Timon McPhearson

A quantitative review of urban ecosystem service assessments: concepts, models, and implementation.

Although a number of comprehensive reviews have examined global ecosystem services (ES), few have focused on studies that assess urban ecosystem services (UES). Given that more than half of the world’s population lives in cities, understanding the dualism of the provision of and need for UES is of critical importance. Which UES are the focus of research, and what types of urban land use are examined? Are models or decision support systems used to assess the provision of UES? Are trade-offs considered? Do studies of UES engage stakeholders? To address these questions, we analyzed 217 papers derived from an ISI Web of Knowledge search using a set of standardized criteria. The results indicate that most UES studies have been undertaken in Europe, North America, and China, at city scale. Assessment methods involve bio-physical models, Geographical Information Systems, and valuation, but few study findings have been implemented as land use policy.

Urban ecosystem cervices

We explore the potential of urban ecosystem services for improving resilience and quality of life in cities. First, we classify and categorize important ecosystem services and disservices in urban areas. Second, we describe a range of valuation approaches (cultural values, health benefits, economic costs, and resilience) for capturing the importance of urban ecosystem service multiple values. Finally, we analyze how ecosystem service assessment may inform urban planning and governance and provide practical examples from cities in Africa, Europe, and America. From our review, we find that many urban ecosystem services have already been identified, characterized and valued, and have been found to be of great value and importance for human well-being and urban resilience. We conclude that the use of the concept of urban ecosystem services can play a critical role in reconnecting cities to the biosphere, and reducing the ecological footprint and ecological debt of cities while enhancing resilience, health, and quality of life of their inhabitants.

Key insights for the future of urban ecosystem services research

Understanding the dynamics of urban ecosystem services is a necessary requirement for adequate planning, management, and governance of urban green infrastructure. Through the three-year Urban Biodiversity and Ecosystem Services (URBES) research project, we conducted case study and comparative research on urban biodiversity and ecosystem services across seven cities in Europe and the United States. Reviewing > 50 peer-reviewed publications from the project, we present and discuss seven key insights that reflect cumulative findings from the project as well as the state-of-the-art knowledge in urban ecosystem services research. The insights from our review indicate that cross-sectoral, multiscale, interdisciplinary research is beginning to provide a solid scientific foundation for applying the ecosystem services framework in urban areas and land management. Our review offers a foundation for seeking novel, nature-based solutions to emerging urban challenges such as wicked environmental change issues.

Urban Ecosystem Services for Resilience Planning and Management in New York City

We review the current state of knowledge about urban ecosystem services in New York City (NYC) and how these services are regulated, planned for, and managed. Focusing on ecosystem services that have presented challenges in NYC—including stormwater quality enhancement and flood control, drinking water quality, food provisioning and recreation—we find that mismatches between the scale of production and scale of management occur where service provision is insufficient. Adequate production of locally produced services and services which are more accessible when produced locally is challenging in the context of dense urban development that is characteristic of NYC. Management approaches are needed to address scale mismatches in the production and consumption of ecosystem services. By coordinating along multiple scales of management and promoting best management practices, urban leaders have an opportunity to ensure that nature and ecosystem processes are protected in cities to support the delivery of fundamental urban ecosystem services.

Opportunities for Increasing Resilience and Sustainability of Urban Social–Ecological Systems: Insights from the URBES and the Cities and Biodiversity Outlook Projects

Urban futures that are more resilient and sustainable require an integrated social–ecological system approach to urban policymaking, planning, management, and governance. In this article, we introduce the Urban Biodiversity and Ecosystem Services (URBES) and the Cities and Biodiversity Outlook (CBO) Projects as new social–ecological contributions to research and practice on emerging urban resilience and ecosystem services. We provide an overview of the projects and present global urbanization trends and their effects on ecosystems and biodiversity, as a context for new knowledge generated in the URBES case-study cities, including Berlin, New York, Rotterdam, Barcelona, and Stockholm. The cities represent contrasting urbanization trends and examples of emerging science–policy linkages for improving urban landscapes for human health and well-being. In addition, we highlight 10 key messages of the global CBO assessment as a knowledge platform for urban leaders to incorporate state-of-the-art science on URBES into decision-making for sustainable and resilient urban development.

Moving Towards a New Urban Systems Science

A bstractResearch on urban ecosystems rapidly expanded in the 1990s and is now a central topic in ecosystem science. In this paper, we argue that there are two critical challenges for ecosystem science that are rooted in urban ecosystems: (1) predicting or explaining the assembly and function of novel communities and ecosystems under altered environmental conditions and (2) refining understanding of humans as components of ecosystems in the context of integrated social-ecological systems. We assert that these challenges are also linchpins in the further development of sustainability science and argue that there is a strong need for a new initiative in urban systems science to address these challenges and catalyze the next wave of fundamental advances in ecosystem science, and more broadly in interdisciplinary and transdisciplinary science.

Local Assessment of New York City: Biodiversity, Green Space, and Ecosystem Services

New York City (NYC) is a complex megacity with a diverse human population situated in a constellation of estuarine and terrestrial ecosystems. With over 20 million people in the metropolitan region, NYC nevertheless has rich biodiversity that provides a broad suite of ecosystem services, with new assessments of biodiversity underway in city government, NGOs, and universities. NYC contains the most parkland of any U.S. city and currently about 21 % of the city is covered by tree canopy. PlaNYC, the environmental and economic sustainability plan for NYC, set a goal of planting one million new trees by 2017, with the hope that canopy cover will reach 30 % by 2030. However, significant challenges to local and regional biodiversity remain, including pollution, climate change, sea level rise, stormwater management, and human population growth. Nonetheless, NYC has made progress in improving the environmental quality of its urban ecosystems and in the provisioning of a broad range of urban ecosystem services. Three elements are key to this progress: (1) coherent governmental support in the form of an overarching long-term planning document, PlaNYC and the NYC Green Infrastructure Plan; (2) systematic investment in natural areas, green infrastructure and civic engagement by a rich variety of organizations; and (3) a commitment to the acquisition of data that facilitate informed decision-making.

Geolocated social media as a rapid indicator of park visitation and equitable park access

Abstract Understanding why some parks are used more regularly or intensely than others can inform ways in which urban parkland is developed and managed to meet the needs of a rapidly expanding urban population. Although geolocated social media (GSM) indicators have been used to examine park visitation rates, studies applying this approach are generally limited to flagship parks, national parks, or a small subset of urban parks. Here, we use geolocated Flickr and Twitter data to explore variation in use across New York Citys 2143 diverse parks and model visitation based on spatially-explicit park characteristics and facilities, neighborhood-level accessibility features and neighborhood-level demographics. Findings indicate that social media activity in parks is positively correlated with proximity to public transportation and bike routes, as well as particular park characteristics such as water bodies, athletic facilities, and impervious surfaces, but negatively associated with green space and increased proportion of minority ethnicity and minority race in neighborhoods in which parks are located. Contrary to previous studies which describe park visitation as a form of nature-based recreation, our findings indicate that the kinds of green spaces present in many parks may not motivate visitation. From a social equity perspective, our findings may imply that parks in high-minority neighborhoods are not as accessible, do not accommodate as many visitors, and/or are of lower quality than those in low-minority neighborhoods. These implications are consistent with previous studies showing that minority populations disproportionately experience barriers to park access. In applying GSM data to questions of park access, we demonstrate a rapid, big data approach for providing information crucial for park management in a way that is less resource-intensive than field surveys.

Estimating stormwater runoff for community gardens in New York City

Community gardens are critical ecological infrastructure in cities providing an important link between people and urban nature. The documented benefits of community gardens include food production, recreational opportunities, and a wide number of social benefits such as improving community stability, reducing crime, and physical and mental health benefits. While much of the literature cites community gardens as providing environmental benefits for cities, there is little empirical evidence of these benefits. Here we examine the stormwater runoff benefits of community gardens by comparing two methods to estimate absorption rates of stormwater runoff in urban community gardens of New York City. The first method uses general land cover classes as determined by a land cover dataset; the second methods adds a land cover specific to community gardens — raised beds, typically used for food production. We find that in addition to the stormwater mitigation performed by pervious surfaces within a garden site, community gardens in New York City may be retaining an additional 12 million gallons (~45 million liters) of stormwater annually due to the widespread use of raised beds with compost as a soil amendment.

Foliar nitrogen characteristics of four tree species planted in New York City forest restoration sites.

Urban forests provide important environmental benefits, leading many municipal governments to initiate citywide tree plantings. However, nutrient cycling in urban ecosystems is difficult to predict, and nitrogen (N) use in urban trees may be quite different from use in rural forests. To gain insight into these biogeochemical and physiological processes, we compared foliar N characteristics of several common northeastern deciduous tree species across four newly planted New York City afforestation sites as well as at the Black Rock Forest (BRF), a rural oak-dominated forest in the Hudson Highlands, New York. Foliage sampled at BRF was consistently depleted in 15N compared to urban foliage, and Amelanchier canadensis, Nyssa sylvatica, Prunus serotina, and Quercus rubra showed significant variation in foliar nitrogen isotope signatures (δ15N) among the four urban sites. A. canadensis and P. serotina showed significantly greater ability to assimilate nitrate at BRF compared to urban sites, as measured through nitrate reductase activity (NRA). There were no significant differences in NRA among tree species growing at the four urban sites. Only P. serotina and N. sylvatica showed significant variation in foliar N concentrations (%N) both among urban sites and compared to BRF. The isotopic and %N data suggest greater N availability but less available nitrate at the newly planted urban sites compared to BRF, possibly due to different anthropogenic inputs or higher rates of nitrification and nitrate leaching at the recently planted urban sites compared to likely lower rates of N cycling in the intact rural forest. In addition, the tree species varied in their response to N availability at the urban sites, with potential implications for growth and survival. Understanding N cycling in urban systems and the associated physiological changes in vegetation is critical to a comprehensive evaluation of urban forest restoration, and may have implications for carbon sequestration and water quality issues associated with nitrate export, two important areas of management concern.