Level-up urban conservation by increasing vegetation complexity

Abstract

Greenspaces provide important habitats for species in urban environments, and their effective management is crucial to achieving biodiversity protection goals. Here we investigate how three habitat features that are readily influenced by management—tree cover, vegetation complexity and water area—are associated with bird richness and species presence within urban greenspaces. Analysing remote sensing and citizen science data from Brisbane, Australia, we find that bird species richness within urban greenspaces has a strong positive association with vegetation complexity, but no significant association with tree cover or water cover. These results suggest that urban greenspace management strategies that focus simply on increasing tree cover might overlook valuable biodiversity enhancement opportunities. We also explore how these three management goals influence the presence of individual species and find that the effect of each variable varies among species. These results highlight the importance of formulating urban greenspace management plans with specific objectives in mind—a particular management approach will benefit some species, but harm others. Management to increase vegetation complexity is likely more beneficial for overall bird species richness than simply increasing the area coverage of vegetation or waterbodies.