Ecology and Ecological Stress - Key terms


The buildup of toxic chemical pollutants in the tissues of individual organisms.


The living components of an ecosystem.


The increase inbioaccumulated 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.


A combination of all living things on Earth—plants, mammals, birds, reptiles, amphibians, aquatic 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 of the trees in a forest. In a closed-canopy forest, the canopy (which may be several hundredfeet, or well over 50 meters, high) protects the soil and lower areas from sun and torrential rainfall.


A meat-eating organism.


A theoretical notion intended to describe a biological community that has reached a stable point as a result of ongoing succession.


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 in to its constituent elements. On Earth, 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.


The study of the relationships 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 term describing the interaction of plants, herbivores, carnivores, omnivores, decomposers, and detritivores in an ecosystem. Each of these organisms consumes nutrients and passes them along to other organisms. Earth scientists typically prefer this name to foodchain, an everyday term for a similar phenomenon. A food chain is a series of singular organisms in which each plant or animal depends on the organism that precedes or follows it. Food chains rarely exist in nature.


The upper part of Earth's continental crust, or that portion of the solid earth on which human beings live and which provides them with most of their food and natural resources.


Warming of the lower atmosphere and surface of Earth. This occurs because of the absorption of long-wave length radiation from the planet's surface by certain radiatively active gases, such as carbon dioxide and watervapor, in the atmosphere. These gases are heated and ultimately re-radiate energy to space at an even longer wavelength.


A plant-eating organism.


The entirety of Earth's water, excluding water vapor in the atmosphere, but including all oceans, lakes, streams, groundwater, snow, and ice.


A term referring to the role that a particular organism plays within its biological community.


An organism that eats both plants and other animals.


At one time chemists used the term organic only in reference to living things. Now the word is applied to most compounds containing carbon, with the exception of carbonates (which are minerals) and oxides, such as carbon dioxide.


The progressive replacement of earlier biological communities with others over time.


Any set of interactions that can be set apart from the rest of the universe for the purposes of study, observation, and measurement.

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