Ap Enviro Ch 08

Front 1

alien species

Back 1

See nonnative species.

Front 2

annual

Back 2

Plant that grows, sets seed, and dies in one growing season. Compare perennial.

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carnivore

Back 3

Animal that feeds on other animals. Compare herbivore, omnivore.

Front 4

climax community

Back 4

See mature community.

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commensalism

Back 5

An 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.

Front 6

competitive exclusion principle

Back 6

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.

Front 7

complexity

Back 7

In ecological terms, refers to the number of species in a community at each trophic level and the number of trophic levels in a community.

Front 8

constancy

Back 8

Ability of a living system, such as a population, to maintain a certain size. Compare inertia, resilience. See homeostasis.

Front 9

disturbance

Back 9

A discrete event that disrupts an ecosystem or community. Examples of natural disturbances include fires, hurricanes, tornadoes, droughts, and floods. Examples of human-caused disturbancesinclude deforestation, overgrazing, and plowing.

Front 10

early successional plant species

Back 10

Plant species found in the early stages of succession that grow close to the ground, can establish large populations quickly under harsh conditions, and have short lives. Compare late successional plant species, midsuccessional plant species.

Front 11

ecological succession

Back 11

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.

Front 12

epiphyte

Back 12

Plant that uses its roots to attach itself to branches high in trees, especially in tropical forests.

Front 13

exotic species

Back 13

See nonnative species.

Front 14

exploitation competition

Back 14

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.

Front 15

habitat fragmentation

Back 15

Breakup of a habitat into smaller pieces, usually as a result of human activities.

Front 16

herbivore

Back 16

Plant-eating organism. Examples are deer, sheep, grasshoppers, and zooplankton. Compare carnivore, omnivore.

Front 17

homeostasis

Back 17

Maintenance of favorable internal conditions in a system despite fluctuations in external conditions. See constancy, inertia, resilience.

Front 18

host

Back 18

Plant or animal on which a parasite feeds.

Front 19

immature community

Back 19

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.

Front 20

immigrant species

Back 20

See nonnative species.

Front 21

indicator species

Back 21

Species that serve as early warnings that a community or ecosystem is being degraded. Compare keystone species, native species, nonnative species.

Front 22

inertia

Back 22

Ability of a living system to resist being disturbed or altered. Compare constancy, resilience.

Front 23

interference competition

Back 23

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.

Front 24

interspecific competition

Back 24

Attempts by members of two or more species to use the same limited resources in an ecosystem. See competition, competitive exclusion principle, intraspecific competition.

Front 25

intraspecific competition

Back 25

Attempts by two or more organisms of a single species to use the same limited resources in an ecosystem. See competition, interspecific competition.

Front 26

keystone species

Back 26

Species that play roles affecting many other organisms in an ecosystem. Compare indicator species, native species, nonnative species.

Front 27

late successional plant species

Back 27

Mostly trees that can tolerate shade and form a fairly stable complex forest community. Compare early successional plant species, midsuccessional plant species.

Front 28

mature community

Back 28

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.

Front 29

midsuccessional plant species

Back 29

Grasses and low shrubs that are less hardy than early successional plant species. Compare early successional plant species, late successional plant species.

Front 30

mutualism

Back 30

Type of species interaction in which both participating species generally benefit. Compare commensalism.

Front 31

native species

Back 31

Species that normally live and thrive in a particular ecosystem. Compare indicator species, keystone species, nonnative species.

Front 32

nonnative species

Back 32

Species that migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem by humans. Compare native species.

Front 33

omnivore

Back 33

Animal that can use both plants and other animals as food sources. Examples are pigs, rats, cockroaches, and people. Compare carnivore, herbivore.

Front 34

parasite

Back 34

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.

Front 35

parasitism

Back 35

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.

Front 36

perennial

Back 36

Plant that can live for more than 2 years. Compare annual.

Front 37

persistence

Back 37

How long a pollutant stays in the air, water, soil, or body. See also inertia.

Front 38

pioneer community

Back 38

First integrated set of plants, animals, and decomposers found in an area undergoing primary ecological succession. See immature community, mature community.

Front 39

pioneer species

Back 39

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.

Front 40

predation

Back 40

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).

Front 41

predator

Back 41

Organism that captures and feeds on parts or all of an organism of another species (the prey).

Front 42

predator&endash;prey relationship

Back 42

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.

Front 43

prey

Back 43

Organism that is captured and serves as a source of food for an organism of another species (the predator).

Front 44

primary succession

Back 44

Ecological succession in a bare area that has never been occupied by a community of organisms. See ecological succession. Compare secondary succession.

Front 45

resilience

Back 45

Ability of a living system to restore itself to original condition after being exposed to an outside disturbance that is not too drastic. See constancy, inertia.

Front 46

resource partitioning

Back 46

Process of dividing up resources in an ecosystem so that 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.

Front 47

secondary consumer

Back 47

Organism that feeds only on primary consumers. Compare detritivore, omnivore, primary consumer.

Front 48

secondary succession

Back 48

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.

Front 49

species equilibrium model

Back 49

See theory of island biogeography.

Front 50

stability

Back 50

Ability of a living system to withstand or recover from externally imposed changes or stresses. See constancy, inertia, resilience.

Front 51

succession

Back 51

See ecological succession, primary succession, secondary succession.

Front 52

symbiosis

Back 52

Any intimate relationship or association between members of two or more species. See symbiotic relationship.

Front 53

symbiotic relationship

Back 53

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.

Front 54

territoriality

Back 54

Process in which organisms patrol or mark an area around their home, nesting, or major feeding site and defend it against members of their own species.

Front 55

theory of island biogeography

Back 55

The number of species found on an island is determined by a balance between two factors: the immigration rate (of species new to the island) from other inhabited areas and the extinction rate(of species established on the island). The model predicts that at some point the rates of immigration and extinction will reach an equilibrium point that determines the island's average number of different species (species diversity).