Vocabulary Vocabulary ReviewReview

Ch 21Ch 21

EcosystemsEcosystems

A large region characterized by a

specific type of climate and

certain types of plant and animal

communitiesBiome

A treeless plain that is located in the Arctic or Antarctic and that is

characterized by very low winter temperatures;

short, cool summers; and vegetation that consists of grasses, lichens, and

perennial herbs

Tundra

In arctic regions, the permanently

frozen layer of soil or subsoil

Permafrost

A region of forest or jungle that is located near the equator and that is characterized by large amounts of

rain and little variation in temperature

Tropical Forest

The layers of treetops that

shade the forest floor

Canopy

A plant that uses another plant for support, but not for nourishment

Epiphyte

A tree belonging to a group of tree species that bear

their seeds in cones and tend to

be evergreen

Coniferous Tree

A tree that sheds and regrows its

leaves in response to seasonal

changes

Deciduous Tree

A region of forest that has pronounced seasons, moderate temperatures,

and moderate precipitation;

characterized by trees that shed their leaves in

the fall

Temperate deciduous

forest

A plain full of grasses and scattered trees and shrubs; found in

tropical and subtropical habitats

and mainly in regions with a dry climate, such as East Africa

Savanna

A type of vegetation that includes broad-

leafed evergreen shrubs and that is

located in areas with hot, dry summers and

mild, wet winters

Chaparral

A region that has little or no vegetation, long periods without rain,

and extreme temperatures; usually

found in warm climates

Desert

The deeper parts of the ocean,

where there is so little light that plants cannot

carry out photosynthesisAphotic zone

The area of an aquatic system that receives

enough light for photosynthesis to

occur

Photic zone

An area along ocean shorelines that lies between

low and high water lines

Intertidal zone

A shallow marine environment that is

near the shore or over the continental shelf

and that is rich in minerals and nutrients

produced by biotic activity

Neritic zone

The regions of the open sea that lie

beyond and between the continental

shelves

Oceanic zone

The upper, central, or open region of a

body of water

Pelagic zone

The bottom region of oceans and bodies of fresh

water

Benthic zone

The mass of mostly microscopic

organisms that float or drift freely in the waters of aquatic (freshwater and

marine) environmentsPlankton

An area where fresh water from rivers mixes with salt water from the

ocean; the part of a river where the tides

meet the river currentEstuary

A lake that contains a large

amount of decaying organic matter and lacks

oxygen as a result

Eutrophic lake

A lake that lacks organic nutrients and, as a result,

contains high levels of dissolved oxygen in its lower

layerOligotrophic

lake

An area of land that is covered in fresh water for at least part of each

year

Freshwater wetland