Crustose lichen
[2] The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes.
The patches, or areolae, can be as large as 1 cm in diameter or very small and raised, giving them the appearance of a wart.
[6] The diameter and area of the thallus exponentially increase, provided that organic substances are distributed uniformly in all parts of the lichens.
[7] The growth of crustose lichens is dependent on several factors, including moisture levels, sunlight, and temperature.
The scientific basis of lichenometric dating and the reliability of lichen growth rate measurements in general have been questioned and critically reviewed in a paper by Osborn et al.
Photosynthetic rates vary among lichen growth forms due to differences and variations in thalli thicknesses.
They can be found, among others, together with epiphytic algae and liverworts, living on the surfaces of leaves of tropical evergreen trees and shrubs.
Various species of crustose lichens, including Biatora granulosa and Lecidea uliginosa, were found covering recently-burned surfaces caused by a subarctic forest fire in an area near the Great Slave Lake.
[16] Crustose lichens also grow in areas of high elevations, such as the western Himalayan region.
Nonetheless, surrounding the central area of cities in which most plants cannot thrive, crustose lichens Physcia or Xanthoria have been found growing, although they do fall short of natural development and size.
The crustose lichen Lecanora conizaeoides is another highly resilient species, and remarkably seems to only grow in industrial areas of the United Kingdom.
In a study conducted by Kitagawa and Watanabe (2004), the crustose genus Porpidia altered minerals, specifically biotite in granite.
The majority of these spores die under the extreme conditions of a rock surface, an area where water evaporates rapidly and daily fluxes in temperatures are quite large.
Eventually the crustose spores form small and round thalli and increase in diameter yearly.
