Bioprotection explored: the story of a little known earth surface process

Bioprotection is identified as an earth surface process. However, it has been little studied, little acknowledged and yet may have major implications for the operation and management of geomorphic systems. Key early observations are traced back to Darwin's 'Voyage of the Beagle', Geikie in the natural environment and Watson for the built environment. Recent field observations and experimental work examining bioprotection are reviewed, with a specific focus on lichens and the landscape, as are its complex interactions with other processes. A conceptual model of bioprotection is presented for the case of an epilithic lichen on a limestone surface.