Simple does not mean poor: grasslands and forests harbor similar ant species richness and distinct composition in highlands of southern Brazil

Abstract

Several studies addressed ant communities in the dense Atlantic Forest that runs along the Brazilian coast. However, comparatively little is known about the mixed forests and grasslands that occur in the southern range of the Atlantic Forest domain. In this study we performed the first standardized assessment of ants in the forest-grassland mosaic found in the highlands of the state of Santa Catarina. We aimed to investigate and compare ant richness and composition between mixed forests and grasslands in the main mountain range of south Brazil. Ants were collected in two years with ground pitfalls, tree pitfalls and litter samples. Sixty ant species were recorded, resulting in 22 new records for "Planalto Serrano" region and three for the state of Santa Catarina: Eurhopalothrix depressa, Pheidole radoszkowskii and Wasmannia williamsoni. There was significant dissimilarity in ant species composition between grasslands and forests, but no difference in ant species richness, even considering the higher number of strata in mixed forests. Similar richness and low number of arboreal species suggest that this ant community is structured similarly to temperate ones. Both habitats presented a large proportion of exclusive species. The fact that species composition between grassland and forest areas differed, coupled with the similarity in species richness between habitats and the record of new ant species for the region, calls for strong conservation efforts in grasslands of southern Brazil, which still are little protected by conservation areas.

Local and regional drivers of ant communities in forest-grassland ecotones in South Brazil: A taxonomic and phylogenetic approach

“…At a local scale, our study did not show differences in ant diversity between adjacent grasslands and forests, corroborating both Pinheiro et al [31] and Klunk et al [32] for South Brazil, even when more than one stratum (ground, leaf litter and arboreal) is considered (as discussed by Klunk et al [32]). Overall, studies have showed open ecosystems such as grasslands/savannas harboring higher ant diversity than forests in ecotones or landscape mosaics, for many regions of the world (e.g.…”

“…Locally, we expect compartmented ant assemblages inhabiting forests and grasslands, but no detection of differences regarding species diversity between habitats, as reported similarly by Pinheiro et al [31] and Klunk et al [32] for the same region. As ants are thermophilic organisms, local temperature should positively influence the diversity of ant species found foraging [33].…”

Ants of the Palouse Prairie: diversity and species composition in an endangered grassland

“…Our systematic review of ant biodiversity surveys in different biomes over the last five years revealed a bias towards Tropical & Subtropical Grasslands, Savannahs & Shrublands (eight studies, Cross et al 2016 , Van Schalkwyk et al 2019 , Arcoverde et al 2016 , Lasmar et al 2020 , Dröse et al 2019 , Hlongwane et al 2019 , de Queiroz et al 2020 , Santoandré et al 2019 ). We found two studies on Tropical & Subtropical Moist Broadleaf Forests ( Lawes et al 2017 , Klunk et al 2018 ), one study on Tropical & Subtropical Coniferous Forests ( Cuautle et al 2016 ), three studies on Temperate Broadleaf & Mixed Forests ( Braschler and Baur 2016 , Helms et al 2020 , Heuss et al 2019 ), one study on Montaine Grasslands & Shrublands ( Jamison et al 2016 ), three studies on Mediterranean Forests, Woodlands & Scrub ( Adams et al 2018 , Catarinue et al 2018 , Flores et al 2018 ) and one study on Deserts & Xeric Shrublands ( Álvarez and Ojeda 2019 ). In the last five years, only two citations have included information on ants in Temperate Grasslands, Savannahs and Grassland biomes ( Ramos et al 2018 , Kim et al 2018 ), the biome that encompasses Palouse Prairie (Fig.…”