ABSTRACT
The mycobiont, a heterotrophic organism, benefits from the carbohydrates produced by the photobiont. In the case of nitrogen-fixing cyanolichens, the my cobiont also gains a nitrogen source. The fungus probably functions as a reservoir
of inorganic nutrients for the photobiont and also creates a humid environment, enhancing water uptake, offers a physical support, and substantially reduces the light intensity for the photobiont.
