04 Glossary

Glossary	Ch01 Ch02 Ch03 Ch04 Ch05 Ch06 Ch07 Ch08 Ch09 Ch10 Ch11 Ch12 Ch13 Ch14
Chapter 4
alien species	See nonnative species.
animals	Eukaryotic, multicelled organisms usually capable of mobility and unable to produce their own food (heterotrophs), such as sponges, jellyfishes, arthropods (insects, shrimp, lobsters), mollusks (snails, clams, oysters, octopuses), fish, amphibians (frogs, toads, salamanders), reptiles (turtles, lizards, alligators, crocodiles, snakes), birds, and mammals (kangaroos, bats, cats, rabbits, elephants, whales, porpoises, monkeys, apes, humans). See carnivores, herbivores, omnivores.
climax community	See mature community.
commensalism	Interaction between organisms of different species in which one type of organism benefits and the other type is neither helped nor harmed to any great degree. Compare mutualism.
community development	See ecological succession.
competition	Two or more individual organisms of a single species (intraspecific competition) or two or more individuals of different species (interspecific competition) attempting to use the same scarce resources in the same ecosystem.
competitive exclusion principle	No two species can occupy exactly the same fundamental niche indefinitely in a habitat where there is not enough of a particular resource to meet the needs of both species. See ecological niche, fundamental niche, realized niche.
disturbance	A discrete event that disrupts an ecosystem or community. Examples of natural disturbances include fires, hurricanes, tornadoes, droughts, and floods. Examples of human-caused disturbances include deforestation, overgrazing, and plowing.
early successional plant species	Plant species found in the early stages of succession that (1) grow close to the ground, (2) can establish large populations quickly under harsh conditions, and (3) have short lives. Compare late successional plant species, midsuccessional plant species.
ecological succession	Process in which communities of plant and animal species in a particular area are replaced over time by a series of different and often more complex communities. See primary succession, secondary succession.
epiphyte	Plant that uses its roots to attach itself to branches high in trees, especially in tropical forests.
exotic species	See nonnative species.
exploitation competition	Situation in which two competing species have equal access to a specific resource but differ in how quickly or efficiently they exploit it. See interference competition, interspecific competition.
fungi	Eukaryotic, mostly multicellular organisms such as mushrooms, molds, and yeasts. As decomposers, they get the nutrients they need by secreting enzymes that speed up the breakdown of organic matter in the tissue of other living or dead organisms. Then they absorb the resulting nutrients.
high-throughput economy	Situation in most advanced industrialized countries, in which ever-increasing economic growth is sustained by maximizing the rate at which matter and energy resources are used, with little emphasis on pollution prevention, recycling, reuse, reduction of unnecessary waste, and other forms of resource conservation. Compare low-throughput economy, matter-recycling economy.
host	Plant or animal on which a parasite feeds.
immature community	Community at an early stage of ecological succession. It usually has a low number of species and ecological niches and cannot capture and use energy and cycle critical nutrients as efficiently as more complex, mature communities. Compare mature community.
immigrant species	See nonnative species.
indicator species	Species that serve as early warnings that a community or ecosystem is being degraded. Compare keystone species, native species, nonnative species.
interference competition	Situation in which one species limits access of another species to a resource, regardless of whether the resource is abundant or scarce. See exploitation competition, interspecific competition.
interspecific competition	Members of two or more species trying to use the same limited resources in an ecosystem. See competition, competitive exclusion principle, intraspecific competition.
intraspecific competition	Two or more organisms of a single species trying to use the same limited resources in an ecosystem. See competition, interspecific competition.
keystone species	Species that play roles affecting many other organisms in an ecosystem. Compare indicator species, native species, nonnative species.
late successional plant species	Mostly trees that can tolerate shade and form a fairly stable complex forest community. Compare early successional plant species, midsuccessional plant species.
low-throughput economy	Economy based on working with nature by (1) recycling and reusing discarded matter, (2) preventing pollution, (3) conserving matter and energy resources by reducing unnecessary waste and use, (4) not degrading renewable resources, (5) building things that are easy to recycle, reuse, and repair, (6) not allowing population size to exceed the carrying capacity of the environment, and (7) preserving biodiversity. See environmental worldview. Compare high-throughput economy, matter-recycling economy.
matter-recycling economy	Economy that emphasizes recycling the maximum amount of all resources that can be recycled. The goal is to allow economic growth to continue without depleting matter resources and without producing excessive pollution and environmental degradation. Compare high-throughput economy, low-throughput economy.
mature community	Fairly stable, self-sustaining community in an advanced stage of ecological succession; usually has a diverse array of species and ecological niches; captures and uses energy and cycles critical chemicals more efficiently than simpler, immature communities. Compare immature community.
midsuccessional plant species	Grasses and low shrubs that are less hardy than early successional plant species. Compare early successional plant species, late successional plant species.
mutualism	Type of species interaction in which both participating species generally benefit. Compare commensalism.
native species	Species that normally live and thrive in a particular ecosystem. Compare indicator species, keystone species, nonnative species.
nonnative species	Species that migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem by humans. Compare native species.
parasite	Consumer organism that lives on or in and feeds on a living plant or animal, known as the host, over an extended period of time. The parasite draws nourishment from and gradually weakens its host; it may or may not kill the host. See parasitism.
parasitism	Interaction between species in which one organism, called the parasite, preys on another organism, called the host, by living on or in the host. See host, parasite.
persistent pollutant	See slowly degradable pollutant.
pioneer community	First integrated set of plants, animals, and decomposers found in an area undergoing primary ecological succession. See immature community, mature community.
pioneer species	First hardy species, often microbes, mosses, and lichens that begin colonizing a site as the first stage of ecological succession. See ecological succession, pioneer community.
plants (plantae)	Eukaryotic, mostly multicellular organisms such as algae (red, blue, and green), mosses, ferns, flowers, cacti, grasses, beans, wheat, rice, and trees. These organisms use photosynthesis to produce organic nutrients for themselves and for other organisms feeding on them. Water and other inorganic nutrients are obtained from the soil for terrestrial plants and from the water for aquatic plants.
precautionary principle	When there is scientific uncertainty about potentially serious harm from chemicals or technologies, decision makers should act to prevent harm to humans and the environment. See pollution prevention.
predation	Situation in which an organism of one species (the predator) captures and feeds on parts or all of an organism of another species (the prey).
predator	Organism that captures and feeds on parts or all of an organism of another species (the prey).
predator-prey relationship	Interaction between two organisms of different species in which one organism, called the predator, captures and feeds on parts or all of another organism, called the prey.
prey	Organism that is captured and serves as a source of food for an organism of another species (the predator).
primary succession	Ecological succession in a bare area that has never been occupied by a community of organisms. See ecological succession. Compare secondary succession.
prokaryotic cell	Cell that does not have a distinct nucleus. Other internal parts are also not enclosed by membranes. Compare eukaryotic cell.
protists (protista)	Eukaryotic, mostly single-celled organisms such as diatoms, amoebas, some algae (golden brown and yellow-green), protozoans, and slime molds. Some protists produce their own organic nutrients through photosynthesis. Others are decomposers and some feed on bacteria, other protists, or cells of multicellular organisms.
r-selected species	Species that reproduce early in their life span and produce large numbers of usually small and short-lived offspring in a short period of time. Compare K-selected species.
r-strategists	See r-selected species.
resource partitioning	Process of dividing up resources in an ecosystem so species with similar needs (overlapping ecological niches) use the same scarce resources at different times, in different ways, or in different places. See ecological niche, fundamental niche, realized niche.
secondary succession	Ecological succession in an area in which natural vegetation has been removed or destroyed but the soil is not destroyed. See ecological succession. Compare primary succession.
succession	See ecological succession, primary succession, secondary succession.
symbiosis	Any intimate relationship or association between members of two or more species. See symbiotic relationship.
symbiotic relationship	Species interaction in which two kinds of organisms live together in an intimate association. Members of the participating species may be harmed by, benefit from, or be unaffected by the interaction. See commensalism, interspecific competition, mutualism, parasitism, predation.