Spodosols Soil order consisting of soils that
have accumulations of amorphous materials
in subsurface horizons.
Steppe
(Also called short-grass prairie)
grassland–shrubland mix characterized by
grasses less than 1 m tall, those grasses widely
spaced exposing much bare soil often grown
with lichens, and shrubs present and typically
conspicuous though often small and
dispersed.
Subtropical high-pressure belts (Also called
cells or zones) belts of persistent high atmospheric pressure tending east–west and centered at about lat. 30
N and S.
Succession The replacement of one community
of plants and animals by another.
Sustainable design The process of prescribing
compatible land uses and building based on
the limits of place, locally as well as
regionally.
Taxon A group of objects; based on the similarity of properties.
Tayga (Also spelled taiga) a parkland or
savanna with needle-leafed (usually evergreen) low trees and shrubs; a Russian word
referring to the northern virgin forests.
Temperate rainforest Dense forest, comprising tall trees, growing in areas of very high
rainfall, such as the Pacific Northwest of the
USA.
Thermoisopleth diagram Drawing that shows
temperature at a station throughout the day for
every day of the year.
Thermokarst The formation of a highly irregular ground surface, as a result of the thawing
of masses of ground ice.
Topoclimate The climate of a very small
space; influenced by topography.
Toposequence A change of a community with
topography.
Trade winds Current of air blowing from the
east on the equatorward side of the subtropical
high-pressure cells.
Transhumance The seasonal movement of
people and animals to and from fresh pastures.
Tundra Slow-growing, low formation, mainly
closed vegetation of dwarf shrubs,
graminoids, and cryptograms, beyond the subpolar or alpine treeline.
Tundra soil Cold, poorly drained, thin layers of
sandy clay and raw humus; without distinctive
soil profiles.
Upwelling Upward motion of cold, nutrientrich ocean waters, often associated with cool
equatorward currents occurring along western
continental margins.
Ultisols Soil order consisting of soils with
horizons of clay accumulation and low base
supply.
Wadi In Arabia and the Sahara, dry desert
valley.
Westerlies Winds blowing from the west on the
poleward side of the subtropical high-pressure
cells.
Wildfire occurrence gradient Differences in
the number of fires in non-urban settings.
Wildland urban interface Zone of transition
between unoccupied land and human development. These lands and communities adjacent to and surrounded by wildlands are at risk
of wildfires.
Woodland Cover of trees whose crowns do not
mesh, with the result that branches extend to
the ground.
Xerophyte A plant adapted to an environment
characterized by extreme drought.
Yellow forest soil (Also called red-yellow podzol) soils with weakly developed horizons but
also have accumulations of sesquioxides of
iron and aluminum; transitional between
podzols and latosols.
Zonal Resulting from the average state of the
atmosphere; variation in environmental
conditions in a north–south direction.
Zonal soil Well-developed deep soils on moderate surface slopes that are well drained.
158
Glossary of Technical Terms
have accumulations of amorphous materials
in subsurface horizons.
Steppe
(Also called short-grass prairie)
grassland–shrubland mix characterized by
grasses less than 1 m tall, those grasses widely
spaced exposing much bare soil often grown
with lichens, and shrubs present and typically
conspicuous though often small and
dispersed.
Subtropical high-pressure belts (Also called
cells or zones) belts of persistent high atmospheric pressure tending east–west and centered at about lat. 30
N and S.
Succession The replacement of one community
of plants and animals by another.
Sustainable design The process of prescribing
compatible land uses and building based on
the limits of place, locally as well as
regionally.
Taxon A group of objects; based on the similarity of properties.
Tayga (Also spelled taiga) a parkland or
savanna with needle-leafed (usually evergreen) low trees and shrubs; a Russian word
referring to the northern virgin forests.
Temperate rainforest Dense forest, comprising tall trees, growing in areas of very high
rainfall, such as the Pacific Northwest of the
USA.
Thermoisopleth diagram Drawing that shows
temperature at a station throughout the day for
every day of the year.
Thermokarst The formation of a highly irregular ground surface, as a result of the thawing
of masses of ground ice.
Topoclimate The climate of a very small
space; influenced by topography.
Toposequence A change of a community with
topography.
Trade winds Current of air blowing from the
east on the equatorward side of the subtropical
high-pressure cells.
Transhumance The seasonal movement of
people and animals to and from fresh pastures.
Tundra Slow-growing, low formation, mainly
closed vegetation of dwarf shrubs,
graminoids, and cryptograms, beyond the subpolar or alpine treeline.
Tundra soil Cold, poorly drained, thin layers of
sandy clay and raw humus; without distinctive
soil profiles.
Upwelling Upward motion of cold, nutrientrich ocean waters, often associated with cool
equatorward currents occurring along western
continental margins.
Ultisols Soil order consisting of soils with
horizons of clay accumulation and low base
supply.
Wadi In Arabia and the Sahara, dry desert
valley.
Westerlies Winds blowing from the west on the
poleward side of the subtropical high-pressure
cells.
Wildfire occurrence gradient Differences in
the number of fires in non-urban settings.
Wildland urban interface Zone of transition
between unoccupied land and human development. These lands and communities adjacent to and surrounded by wildlands are at risk
of wildfires.
Woodland Cover of trees whose crowns do not
mesh, with the result that branches extend to
the ground.
Xerophyte A plant adapted to an environment
characterized by extreme drought.
Yellow forest soil (Also called red-yellow podzol) soils with weakly developed horizons but
also have accumulations of sesquioxides of
iron and aluminum; transitional between
podzols and latosols.
Zonal Resulting from the average state of the
atmosphere; variation in environmental
conditions in a north–south direction.
Zonal soil Well-developed deep soils on moderate surface slopes that are well drained.
158
Glossary of Technical Terms