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.