Two additions to the moss flora of the South Shetland Islands in the maritime Antarctic

Mariusz Wierzgoń,Tomasz Suchan,Michał Ronikier

doi:10.5586/asbp.3598

Abstract

Tortella fragilis (Drumm.) Limpr. (Pottiaceae) and Bryum nivale Müll. Hal. (Bryaceae) are recorded for the first time from the South Shetland Islands in the northern maritime Antarctic. They were discovered in the Admiralty Bay area on King George Island, the largest island of this archipelago. The two species are briefly characterized morphologically, their habitats are described, and their distribution in the Antarctic is mapped. Discovery of these species has increased the documented moss flora of King George Island to 67 species, strengthening it in the leading position among individual areas with the richest diversity of moss flora in Antarctica. Likewise, T. fragilis and B. nivale represent remarkable additions to the moss flora of the South Shetland Islands, which currently consists of 92 species and one variety, making this archipelago by far the richest bryofloristically amongst large geographic regions of the Antarctic. Comparison of recent (2018) and old (1985) photographs revealed a significant retreat of glacial cover and suggests that the collection site was likely opened for colonization only within the last several decades. The record of T. fragilis is biogeographically relevant, and constitutes an intermediate site between the species’ occurrences in the Antarctic Peninsula and southern South America. The present record of B. nivale is the fourth discovery of the species worldwide, which may be helpful for the future designation of the distribution of this extremely rare species.

Highlights

T. fragilis and B. nivale represent remarkable additions to the moss flora of the South Shetland Islands, which currently consists of 92 species and one variety, making this archipelago by far the richest bryofloristically amongst large geographic regions of the Antarctic
The South Shetland Islands are a group of 15 volcanic islands located in the northern maritime Antarctic
In the Admiralty Bay area, we focused, among others, on the isolated and poorly accessible cliff of Klekowski Crag

Summary

Introduction

The South Shetland Islands are a group of 15 volcanic islands located in the northern maritime Antarctic. In the north, this peri-Antarctic archipelago is isolated from South America by the Drake Passage, which is about 770 km wide. The largest island in this archipelago is King George Island, which lies between latitude 61°50'–62°15' S and longitude 57°30'–59°01' W. King George Island was one of the earliest discovered lands in Antarctica, and was the first area from which mosses were collected in this biome during the United States sealing voyage of 1829−1831. Two species collected by James Eights, a member of this voyage, Polytrichastrum alpinum (Hedw.) G.

Methods

Results

Conclusion