A measure of the degree to which an ecosystem possesses large numbers of particular species. An abundant ecosystem may or may not have a wide array of different species. Compare with complexity.
Energy derived from biological sources that are used directly as fuel (as opposed to food, which becomes fuel). Examples of bioenergy include wood or manure that can be burned. Usually, petrochemicals, such as petroleum or natural gas, though they are derived from the bodies of dead organisms, are treated separately from forms of bioenergy.
The living components of an ecosystem.
The increase in bioaccumulated contamination at higher levels of the food web. Biomagnification results from the fact that larger organisms consume larger quantities of food—and, hence, in the case of polluted materials, more toxins.
Materials that are burned or processed to produce bioenergy.
A large ecosystem, characterized by its dominant life-forms.
A combination of all living things on Earth—plants, animals, birds, marine life, insects, viruses, single-cell organisms, and so on—as well as all formerly living things that have not yet decomposed.
A combination of all flora and fauna (plant and animal life, respectively) in a region.
The upper portion or layer of the trees in a forest. A forest with a closed canopy is one so dense with vegetation that the sky is not visible from the ground.
A meat-eating organism, or an organism that eats only meat (as distinguished from an omnivore).
A theoretical notion intended to describe a biological community that has reached a stable point as a result of ongoing succession.
The range of ecological niches within a biological community. The degree of complexity is the number of different species that theoretically could exist in a given biota, as opposed to its diversity, or actual range of existing species.
Organisms that obtain their energy from the chemical breakdown of dead organisms as well as from animal and plant waste products. The principal forms of decomposer are bacteria and fungi.
A chemical reaction in which a compound is broken down into simpler compounds, or into its constituent elements. In the biosphere, this often is achieved through the help of detritivores and decomposers.
Organisms that feed on waste matter, breaking organic material down into inorganic substances that then can become available to the biosphere in the form of nutrients for plants. Their function is similar to that of decomposers; however, unlike decomposers—which tend to be bacteria or fungi—detritivores are relatively complex organisms, such as earthworms or maggots.
A measure of the number of different species within a biological community.
The study of the relation ships between organisms and their environments.
A community of interdependent organisms along with the inorganic components of their environment.
The flow of energy between organisms in a food web.
A plant-eating organism.
A plant or animal that, by its presence, abundance, or chemical composition, demonstrates a particular aspect of the character or quali ty of the environment.
The process whereby some organisms thrive and others perish, depending on their degree of adaptation to a particular environment.
A term referring to the role that a particular organism plays within its biological community.
An organism that eats both plants and other animals.
A disease-carrying parasite, usually a microorganism.
The biological conversion of light energy (that is, electro magnetic energy) from the Sun to chemical energy in plants.
Green plants that depend on photosynthesis for their nourishment.
The amount of bio-mass produced by green plants in a given biome.
The progressive replacement of earlier biological communities with others over time.
Various stages within a food web. For instance, plants are on one trophic level, herbivores on another, and so on.
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