Lichen are plants and fungus that create a mutualistic relationship greater than the sum of their parts. What can we learn from them?  |
| Common Greenshield Lichen. Flavoparmelia Caperata. Photo by Amy Coffman Phillips |
Natural History
How does the lichen fit into this forest?
Walking through the forest for my first iSite in the Harvard Forest, I came upon this beautiful lichen growing on a red maple tree. Up close, it looks like flattened lettuce or cabbage growing in these romantic formations, an example of a foliose (leaf like) lichen. And lichen is unique because it is not one organism, but a symbiotic relationship between two organisms: fungi and algae. To form a lichen, the fungus either encloses the algae in fungal tissue or penetrates the algal cell wall in order to harness their photosynthetic abilities. The fungi form the structure and then recruit algae to come live with them, and the algae benefits from the protection the fungi provide as well as their ability to capture water and nutrients. The mutualistic relationship between these two organisms (although sometimes commensalistic or even parasitic depending on the species) is greater than the sum of its parts because it allows both organisms to survive and thrive in areas they would not be able to alone. Their relationship creates benefits for the ecosystem as a whole as well because as rain water falls down the bark of a tree, it gathers nutrients from the lichen which feeds nitrogen and other nutrients to the soil, and then by extension, the tree and other plants.
How does the lichen fit into this forest?
Walking through the forest for my first iSite in the Harvard Forest, I came upon this beautiful lichen growing on a red maple tree. Up close, it looks like flattened lettuce or cabbage growing in these romantic formations, an example of a foliose (leaf like) lichen. And lichen is unique because it is not one organism, but a symbiotic relationship between two organisms: fungi and algae. To form a lichen, the fungus either encloses the algae in fungal tissue or penetrates the algal cell wall in order to harness their photosynthetic abilities. The fungi form the structure and then recruit algae to come live with them, and the algae benefits from the protection the fungi provide as well as their ability to capture water and nutrients. The mutualistic relationship between these two organisms (although sometimes commensalistic or even parasitic depending on the species) is greater than the sum of its parts because it allows both organisms to survive and thrive in areas they would not be able to alone. Their relationship creates benefits for the ecosystem as a whole as well because as rain water falls down the bark of a tree, it gathers nutrients from the lichen which feeds nitrogen and other nutrients to the soil, and then by extension, the tree and other plants.
