Slow Succession: A Comparison of the Saxicolous Lichens of a 50‐Year‐Old Abandoned Chromite Mine and a Nearby Undisturbed Ultramafic Outcrop

ABSTRACT Pioneering and succession are well‐studied phenomena in the field of ecology but are poorly understood for lithic habitats dominated by cryptogams. Yet pioneering and establishment of epilithic communities constitutes a fundamental ecological process that provides a precursor to the formation of soil terrestrial communities. Abandoned mines offer an exciting opportunity to explore pioneering and succession of lithic habitats. In our study, we quantitatively compared the lichen communities of an approximately 50‐year‐old abandoned chromite mine to a nearby, undisturbed rock outcrop of similar ultramafic parent material. Our results reveal several differences between these two communities. The early successional community of the mined site had significantly lower lichen cover and species richness, as well as a species composition distinct from the late successional community of the undisturbed rock outcrop. The early successional community was characterized by relatively high cover and frequency of endolithic lichen taxa, which were mostly absent from the late successional community. Our results highlight the slow progress of pioneering and succession in newly exposed areas of rock and emphasize the importance of preserving undisturbed, late successional lithic habitats.