Research Interests
- Urban areas have been rapidly expanding in recent decades with now over half of the world’s population living in cities and urban land conversion occurring at unprecedented rates. Now, more than ever, there is a pressing need to evaluate the ecological ramifications of urban development. It is to this need for research at the intersection of urbanization and environmental management that I have dedicated my career. In general, I am interested in understanding the complex relationships between the form and function of urban ecosystems. In particular, I have focused on a number of problems at the forefront of basic science and practical application. My research relies on both theoretical and empirical approaches at multiple spatial scales to investigate how coupled human and natural systems can be designed, planned, and managed in a more sustainable manner. While I primarily think of myself as an ecologist, I also draw extensively on interdisciplinary investigations when studying urban systems -- something I consider an essential component of my research. I describe four core areas of interest below.
- As the spatial extent of urban areas continues to expand, there is
increased interest in designing cities and urban areas with ecologically
functional spaces. These practices are commonly referred to as “designer
ecosystems.” My past research evaluated how one type of designer ecosystem,
vegetated (green) roofs, can convert rooftop space into an ecologically
functional area. We found that green roofs provide numerous ecosystem
services, particularly in densely developed areas. We also performed cost-
benefit analyses and developed policy recommendations for this type of
designer ecosystem.
Many designer ecosystems are starting to be installed, but very few are extensively monitored and studied. To solve this problem, I plan to continue designing, building, and testing innovative functional landscapes in urban ecosystems. Campus test plots in particular hold great promise for this type of research. I have helped design new green roof sites on UGA’s campus which provide additional research data and educational and outreach opportunities for the community. I have also initiated work on designer ecosystems in coastal Georgia to look at the effects of sea level rise scenarios on projected growth areas on the coast. Using constructed wetlands and innovative site design strategies to allow for landward marsh expansion, we will model how these designer ecosystems provide opportunities to mitigate climate change impacts and development pressure.
Since designer ecosystems are rapidly becoming mainstream practices in urban areas, I see the commodification of these ecosystems as an intriguing topic of future research that drives many interesting questions. For example, what is the trade-off when we design and install systems to maximize a particular function? Are we substituting water quality improvement designs for habitat provision? Do these systems have an analogous counterpart in the nonhuman environment that can provide guidance for design? What role does biomimicry play when the designed system already uses “natural” processes to function? Can we learn from other domestication efforts and prevent similar problems from happening in these designer ecosystems? I would speculate that although we design these systems with particular functional goals in mind, there are a number of unintended ecological consequences (e.g. energy-intensive maintenance, pollutant accumulation, introduced species) that could limit the effectiveness of the systems. Ultimate answers to these questions will instigate exciting collaborative research efforts between numerous disciplines, and also increases funding opportunities for the projects. - The ability of human populations to persist over long periods of time
will depend largely on our ability to sustainably manage natural resources.
This has led to significant interest in the development of metrics to
evaluate how natural resource use can continue far into the future without
incurring extreme costs on nonhuman ecosystems and human society. As part
of the Systems and Engineering Ecology Research Group, and in partnership
with colleagues at the University of Maryland, I have worked on projects
that use energy as a currency for environmental accounting. Specifically,
we found that an energetic analysis of “green” building products allows
for surprising insights into sustainable construction practices. Strategies
that appear “green” sometimes have significant amounts of energy embodied
in them and therefore may not be the most sustainable strategy. We have
also expanded this type of environmental accounting statewide, looking
at the direct and indirect connections between the natural and human systems
of state and global resources.
While this energetic approach to environmental accounting works well with energy and matter in ecosystems, it does a poorer job at accounting for information flow and feedback, which is a key feature of human ecosystems. Modern human societies and urban centers in the developed world rely heavily on distal relationships to resources rather than the proximal resources commonly utilized by third-world countries or rural areas. This phenomenon is primarily a result of information in the form of technology that allows for global economies to persist. I’m interested in developing new methods for quantifying and incorporating information flow into sustainable development scenarios. By considering the role that cybernetics, information feedbacks, and human innovation play in the development and maintenance of human ecosystems, we may be able to better understand how economic development and natural resource protection can be managed more sustainably.
My future sustainability research will also target the issue of scale in sustainable development. Bumper stickers often urge us to, “think globally, act locally,” but little is known about whether the cumulative impact of individual actions will, in fact, result in sustainable solutions. The high embodied energy in buildings, transportation and other urban infrastructure, may make individual actions less important for a sustainable society than major industrial or sector-wide changes. Integrating energetic accounting, information flows, and urban scaling into a unified sustainability framework will be a foundational component of my future research. - Urban aquatic ecosystems are often written off as too degraded to provide
any ecological benefits. They usually contain elevated concentrations
of pollutants and nutrients, highly-modified channel morphology, and simplified
biotic communities dominated by highly-tolerant taxa. This urban effect
on aquatic systems can be incorrectly considered universal, however, as
cities have evolved into heterogeneous landscapes that sprawl into numerous
densely developed centers. Urban stream conditions can vary widely depending
on how the city has been and will be constructed through time. I have
performed extensive research on ways that urban land use can be modified
to be more protective of the surrounding stream systems. In particular,
I’ve shown how innovative stormwater management tools such as vegetated
roofs, low impact development (LID), and green infrastructure can be used
to mitigate effects of stormwater runoff in urban systems.
Opportunities abound for future research in this area and I look forward to continue pursuing answers to important questions related to urban land use and aquatic ecosystems. For example, while the general disturbance mechanism stemming from urban stormwater runoff is well-known, what is unclear is whether the hydrologic alteration, pollutant loading, direct human inputs, or other factors associated with development are driving the so-called “urban stream syndrome.” To tease these factors apart, I am leading a group of researchers from over five different departments at the University of Georgia (UGA) on a project funded by World Wildlife Fund, U.S. Fish and Wildlife Service, and Georgia Department of Natural Resources, where we’re using an innovative, paired-watershed approach to study the real-time ecological impacts of large residential and commercial developments. This study targets LID effects, but we anticipate expanding the study to include traditional development sites as well. Results from this work will expand our understanding of urban development impacts and help inform future work on how construction timing, site design and planning, and stormwater management strategies may produce environmentally protective developments. - Conservation of natural resources often involves multiple stakeholders
with sometimes conflicting views on how a resource should be managed.
For the past 6 years I have been part of a team to develop the Etowah
Aquatic Habitat Conservation Plan (HCP), which is a multi-jurisdictional
plan to protect endangered fish species in the Etowah River basin. I have
been actively involved in the development of the HCP linking technical
capacity with outreach activities. As part of the plan we have developed
an innovative stormwater management program which balances the ecological
needs of endangered species of fish with human development interests.
This program was established through technical meetings attended by developers,
engineers, consultants, and county officials who all agreed on standards
to be included as part of a stormwater ordinance. U.S. Fish and Wildlife
Service now include these standards in their plan review for developments
in the watershed.
Our work in the Etowah has shown that scientifically-based environmental policy can be created with local stakeholder consideration and involvement. I believe urban ecological studies must explicitly contain this human component to fully account for key drivers in the system and to offer meaningful recommendations for urban ecosystem management. I’d like to use innovative tools for environmental decision-making to link together science and policy. For example, I’ve been part of an informal group of international researchers working on urban stream systems and we recently completed a conceptual model linking stressors to urban stream processes. By using Bayesian belief networks, we could expand the scientific data collection to identify urban stream policies that have the biggest effect on the modeled system. Coupling the human and natural systems in this framework could produce models that can then be continually informed and refined with ongoing research.
This interdisciplinary approach to studying urban ecology is a fascinating and challenging aspect of the discipline. It also allows for a great deal of collaboration across departments, interaction with other fields which normally have little contact, and many opportunities for applied student projects. I look forward to continued work with local and regional groups to identify pressing environmental concerns and to develop policy solutions that address these concerns. Environmental policies that are based on sound science and recognize that there are solutions that may satisfy competing interests are more likely to succeed.
Designer ecosystems
Sustainable Development
Urban aquatic ecosystems
Environmental policy for conservation