jäkälälle

Jäkälälle is a term used in Finnish to refer to lichen. Lichens are a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi in a symbiotic relationship. The fungus benefits from the sugars produced by the algae or cyanobacteria through photosynthesis. In return, the fungus provides the alga or cyanobacteria with protection from light, dehydration, and other environmental factors.

Lichens are remarkably resilient organisms, capable of growing in extreme environments such as deserts, arctic tundra, and on bare rock. They play a crucial role in ecosystems, acting as pioneer species that colonize barren land and contributing to soil formation. They also serve as a food source for various animals, including reindeer, caribou, and insects.

In Finland, lichens are a common sight, found on trees, rocks, and the ground. Certain species, like reindeer moss (Cladonia rangiferina), are particularly important for the survival of reindeer populations in the northern parts of the country. Historically, lichens have also been used by humans for various purposes, including dyes, medicines, and even as a food source in times of scarcity. The study of lichens is known as lichenology. Their slow growth rate and sensitivity to air pollution make them valuable bioindicators of environmental quality.