Symbiosis
Fungi next to a tree in a coniferous forest.
Symbiosis is the relationship between organisms, typically where both benefit. Fungi, in a coniferous forest, colonizes trees roots. The fungi produce minerals that are helpful to the tree, and the tree produces food, like carbohydrates helpful to the fungi. Another example of symbiosis is when the Western Tananger bird lives in a tree, but does not harm the tree.
Mutualism
Lichen Growing on a rock
Mutualism is a relationship in which one or both organisms benefit from the relationship. Lichens are a combination of algae and fungi that form a mutualistic relationship beneficial to both of them. The fungi provides structure, water, sun protection, and mineral nutrients to the algae. The algae makes food for the fungi through photosynthesis. Another example of mutualism in the coniferous forest is the relationship between the Clark's Nutcracker bird, and the Whitebark Pine. The Clark's Nutcracker collects seeds for food from the pine, and disperses the seeds by storing them in the ground for the winter. The Whitebark Pine has wingless seeds that have no way of dispersing, but is able to spread its seeds with the help of the Clark's Nutcracker. The Clack's Nutcracker gains food and the Whitebark Pine is able to spread and grow new trees.
Commensalism
Great Grey Owl perched in a conifer.
Commensalism is a relationship in which one organism benefits from the other, and the other organism is not harmed. Great Grey Owls live in trees in coniferous forests. The owl has a home in the tree, and the tree is not harmed. Hemlock trees need shade from the sun, and will not thrive if they are in too much sunlight. Douglas Fir are tall, and provide shade for the Hemlocks, the Hemlocks thrive, but do not affect the Douglas Fir.
Parasitism
A deer in a coniferous forest, that may have a tick living on it.
Parasitism is when one organism lives in or on another, and is harmful. For example, in a coniferous forest, when a tick lives on a deer, the tick harms the deer by sucking its blood, and sometimes causing disease. Parasitism can happen among plants, also. Mistletoe lives on trees and can kill the tree by taking the tree's water and nutrients.
Predation
A wolf hunting an elk. Conifers can be seen in the background.
Predation is a relationship between organisms where one eats the other. For example, when a bobcat hunts rabbits for food. This picture shows a wolf chasing an elk, an animal the wolf eats. There are many examples of predation in a coniferous forest.
Competition
Two bears fighting, maybe for that fishing area
Competition is the fight between two organisms for resources. This could be two bears that both fish in one area and fight for the territory. Another example is a group of deer and a group of elk who both want to graze in a small field. Trees often compete for sunlight and water.