Chapter 20, Problem 34A

Summary Introduction

To write:Role of lichens in the artic environments.

Introduction:Lichen is regarded as a symbiotic relationship between an alga or a photosynthetic partner and the fungi. Typically the fungus is an ascomycete but basidiomycetes may also be present in lichens. The photosynthetic partner is either a green algae or a cyanobacterium that provides food to all species.

Explanation of Solution

Lichens can be found in tropics, most of these organisms grow in arctic or temperate areas. They form the tundraprimary ground cover, providing food for the animals to be grazed. Caribou use an enzyme known as lichenase to help them digest lichen.

Conclusion

The pioneer species is a species that can grow on rocks or with little soil. Lichens are often the pioneer species following natural disasters, such as fire or volcanic activity in an area of newly cleared soil or rock.