I am an urban ecologist who works at the interface of science and design. My research focuses on urban plant community dynamics. From forest fragments to green roofs, I study the ecological function and successional trajectories of these systems and how we may facilitate/sustain their ecological and social services over time. As a researcher and educator I strive to engage urban practitioners and integrate ecological research into the planning, design, and management of our cities.
Plant recruitment dynamics in urban ecosystems can be influenced by multiple co-occurring and oft... more Plant recruitment dynamics in urban ecosystems can be influenced by multiple co-occurring and often exacerbated conditions and stressors common to most cities. Urban associated habitat fragmentation and land transformation, altered climate and microclimates, biotic invasion, pollution (e.g. elevated atmospheric carbon and nitrogen), and human activity, both direct and indirect, are all observed to have species-specific effects that may limit or facilitate recruitment success. A core question is whether urban ecosystems are functionally different, and if so, what that means for management and restoration practice. This dissertation investigates the application of plant life history frameworks and analyses in the context of urban forest populations. Chapter 1 presents a review of recent literature and a modified recruitment limitation framework for understanding plant recruitment dynamics within urban ecosystems. In the subsequent chapters (2-5) I present a series of related studies t...
Over the last two decades, there has been a substantial increase in street tree plantings across ... more Over the last two decades, there has been a substantial increase in street tree plantings across the United States. Many cities have set ambitious planting goals, relying on volunteer community groups to meet them. Existing research demonstrates that community stewardship increases the survival of urban street trees. There is a lack of research, however, on how defining characteristics of community groups affect the survival and growth of the trees they plant. This study explores the significance of community group size (# participants), type (apartment, block watch, church, concerned neighbors, park, public housing, school, and social service), planting longevity (# years active), experience level (# trees planted), and neighborhood (geo-political boundaries). Measured for this study were 1393 trees planted from 1995 to 2007, by 134 groups, through the Urban Resources Initiative’s Community Greenspace program in New Haven, Connecticut, U.S. There was an overall survival rate of 76%...
Urban forested natural areas are an important component of the forest and tree canopy in northeas... more Urban forested natural areas are an important component of the forest and tree canopy in northeastern United States urban areas. Although similar to native forests in surrounding regions in structure, composition, and function, these natural areas are threatened by multiple, co-occurring biological and climate stressors that are exacerbated by the urban environment. Furthermore, forests in cities often lack application of formal silvicultural approaches reliant upon evidence-based applied ecological sciences. These include both urban- and climate-adapted silvicultural techniques to increase the resilience and sustainability of native forests in cities. With this in mind, we convened a group of urban forest practitioners and researchers from along a latitudinal gradient in the northeastern United States to participate in a workshop focused on co-developing long-term, replicated ecological studies that will underlie the basis for potential silvicultural applications to urban forests. ...
The benefits of green roofs are derived from their existence as functional, living ecosystems. Wh... more The benefits of green roofs are derived from their existence as functional, living ecosystems. While the architectural elements of a green roof assembly can be thought of as fixed, the biological components of a roof, its vegetation and growing media, are dynamic. This study presents findings from two mature intensive green roofs surveyed six to seven years after installation in Ithaca, New York. While the two green roofs are located on buildings of similar design in close proximity, the roofs vary in initial planting, detailing, and biophysical and microclimatic conditions. Vegetative surveying was utilized to explore changes in plant community structure and establish spatially explicit performance indicators, including species richness, cover, and biodiversity. Additionally, this data was paired with modeling of solar radiation exposure, exploring how site context influences community dynamics.
This report provides an assessment for the potential for an ecosystem services plan to be impleme... more This report provides an assessment for the potential for an ecosystem services plan to be implemented on Yale University's Central Campus. The plan provides a rigorous assessment of the site's existing connectivity, patterns of movement, biophysical character and social fabric. It then suggests potential programmatic options that when adopted may enhance existing ecosystem services and encourage the development of new ones. The recommendations put forth in this report are organized within the framework outlined below (left). The preferred option is Option C, which emphasizes an integrated social plan as the foundation for the development of a comprehensive ecosystem services plan. This social integrated plan would support the installation of green infrastructure strategies as well as improved maintenance regimes, either pursued separately or in tandem (Options A and B). These latter options may be pursued independently of a holistic social plan and undertaken in the short-te...
Rapid urbanization and the global loss of biodiversity necessitate the development of a research ... more Rapid urbanization and the global loss of biodiversity necessitate the development of a research agenda that addresses knowledge gaps in urban ecology that will inform policy, management, and conservation. To advance this goal, we present six topics to pursue in urban biodiversity research: the socioeconomic and social–ecological drivers of biodiversity loss versus gain of biodiversity; the response of biodiversity to technological change; biodiversity–ecosystem service relationships; urban areas as refugia for biodiversity; spatiotemporal dynamics of species, community changes, and underlying processes; and ecological networks. We discuss overarching considerations and offer a set of questions to inspire and support urban biodiversity research. In parallel, we advocate for communication and collaboration across many fields and disciplines in order to build capacity for urban biodiversity research, education, and practice. Taken together we note that urban areas will play an importa...
In cities, naturally regenerating plant populations are critical in sustaining both ecological ... more In cities, naturally regenerating plant populations are critical in sustaining both ecological function and ecosystem services. However, scientists have a limited understanding of the urban ecosystem conditions and stressors that influence basic life‐history processes and constraints for plant populations. Here, we synthesize current research on the recruitment dynamics of urban plants (processes associated with adding individuals to populations) and present a conceptual framework for urban recruitment limitation. From grasslands to forests, and from natural to constructed habitats, multiple urban drivers – including climate, land‐cover change, pollution, and biotic invasions – affect plant recruitment. These drivers often interact, and their effects are frequently species‐, habitat‐, or region‐specific. Furthering a “mechanistic” understanding (one that focuses on the underlying ecological mechanisms of observed phenomena) of how these drivers alter plant population dynamics will improve the conservation, management, and restoration of urban greenspaces.
Plant recruitment dynamics in urban ecosystems can be influenced by multiple co-occurring and oft... more Plant recruitment dynamics in urban ecosystems can be influenced by multiple co-occurring and often exacerbated conditions and stressors common to most cities. Urban associated habitat fragmentation and land transformation, altered climate and microclimates, biotic invasion, pollution (e.g. elevated atmospheric carbon and nitrogen), and human activity, both direct and indirect, are all observed to have species-specific effects that may limit or facilitate recruitment success. A core question is whether urban ecosystems are functionally different, and if so, what that means for management and restoration practice. This dissertation investigates the application of plant life history frameworks and analyses in the context of urban forest populations. Chapter 1 presents a review of recent literature and a modified recruitment limitation framework for understanding plant recruitment dynamics within urban ecosystems. In the subsequent chapters (2-5) I present a series of related studies t...
Over the last two decades, there has been a substantial increase in street tree plantings across ... more Over the last two decades, there has been a substantial increase in street tree plantings across the United States. Many cities have set ambitious planting goals, relying on volunteer community groups to meet them. Existing research demonstrates that community stewardship increases the survival of urban street trees. There is a lack of research, however, on how defining characteristics of community groups affect the survival and growth of the trees they plant. This study explores the significance of community group size (# participants), type (apartment, block watch, church, concerned neighbors, park, public housing, school, and social service), planting longevity (# years active), experience level (# trees planted), and neighborhood (geo-political boundaries). Measured for this study were 1393 trees planted from 1995 to 2007, by 134 groups, through the Urban Resources Initiative’s Community Greenspace program in New Haven, Connecticut, U.S. There was an overall survival rate of 76%...
Urban forested natural areas are an important component of the forest and tree canopy in northeas... more Urban forested natural areas are an important component of the forest and tree canopy in northeastern United States urban areas. Although similar to native forests in surrounding regions in structure, composition, and function, these natural areas are threatened by multiple, co-occurring biological and climate stressors that are exacerbated by the urban environment. Furthermore, forests in cities often lack application of formal silvicultural approaches reliant upon evidence-based applied ecological sciences. These include both urban- and climate-adapted silvicultural techniques to increase the resilience and sustainability of native forests in cities. With this in mind, we convened a group of urban forest practitioners and researchers from along a latitudinal gradient in the northeastern United States to participate in a workshop focused on co-developing long-term, replicated ecological studies that will underlie the basis for potential silvicultural applications to urban forests. ...
The benefits of green roofs are derived from their existence as functional, living ecosystems. Wh... more The benefits of green roofs are derived from their existence as functional, living ecosystems. While the architectural elements of a green roof assembly can be thought of as fixed, the biological components of a roof, its vegetation and growing media, are dynamic. This study presents findings from two mature intensive green roofs surveyed six to seven years after installation in Ithaca, New York. While the two green roofs are located on buildings of similar design in close proximity, the roofs vary in initial planting, detailing, and biophysical and microclimatic conditions. Vegetative surveying was utilized to explore changes in plant community structure and establish spatially explicit performance indicators, including species richness, cover, and biodiversity. Additionally, this data was paired with modeling of solar radiation exposure, exploring how site context influences community dynamics.
This report provides an assessment for the potential for an ecosystem services plan to be impleme... more This report provides an assessment for the potential for an ecosystem services plan to be implemented on Yale University's Central Campus. The plan provides a rigorous assessment of the site's existing connectivity, patterns of movement, biophysical character and social fabric. It then suggests potential programmatic options that when adopted may enhance existing ecosystem services and encourage the development of new ones. The recommendations put forth in this report are organized within the framework outlined below (left). The preferred option is Option C, which emphasizes an integrated social plan as the foundation for the development of a comprehensive ecosystem services plan. This social integrated plan would support the installation of green infrastructure strategies as well as improved maintenance regimes, either pursued separately or in tandem (Options A and B). These latter options may be pursued independently of a holistic social plan and undertaken in the short-te...
Rapid urbanization and the global loss of biodiversity necessitate the development of a research ... more Rapid urbanization and the global loss of biodiversity necessitate the development of a research agenda that addresses knowledge gaps in urban ecology that will inform policy, management, and conservation. To advance this goal, we present six topics to pursue in urban biodiversity research: the socioeconomic and social–ecological drivers of biodiversity loss versus gain of biodiversity; the response of biodiversity to technological change; biodiversity–ecosystem service relationships; urban areas as refugia for biodiversity; spatiotemporal dynamics of species, community changes, and underlying processes; and ecological networks. We discuss overarching considerations and offer a set of questions to inspire and support urban biodiversity research. In parallel, we advocate for communication and collaboration across many fields and disciplines in order to build capacity for urban biodiversity research, education, and practice. Taken together we note that urban areas will play an importa...
In cities, naturally regenerating plant populations are critical in sustaining both ecological ... more In cities, naturally regenerating plant populations are critical in sustaining both ecological function and ecosystem services. However, scientists have a limited understanding of the urban ecosystem conditions and stressors that influence basic life‐history processes and constraints for plant populations. Here, we synthesize current research on the recruitment dynamics of urban plants (processes associated with adding individuals to populations) and present a conceptual framework for urban recruitment limitation. From grasslands to forests, and from natural to constructed habitats, multiple urban drivers – including climate, land‐cover change, pollution, and biotic invasions – affect plant recruitment. These drivers often interact, and their effects are frequently species‐, habitat‐, or region‐specific. Furthering a “mechanistic” understanding (one that focuses on the underlying ecological mechanisms of observed phenomena) of how these drivers alter plant population dynamics will improve the conservation, management, and restoration of urban greenspaces.
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