Role of windbreaks on ants (Hymenoptera, Formicidae) conservation in a cotton-growing agroecosystem of the humid savannah in Togo

Abstract

Intensive agriculture and monoculture lead to significant reduction, or loss, of the initial biodiversity. This reduction or loss of biodiversity, can be mitigated by the presence of windbreaks around the fields that serve not only as natural barrier against adverse weather conditions but also as refuge for critical organisms. The aim of this study was to determine the role of natural windbreaks in the conservation of ants at the Experimental Station of the Centre de Recherche Agronomique de la Savane Humide in Kolokopé (Togo). Ants’ diversity was assessed in two cotton fields and their surrounding natural windbreaks using pitfall traps and monolith method in 100 m x 2 m transects. In total, 58 ant species belonging to 22 genera in six subfamilies (Dolichoderinae, Dorylinae, Formicinae, Myrmicinae, Ponerinae and Proceratinae) were identified. The species richness of ants was higher in the windbreaks (43 and 36 species) than the cotton fields (15 and 19). The occurrence of ants was also higher in the windbreaks (35.65 % and 36.24 %) than the cotton fields (11.69 % and 16.42 %). Thirty-four out of the 58 species were sampled exclusively in the windbreaks, compared to only two species exclusively sampled in the cotton fields (Crematogaster sp.3 and Lepisiota sp.3), while only three species were common for all the habitats (Camponotus flavomarginatus Mayr, 1862, Tetramorium sp.1 and Tetramorium simillimum (Smith, 1851)). The study shows that ants were more diversified and active in the windbreaks than the cotton fields. Windbreaks, characterized by less anthropic disturbance, could function as refuge for ants within this agroecosystem.