A type of plant that produces flowers during sexual reproduc tion.
Earth's atmosphere is a blanket of gases that includes nitrogen (78%), oxygen (21%), argon (0.93%), and a combination of water vapor, carbon dioxide, ozone, and noble gases such as neon (0.07%). Most of these gases are con tained in the troposphere, the lowest layer, which extends to about 10 mi. (16 km) above the planet's surface.
The degree of variety among the species represented in a partic ular ecosystem.
The living components of an ecosystem.
The upper portion or layer of the trees in a forest. A forest with a closed canopy is one so dense with vegeta tion 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 substance made up of atoms, chemically bonded to one another, of more than one chemical element.
A type of tree that produces cones bearing seeds.
A term for a tree or other form of vegetation that sheds its leaves seasonally.
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 earth system, this often is achieved through the help of detritivores and decomposers.
A term for any interruption in the ordinary progression of a forest's life.
Organisms that feed on waste matter, breaking down organic material 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 relation ships between organisms and their environments.
A community of inter dependent organisms along with the in organic components of their environment.
A substance made up of only one kind of atom. Unlike compounds, elements cannot be broken chemically into other substances.
The ability of an object (or in some cases a non object, such as a mag netic force field) to accomplish work.
The total amount of energy available to a system or, more specifically, the difference between the energy flowing into the system and the energy lost by it.
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 them consumes nutrients and passes it along to other organisms. Earth scientists typically prefer this name to food chain, 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 it. Food chains rarely exist in nature.
In general terms, a forest is simply any ecosystem dominated by tree-size woody plants. A number of other characteristics and parameters (for example, weather, altitude, and dominant species) further define types of forests, such as tropical rain forests.
Warming of the lower atmosphere and surface of Earth. This occurs because of the absorp tion of long-wave length radiation from the planet's surface by certain radiatively active gases, such as carbon dioxide and water vapor, in the atmosphere. These gases are heated and ultimately re-radiate energy at an even longer wavelength to space. (Wave-length and energy levels are related inverse ly; hence, the longer the wavelength, the less the energy.)
A type of plant that reproduces sexually through the use of seeds that are exposed, not hidden in an ovary as with an angiosperm.
A plant-eating organism.
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 biological conversion of light energy (that is, electro magnetic energy) from the Sun to chemical energy in plants.
Any set of interactions that can be set apart mentally from the rest of the universe for the purposes of study, observation, and measurement.
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