Rehulisänä

Rehulisänä is a term of Estonian origin that translates to "reindeer lichen" in English. It specifically refers to Cladonia rangiferina, a species of lichen known for its distinctive shrubby, pale grey-green appearance. This lichen is a crucial food source for reindeer and other caribou populations, particularly during the winter months when other vegetation is scarce. Its ability to grow in harsh, cold climates, often on rocky or sandy terrain and in boreal and arctic regions, makes it a vital component of these ecosystems.

The ecological significance of rehulisänä extends beyond its role as a food source. As a lichen, it plays a part in soil formation and nutrient cycling. Its growth can help to break down rock over long periods, contributing to the development of soil. Furthermore, its presence indicates the health of the environment, as lichens are sensitive to air pollution and can therefore serve as bioindicators. While primarily known for its role in the Arctic food web, Cladonia rangiferina has also been used historically by humans for various purposes, including as a primitive stuffing material or even as a source of a dye. Its widespread distribution across the Northern Hemisphere underscores its importance in cold-climate biomes.