barrier islands
	Low, narrow, sandy islands that form offshore from a coastline.
benthos
	The bottom of a sea or lake.
biome
	A broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.
bog
	An area of waterlogged soil that tends to be peaty; fed mainly by precipitation; low productivity; some bogs are acidic.
boreal forest
	A broad band of mixed coniferous and deciduous trees that stretches across northern North America (and also Europe and Asia); its northernmost edge, the taiga, intergrades with the arctic tundra.
cloud forests
	High mountain forests where temperatures are uniformly cool and fog or mist keeps vegetation wet all the time.
conifers
	Needle-bearing trees that produce seeds in cones.
coral reefs
	Prominent oceanic features composed of hard, limy skeletons produced by coral animals; usually formed along edges of shallow, submerged ocean banks or along shelves in warm shallow tropical seas.
deciduous
	Trees and shrubs that shed their leaves at the end of the growing season.
delta
	Fan-shaped sediment deposit found at the mouth of a river.
desert
	A type of biome characterized by low moisture levels and infrequent and unpredictable precipitation. Daily and seasonal temperatures fluctuate widely.
ecosystem management
	An integration of ecological, economic, and social goals in a unified systems approach to resource management.
estuary
	A bay or drowned valley where a river empties into the sea.
fen
	An area of waterlogged soil that tends to be peaty; fed mainly by upwelling water; low productivity.
freshwater ecosystems
	Ecosystems in which the fresh (nonsalty) water of streams, rivers, ponds, or lakes plays a defining role.
grasslands
	A biome dominated by grasses and associated herbaceous plants.
landscape ecology
	The study of the reciprocal effects of spatial pattern on ecological processes. A study of the ways in which landscape history shapes the features of the land and the organisms that inhabit it as well as our reaction to, and interpretation of, the land.
marsh
	Wetland without trees; in North America, this type of land is characterized by cattails and rushes.
mitigation
	Repairing or rehabilitating a damaged ecosystem or compensating for damage by providing a substitute or replacement area.
reclamation
	Chemical, biological, or physical  clean-up and reconstruction of severely contaminated or degraded sites to return them to something like their original topography and vegetation.
re-creation
	Construction of an entirely new biological community to replace one that has been destroyed on that or another site.
rehabilitation
	To rebuild elements of structure or function in an ecological system without necessarily achieving complete restoration to its original condition.
remediation
	Cleaning up chemical contaminants from a polluted area.
restoration
	To bring something back to a former condition. Ecological restoration involves active manipulation of nature to re-create conditions that existed before human disturbance.
restoration ecology
	Seeks to repair or reconstruct ecosystems damaged by human actions.
swamp
	Wetland with trees, such as the extensive swamp forests of the southern United States.
taiga
	The northernmost edge of the boreal forest, including species-poor woodland and peat deposits; intergrading with the arctic tundra.
temperate rainforest
	The cool, dense, rainy forest of the northern Pacific coast; enshrouded in fog much of the time; dominated by large conifers.
thermocline
	In water, a distinctive temperature transition zone that separates an upper layer that is mixed by the wind (the epilimnion) and a colder, deep layer that is not mixed (the hypolimnion).
tropical rainforests
	Forests in which rainfall is abundant--more than 200 cm (80 in) per year--and temperatures are warm to hot year round.
tropical seasonal forest
	Semievergreen or partly deciduous forests tending toward open woodlands and grassy savannas dotted with scattered, drought-resistant tree species; distinct wet and dry seasons, hot year round.
tundra
	Treeless arctic or alpine biome characterized by cold, harsh winters, a short growing season, and potential for frost any month of the year; vegetation includes low-growing perennial plants, mosses, and lichens.
wetlands
	Ecosystems of several types in which rooted vegetation is surrounded by standing water during part of the year. See also swamp, marsh, bog, fen.

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