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.

Diversidad taxonómica de hormigas en áreas verdes urbanas en una ciudad de tamaño medio en los Andes centrales de Colombia

“…Este mismo patrón se ha encontrado en estudios que han constatado que los fragmentos urbanos de bosque contienen mayor riqueza de hormigas que otros tipos de hábitats, por ejemplo, jardines, lotes baldíos, parques, y áreas pavimentadas (Santos, 2016). De hecho, los fragmentos de bosque inmersos en las matrices urbanas pueden llegar a tener una diversidad semejante o mayor que los bosques de las zonas rurales de las ciudades (Ramos-Ortega & Guerrero, 2023;Forero-Chávez et al, 2024). En este sentido, el nuestro constituye uno de los primeros estudios en Colombia que evalúa y compara la diversidad de hormigas en diferentes áreas verdes inmersas en una ciudad, registrando una riqueza que dista de la de otras zonas urbanizadas del país, por ejemplo, los bosques secos urbanos de Santa Marta (Ramos-Ortega & Guerrero, 2023) y Cali (Forero-Chávez et al, 2024), donde se reportaron 97 y 109 especies de hormigas, respectivamente.…”