Tree canopy cover is a critical component of the urban environment that supports ecosystem services at multiple spatial and temporal scales. Increasing tree canopy across a matrix of public and private land is challenging. As such, municipalities often plant trees along streets in public rights‐of‐way where there are fewer barriers to establishment, and composition and biomass of street trees are inextricably linked to human decisions, management, and care. In this study, we investigated the contributions of street trees to the broader urban forest, inclusive of tree canopy distributed across both public and private parcels in Baltimore, MD, USA. We assess how species composition, biodiversity, and biomass of street trees specifically augment the urban forest at local and citywide scales. Furthermore, we evaluate how street tree contributions to the urban forest vary with social and demographic characteristics of local residential communities. Our analyses demonstrate that street trees significantly enhanced citywide metrics of the urban forests' richness and tree biomass, adding an average six unique species per site. However, street tree contributions did not ameliorate low tree canopy locations, and more street tree biomass was generally aligned with higher urban forest cover. Furthermore, species richness, abundance, and biomass added by street trees were all positively related to local household income and population density. Our results corroborate previous findings that wealthier urban neighborhoods often have greater tree abundance and canopy cover and, additionally, suggest that investment in municipally managed street trees may be reinforcing inequities in distribution and function of the urban forest. This suggests a need for greater attention to where and why street tree plantings occur, what species are selected, and how planted tree survival is maintained by and for residents in different neighborhoods.
Urban community gardens offer unique social and ecological benefits in cities. However, given the dynamic nature of cities and the profound effects of variable land uses on green space provisioning for people and wildlife, investigating community gardens from a landscape perspective offers valuable insight into the functions of these spaces in terms of ecosystem services and sustainable development. In this study, we use garden locations provided by stakeholder groups and fine-scale spatial data to compare community gardens across three cities: New York City, NY, Chicago, IL, and Baltimore, MD (USA). In each city, we assess the spatial distribution of gardens and compare the natural vegetation and impervious surface cover within these gardens to the surrounding neighborhood and landscape. We then compared these cities to clarify the role of community gardens in metropolitan development. Our findings demonstrate that gardens cluster in neighborhoods in New York City and Chicago, but they are more spatially distributed across the landscape in Baltimore. The distribution of Baltimore’s community gardens is more likely to be contributing to a greater network of ecosystem services across a broader urban landscape. Moreover, at the garden scale, gardens in NYC and Chicago have more canopy cover and built infrastructure than the more herbaceous gardens in Baltimore. This suggests that our case study cities exhibit different garden typologies, histories, and potential for ecosystem services. This work provides critical insight into the typology in and around community gardens in different cities, which is useful in understanding the potential ecosystem services and planning trajectories of these cities.
Landscape connectivity is a critical component of dynamic processes that link the structure and function of networks at the landscape scale. In the Anthropocene, connectivity across a landscape-scale network is influenced not only by biophysical land use features, but also by characteristics and patterns of the social landscape. This is particularly apparent in urban landscapes, which are highly dynamic in land use and often in social composition. Thus, landscape connectivity, especially in cities, must be thought of in a social-ecological framework. This is relevant when considering ecosystem services—the benefits that people derive from ecological processes and properties. As relevant actors move through a connected landscape-scale network, particular services may “flow” better across space and time. For this special issue on dynamic landscape connectivity, we discuss the concept of social-ecological networks using urban landscapes as a focal system to highlight the importance of social-ecological connectivity to understand dynamic urban landscapes, particularly in regards to the provision of urban ecosystem services.