“Mimosa L. (Leguminosae, Caesalpinioideae) no Pantanal brasileiro: estudo florístico e avaliação das espécies resilientes ao fogo e a inundação. "

Abstract

Mimosa L. (Leguminosae, Caesalpinioideae) has 615 species, with a pantropical distribution, occurring mainly in dry forests and savannas. In the Pantanal, Mimosa is the most diverse genus of Leguminosae, recorded in different phytophysiognomies, especially in fields and monodominant formations subject to fire and flooding. In grasslands, it is common for distinct species of Mimosa to colonize, sometimes consumed by cattle. Thus, this dissertation aims to fill a gap in the floristic-taxonomic knowledge of Mimosa species in the Pantanal, with information on distribution, preferred environments and ecological information. The dissertation is divided into articles. In article 1, entitled "Mimosa L. (Leguminosae, Caesalpinioideae) in the Brazilian Pantanal", we aim to 1.1) evaluate the richness of Mimosa in the Brazilian Pantanal and 1.2) characterize the taxa in terms of morphology and ecological aspects. In article 2, entitled "Evaluation of the infestation potential of Mimosa L. (Leguminosae, Caesalpinioideae) in the Brazilian Pantanal", we sought to 2.1) identify which species of Mimosa are infesting pastures in the Pantanal, and 2.2) indicate appropriate management options for these species. For the Pantanal, we confirmed 40 Mimosa taxa (29 specific, 11 infraspecific), including twelve new occurrences and two new species. We identified six Mimosa taxa that infest pastures, mainly after fire and flooding disturbances. Underground structures, when present, favor the persistence of certain species in pastures. The addition of taxa for the Pantanal is the result of analysis of hundreds of herbarium specimens, botanical collections, and field observations that allowed verification of Mimosa identifications. Certain weed species require frequent management to remove the underground structures that encourage regrowth. Areas with few collections, such as the Kadiwéu indigenous land in Mato Grosso do Sul and other sites in Mato Grosso, should be prioritized for new botanical expeditions, as they should directly influence the addition of species occurrences in the Pantanal, as verified for Mimosa.