Chapter 25

biome: the kind of biological community typically associated with a

particular physical environment; often named for its plant cover

tropical rain forest: the most complex of all biomes located near the

equator, where rainfall is abundant; harbors more species of plants and

animals than any other biome; light is the major limiting factor

savanna: a tropical grassland biome with scattered individual trees and large

herbivores; water is the major limiting factor

desert: biome characterized by a lack of precipitation and by extreme

temperature variation; may be hot or cold

perennial: a plant that lives for more than 2 years

succulent: a plant, such as a cactus, with thick, fleshy tissues that store

water

chaparral: a coastal scrubland biome of dense, spiny evergreen shrubs found

at midlatitudes; characterized by mild, rainy winters and long, hot, dry

summers

temperate grassland: a biome similar to savanna; characterized b y low

precipitation and lack of trees, except along steam course, such as the

prairies of North America

temperate deciduous forest: a biome characterized by enough precipitation to

support large trees that shed their leaves in the fall

taiga: the coniferous or northern forest biome characterized by considerable

snow, harsh winters, short summers, and evergreen trees

tundra: a biome at the northernmost limits of plant growth and at high

altitudes where plant forms are limited to low, shrubby, or matlike vegetation

phytoplankton: small, floating aquatic organisms, many microscopic, that

carry on photosynthesis

zooplankton: very small, floating or feebly swimming, heterotrophic aquatic

organisms, including some protists and small animals

photic zone: the shallow surface portion of the ocean where light penetrates

sufficiently for photosynthesis

aphotic zone: the part of the ocean beneath the photic zone; does not have

enough light for photosynthesis

intertidal zone: the area of the seashore between the water levels at high

tide and low tide

neritic zone: the shallow regions of the ocean overlying the continental shelf

oceanic zone: the region of water lying over deep areas beyond the

continental shelf

pelagic zone: the area of the ocean past the continental shelf; open water

often reaching to great depths

benthic zone: the bottom surface of the ocean

abyssal zone: the deepest portion of the ocean floor, where light does not

penetrate, temperatures are cold, and pressure is extreme

colonize: occupy a new habitat

exotic: describes a species that is not native to a given area but was either

intentionally transplanted from another region or introduced accidentally

primary succession: the process of colonization and species replacement on a

site that was previously uninhabited

secondary succession: the sequential replacement of species after a major

disruption in a community

annual: a plant that completes its life cycle in 1 year or growing season

climax community: a stable, self-penetrating community established by

succession and sequential development and considered semipermanent; persists

until interrupted or destroyed by environmental change

common pool resource: a resource that is shared by many people and is not

controlled by any one person

commons: a natural resource (such as a pasture, a forest, the ocean, or the

air) that is shared by many but controlled by no one person

free radical: a highly reactive molecular fragment that contains one or more

unpaired electrons

catalyst: a chemical that promotes a reaction between other chemicals by

reducing the energy required to activate the reaction; may take part in the

reaction but emerges in its original form

ozone hole: the reduction in the ozone layer over Antarctica; a layer of

molecules of ozone (O3) and oxygen about 17-25 kilometers above the Earth,

which absorbs lethal wavelengths of ultraviolet light