Lichens!

Lichens are key ecological components of the Adirondack forrest and serve as perfect examples of true symbiosis. They form a unique niche in the web of life and play a fundamental role in forrest ecology. Found extreme environments like the tundra and within rocks, lichens are adapted to rely on very few nutrients while creating so much for the environment.

Lichen aren't actually one single organism, but rather the combination of two. Being half alga, half fungus, the lichen survives as the two cell types work together. The alga provides photosynthate and the fungus provides structural and nutritional support. With this codependence comes less dependance on the surrounding environment. As a result, lichens are found in very remote places with little surrounding nutrients. Rather, the alga are able to fixate nitrogen through structures known as heterocysts. Their ancestor even invented the process of photosynthesis. Although they are found in the most remote and random places, lichen are very specific to their environment. Moving one from one place to another will kill off the lichen.

Ecologically, they support the ecosystem with their supply of nitrogen and basic sugars as autotrophs like plants do. Lichens are eaten by anything the size of an insect to the size of a moose. These lichen are, however, very sensitive to pollution and poor air quality. Researchers can tell the health of a forrest by the quantity and quality of lichen growing.


http://www.adirondackalmanack.com/2016/02/lichens-not-technically-a-plant.html

http://www.ucmp.berkeley.edu/fungi/lichens/lichenlh.html

Marchand book p. 120