Relações das características morfológicas de formigas com processos ecológicos de predação e de remoção de sementes e variáveis ambientais em fragmentos florestais

Abstract

Different approaches can be used to determine the resilience of ecosystems to environmental changes, such as understanding the relationship between the functional attributes of organisms and ecosystem functioning. Ants can be used in studies of this relationship, as they participate in important interactions in practically all terrestrial ecosystems on the planet. We investigated the relationship between ant body morphology and resource size through two types of ecosystem processes: larval predation and seed removal. We also investigated the association between morphological traits and environmental variables. For this, we used a broad morphological characterization of ants collected in five areas of Atlantic Forest fragments and Cerrado phytophysiognomies. In these environments, we collected the variables canopy opening, litter dry weight and circumference at the height of the tree base. To characterize predation and seed removal, larvae of Tenebrio molitor Linnaeus 1758 and artificial seeds were made available in three size classes (small, medium and large), respectively. The ant fauna that interacts with these resources was also characterized. In both processes, the relationship between morphological characteristics and resource size, as well as between environmental variables, was only detected when species identity was considered. Body size (Weber length) and mandibular measurements were related to small and medium seed size in Pachycondyla striata and Camponotus rufipes, while scape size in Pheidole bucculenta. Each species had a different association for each microclimatic environmental variable. Litter dry mass was the environmental variable with the highest number of associations with morphological characteristics in the species surveyed. The relationship between resource size and ant morphology may not be a determining factor for performance and/or behavior in the process, if species identity is disregarded. Our results point to the use

of morphological characteristics of the species as a parameter for the study of the organism- environment relationship.