# From Herbarium to Landscape: New Records and Mapping Rare and Threatened Species of Brazilian Atlantic Rainforest

## TL;DR

This study documents new and rare plant species in the under-sampled mountainous regions of Brazil's Atlantic Rainforest, emphasizing the need for better data to guide conservation efforts.

## Contribution

The study combines field surveys and digital repository analysis to document new species records and highlight data gaps in biodiversity monitoring.

## Key findings

- 17 new records and 243 previous records of 12 rare and endemic plant species were documented.
- Homalolepis insignis and Rhodostemonodaphne anomala were first recorded in Minas Gerais state.
- Identification errors and imprecise coordinates in collections hinder accurate biodiversity assessments.

## Abstract

The Atlantic Rainforest is a biodiversity hotspot with high endemism. Botanical sampling in its interior mountains is limited, affecting knowledge of locally endemic or undescribed species. The aim was to investigate the presence and distribution of rare and threatened species in different Atlantic Rainforest fragments. Atlantic Rainforest of Minas Gerais state, Brazilian southeastern. We used multi‐level forest inventory data from 137 plots across nine Semideciduous Seasonal Forest fragments, sampled 1–9 times over 30 years. We selected species with ≤ 60 previous records, associating coordinates to plot distribution maps. We analyzed species' distribution in the biodiversity repositories SpeciesLink, JABOT, and GBIF to avoid omitting exclusive records on any of these platforms. We documented 17 new records and listed 243 previous records of 12 rare species in eight families. These species are endemic to the Atlantic Rainforest, with most showing some level of threat. The new records expanded species' occurrence zones, and Homalolepis insignis and Rhodostemonodaphne anomala were documented for the first time in Minas Gerais state, highlighting that collection in under‐sampled regions is essential for improving species knowledge and reducing sampling bias. The previous record numbers varied across species, with misidentifications causing inconsistencies in occurrence records, particularly for Didymopanax longipetiolatus. Physical and digital collections need review to correct identification errors, synonyms used improperly, and imprecise coordinates. This information is crucial for identifying priority areas for conservation, especially rare and threatened species. A concerning lack of synchronization between scientific publications, biodiversity repositories, and government organizations may compromise policy development for environmental management and resource allocation to protect vulnerable areas.

Botanical collections remain limited in the mountainous areas of the Brazilian Atlantic Rainforest, which compromises biogeographic knowledge of endangered and locally endemic species and many others that have not yet been described. These gaps hinder the accuracy of biodiversity indicators, limit the discovery and description of new species, restrict the advancement of taxonomic knowledge, and challenge the precise delimitation of distribution ranges, particularly for rare species. Our research, which used an approach that combines extensive field surveys and investigations of rare species in digital repositories, documented 17 new records and listed 243 previous records of 12 rare and endemic species from the Atlantic Rainforest. Furthermore, we demonstrated that both physical and digital collections need to be reviewed to correct identification errors and imprecise collection locations, which are crucial for identifying priority areas for conservation.