Scientists & Staff

Nancy Falxa Sonti

Baltimore Field Station
5523 Research Park Drive
Baltimore, MD, 21228
Phone: 929-400-1700

Contact Nancy Falxa Sonti

Current Research

My current research spans the social and biological sciences in asking many questions about urban social-ecological systems.

URBAN TREE HEALTH. Every tree in an urban forest is expected to provide a multitude of benefits to the city. Because of this, municipalities invest tremendous resources in their urban trees, making the trees' growth and success even more important. The ability to quantify urban tree health will provide added value to urban forest managers, allowing them to make proactive management decisions and plan for stress mitigation. I am working with Rich Hallett to develop a rigorous methodology designed to quantify urban tree health at a relatively fine scale, and throughout all phases of tree decline. Tree health metrics include: chlorophyll fluorescence, canopy transparency, fine twig dieback, leaf discoloration and live crown ratio. Working with the NYC Parks and other partners, we are testing the efficacy and feasibility of this approach for a broad-scale assessment of urban forest health, invasive detection, and long-term monitoring efforts.

URBAN FOREST RESTORATION. How successfully do constructed, native, urban forests sustain themselves; and how resilient are they to the invasion of non-native invasive plant species? The New York City Afforestation Project, led by Yale University and US Forest Service researchers, investigates the sustainability of constructed, native, urban forests and their resilience to invasive species. Other research conducted in partnership with the NYC Department of Parks & Recreation evaluates the success of urban forest restoration efforts in establishing closed canopy native forest cover with reduced invasive species impacts.

COMMUNITY GARDENS. Community gardens are an important and unique type of urban green space, one that provides a space for democracy and creative expression, as well as a much needed connection with nature. Building on a data set of interviews conducted with NYC Parks GreenThumb garden representatives since 2003, this research examines garden membership, programming, partnerships, and individual motivations for gardening. One particular focus of this research addresses the questions: 1) What are community gardeners' motivations for gardening? and 2) Do these motivations remain consistent or change over time?

ENVIRONMENTAL LITERACY. I have worked to evaluate environmental education and job training programs, finding that the impacts go far beyond participants' environmental knowledge to include increased self-esteem and changes in attitudes and behavior towards themselves, their community, and the environment. I am also part of the Wave Hill Woodland Ecology Research Mentorship program for New York City high school students.

LANDSCAPES OF RESILIENCE. This cross-disciplinary project explores the creation and stewardship of open spaces/sacred places in the aftermath of disturbance. Currently, we are looking at how these urban green spaces promote individual and community resilience in Joplin, MO and New York City. The two cities face distinct stressors and are in different stages in their recovery timeline (a devastating EF5 tornado in May 2011 vs. Hurricane Sandy in October 2012). The emergent and adaptive nature of urban green space in both Joplin and New York City makes it a crucial public resource. This research is conducted with US Forest Service scientists Erika Svendsen and Lindsay Campbell, and Keith Tidball of Cornell University.

Research Interests

My research projects have integrated the social, biological, and physical sciences in the study of urban ecosystems. I am interested in many aspects of urban ecology, including plant physiological ecology, forest health, and dynamics of urban afforestation. I am also interested in the social and psychological impacts of human interactions with urban nature across different populations.

Past Research

GREEN JOBS. The demand for a well-trained green-collar labor force will increase as many cities implement sustainability and green infrastructure plans. Additionally, many green jobs training programs are intended to provide pathways out of poverty for low-skilled workers. Despite the well-documented benefits of nature on individual socio-psychological well-being, scant research has investigated the effects of working professionally in urban natural resources management. Case study findings from a NYC green jobs training program reveal the significant challenges facing training program graduates and their supervisors, but also the benefits of urban conservation job training and employment that are potentially transformational for these economically disadvantaged young adults. Green job training and employment present real opportunities for intellectual stimulation and an increased sense of accomplishment, due in part to the uniqueness of environmental work. Individuals reported positive environmental attitudes and behaviors as a result of green jobs training and employment.

FOLIAR NITROGEN IN URBAN TREES. Urban forests provide important environmental benefits, leading many municipal governments to initiate citywide tree plantings. However, nutrient cycling in urban ecosystems is difficult to predict, and nitrogen use in urban trees may be quite different from use in rural forests. To gain insight into these biogeochemical and physiological processes, this study compared foliar N characteristics of several common northeastern deciduous tree species across four newly planted New York City afforestation sites as well as at the Black Rock Forest, a rural oak-dominated forest in the Hudson Highlands, New York. Understanding nitrogen cycling in urban systems and the associated physiological changes in vegetation is critical to a comprehensive evaluation of urban forest restoration, and may have implications for carbon sequestration and water quality issues associated with nitrate export, two important areas of management concern.

Falxa-Raymond, N. and L.K. Campbell. 2013. East New York Farms! Youth Internship Alumni Evaluation Report. Prepared for East New York Farms! USDA Forest Service New York City Urban Field Station, 21 pp.

Falxa-Raymond, Nancy; Patterson, Angelica E.; Schuster, William S. F.; Griffin, Kevin L. 2012. Oak loss increases foliar nitrogen, d15N and growth rates of Betula lenta in a northern temperate deciduous forest. Tree Physiology 32(9): 1092-1101.

Why This Research is Important

Given the level of investment in urban green infrastructure, it is important to make quality scientific knowledge available to the environmental stewards who care for our urban natural areas, from municipalities to local community groups. A greater understanding of plant physiological ecology in urban ecosystems will help future restoration efforts ensure the integrity of ecological processes and the preservation of biodiversity. An understanding of how plants perform in urban environments will help us plan for the future of these critical open spaces, which make cities more liveable and provide people with a much needed connection to the natural world.


  • Columbia University, Evolution and Environmental Biology, M.A. Conservation Biology, 2011
  • Stanford University,Departments of History and Biology, B.A. , 2007

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National Research Highlights

Nancy Falxa Sonti shows students how to evaluate tree health in the Bronx as part of the Wave Hill mentoring program. Rich Hallett, USDA Forest Service

Forest Service Program Mentors New York City Students in Environmental Science

Year: 2014

An innovative research mentorship with a Forest Service scientist gets New York City teens out into the urban woods, learning how to measure forest plots and quantitatively evaluate tree health across the city. The high school students have the opportunity to spend time with a Forest Service scientist, helping to make important connections between classroom science lessons and real-world applications. The program encourages students to explore career possibilities in environmental science as they transition to college.

Last modified: Wednesday, September 03, 2014