Exotic Tree Plantation Types and Their Distance to Urban Areas in Central Argentina Affect Various Facets of Bird Diversity

Abstract

Tree plantations are expanding worldwide, negatively affecting native bird communities. However, most research has focused on the impact of tree monocultures on bird taxonomic diversity, while studies on their effects on functional and phylogenetic diversities are limited. This study aimed to compare different bird diversity facets between Eucalypt monocultures and mixed tree plantations, as well as the impact of proximity to urban areas. Bird surveys were conducted during spring using point counts in central Argentina. The mixed tree plantations consisted of Cedrus deodara, Eucalyptus globulus, Ligustrum lucidum, Pinus taeda, and Celtis australis, with more understorey cover compared to Eucalypt monocultures. Although bird species richness and Simpson diversity were similar between tree plantations, mixed plantations exhibited higher Shannon diversity. Functional and phylogenetic diversities were comparable across plantation types but were significantly influenced by the distance to urban areas. Functional diversity decreased near urban areas, while phylogenetic diversity showed the opposite pattern. The results showed that the increased habitat heterogeneity of mixed plantations likely supported more diverse bird communities, including a greater number of species typical of native woodlands in central Argentina. Additionally, the landscape context significantly influenced the bird communities in tree plantations.