How does urbanization affect the fauna of the largest urban forest in Mexico?

Abstract

Animals in urban forests provide ecological and cultural services, but the quality of these services often depends on floral diversity and animal diversity. In turn, animal diversity in urban forests is influenced by various aspects of habitat quality, in spatial scale- and taxon-dependent ways. Understanding the effect of individual habitat factors on different animal groups can provide valuable information for urban forest management. We estimated the relationships of 25 environmental, vegetation, land cover and anthropogenic perturbation variables to the fauna of Chapultepec Forest within Mexico City, Mexico. We included flower-visiting flies (Diptera: Bombyliidae, Syrphidae), bees (Hymenoptera: Apoidea), butterflies (Lepidoptera: Papilionoidea), birds, and reptiles (Squamata and Testudines). Insect populations were more strongly affected by herb and flower variables, while variables related to trees and shrubs were more important to vertebrate taxa. In general, human density, buildings cover and pavement cover were the most relevant anthropogenic perturbation factors. Birds and butterflies were more tolerant of urbanization than the other groups. Effects for each taxon are discussed. Our results suggest that urban park management plans should focus on enhancing habitat heterogeneity and vegetation structure complexity. Specifically, maintaining herb and tree diversity would likely promote animal diversity and ecosystem services in the Chapultepec Forest.