Urban patches of dry forest as refuges for ants and carabid beetles in a neotropical overcrowded city

Abstract

Cali is the third most prominent, and one of the most crowed, Colombian cities. It still harbours some tropical dry forest patches that can mitigate the impacts of the urban transformation; however, there is an almost total absence of information on the biological importance of these sites and their potential for future ecological restoration processes. To assess if they serve as important refuges for insect bioindicator species, we sampled five urban patches of tropical dry forest in the city, plus one nearby rural patch, using specific trapping procedures for ants and carabid beetles. Patch areas were variable, from 1 to 50 ha. We found that the smallest patch presented the highest ant richness, with a tendency towards generalists and a few unique species. Meanwhile, some specialist species were found in the rural patch. A total of 109 ant and 13 carabid species were recorded, including four new records of ants for Colombia. Results suggest that environmental variables favour the presence of generalist and opportunistic ants. Despite this, the high ant richness demonstrates that. Urban forest patches are important refuges for biodiversity. The low richness observed for carabids could be a sign of the challenges that urban forests face considering the ecological importance of beetles. The possible dangers of intensive internal use of these forests is discussed to prevent local extinctions, since the biggest forests are not necessarily conserving a higher richness. This work represents an important contribution to urban ecology in the region, with possibilities of further restoration in urban environments.