GLOSSARY OF TERMS 316
cuesta: a hill or ridge with a steep face on one side and a gentle slope on the other.
ecoregion: relatively large unit of land delineated by large-scale abiotic and biotic factors that broadly
shape the structure and function of biological communities within them.
endangered species: a species or subspecies in danger of extinction throughout all or a significant
portion of its range, as rated and listed by the USFWS.
endemic (endemism): species restricted to a particular geographic area; usually a single drainage, or an
ecological section.
estuarine: of or relating to an estuary, which is an inlet or arm of the sea, especially the lower portion or
wide mouth of a river where salty tide meets freshwater current.
exotic species: (also commonly called alien, non-indigenous, or non-native): a species occurring outside
of its native range.
extant: still living or present.
extirpation: elimination of a species in part of its range.
floodplain: low, relatively flat land adjoining inland and/or coastal waters, which is subject to periodic
flooding.
forb: non-grassy, herbaceous plants, other than grass, sedge or rush.
forest: an assemblage of woody vegetation typically attaining positions in a plant community at the
tallest level; attains height and diameter growth of canopy-layer trees within established averages for the
species.
fragmentation: the process by which a landscape is broken into small islands of forest within a mosaic
of other forms of land use or ownership
fresh-water: water that contains less than 1,000 milligrams per liter (mg/L) of dissolved solids.
geomorphology: a science that deals with the land and submarine relief features of the earth's surface
and seeks a genetic interpretation of them; physiography.
graminoids: grasses and grass-like plants such as sedges and rushes.
habitat: the specific place(s) where a particular plant or animal lives
hydric soil: a soil that is saturated, flooded, or ponded long enough during the growing season to
develop anaerobic (oxygen-lacking) conditions that favor the growth and regeneration of hydrophytic
vegetation.
hydrology: the science dealing with the study of water on the surface of the land, in soil and underlying
rocks and in the atmosphere.
impoundments: human-engineered and dammed lakes, ponds and reservoirs.
introduced species: a species whose existence in a given area is due to human action or activity; this
activity has led to its dispersal across natural geographic barriers and/or has produced conditions
favorable to its growth and spread.
invasive species: a species occurring outside of its native range and whose introduction does or is likely