Ecology Ecology is the study of the relationships among living and nonliving parts of an area. Tools A B ecosystem all the living and nonliving parts in an area habitat place where a species lives niche the role of a species in an ecosystem population all of the members of one species that live in the same area community all the populations living tigether in one area photosynthesis the process by which plants use sunlight to make sugar from water and carbon dioxide producer an organism that uses sunlight to make sugar from water and carbon dioxide consumer an organism that consumes other organisms for food herbivore consumer that eats only plants omnivore consumer that eats plants and animals scavenger an animal that feeds on the bodies of recently dead organisms decomposer an organism that hepls to break down and decay dead organisms and the wastes of living organisms carnivore consumer that eats only meat energy pyramid a diagram that compares the amount of energy available at each position in the feeding order food web a combination of all the food chains in a community water cycle water cycles through the living and nonliving parts of an ecosystem