Urban tree diversity—Taking stock and looking ahead

• Relevant themes from the 1st International Conference on Urban Tree Diversity are explored.
• We identify the role of urban tree species diversity for ecosystem service provision.
• We question whether cities are suited to supporting high levels of urban tree species diversity.
• We discuss how to govern and manage urban forests to support urban tree species diversity.

The first International Conference on Urban Tree Diversity hosted in June 2014 by the Swedish University of Agricultural Science in Alnarp, Sweden highlighted the need for a better understanding of the current state of urban tree diversity. Here we present and discuss a selection of urban tree diversity themes with the intention of developing and sharing knowledge in a research area that is gaining momentum. We begin by discussing the specific role of species diversity in ecosystem service provision and ecosystem stability. This is followed by exploring the urban conditions that affect species richness. Having determined that many ecosystem services depend on urban tree species diversity and that urban environments are capable of supporting high species diversity, we conclude by addressing how to govern for urban tree diversity.