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Economics of Conserving Ecosystem Integrity with Residential Development around Vernal Pools

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The proposed research intends to identify economic and ecological (conservation biological) factors that influence society's ability to maintain a well functioning ecosystem in the face of sprawl or rural residential development. The research concerns the population dynamics of species characterized by spatially-dispersed subpopulations (forming metapopulations) and the economic value of development opportunities forgone by decisions that encourage the conservation of these species and sustenance of the ecosystem integrity that is correlated with these species. The proposed research represents an initial step in understanding whether or how society might maintain ecosystem integrity as residential development encroaches on the landscape. Particular emphasis is given to modeling amphibian metapopulations dependent upon vernal pools (seasonal wetlands) and habitats connecting the vernal pools.
The objectives are: (1) to assess the baseline value of foregone opportunities for development and amphibian metapopulations that can be anticipated after rural residential development expands under current wetland regulations; (2) to evaluate economic and ecological factors affecting the cost of maintaining metapopulations for an assemblage of amphibians, as represented by vernal pool ecosystems in southern New England, at a variety of geographic scales; (3) to examine the ecological and economic implications of alternative regulatory or development incentive mechanisms that influence the probability of land development within or around vernal-pool based ecosystems.

Approach: The approach involves development of an economic-ecological framework and simulation of the impacts of residential development on ecosystem integrity, as represented by amphibians that depend upon vernal pools, and the impacts of local, regional, or state goals for ecosystem integrity on the value of foregone development. The framework will rely on a classification of land according to ecological-oriented qualities and development-oriented qualities. Using a stylized amphibian species, with different dispersal characteristics in relation to land use, the investigators will model the link between metapopulation persistence, number of occupied habitat patches, and expected duration of occupancy. Land use characteristics will include the influence of economic benefits of land development on the probability that a land parcel is developed.

Expected Results: The research will improve the integration of economic and ecological science for use in policy decisions, especially in relation to state or local policies associated with wetland conservation. Results may alter intuitive advice of both economists and ecologists. For example, heterogeneity in habitat quality may reverse the economic advice for developers to pursue land parcels associated with the highest economic rents, while accounting for the economic value of land development may modify ecologists advice to focus conservation effort on habitats with a high diversity. Therefor, the research may aid, for example, state or local efforts to maintain ecosystem integrity cost-effectively.

Metadata

EPA/NSF ID:
R829384-01
Principal Investigators:
Swallow, Stephen K.
Paton, Peter
Technical Liaison:
Research Organization:
Rhode Island, University of
Funding Agency/Program:
EPA/ORD/Valuation
Grant Year:
2001
Project Period:
January 1, 2002 - December 1, 2003
Cost to Funding Agency:
$200,017
Project Status Reports:
For the Year 2002
Objective:
The overall objective of this research project is to develop a framework for identifying and understanding the economic and ecological factors that influence society’s ability to maintain well-functioning ecosystems in the face of sprawl or urban development. Particular emphasis is given to modeling the effects of residential development on amphibian metapopulations dependent upon vernal pools and upland habitats connecting these pools. The specific objectives of this research project are to: (1) assess the baseline value of foregone opportunities for development and amphibian metapopulations that can be anticipated after rural residential development expands under current regulations; (2) evaluate the economic and ecological factors affecting the cost of maintaining metapopulations for an assemblage of amphibians, as represented by vernal pool ecosystems in southern New England; and (3) examine the economic and ecological implications of alternative regulatory or development incentive mechanisms that influence the probability of land development within or around vernal pool based ecosystems.

Progress Summary:
Research during this period focused on two major work efforts. The first effort, development of a land classification framework to be used in the conceptual model, began by identifying key land parcel attributes that affect the probability of land being developed or the probability of amphibian metapopulation persistence. Literature reviews identified several key factors, including road density, housing density, distance between roads, houses, and vernal pools, traffic, quantity of forested upland, and landscape fragmentation. Investigation of the literature on the land development process discovered that land rents are based not only on distance to the nearest preserved open space, but also on the current amount of nearby unprotected, undeveloped land. These land rents capture the values associated with the aesthetics of being close to nature, but also values related to privacy and reduced traffic congestion. This has led to a “leapfrog” pattern of residential development in rural areas at the urban fringe. Our model will need to incorporate this fragmented spatial arrangement of land parcels.

For amphibian metapopulation persistence, land use attributes can be divided into: (1) those affecting the upland habitat immediately surrounding vernal pools where amphibians over-winter (i.e., migration parameters) and (2) those affecting the permeability of the landscape connecting one vernal pool to its neighbors (i.e., dispersal parameters). Investigation of the literature on amphibian conservation biology showed a major lack of empirical research related to the effects of residential development on amphibian metapopulations (though, as described below, we have a set of empirical data that we are in the process of analyzing). Although a number of studies have looked at the effects of roads, these were typically conducted in a forested landscape. Other studies indicated, for at least some amphibian species, an aversion to crossing open fields (undeveloped land in an early stage of succession) or cropland. No studies were found measuring the permeability of manicured lawns for amphibians. This is of relevance to our modeling effort, as housing density may not be the appropriate critical factor. Rather, the size and quantity (i.e., number of fragments) of manicured lawns may be more significant. Personal communications with several ecologists during an amphibian workshop did not provide any assistance. Our conceptual model and simulations will need to include multiple “lawn crossing” scenarios.

The second major effort involved analysis of previously collected amphibian egg mass count data to identify quantitative relationships between land use characteristics and viability of metapopulations. Initial regression results indicated no significant effect of residential development on either of the amphibian species for which we have data. This led us to engage in an extensive (and time-consuming) reconfiguration and enhancement of the data. Several new geographic information system layers, incorporating actual road and housing densities (captured from aerial photographs) in a series of concentric circles around each vernal pool, are being added. We expect that this increase in detail will result in improved significance of residential land use attributes at least in the inner most circles.

Future Activities:
The researchers will continue to develop an analytical model relating residential development and amphibian metapopulation dynamics, based on the land development attributes previously identified. It is anticipated that this model will be presented at a conference in the summer of 2003. Based on the analytical model, a computer simulation will be developed to perform more detailed sensitivity analysis of model parameters. In addition, further monitoring of the relevant literature and analysis of our empirical vernal pool data will continue. Results from these efforts will assist in the parameterization of our simulation model.

Publications and Presentations:
TypeCitation
Journal ArticleEgan RS, Paton PWC. Assessing the influence of landscape structure on pond-breeding amphibians across a rural-urban gradient in Rhode Island. Conservation Biology (submitted, 2004).
Journal ArticlePaton PWC, Yong W. Non-random migration by pond-breeding amphibians across a fragmented landscape. Journal of Herpetology (submitted, 2004).
Journal ArticleEgan RS, Paton PWC. Within-pond parameters affecting oviposition by wood frogs and spotted salamanders. Wetlands 2004;24(1):1-13.
Supplemental Keywords:
indicators, ecosystem indicators, landscape indicators, amphibian, frogs, salamanders, anthropogenic stresses, sustainable development, Northeast, policy analysis, community based, decision-making, public policy, wetland regulation, conservation biology, conservation reserve network, cost-effective ecosystem protection, economic, social, and behavioral science research program, ecosystem protection/environmental exposure and risk, ecology and ecosystems, economics and decision-making, ecosystem protection, ecosystem/assessment/indicators, social science, conserving ecosystem integrity, cost effectiveness, ecological exposure, ecosystem integrity, ecosystem integrity and residential development, environmental policy, environmental values, residential development, vernal pool ecosystems, vernal pools, , Economic, Social, & Behavioral Science Research Program, Ecosystem Protection/Environmental Exposure & Risk, RFA, Scientific Discipline, Ecology and Ecosystems, Economics, Economics & Decision Making, Ecosystem Protection, Ecosystem/Assessment/Indicators, Social Science, decision-making, community-based, conservation biology, conserving ecosystem integrity, cost effectiveness, cost-effective ecosysem protection, cost-effective ecosystem protection, decision making, ecological exposure, ecosystem integrity, ecosystem integrity and residential development, environmental policy, environmental values, public policy, residential development, vernal pool ecosystems, vernal pools

For the Year 2003:
Objective:
The purpose of this research project is to develop a framework for identifying and understanding the economic and ecological factors that influence society’s ability to maintain well-functioning ecosystems in the face of sprawl or urban development. Particular emphasis is given to modeling the effects of residential development on amphibian metapopulations dependent upon vernal pools and upland habitats connecting these pools. The objectives of this research project are to: (1) assess the baseline value of foregone opportunities for development and amphibian metapopulations that can be anticipated after rural residential development expands under current regulations; (2) evaluate the economic and ecological factors affecting the cost of maintaining metapopulations for an assemblage of amphibians, as represented by vernal pool ecosystems in southern New England; and (3) examine the economic and ecological implications of alternative regulatory or development incentive mechanisms that influence the probability of land development within or around vernal pool based ecosystems.

Progress Summary:
Research during this period focused on two major areas. First, investigators continued to develop a geographic information system database that included land use and land cover variables and land value data. The database concerns the Wood-Pawcatuck River Watershed and vernal pools (seasonally flooded wetlands) in southwestern Rhode Island. Data also included egg-mass counts at vernal pools, with respect to the wood frog and the spotted salamander. A statistical model to predict egg mass counts to wetland and land use variables was developed and used to forecast egg mass values at all ponds in the watershed (more than 1,200 vernal pools). These estimated egg mass counts were then used to develop an index of the quality or importance of land in and around vernal pools to the survival of amphibian populations under current conditions. Investigators used a spatial-averaging method to assign index values to land within a one or two-hectare grid across the watershed.

Economic data on land values were obtained from most towns in the watershed. Efforts will continue, however, in additional towns early in the next year. Investigators are beginning with tax-assessor estimates of the tax value of land, particularly undeveloped land. In some towns, land values are not available at the parcel level, and can only be assigned to a postal address (street number address). Therefore, land values will be estimated across the watershed through a spatial averaging process using postal addresses as the record for land value.

Second, research proceeded on developing a theoretical model both for analytical and simulation-based evaluation of residential development in relation to amphibian metapopulations. The spatially explicit metapopulation model of Hanski and colleagues will likely form the basis of evaluations focused on the presence or absence of amphibian species in specific vernal pools.

A third area of activity included additional literature review, particularly on mechanisms to identify land for conservation in relation to a budget or minimizing the cost of achieving an ecological quality goal. This literature will support future simulation analyses that aid decisionmakers in establishing land conservation priorities (selecting land parcels) while staying within a budget and providing the best possible ecological quality within the budget (and land conserved). Modeling of this type, however, did not commence during this reporting period.

Future Activities:
The researchers will substantially refine an analytical model relating residential development and amphibian metapopulation dynamics, based on the land development attributes previously identified. Completion of the land value database will occur in 2004. Based upon the analytical model, a computer simulation will be developed to perform more detailed sensitivity analysis of model parameters. In addition, further monitoring of the relevant literature and analysis of our empirical vernal pool data will continue. Results from these efforts will assist in the parameterization of our simulation model.

Publications and Presentations:
TypeCitation
Journal ArticleEgan RS, Paton PWC. Within-pond parameters affecting oviposition by wood frogs and spotted salamanders. Wetlands 2004;24(1):1-13.
Supplemental Keywords:
indicators, ecosystem indicators, landscape indicators, amphibian, frogs, salamanders, anthropogenic stresses, sustainable development, Northeast, policy analysis, community based, decisionmaking, public policy, wetland regulation, conservation biology, conservation reserve network, cost-effective ecosystem protection, economic, social, and behavioral science research program, ecosystem protection/environmental exposure and risk, ecology and ecosystems, economics and decisionmaking, ecosystem protection, ecosystem/assessment/indicators, social science, conserving ecosystem integrity, cost effectiveness, ecological exposure, ecosystem integrity, ecosystem integrity and residential development, environmental policy, environmental values, residential development, vernal pool ecosystems, vernal pools, , Economic, Social, & Behavioral Science Research Program, Ecosystem Protection/Environmental Exposure & Risk, RFA, Scientific Discipline, Ecology and Ecosystems, Economics, Economics & Decision Making, Ecosystem Protection, Ecosystem/Assessment/Indicators, Social Science, decision-making, community-based, conservation biology, conserving ecosystem integrity, cost effectiveness, cost-effective ecosysem protection, cost-effective ecosystem protection, decision making, ecological exposure, ecosystem integrity, ecosystem integrity and residential development, environmental policy, environmental values, public policy, residential development, vernal pool ecosystems, vernal pools

Project Reports:

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