Urban tree planting programs, function or fashion? Los Angeles and urban tree planting campaigns Stephanie Pincetl • Thomas Gillespie • Diane E. Pataki • Sassan Saatchi • Jean-Daniel Saphores Ó Springer Science+Business Media B.V. 2012 Abstract Tree planting programs are being imple- mented in many US cities (most notably New York, Los Angeles, and Chicago) on the basis of the multiple environmental and health benefits they may provide. However, the magnitude and even the direction of the impacts of trees on specific urban environments have seldom been directly measured. In addition, there has been little research on the historical, cultural, political or institutional origins of such programs, or on their implementation process. Pending questions include the degree to which these programs are integrated in the existing frameworks of city government and infrastructure management, how they are paid for, and the kinds of collaborations between nonprofit organizations, the public, and public agencies at all levels they may require in order to succeed. This paper reports on an interdisciplinary research project exam- ining the Million Tree Program of the City of Los Angeles. Keywords Urban forestry Á Ecosystem services Á Implementation Á Hedonic valuation Á GIS, green infrastructure Tree planting programs are being implemented in many US cities for their multiple environmental and health benefits. These include reducing stormwater runoff; providing shading, which reduces the urban heat island; improving air quality by intercepting various pollutants; sequestering carbon; enhancing health by fostering walking and providing a connection with nature; and beautifying neighborhoods (McFar- land 1994; Brack 2002; de Vries et al. 2003; Foster and Hillsdon 2004; McPherson et al. 2005, 2011a, b). However, the magnitude and even the direction of the impacts of urban trees on specific urban environments have seldom been directly measured. In addition, there has been little research on the historical, cultural, political or institutional origins of such programs, or on how to design them and implement them effectively. In this context, this paper presents results of a research project conducted by an interdisciplinary team consisting of ecologists, economists, geogra- phers, remote sensing experts and urban planners to examine some facets of the ecosystem services provided by urban trees in Los Angeles. More specifically, we examined the following questions: 1. What will be the impacts on water use in Los Angeles, which is located in a semi-arid climate and where water shortages may be exacerbated by climate change, of planting one million additional trees? 2. What is the carbon sequestration value of planting a million new trees? S. Pincetl (&) Á T. Gillespie Á D. E. Pataki Á S. Saatchi Á J.-D. Saphores University of California, Los Angeles (UCLA), Los Angeles, CA, USA e-mail: spincetl@ioes.ucla.edu 123 GeoJournal DOI 10.1007/s10708-012-9446-x