Planting the Living City

Problem: Critics have problematized infrastructure for its inability to keep pace with the rising social and ecological impacts of urbanization. Researchers identify urban green infrastructure (GI), including urban forests, as an important strategy for providing public goods and increasing resiliency while reducing ecological footprints and social inequity in metropolitan areas; however, realizing these benefits through planning is still uncertain ground, as most contemporary urban GI endeavors in the United States are small, individual projects rather than integrated, community-wide efforts. This underinvestment has left planners with little experience in developing GI at a metropolitan scale. Purpose: We address this deficit in infrastructure planning by studying planning's role in advancing large-scale, urban tree-planting initiatives (TPI) in eight major U.S. cities and one metropolitan county. In this study, we explore stakeholder perspectives on successes and setbacks in TPI planting, stewardship, business, and outreach plans. From these perspectives, we identify possible best practices that can better inform future efforts to plan GI on a metropolitan scale. Methods: From a review of the literature, we identified ideal planning elements researchers and practitioners considered fundamental to well-planned, urban forestry-based GI programs. We interviewed key stakeholders (n = 86) in eight major cities and one metropolitan county (New York, Los Angeles, Houston, Baltimore, Seattle, Denver, Albuquerque, Sacramento, and Salt Lake County), using multiple-choice and open-ended questions to explore their perceptions of TPI successes, failures, and opportunities for improvement. We used this data to compare TPI planning and implementation with ideal urban forestry and GI planning elements, to identify TPI best practices, and to locate TPI program elements such as business and stewardship planning in relation to traditional infrastructure. We discuss these findings in light of opportunities to bring GI into the mainstream of metropolitan infrastructure planning. Results and conclusions: We found that cities employed a spectrum of planning strategies to advance TPI, ranging from highly institutionalized, data-driven initiatives to decentralized, grassroots efforts. Participants viewed TPI as bringing GI to the mainstream; however, uncertainties in funding and long-term stewardship belie this perspective. Lacking access to traditional infrastructure financing, several TPI used creative development and contracting strategies to maintain program funding and momentum, while others stagnated. Additionally, programs lost momentum when mayors who launched TPI were not reelected. Successful underfunded initiatives focused on community-level engagement. However, institutionalized, diverse funding structures and robust, agency-level commitment to maintaining and expanding urban forests were considered most effective in advancing urban forestry-based GI. Overall geographic distribution of TPI, and the relatively sophisticated financial and institutional approaches achieved by New York and Seattle, provide insight into possible national strategies to advance metropolitan-scale GI. Similarly, Los Angeles's and Baltimore's use of focused corporate sponsorship and community engagement to advance underfunded programs could inform international GI efforts. Takeaway for practice: Through large-scale TPI, planners are beginning to engage in planning metropolitan-scale GI as a conscious strategy to address urban ecological issues and deliver public goods. Initiatives benefit from being launched early in an administration's term. Further, detailed, data-driven planting plans, combined with diversified funding sources and the institutionalization of tree-acquisition in the capital budget, can enable TPI to establish a) long-term contracts, b) control over supply chains, and c) stability in recessionary times. Contracting with grassroots and advocacy organizations to perform education and fieldwork can provide means for underfunded programs to maintain momentum toward meeting TPI goals; however, accessing traditional infrastructure financing mechanisms and institutionalizing stewardship plans are fundamental to long-term expansion and maintenance of investments in metropolitan GI. Research support: None.