ECOLOGY
Ecology and Ecosystems
Vocabulary:
Abiotic: the factors in the environment that are non-living, such as sunlight, temperature, rainfall and soil.
Biome: a large region defined by a particular climate and specific animal and plant communities. Examples of biomes
are: desert, forest, grassland, tundra, freshwater, and marine.
Biotic: the living factors of the environment.
Carnivore: a consumer that eats only animals. Carnivores are predators, such as lions, wolves and sharks.
Commensalism: a symbiotic relationship between two species in which one of them benefits and the other neither
benefits nor is harmed. An example of commensalism is the relationship between sharks and remoras. The remora
benefits and the shark is not affected either positively or negatively.
Community: all of the species that live together in the same habitat and interact with each other.
Consumer: an organism that gets its food by feeding on other organisms.
Decomposer: an organism that gets its food by breaking down dead organisms. Bacteria and fungi are
decomposers.
Ecosystem: a community of organisms and their abiotic (non-living) environment.
Food chain: the flow of energy that is transferred from one organism to another. Primary producers such as plants or
algae, which get their energy from the sun, are at the base of the food chain. They are eaten by herbivores, which are
eaten by carnivores. An example of a food chain is: grass eaten by an insect, which is eaten by a frog, which is eaten
by a snake, which is eaten by an owl. The owl is at the top of this food chain.
Food web: the feeding relationships between all of the members of an ecosystem.
Herbivore: a consumer that eats only plants; deer, sheep and rabbits are herbivores.
Mutualism: a symbiotic relationship between two species in which both of the organisms benefit. An example of
mutualism is the relationship between bees and flowers. The bees benefit by getting nectar, and the flowers benefit
by having their pollen transferred to other flowers.
Omnivore: a consumer that eats both plants and animals; bears, raccoons and chimpanzees are omnivores.
Parasitism: a symbiotic relationship between two species in which one benefits and the other is harmed. The
parasite takes nourishment from the host, and the host is harmed. Examples of parasitism are mistletoe (parasite)
growing on an oak tree (host), or a tick (parasite) living on a dog (host).
Population: a group of organisms of the same species living together in an ecosystem.
Predator: an animal that kills and eats other animals. Predators are carnivores, such as mountain lions, wolves and
sharks.
Prey: an animal that is killed and eaten by another animal. A rabbit (prey) is killed and eaten by a fox (predator).
Primary consumer: an animal that eats producers; primary consumers are herbivores.
Producer: an organism that converts energy in the environment, such as sunlight, into food. Producers include
plants, algae and some bacteria that are capable of photosynthesis.
Secondary consumer: an animal that eats primary consumers. Secondary consumers are carnivores. A coyote that
eats a rabbit is a secondary consumer. Secondary consumers are higher up the food chain than primary consumers.
Symbiosis: a relationship between two or more species; organisms in symbiotic relationships can benefit, be
harmed, or be unaffected by the relationship.
The Approximate 10% Rule