# Bryophytes of the Serra dos Órgãos National Park: Endemism and Conservation in the Atlantic Forest

## TL;DR

This study cataloged bryophytes in a Brazilian national park, revealing high diversity and several endemic and threatened species.

## Contribution

The study provides the first comprehensive bryophyte inventory for Serra dos Órgãos National Park, identifying endemic and threatened species.

## Key findings

- A total of 504 bryophyte species were recorded across 76 families.
- PARNASO hosts 69 Brazilian endemic species and 11 threatened species according to IUCN criteria.
- Montane Forest had the highest bryophyte species richness in the park.

## Abstract

This study presents a comprehensive inventory of bryophytes in Serra dos Órgãos National Park (PARNASO), aiming to evaluate species richness, floristic composition and threatened taxa. Despite the state of Rio de Janeiro being one of the most extensively sampled regions for bryophytes in Brazil, detailed surveys of its conservation units remain scarce. Data were obtained through bibliographic review, herbarium specimen analysis, and new field collections. A total of 504 species were recorded, belonging to 202 genera and 76 families. The park harbors three locally endemic species, eight endemic to Rio de Janeiro, and sixty-nine species endemic to Brazil. Additionally, eleven species were identified as threatened, comprising seven Endangered (EN), two Critically Endangered (CR), and two Vulnerable (VU) according to the IUCN guidelines. PARNASO includes four distinct ecosystems along an altitudinal gradient: sub-montane forest (up to 500 m), montane forest (500–1500 m), upper-montane forest (1500–2000 m), and high-altitude fields (above 2000 m). Montane Forest showed the highest species richness, followed by high-altitude fields, upper-montane forest, and sub-montane forest. The findings highlight PARNASO’s importance in preserving bryophyte diversity in a highly diverse yet understudied region. This work contributes valuable baseline data to support conservation strategies and future ecological studies in Atlantic Forest remnants.