Primary productivity in cities and their influence over subtropical bird assemblages

- Urbanization process alters vegetation within cities modifying bird assemblages.
- Birds' richness and diversity increase with higher photosynthetic productivity and decreasing distance to forests.
- Photosynthetic productivity is a useful tool to relate with birds' assemblages such as species adapted to urban environments.
- Native birds' species assemblages were more dependent on vegetation cover and closeness to mature forests.

Changes in ecosystem structure caused by urbanization produce a reduction in photosynthetic productivity, which can lead to reductions in resource availability for birds. Here, we analyzed the relation between photosynthetic productivity and bird assemblages in a subtropical urban ecosystem, in North-Western Argentina. We used Generalized Linear Models to assess the responses of bird abundance, richness and diversity to photosynthetic productivity, vegetation cover and distance to main natural forest. We found higher bird richness and diversity with increasing photosynthetic productivity and vegetation cover, and with decreasing distance to forests; while total bird abundance was positively related to vegetation cover. When we classified bird species in different groups, based on their use of the environment, we found that species adapted to urban environments were more dependent on photosynthetic productivity, while species related to native forests were more dependent on the distance to source forests. Understanding the factors that affect bird assemblages in cities is important for the development of strategies for urban planning and conservation.