People, pavement and trees: Challenges in urban forests

Urbanization dramatically changes landscapes by adding physical structures, replacing natural vegetation, and directly modifying the availability of water and nutrients. These changes in turn have many effects on local and regional ecosystem processes, such as evaporation, runoff, and carbon storage, as well as factors that directly impact human wellbeing such as local temperature. Assessing these effects is challenging because of high spatial variability within cities, resulting from the combined decisions of many individuals and institutions. However daunting, patterns can be extracted from this chaotic backdrop, drawing on data collected at different scales.