• Antarctica;
  • Deschampsia Antarctica;
  • Facilitation;
  • Nurse effect;
  • Positive interactions


In a current article in the Journal of Vegetation Science, Casanova-Katny et al. addressed a comment about an article by Molina-Montenegro et al., which demonstrated the climate modification induced by the macrolichen Usnea antarctica and its role as facilitator. They provided useful corrections concerning species identification and pointed out several issues that, in their view, weakened our study. They indicated that the role of U. antarctica as a facilitative species in the maritime Antarctica is merely philosophical and has no ecological relevance. In this commentary, we argue why these critiques are unsubstantial, and provide evidence that the macrolichen can modify the microclimate, ameliorating the harsh conditions prevailing in Antarctica, establishing positive interactions and eventually facilitating vascular species. Thus, the macrolichen U. antarctica would act as a ‘nurse species’, playing a key role in structuring the maritime Antarctic plant community.