Grantee Research Project Results
2000 Progress Report: Impact of Social Systems on Ecology and Hydrology in Urban-Rural Watersheds: Integration for Restoration
EPA Grant Number: R825792Title: Impact of Social Systems on Ecology and Hydrology in Urban-Rural Watersheds: Integration for Restoration
Investigators: Pickett, S.T.A. , Foresman, Timothy W. , Band, L. R. , Burch, W. R. , Zipperer, W. C. , Pouyat, R. V. , Grove, J. M. , Carerra, J. M.
Current Investigators: Pickett, S.T.A. , Zipperer, W. C. , Grove, J. M. , Carerra, J. M. , Band, L. R. , Burch, W. R. , Pouyat, R. V. , Foresman, Timothy W.
Institution: Cary Institute of Ecosystem Studies , University of North Carolina at Chapel Hill , University of Maryland - Baltimore County , Yale University
Current Institution: Cary Institute of Ecosystem Studies , USDA , University of Maryland - Baltimore County , University of North Carolina at Chapel Hill , Yale University
EPA Project Officer: Packard, Benjamin H
Project Period: June 1, 1998 through May 31, 2001 (Extended to September 30, 2001)
Project Period Covered by this Report: June 1, 2000 through May 31,2001
Project Amount: $999,932
RFA: Water and Watersheds Research (1997) RFA Text | Recipients Lists
Research Category: Watersheds , Water
Objective:
The objective of this project is to provide decision makers with options to ameliorate water quality by integrating social, ecological, and hydrological processes. We will develop a new hydrological-ecological model that integrates key social drivers at various scales. The model will incorporate spatial heterogeneity, shifting land uses, and ecological structure of watersheds in urban areas. We will test whether social processes affect watershed dynamics and water quality, and whether such effects act directly through pollution, or indirectly through the ecological features of the watershed. This knowledge is necessary for most effective control of water quality in urban watersheds. We will develop the model into a decision making tool by interacting with urban communities and institutions.
Progress Summary:
A. Work Status. This project complements the Baltimore Long-Term Ecological Research (LTER) program, and with it constitutes the Baltimore Ecosystem Study (BES). During the third year of this program, we have continued to analyze social, ecological, and hydrological processes and integrating them for use in policy and education. The interactions between the Water and Watersheds grant, the LTER, and substantial in-kind support from the U.S. Forest Service, Northeastern Research Station has leveraged the activities of the Water and Watersheds project. As a result of this leveraging, the following additional researchers have contributed to the work reported here: Mr. K. Belt (U.S. Forest Service, stream dynamics), Dr. G. Brush (Johns Hopkins University, vegetation and paleoecology), Dr. Dr. C. Boone (Ohio University, social geography), G. Buckley (Ohio University, geography and history), Dr. M. Cadenasso (Institute of Ecosystem Studies, landscape ecology and vegetation), Dr. R. Costanza (University of Maryland, ecological economics), Mr. E. Doheny (U.S. Geological Survey, hydrology), Mr. G. Fisher (U.S. Geological Survey, hydrology), Dr. P. Groffman (Institute of Ecosystem Studies, N dynamics and trace gas flux), Dr. G. Heisler (U.S. Forest Service, urban micrometeorology), Dr. D. Nowak (U.S. Forest Service, urban modeling and C dynamics), Dr. C. Schweik (University of Massachusetts, Amherst, social science data management and programming), and Dr. K. Szlavecz (Johns Hopkins University, soil invertebrates and exotic species).
Our research is integrating activities and results in the following categories to satisfy the project objectives: (1) social processes and environmental hazards, (2) stream and riparian processes, (3) micrometeorology and climate, (4) soil structure, function and organisms, four vegetation dynamics and structure, and (5) watershed modeling.
The project focuses on the Gwynns Falls watershed, which encompasses land now undergoing the transition from agriculture to suburban development, through old suburbs and urban residential areas, to dense, old residential and industrial areas. A reference forested watershed is located at Oregon Ridge County Park and permanent point samples have been established throughout Baltimore City. The research is integrated by the patch dynamic approach, the human ecosystem model, and the small watershed approach, all applied in a spatially explicit manner in the 17,000 ha Gwynns Falls watershed, which drains into the environmentally sensitive Chesapeake Bay.
We are conducting research to discover the social processes that drive and are affected by biogeophysical processes in the urban ecosystem. We have developed a framework for the analysis of land use models, and social field data collection methods that can be linked to market and US Census surveys, to administrative records, and to remotely-sensed data. Social capital has been assessed through organizational analysis and assessment of regulations and programs that affect environmental management and water quality. Measurements of boundaries, pattern and process in social patches have been compared with biophysical approaches. Patterns and processes of environmental equity are being addressed through Census data and EPA Toxics Release Inventory data, and local historical records.
Our research on stream processes is based on U.S. Geological Survey (USGS) gauging stations in the Gwynns Falls watershed and elsewhere in the Baltimore region. These stations provide a continuous data record. USGS scientists associated with BES are investigating new approaches for high-flow storm sewer outfalls, as well as ground water hydrology. Geologic remapping is being conducted to improve hydrological data. Flow and stream chemistry are being measured at the gauging stations. Water samples are archived.
Riparian areas are key locations in which to assess the function of urban watersheds and to link human history with ecological processes. Integrated studies of soils, vegetation, and biogeochemical processes are being conducted in riparian zones along the Gwynns Falls watershed. These studies also include paleoecological core sampling resolved into 1 cm depth increments. Cores also are collected from the Inner Harbor.
Meteorology drives important processes in the watershed. We now have an LTER Network Class 4 meteorological station installed at the McDonogh School. Additional stations are being planned and intensification of the type of data collected at existing stations is being evaluated. Data from the Global Historical Climate Network have been used to assess the status and change of Baltimore heat island, and to compare this with Phoenix, AZ. Existing meteorological stations were examined for usefulness in climate change study. Permission has been obtained to install a UVB and radiation flux sensor at a prominent city location. A flux tower installation has been selected.
Soils and ecosystem processes are a core part of our effort to understand and predict watershed behavior. Long-term biogeochemical monitoring encompasses 2 years of monthly data on soil nitrogen cycling (mineralization, nitrification, denitrification, nitrate leaching, and N2O flux) in eight forested permanent plots. One year of data exists on two permanent grass plots. Extensive surveys for biogeochemical processes include 12 forest, 12 grass, and 12 cropland plots where soil N and microbial processes were measured. The role of exotic species on nutrient dynamics continues to be investigated.
Ecosystem process studies described above require detailed knowledge of the urban soils. Soil survey at a fine scale has been conducted on 130 plots throughout Baltimore City. Riparian soils have been examined in 70 undisturbed cores. Heavy metals content has been assessed in soils.
Soil organisms are being investigated using two approaches. Monthly pitfall sampling and has been conducted in forested plots in Oregon Ridge, Hillsdale Park, and Leakin Park. These plots also have been sampled for earthworms. Qualitative sampling of Isopoda and Diplopoda is conducted in unmanaged grass plots, managed lawns, city parks, roadsides and abandoned fields. Arthropod sampling is conducted at sites with data on soils, biogeochemical processes, and vegetation. Soil organism data are being compared with climatic models.
Interaction of exotic arthropods and vegetation can have major impacts on urban vegetation and hence on watershed function. Data from permanent point-based plots throughout Baltimore City was analyzed and integrated with data from other metropolitan areas to assess: (1) the potential impact of Asian long-horned beetle on U.S. urban forests, (2) the total compensatory value of carbon in U.S. urban forests, and (3) national carbon storage and sequestration rates by U.S. forests.
Vegetation processes in and around the urban center are a fundamental structural and dynamic component of metropolitan watersheds. Maryland forest history is being analyzed using historical maps, State Forestry Board archives, and other archival data. The status of Maryland forest and parkland conservation and management is being compared with other states. High-resolution, digital imagery was obtained for the Gwynns Falls watershed and Oregon Ridge in October 1999, extending our long-term record of growing season coverages. Forest patches are being quantified, and the vegetation structure and composition of forested permanent plots, extensive permanent point samples, forest gaps, and riparian zones assessed. Ecological delimitation of patches types in and around the small gauged catchments along Gwynns Falls is being conducted, and the patterns of heterogeneity in those areas assessed via transects.
Integrated watershed modeling has focused on construction, linking, and accessing data to support the models. Acquisition of new databases for modeling has been accomplished. Spatial data frameworks and simulation models are being developed for water, energy, carbon, and nutrient balance in catchments of the Baltimore region. The BASINS simulator is being employed over the period 1973-1990 for land use change. The models include social survey data on management decisions at the household level. Large scale unit models of landscape processes have been modularized for Gwynns Falls. The General Human Ecosystem model is being run using demographics from Baltimore. Social capital is being translated into a simulation module. The carbon dynamics of built capital is being incorporated. The Human Ecosystem Model is being linked to the Global Unified Metamodel of the Biosphere to integrate social and natural processes. Valuation will be possible using this model.
B. Preliminary Results. Our survey of land use change models has demonstrated that they rarely include human decision making. A modular approach to land use change models is advanced, which exploits the comparability of social, ecological, and physical assessments of patch types. Social patches have a high degree of local scale homogeneity and contribute to high diversity at larger landscape scales. Comparison of social process models focusing on Baltimore with those used in the international development arena confirms that accounting for property institutions is a key process in the role of humans as ecological agents.
The kind and location of environmental hazards is a key component of urban structure and linked social-ecological dynamics. Distribution of toxic releases in Baltimore is uneven and concentrated primarily in working class, white neighborhoods. A history of residential segregation and varying perceptions emerge as potential explanations for this pattern.
The stream flow record is published annually with some data available in near real time (http://md.water.usgs.gov/BES/ ). The stream data represent the four subwatersheds, and four additional sites along the Gwynns Falls that exhibit different degrees of urban land use and demographic characteristics. Variation in stream chemistry shows improvements downstream. Initial analysis of trends reflects road density and housing age, among other features. Questions of the role of agricultural legacies in upstream and rural stations have emerged.
Urban riparian zones tend to be relics that now are separated from stream influence by stream downcutting. Many riparian soils have buried surface or organic horizons and lowered water tables. Species distributions differ along the length of the watershed, with an increase in some fast growing exotic riparian species in lower reaches. Exotics are more prevalent among the herbaceous than the arboreal flora. Distributions of groups of plants correspond to rural, urban residential and dense urban residential-industrial zones, and relate to history of disturbance, mode of invasion and life cycles of individual species.
Urban heat island development has followed expected increase with population change. Movement of meteorological stations has compromised their utility for climate change studies. We compared the heat islands of contrasting cities to better assess the potential hydrological relationships of urban heat islands. The heat island is better developed in Baltimore compared to Phoenix due to the cooling effect of watering of urban plantings in the arid Southwest. Urban maximum is cooler than rural sites in Phoenix, but higher in Baltimore, as expected for urban heat islands.
Soils with recognizable profiles behave differently in urban sites than rural sites. Most urban soils in Baltimore have high base saturation, often approaching 100 percent. Nitrogen transformation processes are highest in agricultural plots, followed in order by lawns and forest soils. Lawn areas near roads have the highest heavy metal contents.
All 10 species of isopods found are exotic. One is new to the fauna of North America. The highest numbers of individuals are found in the urban forest sites, and decrease in the rural reference forest stand. Eight species of earthworms include two natives, and six exotics. The rural reference forest contains all eight species, but natives are rare. The two remaining urban sites have only exotics, with biomass declining from urban to rural forest soils.
The Asian long-horned beetle, recently found in New York and Chicago has prompted removal of trees in an attempt to control the invader. Data from nine cities including Baltimore, based on tree species preference by the beetle, show from 12-61 percent of trees to be at risk, with potential damage ranging from $72 million to $2.3 billion per city. The maximum potential national urban impact of the beetle is associated with a value loss of $669 billion.
Data on forest vegetation exposes important features of the urban ecosystem and its dynamics. Maryland forests were in relatively poor condition for the 1906-1916 survey, and the state established the third state forester position in the nation. Multiple forest uses were promoted. At present, urban forested plots are more structurally and compositionally heterogeneous than rural reference stands, and urban and suburban forest gaps support more exotic vines than rural.
Integrated watershed models have yielded promising results. The BASINS software adequately simulates land use change and runoff production. This model uses the lumped hydrological approach to watershed covers. This approach is not as useful for changing nutrient regimes, since integration of distributed hydrological modeling regime with a plot-based ecosystem modeling approach improves the simulation of terrestrial delivery of nitrate to stream channels in the BES forest reference watershed. Growing season nitrate export in the reference watershed does not indicate nitrogen saturation, but results from seasonal dynamics of the distribution of nitrate sinks and sources along the hydrological flowpaths.
C. Significance to the Field. This third year of the Baltimore Water and Watersheds project has continued to extend the scope of ecology to the relatively neglected urban realm. The world-wide increase in urbanization makes ecological attention to urban systems both practically and intellectually appropriate. The testing of patch theory in a novel ecosystem type is an intellectual benefit to ecology. An additional benefit is the comparison spatially explicit watershed models with spatially lumped models. We have obtained initial results that confirm the applicability of patch theory to integrated social and ecological systems, and the improved capacity of spatially explicit watershed models in urban systems. We continue to explore research and modeling approaches in disciplines outside ecology as potential tools for integration with ecology and within ecology per se. We have furthered the articulation of socio-economic principles for research in human-dominated ecosystems that will be of use in a wide variety of environments.
We are discovering variables and approaches that are useful for integration. Patch dynamics, spatially explicit catchment models, social capital models, and now different scales of environmental valuation are issues that we have begun to investigate. We continue to be a source for importing spatially explicit simulations to additional natural and social science specialties. Our work also continues to illustrate the utility of metadata in physical sciences.
D. Relevance to Project Goals. To reiterate, the project goals are to:
- Develop a new hydro-ecological model that integrates key social drivers at various scales, incorporating spatial heterogeneity, land uses, and ecological structure of watersheds in urban areas;
- Test whether social processes affect watershed dynamics and water quality, and whether such effects act directly through pollution, or indirectly through the ecological features of the watershed.
- Develop the model into a decision making tool by interacting with urban communities and institutions.
The project activities are relevant to the goals in the following ways. Measurements of water flow and water quality in the reference watershed and along the length of the Gwynns Falls are fundamental to calibrating and validating the integrated watershed model. Participation of the USGS assures comparability and quality of the data. Linkages of in-stream flow and flows in the sewer system are crucial for determining the water budget precisely, and for determining sources of contamination in streams.
Studies of the structure and function of riparian systems in Baltimore are crucial for understanding their altered role in water quality, and their potential for restoration. Meteorological data are important to refine hydrological flow models because substrate permeabilities, presence and persistence of natural litter and physical impedances on built and natural surfaces depend on temperature and seasonal patterns of microclimate. Leaf-on and leaf-off periods and intensities may relate to microclimate.
Detailed and fine scale studies of urban soils have been neglected. Yet the structure, layering, and complex origin and pollutant content in urban soils are significant to their hydrological and water quality functions. The processing of N by soils is key to water quality in urban streams and in the receiving waters of the Chesapeake Bay. How much different cover types, ranging from agriculture, to lawns, to forests contribute to N flux in the system is relevant for understanding non-point sources in the urban matrix.
The composition of species in different land cover types is important for watershed function because they may affect hydrological flows differentially. Exotic plants have different canopy structures and phenologies than natives. Exotic soil invertebrates alter the hydrological permeability of the soil and litter cover. Many of these compositional data will be related to vegetation and social patch structure. Changes in patch cover through time will feed into the models for scenario development.
Finally, the hydrologically based modeling is the principal tool for synthesis in the research. It is in the models that much of the social and ecological data will be unified as well as spatially related.
The interactions with community groups, schools, and non-governmental organizations are relevant both because they help educate the public who will ultimately use the models for formal and informal decision making, but also because we learn how to link our model input and output with the needs of diverse constituencies in the Baltimore metropolitan region.
E. Relevance to Environmental Protection and Human Health. The research is relevant to environmental protection and human health for several reasons. Meeting the mandated 40 percent reduction in N loading to the Chesapeake Bay necessarily will involve control of non-point inputs and discovering options that households and organizations have for altering their negative impacts through urban hydrology. Our data are documenting health hazards in urban streams, and are relating toxic release inventory sites to social and economic factors in Baltimore. Documentation of the spatial relationships among social, hydrological, and ecological factors can help planners design and implement restoration plans that go beyond the space-filling paradigm that dominates urban planning practice, and to base their decisions on ecologically motivated, integrated data.
Notable among our attempts to contribute to environmental protection and human health is our interaction with EPA's Mid-Atlantic Integrated Assessment Program. We are working with Tom DeMoss and colleagues to improve environmental valuations in urban areas and address a mesoscale appropriate to local and metropolitan area decision making. An additional example of contribution to environmental protection is our interaction with the Baltimore City Department of Public Works in evaluating its forest management plan for the city reservoir lands.
BES continues its manifest commitment to involve students from K-12, through postdoctoral levels. Teacher training and curriculum development reaches urban and suburban, and public and private schools. We work substantially with under represented populations in all our educational and outreach activities. Thus, we are enhancing the environmental literacy in consistencies that have been undeserved by traditional environmental education.
Future Activities:
In the upcoming final year of the project, we will assemble the final social data and construct a comprehensive patch mosaic. This will permit us to extend the integrated ecological-social-hydrological models throughout the Gwynns Falls watershed. Workshops and meetings with policy makers and managers will refine the model and explore user-friendly interfaces. Newly digitized historical maps and images will expand our ability to test our models and improve their forecasting ability. Productivity measurements and a carbon budget for the metropolitan area will be completed. The significance of exotic species in watershed function will be further assessed and the spatial heterogeneity of the system will be tested using our models. The final year will emphasize integration and field application of the project models.
Journal Articles on this Report : 12 Displayed | Download in RIS Format
Other project views: | All 237 publications | 51 publications in selected types | All 29 journal articles |
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Belt KT, Gresens SE, Gwinn DC, Banks P, Tang JA. The effects of urban impervious watershed cover on benthic macroinvertebrate populations in streams with particular reference to disturbance from storm event frequency and magnitude. Bulletin of the North American Benthological Society 1998;16(l):208. |
R825792 (1999) R825792 (2000) R825792 (Final) |
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Brun SE, Band LE. Simulating runoff behavior in an urbanizing watershed. Computers, Environment and Urban Systems 2000;24(1):5-22. |
R825792 (1999) R825792 (2000) R825792 (Final) |
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Costanza R, Voinov A, Boumans R, Maxwell T, Villa F, Wainger L, Voinov H. Integrated ecological economic modeling of the Patuxent River watershed, Maryland. Ecological Monographs 2002;72(2):203-231. |
R825792 (1999) R825792 (2000) R825792 (Final) R824766 (1998) R824766 (Final) R827169 (Final) |
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Foresman TW, Adams D, Walker S, Daniel C, Defries V, Hennesee L. Entrenchment of GIS technology for enterprise solutions in Maryland's state and local government. Photogrammetric Engineering and Remote Sensing 1999, Volume: 65, Number: 11 (NOV), Page: 1277-1286. |
R825792 (1999) R825792 (2000) |
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Gresens SE, Belt KT, Gwinn DC, Banks P, Tang JA. Level of taxonomic resolution and the response of lotic invertebrate communities to increased watershed imperviousness. Bulletin of the North American Benthological Society 1999;16(l):215. |
R825792 (1999) R825792 (2000) R825792 (Final) |
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Grimm NB, Grove JM, Pickett STA, Redman CL. Integrated approaches to long-term studies of urban ecological systems. Bioscience 2000;50(7):571-584. |
R825792 (1999) R825792 (2000) R825792 (Final) |
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Pasternack GB, Brush GS. Sedimentation cycles in a river-mouth tidal freshwater marsh. Estuaries and Coasts 1998;21(3):407-415. |
R825792 (1999) R825792 (2000) R825792 (Final) |
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Pickett STA, Burch Jr WR, Grove JM. Interdisciplinary research: maintaining the constructive impulse in a culture of criticism. Ecosystems 1999;2(4):302-307. |
R825792 (1999) R825792 (2000) R825792 (Final) |
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Pickett STA. The culture of synthesis: habits of mind in novel ecological integration. Oikos 1999;87(3):479-487. |
R825792 (1999) R825792 (2000) R825792 (Final) |
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Thompson HC. Exotic plant species in urban and suburban forest gaps as a management criterion. Ecological Restoration. |
R825792 (1999) R825792 (2000) |
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Villa F, Boumans RMJ, Costanza R. Design and use of a Model Performance Index (MPI) for the calibration of ecological simulation models. Journal of Environmental Modeling Software. |
R825792 (1999) R825792 (2000) |
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Voinov A, Costanza R, Wainger L, Boumans R, Villa F, Maxwell T, Voinov H. Patuxent landscape model: integrated ecological economic modeling of a watershed. Environmental Modelling & Software 1999;14(5):473-491. |
R825792 (1999) R825792 (2000) R825792 (Final) R824766 (1998) R824766 (Final) R827169 (Final) |
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Supplemental Keywords:
patch dynamics, invasive species, erosion, storm water, ecosystem management, multi-scale imagery analysis, Chesapeake Bay., RFA, Scientific Discipline, Water, Ecosystem Protection/Environmental Exposure & Risk, Hydrology, Ecosystem/Assessment/Indicators, Ecosystem Protection, Restoration, Ecological Risk Assessment, Aquatic Ecosystem Restoration, ecological effects, ecological exposure, rural watersheds, impact of social system, biodiversity, community involvement, watersheds, decision making, urban watersheds, restoration strategies, ecological recovery, aquatic ecosystems, social resistance, water quality, ecological impact, public policy, spatial analysis, ecosystem response , land use, watershed restorationRelevant Websites:
Maryland-Delaware-D.C. Water Science Center
Parks and People Foundation Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.