Fault, normalA fault occurring usually as a result of extensional forces, such as when a hanging wall drops down relative to the footwall forming a graben or half…
Fault, potentially activeGenerally denotes that a fault has shown evidence of surface displacement during Quaternary time.
Fault, right-lateralA strike-slip fault on which displacement of the block opposite the observer is to the right. See also Strike-slip fault
Fault, transformA strike-slip fault forming the boundary between tectonic plates (e.g., the San Andreas Fault system is a transform fault zone that marks the boundary…
Fault, zonedUnder the Alquist-Priolo Act, zoned faults include those that are "sufficiently active," showing evidence of surface displacement within the past 11,000…
FaunaThe community of animals in a specific region or habitat.
FeatureA large, complex artifact, or part of a site, such as a hearth, cairn, housepit, rock alignment, or activity area.
Federal landLand owned by the United States, without reference to how the land was acquired or which Federal agency administers the land, including mineral and coal…
Federal RegisterA daily publication which contains federal administrative rules and regulations.
Federal Water Pollution Control Act (CWA)(CWA)A federal regulatory law administered by the states. The act created the National Pollution Discharge Elimination System.
FeedstockA raw material that can be converted to one or more products.
FellTo cut down a tree. Cutting down trees and sawing them to manageable lengths is referred to as "felling and bucking" or "falling and bucking."
Feller-buncherA self-propelled machine that cuts trees with giant shears near ground level and then stacks the trees into piles to await skidding.
FermentationThe anaerobic breakdown of complex organic substances, especially carbohydrates, by micro-organisms, yielding energy.
FillMan-made deposits of soil and rock and/or waste material.
Fischer-Tropsch FuelsLiquid hydrocarbon fuels produced by a process that combines carbon monoxide and hydrogen.
Fissure, earth or groundSurface fractures resulting from subsidence, often due to the withdrawal of groundwater and compaction of an aquifer.
fixed bedA bed of closely spaced particles through which gases move up or down for purposes of gasification or combustion.
fixed carbonThe carbon remaining after heating in a prescribed manner to decompose thermally unstable components and to distill volatiles.
FlakeA thin, flattened piece or chip of stone, intentionally removed from the core rock by chipping with either a stone or bone hammer.
Flash FloodA sudden flood event through a valley, canyon, or wash, following a short duration, high-intensity rainfall.
Flash PointThe minimum temperature at which a liquid gives off vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the…
Flat-plate PVA type of photovoltaic solar energy technology that uses a flat plate onto which are installed solar cells.
Flat-plate reflector (heliostat)One of many components of a CSP power tower facility consisting of a large nearly-flat mirror, mounted on a support structure that tracks the sun's…
FlatsLevel or nearly level areas of land marked by little or no relief.
Flats wetlandA level landform composed of unconsolidated sediments, usually mud or sand. Flats are unvegetated or support sparse plant communities, often composed of…
Flexible-fuel vehicleA vehicle with a single fuel tank designed to run on varying blends of unleaded gasoline with either ethanol or methanol.
Flood irrigationWater is pumped or brought to the fields and is allowed to flow along the ground among the crops.
FloodplainAny land area susceptible to being inundated by floodwaters from any source.
FloraPlants, especially those of a specific region, considered as a group.
Flow rateThe amount of water that moves through an area (usually pipe) in a given period of time.
FLPMAFederal Land Policy and Management Act of 1976.
fluidized bedA gasifier or combustor design in which feedstock particles are kept in suspension by a bed of solids kept in motion by a rising column of gas.
Fluidized-bed boilerA large, refractory-lined vessel with an air distribution member or plate in the bottom, a hot gas outlet in or near the top, and some provisions for…
FluvialPertaining to a river. Fluvial sediments are deposited by rivers.
Fly ashThe fine particulate matter entrained in the flue gases of a combustion power plant.
FlywayA seasonal route followed by birds migrating to and from their breeding areas.
FootprintThe land or water area covered by a project. This includes direct physical coverage (i.e.
ForageSmall baitfish, crayfish and other creatures that bass or other predator fish eat.
ForbsHerbaceous (nonwoody), broad-leaved flowering plants; non-graminoid (grasses, sedges, and rushes) herbaceous plants. See also Graminoid herbaceous
Forest healthA condition of ecosystem sustainability and attainment of management objectives for a given forest area.
Forest PlanThe document that sets goals, objectives, desired future condition, standards and guidelines, and overall programmatic direction for a National Forest.
Forest residuesMaterial not harvested or removed from logging sites in commercial hardwood and softwood stands as well as material resulting from forest management…
Forested areas or landAny land that is capable of producing or has produced forest growth or, if lacking forest growth, has evidence of a former forest and is not now in other…
forestry residuesIncludes tops, limbs, and other woody material not removed in forest harvesting operations in commercial hardwood and softwood stands, as well as woody…
formThe mass or shape of an object or objects that appears unified, such as a vegetative opening in a forest, a cliff formation, or a water tank.
ForwarderA self-propelled vehicle to transport harvested material from the stump area to the landing.
FossilRemains of ancient life forms, their imprints or behavioral traces (e.g., tracks, burrows, or residues) and the rocks in which they are preserved.
Fossil fuelSolid, liquid or gaseous fuels formed in the ground after millions of years by chemical and physical changes in plant and animal residues under high…
Fossil FuelsFuels formed in the ground from the remains of dead plants and animals. It takes millions of years to form fossil fuels.
FragmentationProcess by which habitats are increasingly subdivided into smaller units, resulting in their increased insularity as well as losses of total habitat area.
Fragmentation of habitatThe breaking up of a single habitat area into two or more smaller habitat patches that are separated from each other.
Francis TurbineA type of hydropower turbine that contains a runner that has water passages through it formed by curved vanes or blades.
Fresnel LensAn optical device for concentrating light that is made of concentric rings that are faced at different angles so that light falling on any ring is focused…
FriableA term commonly used to describe a crumb-like callus. In this state, the callus is easily dissected and readily dispersed into single cells or clumps of…
Fuel cellA holding tank for a race car's supply of gasoline. Consists of a metal box that contains a flexible, tear-resistant bladder and foam baffling.
Fuel cycleThe series of steps required to produce electricity. The fuel cycle includes mining or otherwise acquiring the raw fuel source, processing and cleaning…
Fuel handling systemA system for unloading wood fuel from vans or trucks, transporting the fuel to a storage pile or bin, and conveying the fuel from storage to the boiler or…
Fuel-cell furnaceA variation of the Dutch oven design, that usually incorporates a primary and secondary combustion chamber (cell).
Fugitive DustThe dust released from any source other than a definable point source such as stack, chimney, or vent.
Fujita ScaleThe official classification system for tornado damage. The scale ranges from F0 (gale tornado, minor damage, winds up to 72 mph) to F5 (devastating…
Full-time equivalent (FTE)(FTE)Equivalent to a full-time worker/employee. For example, two people, each working half time, constitute one FTE.
FungiPlant-like organisms with cells with distinct nuclei surrounded by nuclear membranes, incapable of photosynthesis.
FurbearerAn animal that is hunted or farmed for its fur.
furfuralAn aldehyde derivative of certain biomass conversion processes; used as a solvent.
FurnaceAn enclosed chamber or container used to burn biomass in a controlled manner to produce heat for space or process heating.
galactanThe polymer of galactose with a repeating unit of C6H10O5. Found in hemicellulose it can be hydrolyzed to galactose.
galactoseA six-carbon sugar with the formula C6H1206. A product of hydrolysis of galactan found in the hemicellulose fraction of biomass.
Gallium (Ga)(Ga)A chemical element, metallic in nature, used in making certain kinds of solar cells and semiconductor devices.
gapA missing section on one of the strands of double-stranded DNA. The DNA will therefore have a single-stranded region.
Gas engineA piston engine that uses gaseous fuel rather than gasoline. Fuel and air are mixed before they enter cylinders; ignition occurs with a spark.
Gas shift processA process in which carbon monoxide and hydrogen react in the presence of a catalyst to form methane and water.
Gas turbineA type of turbine in which combusted, pressurized gas is directed against a series of blades connected to a shaft, which forces the shaft to turn to…
GasificationThe process in which a solid fuel is converted into a gas; also known as pyrolitic distillation or pyrolysis.
GasifierA device for converting a solid fuel to a gaseous fuel.
GasoholA registered trademark of an agency of the state of Nebraska, for an automotive fuel containing a blend of 10 percent ethanol and 90 percent gasoline.
GDAsSee Renewable Resource Generation Development Areas
Generalist (species)An organism that can survive under a wide variety of conditions, and does not specialize to live under any particular set of circumstances.
GeneratorA device for converting mechanical energy to electrical energy.
GeoglyphsGround markings of a figure or shape produced by the clearing or alignment of stones.
Geographic air basin: A land area with generally similar meteorological and geographic conditions throughout.
Geographic Information System (GIS)(GIS)A set of computer tools and procedures used to collect, manage, analyze and display information associated with a specific location; a computerized…
GeologyThe science that deals with the study of the materials, processes, environments, and history of the Earth, including the rocks and their formation and…
Geometric spreadingAs the sound moves away from the source, the area that the sound energy covers becomes larger and thus sound intensity decreases.
GeomorphicPertaining to those processes that affect the form or shape of the surface of the earth.
GeotechnicalRefers to the use of scientific methods and engineering principles to acquire, interpret, and apply knowledge of earth materials for solving engineering…
Geotextile matsPermeable fabrics that interact with soils in manners used to reinforce soil surfaces for erosion, as well as act as filters for water, solutes, and fine…
Geothermal energyEnergy produced by the internal heat of the earth; geothermal heat sources include: hydrothermal convective systems; pressurized water reservoirs; hot dry…
Geothermal generating plantA plant in which the prime mover is a steam turbine. The turbine is driven either by steam produced from hot water or by natural steam that derives its…