Spatial and temporal variation of potential resource availability provided by street trees in southeastern Brazil

Street trees provide several ecosystem services in urban areas, including food for fauna. Tree species richness, composition and the relative abundance of native vs. non-native species can affect the populations of pollinators and dispersers. This work aims to evaluate the potential availability of food resources provided by street trees, in space and time, considering different pollination and seed dispersal syndromes at Santo Andre city (Southeastern Brazil). The georeferenced data for all catalogued tree individuals in the Urban Macrozone constituted our sampling domain. The species were categorized according to its geographical origin, pollination and seed dispersal syndromes, flowering and fruiting season. We divided the study area into cells and calculated: number of individuals, species richness, species diversity; richness and diversity of potentially flowering and fruiting individuals in each season of the year. 38,379 trees were catalogued, representing 578 trees/km2, totalizing 230 species. Most individuals (73%) were non-native. The number of individuals, species richness and diversity varied spatially. The pollination syndrome with higher potential resources availability was melittophily (pollination by bees and wasps) has during spring whereas ornithochory (seed dispersal by birds) was the dispersal syndrome with higher potential resources availability which occurred in summer. Despite the dominance of exotic individuals, the most common syndromes are in accordance with what is expected for tropical Atlantic rainforest regions. However, some pollination and dispersal syndromes presented very low potential resource availability in different seasons and no availability in some regions. These results should be taken into account by stakeholders for a better planning of planting efforts, considering the distribution, in space and time, of the potential availability of resources provided by street trees to fauna in order to improve connectivity.