also for successful climate change adaptation of local communities. Dr. Barbosa speaks fluent Spanish (native) as well as English.

Nate Bogie, Ph.D.

Agroecology, Soil Hydrology, Carbon Cycling, Hydrogeology

Nate researches how deficit and drip irrigation and management of cover crops affect soil carbon cycling and soil hydro-physical properties in California’s Central Valley. He completed his PhD dissertation in 2016 at UC Merced where he studied how the traditional practice of intercropping with deep rooted native shrubs in the West African Sahel can serve as pumps to transfer water from deep, moist soil layers to shallow-rooted food crops growing nearby during extreme drought. Nate’s work has taken him to Senegal, France, and the Western US. Nate received a bachelor’s degree in Earth Sciences from UC Santa Cruz and worked as a geologist and field scientist in the renewable energy, environmental,  and water resources fields before entering graduate school. He has experience interacting with a wide array of stakeholders including subsistence farmers, water managers, forest managers, and academic researchers. Nate speaks near fluent French and is proficient at writing in French.

Antoine Champetier, Ph.D.

Agricultural and Natural Resource Economics, Ecosystem Services, Agricultural Engineering

Antoine Champetier is an agricultural and resource economist with expertise in environmental issues and policies in agriculture. He is currently a post-doctoral researcher at the Agricultural Issues Center of the University of California and his recent projects have focused on pollination and nitrogen use, two prominent examples of ecosystem services. His work integrates economic models of farmer behavior and bio-physical models of the processes that underlie ecosystem services. This modeling allows one to evaluate the performance of alternative policies and incentives for the provision of ecosystem services both to and from agriculture. Antoine holds a Ph.D. in agricultural and resource economics from UC Davis and acquired a solid background in agronomy and ecology at the French National Institute of Agronomy (AgroParisTech).  He speaks fluent French (native), English, and Spanish after having spent many years in France, the U.S., and Mexico.

Phil DeVries, Ph.D.

Tropical Ecology and Biodiversity

Phil DeVries is a tropical biologist who works in the areas of biodiversity, evolutionary ecology and conservation of insects, with particular emphasis on understanding butterflies in the context of their habitats. He employs vigorous field and museum work to develop long-term studies for understanding the factors affecting spatial and temporal patterns of diverse species assemblages. He also conducts studies that focus on the evolution and ecology of symbiotic associations, insect flight, communication, mimicry, and animal-plant interactions. He has been involved in research projects in numerous areas of Central and South America, Africa and Southeast Asia. His work has motivated research on an international scale including comparative diversity assessments among tropical forests, effects of disturbance on insect diversity, development of demographic models, temporal partitions for co-existence of hyper-diverse communities, wing-shape evolution in the forest canopy and understory butterflies, seasonal cycles of species diversity and similarity in tropical insect communities, and communication systems among insect symbionts. He has published two major books on the comparative biology of Costa Rican butterflies, over 90 separate research articles on biodiversity, ecology, evolution and conservation, and has worked as a presenter in a number of critically acclaimed natural history films. He has been awarded several significant honors including a MacArthur Foundation Fellowship, a Dodge Foundation Fellowship, a Guggenheim Fellowship, and grants from the National Science Foundation and National Geographic Society. He holds a BSc from the University of Michigan and a PhD from the University of Texas at Austin. He speaks English and Spanish.

V. Ryan Haden, Ph.D.

Agronomy, Agroecology, Soil Science, Climate Change Adaptation, Integrated Pest Management

Ryan Haden is an agroecologist and soil scientist with expertise in agricultural strategies to mitigate greenhouse gas emissions and adapt to climate change. His work examines the intersection between water, energy, land use change and sustainable agriculture, with an eye towards understanding the benefits and trade-offs for society and the environment. Ryan has recently developed carbon accounting methods consistent with international guidelines, which are being used by local governments in California to monitor agricultural emissions and implement community-wide mitigation strategies. His work on climate change adaptation has focused on the links between water management at the field, district and watershed scales. On the international stage, Ryan has cultivated consulting and research partnerships with a range of development organizations based in Asia and Latin America. These projects have involved vegetable, rice and agroforestry systems and sought to enhance adaptive management through participatory methods. Ryan holds a Ph.D. in soil science from Cornell University. He is currently a postdoctoral researcher at the University of California, Davis. He has also been a visiting scholar at the International Rice Research Institute in the Philippines and the Bogor Agricultural Institute in Indonesia. He speaks English (native) and Indonesian (intermediate).

Jonathan D. Kaplan, Ph.D.

Agricultural and Natural Resource Economics, Applied Econometrics, Policy Modeling and Evaluation, Experimental Economics

Jonathan Kaplan is an economist with expertise in water resource management, agricultural production modeling, and economic experiments. His work has looked at such topics as the consequences of water salinity management in the Mekong Delta of Vietnam, to the cost of salinity on animal feeding operations in California, to the value of wetlands in the Sacramento – San Joaquin Delta. The majority of his work has focused on developing mathematical programming models to better understand the economic consequences of agri-environmental policy. Dr. Kaplan has built numerous models depicting such problems as nonpoint source pollution, nutrient and salinity loading from animal feeding operations at local, regional, and national scales. His most recent programming model captures California wine grape production, and is currently being used to explore the ramifications of Pierce’s Disease management. His work in experimental economics has examined the efficiency of water options markets, the role of information in mitigate congestion externalities, and the design of solicitation mechanisms to reduce free-riding in public good provision. Jonathan holds a Ph.D. in agricultural and resource economics from UC Davis. He has consulted with the Organization for Economic Cooperation and Development, the California Water Resources Control Board, and Environmental Defense, among others.  Notably, he has also been an invited guest of Nobel Laureate Vernon Smith at his economic experiment laboratory at the University of Arizona where he was able to learn about the use of the laboratory as a policy test bed.

Erica R. McKenzie, Ph.D.

Environmental chemistry, Environmental engineering, Point-of-use drinking water treatment

Erica McKenzie is environmental engineer who has spent most of her energies in two areas: pollutant fate and transport in the environment, and point-of-use drinking water treatment.  Her pollutant fate and transport work has included both organic and inorganic contaminants, and has covered natural and engineered systems.  She is excited to investigate pollutant interaction with environmental constituents so that chemicals can be effectively used, treatment solutions can be efficiently deployed, and negative environmental impacts can be successfully avoided. Dr. McKenzie’s work on point-of-use drinking water treatment technologies and strategies has been pursued with in-home assessments in Uganda and Kenya, as well as product development and verification with a industry collaborator. Dr. McKenzie holds a M.S. and Ph.D. in environmental engineering, both from UC Davis, and she is currently a postdoctoral researcher at the Colorado School of Mines. She speaks English (native) and German (working).

Daniel M. Nover, Ph.D.

Water Quality Engineering, Water Treatment, Sanitation, Water Resource Policy

Dan Nover is an expert in the physical and biogeochemical processes that influence water quality in freshwater systems, technologies available to safeguard water quality, and policy options available for water resources management. In particular, his work has focused on the role of fine particles and nutrients in surface water quality and ecosystem health.  He has been involved in research projects in numerous study areas and worked on diverse issues ranging from nutrient enrichment in urban lakes, to nutrient control in drinking water reservoirs to managing lake clarity in Lake Tahoe, work California funded through the Southern Nevada Public Lands Management Act and the US EPA.  His international development work focuses on small-scale systems for water supply, water treatment, sanitation and hygiene (WASH) projects, most recently in Uganda, where funding from the US Embassy, Caterpillar Corporation and Engineers Without Borders were leveraged in order to enhance water supply and sanitation in rural communities. He served in the Philippines as US Peace Corps Volunteer. He holds a BSc in Ecology from McGill University, a MSc in Environmental Engineering from Michigan Tech and a PhD in Environmental Engineering from UC Davis. He speaks English (native), Bikol (fluent), and Tagalog (intermediate).

Emma C. Underwood, Ph.D.

Conservation Ecology, Return on Investment, Invasive Species, Ecosystem Services, Invertebrate Ecology

Emma Underwood is a senior conservation ecologist and research scientist with an interest the application of geospatial tools and remote sensing techniques to address biodiversity and conservation issues and inform environmental decision making. Her areas of expertise include conservation assessments of biodiversity, estimating conservation return on investment, evaluating the impact of management scenarios on ecosystem services, and mapping and predicting the distribution of invasive plant species. During the past 15 years Emma’s research has spanned multiple spatial scales from sites to ecoregions and has focused on a variety of ecosystems including tropical forests in central Africa, Mediterranean-type habitats globally, the central coast and Sierra Nevada of California, and the Mojave Desert. She has worked previously for the World Wildlife Fund, and has undertaken extensive collaborative research with The Nature Conservancy and the US Geological Survey and is a member of the IUCN Invasive Species Specialist Group. Emma received her Ph.D. in Ecology from the University of California, Davis.

Mehrey Vaghti, MSc.

Riparian Systems Restoration, Terrestrial Ecology, Vegetation Community Ecologist

Mehrey Vaghti guides the implementation and monitoring of ecological process-based restoration of terrestrial ecosystems, with a particular focus on riparian systems. She has studied the environmental drivers of riparian vegetation recruitment and establishment throughout California, with over a decade of experience in the direction of vertically integrated research in support of ecosystem management objectives. She is a recognized and authoritative expert in the riparian ecology of California’s Mediterranean river systems.  She has engaged with numerous resource management agencies and non-governmental organizations in the development of appropriate data capture methods and experimental design to leverage field-level observations into landscape-level decisions. She holds a BSc in Environmental Biology and Management, with highest honors, and a MSc in Ecology, both from UC Davis. Ms. Vaghti speaks English (native), French (working), and Farsi (elementary).