Orchidaceae na região insular de Belém, Pará, Amazônia Oriental: diversidade, conservação e uso da terra

Abstract

Islands are fundamental for the conservation of species and plant communities, as they represent a model of continental diversity and exhibit high species richness. In the state of Pará, studies on biodiversity in island environments are still incipient. Therefore, the present study aims to document the diversity of Orchidaceae in the insular region of Belém through a floristic–taxonomic survey, including species descriptions, illustrations, photographs, data on geographic and local distribution and habitat, ecological and taxonomic comments, as well as an identification key for the species. An on-site survey of the collections housed in the herbaria HBRA, HCP, HF, HIFPA, IAN, MFS, and MG was conducted, in addition to searches on online platforms. Furthermore, field collections were carried out from June 2024 to December 2025 on the islands of Caratateua, Combu, Cotijuba, Mosqueiro, and Tatuoca. Based on a revisionary analysis, it was verified that land occupation and land-use processes have had a direct impact on territorial dynamics on the islands, promoting colonization and the indiscriminate use of land and forest resources as a result of increasing urbanization and political and social pressures. Nevertheless, 34 species distributed across 23 genera of Orchidaceae were recorded, with emphasis on Maxillaria Ruiz and Pav. (five spp.), Epidendrum L. (four spp.), Catasetum Rich. ex Kunth, Polystachya Hook., and Vanilla Mill. (two spp. each). Encyclia bohnkiana Castro & Campacci is here synonymized under Encyclia thienii Dodson, and a lectotype is designated for E. thienii. The results reinforce the importance of the insular region for the conservation of Amazonian biodiversity in the face of anthropogenic and climatic pressures, and provide crucial data for the development of ecological, biogeographic, and phylogenetic studies.