Chapter 6: Ecosystems and Ecosystem Management

194659298	autotrophs	organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer
194659299	community-level interactions	when the interaction between two species leads to changes in the prescenes or absence of other species or in a large change in abundance of other species, then a community effect is said to have occurred
194659300	decomposers	organisms such as bacteria and fungi, that break down wastes and dead organisms and return raw materials to the environment
194659301	ecological community	(1) A conceptual or functional meaning: a set of interacting species that occur in the same place (sometimes extended to mean a set that interacts in a way to sustain life), (2) An operational meaning: a set of species found in an area, whether or not they are interacting
194659302	food chain	the pathway of energy transfer through various stages as a result of the feeding patterns of a series of organisms; a linkage of who feeds on whom
194659303	food web	network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem; a series of interconnected food chains in an ecosystem
194659304	keystone species	a species that is critical to the functioning of the ecosystem in which it lives because it affects the survival and abundance of many other species in its community
194659305	succession	the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established; the process of establishment and development of an ecosystem
194659306	trophic level	all organisms that are the same number of energy transfers away from the original source of energy (for example, sunlight) that enters an ecosystem. For example, all producers belong to the first trophic level, and all herbivores belong to the second trophic level in a food chain or a food web
194659307	watershed	an area of land that forms the drainage of a stream or river