Ecology
Vocabulary:
Ecology - The study of how organisms fit into their environment.
Community - The organisms which live in a particular environment.
Habitat - Physical location of a community
Ecosystem - Self-sustaining collection of organisms & their physical environment.
Diversity - a measurement of the number of organisms inhabiting an ecosystem
Energy in ecosystems:
Life in any ecosystem is driven by the flow of energy.
All energy entering the earth's Biome is from the sun.
Living things are divided into 3 major categories based on how they obtain their energy
Producers - Obtain energy from their surroundings (eg.light)
Consumers - Obtain energy from consuming other organisms
Decomposers - Obtain energy from consuming wastes.
Energy in an ecosystem always flows from producers to consumers
Organisms are assigned "trophic levels" according to how many "steps" they are away from the source of their energy.
Autotrophs (like plants) occupy the first level since they obtain their energy directly from the source
Herbivores occupy the second level, since they obtain their energy from eating the autotrophs.
Carnivores occupy all higher levels, since they obtain energy from eating herbivores (and other carnivores)
Omnivores can occupy more than one trophic level since they can eat all of the above.
Note: All organisms above the the first trophic level are known as heterotrophs since they cannot make their own food, but must obtain it by consuming other organisms.