Urban ecology, social psychology, landscape, nitrogen, interdisciplinary, mixed methods


Driven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen inputs to aquatic systems requires a better understanding of the links between residential landscape management and the potential for fertilizer loss. This dissertation examines the linkages between the human behaviors contributing nitrogen to the suburban landscape and the resulting environmental impacts. Framed in socio-psychological theory and social marketing research, the outcomes of this dissertation contribute much needed information to the growing realm of interdisciplinary science that expands integrative theory, develops mixed methods, utilizes spatial and temporal analyses, and conducts actionable research. Using a suite of research tools, this dissertation examines relevant urban ecology questions:  What behavioral and socio-demographic variables most strongly influence individual residential landscape design and management practices?  What types of communities are more likely to contribute more nitrogen inputs?  What social constraints prevent homeowners from implementing a more sustainable residential landscape? iv  What outcome measures can be used to evaluate the environmental impact associated with landscape maintenance behaviors? Social and environmental data were collected over five years from three distinct projects to advise environmental marketing strategies and targeted communications. The research questions provided important information for water quality stakeholders and environmental marketers to prioritize strategies and target audiences based on the power of forces that are influencing landscaping behaviors. The research drew on the methods of urban ecology to understand nutrient dynamics by spatially integrating social and environmental data. It used social-psychology theory to define influences that can motivate or deter landscape management behaviors and preferences. It applied the methods of social marketing to advise implementation strategies. Completing this research involved ethnographic, social survey, and environmental quality data collection. Suburban homeowners were recruited as research participants to collect important qualitative information about individual and social forces of suburban landscape management and the perceptions of environmentally-friendly landscaping. Questions were developed to operationalize the dimensions of individual and social influences and quantitative data were collected at two different scales, regional and statewide. Homeowners were defined in terms of their polluting potential, influences and mandates as well as their potential for adopting a more sustainable landscape. The research mapped behavioral and environmental data to understand human-ecosystem linkages and recommended environmental quality indicators to continue building future outcomes. This dissertation research was conducted in three distinct projects. v The Landscape Exchange project collected telephone survey data, interview data, and ethnographic information from project participants for three years in a subdivision in southwest Florida. In the Wekiva Basin of Central Florida, the Land-water Connection (LWC) project studied sources of nitrogen by examining the linkages between human behaviors, community land use patterns, and environmental quality. In the LWC project, patch dynamics of a suburbanizing watershed were mapped to link residential fertilizer frequency with water resource impacts. By collecting socio-economic information key to understanding the households and neighborhoods within the watershed, LWC attempted to better understand and characterize polluting potential and impact. This investigation of the human-ecosystem connection provided valuable insight to the potential source contributed by residential landscape management while demonstrating a tool for visualizing human-environment interactions. Integrating data and understanding processes that are being carried out at different spatial and temporal scales requires research that crosses interdisciplinary boundaries and extends beyond simple models to understand complex causal relationships (Young et al 2006). The LWC project integrated socio-demographic data like housing age and property values, household and lifestyle behaviors, and individual application rates with environmental data such as soil nutrients and groundwater NO3 - concentrations. Results demonstrated that significant relationships existed between structural features like Homeowners Associations (HOA) and golf courses and high fertilizer frequency, but that these areas did not consistently show patterns of elevated nitrogen concentrations in ground and surface water. vi Confounding geophysical features, limited data availability, and a temporal lag between land-based fertilizer activity and groundwater nitrogen concentrations are likely. In the Predicting Maintenance Intensity (PMI) project, I collected statewide survey data from Florida homeowners and used multivariate analyses to determine if the same variables that predicted landscape maintenance intensity also influenced the odds of adopting an environmentally-friendly landscape (EFL). The purpose was to see how landscape maintenance and EFL adoption related and which human psychological or socio-economic variables predicted them. I used the framework of the Theory of Planned Behavior and Normative Action Theory to measure the extent that individual beliefs or community influences predicted landscape maintenance intensity. Although most of the alternative hypotheses that I posed in the research were significantly related to landscape maintenance intensity and EFL adoption in the predicted direction, the findings were somewhat unexpected. This was particularly the case when comparing household’s position on environmentally-friendly landscaping (EFL) adoption and landscape maintenance intensity. I found that those who adopted EFL practices had similar landscape maintenance intensity scores as those who did not intend to ever change their landscape practices and that those who intended to do more EFL had the highest landscape maintenance intensity score. This indicated that landscape maintenance intensity was a useful measure of product inputs but did little to explain individual attitudes about EFL adoption. Similar to the findings of the Land-Water Connection in Wekiva referenced previously, the statewide PMI project also found that community norms, living in a HOA governed community and household income were significant positive predictors of high vii landscape maintenance and that environmental consciousness, awareness of consequences, and house age were significant negative predictors. Environmental consciousness and enjoying gardening significantly increased the odds of currently practicing or intending to practice EFL relative to never changing their landscape, but community norms only significantly influenced the likelihood to intend to do more EFL. Another interesting finding of this dissertation was the differences of predictive powers of variables over scales. For example, the individual scale versus the community scale of influence. EFL Adoption was related more to individual characteristics such as personal norms, attitudes about the garden, and awareness of consequences while landscape maintenance intensity was more influenced by structural differences like who was responsible for maintenance and socio-demographics like house age and income were strongly significant and community norms. The findings of this dissertation supported the concept of lawn anxiety described by Robbins (2007), regarding those who are aware of the environmental consequences, but still applied lawn care products. It would be interesting to explore the relationships further to understand why those who are environmentally aware are motivated to high maintenance regardless. From these results, it appears they are influenced by their community norms and HOA mandates. More investigation of the human dimensions of the suburban landscape is warranted. Further research on human life-history measures, perceived behavioral controls and normative influences of those who adopt alternative landscapes would help guide communications. Understanding more specifically what mechanisms are needed to enable a societal change to a sustainable landscape requires further exploration of the motives and barriers that will prevent it from happening. viii Further research is also needed to better understand suburban nitrogen system dynamics. Studies that focus at the community scale should be conducted to apply and trace residential fertilizes from the yard to the street and into aquatic systems. The use of labeled nitrogen fertilizer can be used identify fertilizer from background nitrogen. Lastly, land use planning and development must seek to rebalance the scale that promotes both environmental protection and economic growth back toward environmental protection. It has been too long tipped in favor of development pressure and short-term economic growth to the demise of our aquatic systems.


If this is your thesis or dissertation, and want to learn how to access it or for more information about readership statistics, contact us at

Graduation Date





Hinkle, Charles


Doctor of Philosophy (Ph.D.)


College of Sciences



Degree Program

Conservation Biology; Applied Conservation Biology








Release Date

December 2015

Length of Campus-only Access

3 years

Access Status

Doctoral Dissertation (Open Access)


Dissertations, Academic -- Sciences, Sciences -- Dissertations, Academic

Included in

Biology Commons