Cities need to be integrated in local and regional conservation planning and sustainability strategies. There has been a surge in plant diversity studies in urban areas for the past 15 years showing that these areas have high levels of plant diversity and changing the way old vision of cities as diversity-poor. Studies have focused on quantifying this diversity, evaluating its structure and composition as well as the drivers of its variation. Previous meta-analyses for urban areas clearly show a geographical bias towards temperate cities and lack data on neotropical areas. While some general patterns emerge, an obligatory question is whether or not these patterns extend to cities in tropical areas. In this study we do an overview of published work in tropical cities and ask: What are the patterns of species diversity between managed and unmanaged areas in tropical cities including the relative distribution and dominance patterns of native and non-native species? How do they compare to temperate cities? What can we say about the social drivers of plant diversity in the tropics when we implement social-ecological approaches to their study?
Results/Conclusions
For two cities (Mexico City, Mexico; San Juan, Puerto Rico), the diversity of species is higher in residential yards relative to semi-natural areas. In this regard, these tropical cities showed patterns that were similar to generalized patterns found for temperate cities. On the other hand, the relative abundance of native and non-native species in natural vs residential locations showed contrasting results between these two cities. In Mexico city, non-native species were more abundant in both semi-natural and urban managed areas whereas in the Caribbean city of San Juan, native species dominated semi natural landscapes but not residential yards. The relative distribution of native and non-native species in San Juan, was in fact more similar to patterns described for temperate cities. In at least two other tropical cities (Sao Louis, Brazil; Havana, Cuba), plants with provision services (food/timber) dominate the composition of urban residential yards. In two others (San Juan, Puerto Rico; Leon, Nicaragua), ornamental species dominate the flora of residential yards, a pattern that is shared with temperate cities. Differences in the relative proportion of ornamental vs provision species in residential yards across tropical cites may relate to differences in city-specific social-economic contexts that influence management decisions related to residential green spaces.