Biodiversity conservation in urban parks: a study of ground-dwelling ants (Hymenoptera: Formicidae) in Rio de Janeiro City

Abstract

Urban green recreational spaces may provide habitat for animals and plants. We investigated the importance of urban public parks in the city of Rio de Janeiro with regard to the conservation of ant species by comparing both the structure of the ground-dwelling ant community between urban parks and continuous forests and the influence of environmental factors on possible differences. Fifteen urban areas were sampled (5 isolated parks, 5 non-isolated parks and 5 forest areas). Ants were sampled at sardine bait stations and through manual/visual searching in quadrats around the baits. We identified 120 ant species (4 exotic species) distributed across 38 genera and 7 subfamilies. The four exotic species were Monomorium floricola, Paratrechina longicornis, Pheidole megacephala and Tetramorium simillimum. Both the taxonomic and functional diversity of ground-dwelling ants were higher in continuous forests, followed by non-isolated and then isolated urban parks. Environmental factors were found to be key drivers influencing the differences in ant community structure among continuous forests and urban parks. Soil compaction and canopy cover predicted the diversity patterns of the taxonomic and functional compositions of the ant communities. The ant species in the study areas exhibited a non-random pattern of distribution and a spatial association of species segregation. There was high spatial turnover of ant species in the study areas, indicating that conservation efforts are required in all studied urban areas, not just those areas considered to be species rich. Therefore, we need to conserve more species in more areas, not necessarily those high in richness.