Residential landscapes are hotspots of nutrient input and unregulated non-point source pollution into urban and surrounding ecosystems. Because they compose a significant fraction of the heterogeneous urban matrix, residential landscape variables such as yard size, age, and homeowner management practices may provide a great deal of variation in the ecological properties of cities. However, studies on these important ecosystem components are few. We synthesized the available literature to answer the following question: What factors influence ecosystem properties and nutrient cycling in residential landscapes? Using keywords such as residential landscape, yard, ecological, we found 48 studies in 35 different journals, the earliest published in 1984.
Results/Conclusions
Relatively few studies focused specifically on the characteristics and ecological processes in residential yards. Rather, a significant proportion classify ‘residential’ as one site type to be compared with other land uses, such as agricultural and commercial sites. These studies neglect to account for biotic variability within a single yard or across residential landscape types (e.g. lawn, xeriscape) that may be important in regulating ecological outcomes such as water use, climate modification, or nutrient cycling. Furthermore, the ecological properties of residential landscapes are inherently connected to social factors, as humans manage the species composition, and nutrient and water additions to fit their landscaping preferences. However, only a quarter of the studies utilize an integrated socio-ecological study design and none directly address the questions of social drivers influencing the ecological functioning of yards. From the integrated socio-ecological studies, income is reported as a significant driver of highly managed landscapes. In addition, income is positively correlated, along with housing age and land use, to plant diversity. Housing age and vegetation cover are also closely tied to nutrient runoff and storage of soil carbon, nitrogen, phosphorus and potassium. Therefore, we conclude that households with a higher socioeconomic status are likely to have significantly higher nutrient runoff and lower nutrient storage in their yards than households of lower socioeconomic status. Several studies included housing age as an important variable influencing the biological functioning of residential yards. Specifically, younger homes were reported to have higher bulk density and higher rates of fertilizer application and thus higher rates of nutrient runoff. Likewise, other studies report that as houses age, disturbances are reduced and the nutrient storage increases within the lawn. This synthesis gives a comprehensive insight to the major drivers influencing the ecological properties of residential landscapes.
