lichenology

Lichenology is the branch of biology that studies lichens, which are symbiotic associations between a fungus (the mycobiont) and a photosynthetic partner (the photobiont, mostly green algae or cyanobacteria). The field covers taxonomy, systematics, ecology, physiology, chemistry, distribution, and conservation of lichens.

Historical note: The concept of lichens as mutualistic partners was proposed by the German-Swiss botanist Simon Schwendener in 1867. The formal study and classification of lichens were advanced by Erik Acharius, often regarded as the father of lichenology, in the late 18th to early 19th centuries. Techniques evolved from microscopy and chemical spot tests to molecular phylogenetics in recent decades.

Biology: Lichens are composite organisms; the thallus forms crustose (crust-like), foliose (leaf-like), fruticose (shrubby). They reproduce via fungal spores, but also through vegetative propagules like soredia and isidia that contain both partners. The photobiont lives in symbiosis with the fungus, bridging carbon and nutrients.

Ecology and significance: Lichens inhabit diverse environments, from forests to deserts and Antarctic shores, often pioneering harsh substrates. They are sensitive indicators of air quality and ecological change; some fix atmospheric nitrogen (cyanobacterial partners). They contribute to soil formation, provide food and habitat for invertebrates, and have cultural uses.

Research and practice: Field identification relies on morphology, chemistry, and increasingly DNA analysis. Specimens are stored in herbaria; field guides and online databases support taxonomy and distribution mapping.