Residential development choices and consequences: Urban land cover change, perceptions and value of alternative subdivision designs, and the benefits of protected ecosystem services.

摘要

Municipal officials are often faced with difficult decisions about land uses in and around city boundaries. Urban expansion often causes negative environmental impacts, but there are designs for development which can mitigate some of these effects at the site scale. This dissertation examines urban land cover change in four Iowa cities, examines familiarity with and value for conservation subdivision (CSD) and low-impact design (LID) features, and explores how conservation subdivision design can protect urban ecosystem services. Public datasets and GIS software were used to assess land cover change for four municipalities in Iowa as a framework for predicting land cover change impacts by determining where loss of natural areas has occurred and where future losses are most likely to happen. Urban land cover increased by 28-80% in the four communities examined, primarily involving transitions from grassland and cropland. Losses of mature forest areas occurred (348 to 1335 ha) but were masked by transitions of other lands to early-successional forests. A contingent valuation survey of 777 households and experimental real estate negotiations with 27 participants in Ames, IA assessed residents' familiarity with alternative residential designs and estimated their willingness to pay for CSD and LID features. Most respondents were not familiar with CSD or LID features, but indicated willingness to pay for some of them (52% indicated WTP for buffered streams, 66% for rain gardens), except for clustered housing (only 27%). Negotiation participants indicated added value for homes in neighborhoods with integrated forest (+22% increment) and open spaces (+17%), and streams buffered by forest cover (+13%). A spatial hedonic model estimated effects on housing values and indicated that the presence of neighborhood-owned forest and water features had positive effects on housing prices, both increasing the value of a home by approximately 6%. Surveys and focus groups involving developers and city officials assessed their familiarity with, and interest in, alternative development designs. Developers and planners were more familiar with LID than CSD, but indicated misperceptions about both designs. Both groups also indicated a preference for alternative designs compared to standard designs. Subdivision regulations and perceived lack of demand were identified as barriers to wider implementation of CSD and LID approaches. Alternative designs could provide protection for ecosystem services in urban areas if implementation is goal-oriented, monitored for effectiveness, and when the design is configured to create broad appeal.