After the retreat of the Glaciar Frías in the Patagonian Andes, Argentina, Placopsis perrugosa dominated the pioneer stage on newly exposed rock outcrops. This was followed by a mid-successional stage, in which a lichen-moss mat was dominated by the moss Racomitrium lanuginosum, providing the foundation for a larger diversity of vascular plants in the final successional stage. Like other members of genus Placopsis, P. perrugosa is a fast-growing crustose lichen; this allows them to dominate as early colonisers on snow-free moraines of exposed land surfaces.
