Ecosystems and Communities

The mistletoe plant is a parasite that buries its roots in the trunk of its host plant

Ecologists study the roles and interactions of organisms at many different levels in the environment. Ranging from the individual organism up to regional biomes, these levels help scientists identify how energy and resources are distributed through a system. In this topic, you explored each of these levels. In addition, you examined the long-term, close relationships that some organisms share. These symbiotic relationships can benefit both partners, harm a partner, or have a positive impact on one partner.