How well do trees fit the city? Lessons from an urban tree survey in Córdoba, Argentina.

Abstract

Background and aim: Urban tree composition is generally highly diverse and largely non-native in origin. Species selection, however, should consider not only future predicted climate and species' environmental requirements, but also the regional invasion risk assessments and the respiratory health potential of species. Here, we assessed the suitability of the most frequent urban tree species by using available online databases.  M&M: Suitability was assessed by analysing tree attributes in relation to their invasive status in the study area, the respiratory health potential of the species given by their known pollination strategy and the bioclimatic match of species with the plantation zone. We grouped species according to their nativeness as non-native, regionally native and local native. After filtering those with undesirable characteristics (i.e., invasive species and/or with anemophilous pollination strategy) we analysed three bioclimatic variables: annual temperature, annual precipitation and precipitation seasonality. Results: Results showed that the composition of Córdoba's street trees is heavily biased towards non-native species, many of which are invasive, have an anemophilous pollination strategy and/or exhibit high bioclimatic mismatch. In addition, the strong bias in the current tree composition towards species from more humid, temperate regions is evident.  Conclusions: Our results highlight the importance of revising current policy decisions to adjust urban tree flora in the face of climate change.