Mutualism: A relationship between two organisms in which they both benefit. An example of a mutual relationship or mutualism in the taiga is a lichen and a tree. The lichen gets nutrients from the dead matter from the tree and the tree gets nutrients from the lichen.
Parasitism: The relationship between a parasite and a host in which the parasite gets benefited, and the host gets hurt. An example of this would be a winter tick and a moose. The winter tick gets benefit from it because they get food and a place to stay, but the moose gets no benefit from it and gets hurt.