organized that a change in any one component
will bring about a change in the other
components, and in the operation of the
whole system.
Edaphic Pertaining to soil.
Edaphic climax Stable community of plants
that develops on soils different from those
supporting a climatic climax.
Elevational zonation Vertical differentiation of
climate, vegetation, and soil based on the
effects of elevation change.
Empirical Source of knowledge acquired by
means of observation or experimentation.
Epiphyte Organism that lives on the surface of
a plant, but does not draw nourishment from it.
Erg A very large area of sand dunes within a
desert.
Evergreen Plants, or pertaining to plants,
which remain green in parts the year around,
either by retaining at least some of their leaves
at all times, or by having green stems which
carry on photosynthesis.
Exotic river Stream that flows across a region
of dry climate and derives its discharge from
adjacent uplands where a water surplus exists.
Fjord A deeply glaciated valley in a coastal
region
Fire cycle See fire regime
Fire regime Character of fire occurrence; e.g.,
frequent surface fire.
Fire regime condition class A classification of
the amount of departure from the natural fire
regime.
Forest Open or closed vegetation with the principal layer consisting of trees averaging more
than 5 m in height.
Forest Inventory & Analysis (FIA) USDA
Forest Service program provides information
to assess the nation’s forests.
Forest-steppe Intermingling of steppe and
groves or strips of trees.
Forest-tundra Intermingling of forest and
tundra.
Formative process A set of actions and
changes that occur in the landscape through
collective geomorphic, climatic, biotic, and
cultural activities.
Front Division between two air masses with
different origins and different characteristics.
Galeria forest Dense tropical, or prairie, forest
living along the banks of a river.
General circulation model (GCM) A class of
computer-driven models for forecasting
weather,
understanding
climate,
and
projecting climate change.
Geostrophic Pertaining to deflective force due
to rotation of the earth.
Germplasm Substance of the germ cells by
which the hereditary characteristics are
believed to be transmitted.
Grassy savanna Savanna in which woody
plants are entirely lacking.
Gray brown podzol soil Acid soil under broadleaf deciduous forest; has thin, organic layer
over grayish brown, leached layer; layer of
deposition is darker brown.
Greenhouse effect Accumulation of heat in the
lower atmosphere resulting from the absorption
of long-wave radiation from the earth’s surface.
Growth and yield model
A set of
relationships, usually expressed as equations
and embodied in a computer program, that
provides estimates of future stand development given initial stand conditions and a
specified management regime.
Hamada An eroded rock-surface found in
deserts.
Histosol Soil order consisting of soils which are
organic.
Horse latitudes Subtropical high-pressure belt
of the oceans.
Humus Organic material derived, by partial
decay, from the organs of dead plants.
Hydrograph Graph showing the rate of flow
(discharge) versus time past a specific point in
a river or stream.
Igneous rock A type of rock formed by the
solidification of magma, either within the
earth’s crust or at the surface.
Inceptisols Soil order consisting of soils with
weakly differentiated horizons showing alteration of parent materials.
Impute Estimate; process of replacing missing
data.
Glossary of Technical Terms
155
will bring about a change in the other
components, and in the operation of the
whole system.
Edaphic Pertaining to soil.
Edaphic climax Stable community of plants
that develops on soils different from those
supporting a climatic climax.
Elevational zonation Vertical differentiation of
climate, vegetation, and soil based on the
effects of elevation change.
Empirical Source of knowledge acquired by
means of observation or experimentation.
Epiphyte Organism that lives on the surface of
a plant, but does not draw nourishment from it.
Erg A very large area of sand dunes within a
desert.
Evergreen Plants, or pertaining to plants,
which remain green in parts the year around,
either by retaining at least some of their leaves
at all times, or by having green stems which
carry on photosynthesis.
Exotic river Stream that flows across a region
of dry climate and derives its discharge from
adjacent uplands where a water surplus exists.
Fjord A deeply glaciated valley in a coastal
region
Fire cycle See fire regime
Fire regime Character of fire occurrence; e.g.,
frequent surface fire.
Fire regime condition class A classification of
the amount of departure from the natural fire
regime.
Forest Open or closed vegetation with the principal layer consisting of trees averaging more
than 5 m in height.
Forest Inventory & Analysis (FIA) USDA
Forest Service program provides information
to assess the nation’s forests.
Forest-steppe Intermingling of steppe and
groves or strips of trees.
Forest-tundra Intermingling of forest and
tundra.
Formative process A set of actions and
changes that occur in the landscape through
collective geomorphic, climatic, biotic, and
cultural activities.
Front Division between two air masses with
different origins and different characteristics.
Galeria forest Dense tropical, or prairie, forest
living along the banks of a river.
General circulation model (GCM) A class of
computer-driven models for forecasting
weather,
understanding
climate,
and
projecting climate change.
Geostrophic Pertaining to deflective force due
to rotation of the earth.
Germplasm Substance of the germ cells by
which the hereditary characteristics are
believed to be transmitted.
Grassy savanna Savanna in which woody
plants are entirely lacking.
Gray brown podzol soil Acid soil under broadleaf deciduous forest; has thin, organic layer
over grayish brown, leached layer; layer of
deposition is darker brown.
Greenhouse effect Accumulation of heat in the
lower atmosphere resulting from the absorption
of long-wave radiation from the earth’s surface.
Growth and yield model
A set of
relationships, usually expressed as equations
and embodied in a computer program, that
provides estimates of future stand development given initial stand conditions and a
specified management regime.
Hamada An eroded rock-surface found in
deserts.
Histosol Soil order consisting of soils which are
organic.
Horse latitudes Subtropical high-pressure belt
of the oceans.
Humus Organic material derived, by partial
decay, from the organs of dead plants.
Hydrograph Graph showing the rate of flow
(discharge) versus time past a specific point in
a river or stream.
Igneous rock A type of rock formed by the
solidification of magma, either within the
earth’s crust or at the surface.
Inceptisols Soil order consisting of soils with
weakly differentiated horizons showing alteration of parent materials.
Impute Estimate; process of replacing missing
data.
Glossary of Technical Terms
155