Ant diversity and composition in Silvopastoral system with nuclei: biodiversity conservation through agroecological applied nucleation

Abstract Applied nucleation is an ecological restoration technique used to enhance forest restoration in large scale projects. Silvopastoral System with Nuclei (SPSnu) was based on applied nucleation where trees nuclei and animals are integrated synergically to provide shade, non-timber forest products and increase diversity. While agroforestry systems are recognized for biodiversity conservation, the mechanistic role of tree nuclei in shaping ant communities remains underexplored. This study evaluated the effects of a silvopastoral system with tree nuclei (1.SPSnu) on ant (myrmecofauna) diversity and community composition compared with treeless pasture (2.TLP) and small forest remnants (3.FR). Epigeic ant communities were sampled using pitfall traps in these three habitats on three dairy farms located in the Atlantic Forest biome in southern Brazil. Based on Hill-number richness estimates standardized by sample size and coverage, SPSnu tended to exhibit richness values comparable to forest remnants and higher than treeless pastures (48, 55 and 31 species recorded, respectively), while species composition was more similar to treeless pastures. Species composition differed significantly among habitats (SIMPROF, p < 0.05), with forests forming a distinct group, while SPSnu clustered more closely with treeless pastures. Forest remnants were characterized by frequent occurrences of Pachycondyla striata , Holcoponera striatula , Odontomachus chelifer , and Pheidole sarcina , whereas treeless pastures were dominated by Solenopsis spp. and Nylanderia sp. SPSnu shared dominant taxa with both habitats but lacked several forest-associated species. Our study showed the benefits of agroecological applied nucleation to ant communities in SPSnu, and suggests that its application in agroecosystems may reconcile agriculture, ecological rehabilitation, and biodiversity conservation.