The ecology of the tundra is defined by the range of species at all levels, forming food chain. Many of these species are highly specialised, and the relationship between microbes, fungi, plants and animals is often highly interdependent, with these populations reliant on each other and each other's biological and ecological behaviour. Reindeer, for example, are dependent on species of moss at various times of year. Predators at the top of the food chain like bears are therefore dependent on all the lower levels of the food chain operating at a certain level. The nature of the tundra environment means that species can become very vulnerable if any links in the food chain break down.
Examples of Tundra Food Chain: