POLAR ROCKS: Gas-exchange experiments on samples of Usnea aurantiaco-atra and Andreaea gainii

Samples of the lichen species Usnea aurantiaco-atra as well as of the moss species Andreaea gainii were collected from two locations in the vicinity of the Spanish Antarctic Station Juan Carlos I on Livingston Island (South Shetland Islands, Antarctica): Punta Polaca (50 m.a.s.l.), and El Castillo Nunatak (449 m.a.s.l.). During the 2022-2023 Antarctic Campaign, the collected samples underwent gas-exchange experiments under controlled conditions of light, temperature and humidity using a GFS-3000 gas-exchange system (Heinz Walz GmbH, Germany). These experiments took place in the laboratory of the Spanish Antarctic Station Juan Carlos I. In our facilities at the Complutense University of Madrid, we also carried out gas-exchange experiments on samples of Usnea aurantiaco-atra using a CMS-400 gas-exchange system (Heinz Walz GmbH, Germany). The aim of these analysis is to quantify the photosynthetic activity of the various studied species and to construct their ecophysiological profiles.