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Introduction Integrated social and ecological processes shape urban plant communities, but the temporal dynamics and potential for change in these managed communities have rarely been explored. In residential yards, which cover about 40% of urban land area, individuals make decisions that control vegetation outcomes. These decisions may lead to relatively static plant composition and structure, as residents seek to expend little effort to maintain stable landscapes. Alternatively, residents may actively modify plant communities to meet their preferences or address perceived problems, or they may passively allow them to change. In this research, we ask, how and to what extent does residential yard vegetation change over time? Methods We conducted co-located ecological surveys of yards (in 2008, 2018, and 2019) and social surveys of residents (in 2018) in four diverse neighborhoods of Phoenix, Arizona. Results 94% of residents had made some changes to their front or back yards since moving in. On average, about 60% of woody vegetation per yard changed between 2008 and 2018, though the number of species present did not differ significantly. In comparison, about 30% of woody vegetation changed in native Sonoran Desert reference areas over 10 years. In yards, about 15% of woody vegetation changed on average in a single year, with up to 90% change in some yards. Greater turnover was observed for homes that were sold, indicating a “pulse” of management. Additionally, we observed greater vegetation turnover in the two older, lawn-dominated neighborhoods surveyed despite differences in neighborhood socioeconomic factors. Discussion These results indicate that residential plant communities are dynamic over time. Neighborhood age and other characteristics may be important drivers of change, while socioeconomic status neither promotes nor inhibits change at the neighborhood scale. Our findings highlight an opportunity for management interventions, wherein residents may be open to making conservation-friendly changes if they are already altering the composition of their yards. 

Despite the social and ecological importance of residential spaces across the country, scant research examines urban yard management policies in the U.S. Governance scholarship points to the implementation challenges of navigating policy language. Our research provides an exploration of yard ordinance language, with implications for communities across the U.S. Specifically, we sought to determine whether—and in what instances—vegetation- and groundcover-related yard ordinances in the U.S. are ambiguous or clear. Our findings suggest that ordinances are often ambiguous when referring to the state or quality of the constituent parts that make up the residential yard (e.g., “neat” or “orderly”). Yet they are clear when providing guidance about what plant species are or are not allowed, or when articulating specific requirements regarding the size or dimensions of impervious surfaces and plants. We discuss the policy implications of these findings, especially in the context of how such policies may invite the subjective judgment by enforcers, leaving open the potential for discriminatory enforcement, especially with regard to marginalized communities where different cultural values and esthetics may be expressed in yards. 

Abstract Urban nature—such as greenness and parks—can alleviate distress and provide space for safe recreation during the COVID-19 pandemic. However, nature is often less available in low-income populations and communities of colour—the same communities hardest hit by COVID-19. In analyses of two datasets, we quantified inequity in greenness and park proximity across all urbanized areas in the United States and linked greenness and park access to COVID-19 case rates for ZIP codes in 17 states. Areas with majority persons of colour had both higher case rates and less greenness. Furthermore, when controlling for sociodemographic variables, an increase of 0.1 in the Normalized Difference Vegetation Index was associated with a 4.1% decrease in COVID-19 incidence rates (95% confidence interval: 0.9–6.8%). Across the United States, block groups with lower income and majority persons of colour are less green and have fewer parks. Our results demonstrate that the communities most impacted by COVID-19 also have the least nature nearby. Given that urban nature is associated with both human health and biodiversity, these results have far-reaching implications both during and beyond the pandemic. 

Preserving and restoring wildlife in urban areas benefits both urban ecosystems and the well‐being of urban residents. While urban wildlife conservation is a rapidly developing field, the majority of conservation research has been performed in wildland areas. Understanding the applicability of wildland science to urban populations and the relative importance of factors limiting species persistence are of critical importance to identifying prescriptive management strategies for restoring wildlife to urban parks.

We evaluated how habitat fragmentation, habitat quality and mortality threats influence species occupancy and persistence in urban parks. We chose California quailCallipepla californicaas a representative species with potential to respond to urban conservation. We used publicly available eBird data to construct occupancy models of quail in urban parks across their native range, and present an application using focal parks interested in exploring quail reintroduction.

Urban parks had a 0.23 ± 0.02 probability of quail occupancy, with greater occupancy in larger parks that were less isolated from potential source populations, had higher shrub cover and had lower impervious cover. Less isolated parks had higher colonization rates, while larger parks had lower extinction rates. These results align with findings across urban ecology showing greater biodiversity in larger and more highly connected habitat patches.

A case study highlighted that interventions to increase effective park size and improve connectivity would be most influential for two highly urban focal parks, while changes to internal land cover would have a relatively small impact. Low joint extinction probability in the parks (0.010 ± 0.013) indicated reintroduced populations could persist for some time.

Synthesis and applications. We show how eBird data can be harnessed to evaluate the responsiveness of wildlife to urban parks of variable size, connectivity and habitat quality, highlighting what management actions are most needed. Using California quail as an example, we found park size, park isolation and presence of coyotes are all important drivers of whether quail can colonize and persist in parks. Our results suggest reintroducing quail to parks could be successful provided parks are large enough to support quail, and management actions are taken to enhance regional connectivity or periodic assisted colonization is used to supplement local populations.