Integrated Social-Ecological Research: Insights on Urban Environmental Dynamics for Landscape Sustainability

Presented by Professor Kelli Larson, School of Sustainability, Arizona State University as part of the annual  Harold and Florence Mayer Lecture.

Abstract: Residential landscapes, including lawns and other types of vegetation, are an increasingly important component of urban ecosystems. Turfgrass lawns are now among the largest irrigated crops in the U.S., contributing to high rates of water and fertilizer use. Yet we know little about the social and ecological dynamics of different landscape types, such as mesic lawns and xeric yards, which involve a diverse array of potential values and associated decision tradeoffs. Past research has largely focused on either social or ecological elements of residential landscapes, for example, historic and modern aesthetic preferences or the composition and diversity of species. Our ongoing project aims to advance integrated knowledge about residential landscapes as important components of urban ecosystems by examining how cognitive (cultural values, beliefs, and norms) and structural (social institutions and urban form) factors drive yard management practices, and in turn, affect biogeochemical and ecological processes at the household and neighborhood scales. Within this overarching framework, our workshop course explored two primary research objectives. First, we examined the influence of residents’ values on landscape structure and the degree to which expressed preferences match actual landscape choices, and second, we assessed how neighborhood-level institutions impact landscape structure, with special focus on the legacy effects of development decisions. To address the first objective, we linked social survey data with extensive observational field surveys in four case study neighborhoods throughout Phoenix, Arizona. For the second goal, we examined the Covenants, Codes and Restrictions (CCRs) in Homeowner Associations (HOAs) that govern landscaping, in addition to conducting interviews with developers about their landscaping decisions and how they have changed over time. Our findings highlight the significance of multiple scales of human drivers (see Figure 1) in the broader context of the social-ecology of residential landscapes. Although values were not a strong driver of yard choices, they mildly influenced both expressed preferences and manifest choices in diverse Phoenix neighborhoods, particularly domain-specific values embodied in environmentally-oriented yard maintenance priorities. Meanwhile, our analyses of institutional forces highlights the role of broader structural forces that influence residential landscape structure and management. As developers respond to market conditions and broader constraints in producing residential landscapes over time, the effects may last long into the future since original development decisions establish the built context and become institutionalized in HOA CCRs. Our analysis of a sample of Covenants, Codes, and Restrictions for Phoenix-area subdivisions specifically indicated the potential for neighborhoodlevel private institutions to dictate landscape maintenance and structure, topography and water management, and species composition, with potentially significant impacts on the ecosystem services provided. In sum, further interdisciplinary analysis of the human drivers of yard structure and management at multiple scales (see Figure 1)—from households and neighborhoods to municipalities and broader regional forces—will reveal the complex dynamics involved in the production of residential landscapes and their social and ecological consequences for current and future generations.