Taxonomic diversity of green plants (Viridiplantae) in the Caatinga Phytogeographic Domain: a study supported by environmental licensing

Abstract

Background Limited access to taxonomic and biogeographical data on plants across large spatial scales poses challenges for biodiversity research. This study examined richness, taxonomic contributions and biogeographic insights derived from a floristic inventory encompassing 56,144 km2 of the Caatinga Phytogeographic Domain (CPD), carried out within the framework of environmental licensing for a water infrastructure project (São Francisco River Transposition Project – PISF). Over a period of fifteen years, specimens from various plant groups (algae, angiosperms, bryophytes, ferns and lycophytes) were collected and taxonomic, ecological and biogeographic data were compiled for the species occurring in the study area (e.g. threat status, life form, geographic origin, endemism within the CPD), resulting in a checklist and a biodiversity dataset. The number of plant samples and species richness recorded in the study area was compared with previously available data. Rarefaction curves were used to assess the increase in species richness in relation to sampling effort within the study area.