Future Range Shifts and Diversity Patterns of Antarctic Lecideoid Lichens Under Climate Change Scenarios

ABSTRACT Being uniquely adapted to extreme environmental conditions, rock‐dwelling lecideoid lichens are a diverse and major component of terrestrial vegetation in Antarctica. Climate change is reshaping Antarctic ecosystems, forcing cold‐adapted species to migrate to maintain their climatic niche. The study surveyed the circum‐Antarctic lecideoid lichen diversity and modeled the impacts of two climate change scenarios on their distributional range shifts across Antarctica. Fungal and algal symbionts of lecideoid lichen species from a circum‐Antarctic sampling were classified using classical barcoding methods. The climatic niches of nine common fungal (mycobiont) species and four algal (photobiont) OTUs were predicted, and spatial range shifts were projected across four Antarctic bioregions under three Shared Socioeconomic Pathways: (1) SSP1‐2.6: sustainable development, (2) SSP3‐7.0: medium–high reference scenario with high methane emissions and (3) SSP5‐8.5: continued dependence on fossil fuels. DNA‐barcoding revealed altogether 34 species of lecideoid lichens associated with 9 photobiont OTUs for the Antarctic continent. In addition to the already known lichen species in Antarctica, three newly detected species of the genus Lecidella could be identified. The calculated climate change scenarios across bioregions predict overall range expansion for mycobiont species and photobiont OTUs. While a reduction in suitable habitat size is expected in maritime Antarctica, species distributions are predicted to expand in continental regions, primarily due to inland shifts. These inland areas may serve as emerging climatic refugia for certain mycobiont species. Overall, these results suggest that, under future warming, lecideoid lichens undergo an overall range expansion, particularly in previously uncolonized inland areas in continental Antarctica.