Role of Vegetation Structure in Shaping Ant Assemblage in Urban Greenspaces of Abidjan, Côte d’Ivoire, West Africa

Abstract

Greenspaces constitute important mitigation strategies against local global warming, functioning as ecological corridors and biodiversity refugia in urban environments. They also enhance ecological resilience and urban quality of life. This study aims to address this knowledge gap by evaluating the influence of soil vegetation cover and tree density on the diversity and spatial distribution of Formicidae (ants) within the tropical urban landscape of Abidjan, Côte d'Ivoire. Sampling was conducted across seven distinct greenspaces within Abidjan using tuna baits and pitfall traps. To correlate faunal data with environmental variables, tree density and soil vegetation cover were also quantified within 5 m x 5 m standardized quadrats. The study identified a diverse ant community comprising 69 species distributed across 25 genera and five subfamilies. The data reveal significant variation in species richness, diversity indices, and relative abundance across the greenspaces. Greenspaces characterized by dense vegetation consistently yielded the highest biodiversity metrics. Results demonstrated that structural parameters, specifically tree density and soil vegetation cover exert a primary influence on community assembly. Native species dominated ant communities, representing 66.5% of total occurrence (i.e 5027 out of 7563) against 33.5% (i.e 5027 out of 7563) for invasive ant species. Well wooded areas exhibited a more balanced diversity, supporting specialized species and a stable distribution. Conversely, sparsely vegetated zones were characterized by low taxonomic diversity and were dominated by a limited number of opportunistic and invasives ant like Paratrechina longicornis (24.7%), Tapinoma melanocephalum (5.3%), Tetramorium simillimum (0.9%), Solenopsis globularia (1.2%), Monomorium floricola (0.2%) and Cardiocondyla emeryi (1.1%) adapted to anthropogenic disturbance. These findings underscore the vital role of structurally complex urban greenspaces in maintaining insect biodiversity within cities. We advocate for rigorous ecological management of these habitat, which is essential for establishing a sustainable equilibrium between urban development and wildlife conservation.