Richness of Native and Exotic Plants in Parks in São Paulo is Determined by Urban Park Size and Age

Abstract

Green areas have important social, biological and aesthetical values. They might provide house and food for fauna, protect biodiversity and can provide several ecosystem services of provision, regulation, support and culture. This research aimed to analyze composition of native and exotic species in urban parks in São Paulo (Brazil), in response to variables considered drivers of diversity adapted to urban environment and to socioeconomic aspects. We expected that socio-economic factors and age and size of parks would be important determinants of species richness All county parks (municipal management) larger than 1 ha were selected, which summed 68 parks throughout São Paulo. Socioeconomic variables for this study were population, growth rate of population, average per capita income, IDH and population density. We also accessed native and exotic species richness of plants and trees from the flora list of each park. In order to determine the effects of park size and age and neighbourhood socio-economic status on richness of plants and trees we used multiple regression analyses. We found a great species richness in urban parks in São Paulo and that richness associated to park age and size, and to some socio-economic factors, especially when combined to age and size of parks. Bigger sites could offer more resources and area for the growth and establishment of native plants, and older parks in São Paulo likely had more management and interventions improving its biodiversity. Lastly, in vulnerable regions and in smaller and newer parks, we recommend improvement in plant species diversity by managers.