Bryophyte Diversity and Distribution in the Virgin Islands Based on Historical Collections

Abstract In botanical research, vascular plants tend to overshadow their counterparts, the bryophytes. This trend can be observed in the Virgin Islands, with roughly 1,200 tracheophytes identified in the region and no official count of bryophytes on record. In this study, we documented the diversity and distribution of the bryophyte species of the Virgin Islands (British, United States, and Puerto Rico) using historical data from collections available through online herbaria. We also documented which islands had the most species recorded, as well as which species and families were the most abundant. Linear regression tests were used to explore what factors may have a strong influence on the total number of species on a particular island, such as elevation, average annual rainfall, and land area. Lastly, we investigated the possibility of collection biases between the study sites by comparing the number of collections to the number of species recorded for each island. Overall, we found 115 species of bryophytes that belong to 28 families: 83 mosses, 30 liverworts, 2 hornworts. A positive correlation was found between the total number of species and the elevation of the island, but no correlation was found for land area and annual rainfall. With 55% of the collections being recorded there, St. Thomas was the island with the most collections. The results of this study will help broaden what is known about the bryophyte species of this region and can potentially open doors for more modern botanical expeditions.