Exploring the Effects of Yard Management and Neighborhood Influence on Carbon Storage in Residential Subdivisions

Abstract

The dramatic land-use shift from forest and agricultural to exurban residential land uses creates an excellent opportunity for ecosystem restoration and carbon sequestration through yard design and management. Yard management in a residential subdivision is rarely an autonomous endeavor. Cultural and local norms play an important role in how residents design and maintain their yards. Studies show that residents are influenced by the behavior of their neighbors. Yet, social influence has rarely been incorporated into carbon sequestration studies in residential landscapes. Agent-based modeling offers an ideal framework for exploring how social complexities among humans could affect their environment. An agent-based model called ELMST (Exploratory Land Management and Carbon Storage), was developed to explore how management of individual yards and neighborhood influence could affect carbon storage at the scale of a residential subdivision. The model was run under four scenarios: (tier-0) no management, (tier-1) individual management without influence (tier-2) individual management with opportunity to adapt based on neighbor behaviors, and (tier-3) adaptive management, as in tier-2, but several residents were given an incentive to innovate their yard to a native prairie design upon model start-up. The model was parameterized with interview and fieldwork data from exurban homes Southeast Michigan. Total carbon within the subdivision was compared among scenarios for year 30. Tier-1 showed a significantly higher quantity of carbon than all others, including tier-0 (no management). Results from tier-2 and tier-3 showed a greater variability of carbon storage at the subdivision level, suggesting that a wide range of outcomes can emerge as a result of neighborhood influence and divergent local norms. Considering model sensitivity of individual management behaviors, the model showed that turfgrass fertilization and mowing the lawn while allowing grass clippings to decompose on-site dramatically increased carbon stored at the parcel level, when compared with the no management scenario. Comparatively, removing grass clippings dramatically decreased carbon stored at the parcel level, when compared with the no management scenario. The native prairie innovation was able to propagate through the subdivision in tier-3 in the ELMST model. Prairie-based parcels were shown to store less carbon overall than the conventional lawn-based parcels that were fertilized or mown while allowing grass clippings to remain on-site, but stored more carbon than if grass clippings were removed all together. Model results imply that trade-off between carbon storage and other ecosystem services may need to be considered when developing policies for environmentally-friendly residential landscapes. The ELMST model was developed to be expanded and re-used for a variety of locales, cultures and climates. Results from this study may be used to formulate better research questions and hypothesis, inform data collection, expand intuition of policy makers, and advance the development of agent-based models with regards to coupled human and natural systems.