L-20 Regulations: The first systematic program of wilderness protection promulgated by the US Forest Service in 1929. It was primarily a list of permitted and prohibited uses for designated roadless areas on national forests.
Lactate Threshold: The exertion level at which the body can no longer produce energy aerobically, resulting in the buildup of lactic acid. This is marked by muscle fatigue, pain, and shallow, rapid breathing. Also called anaerobic threshold.
Lactic Acid: A substance formed during anaerobic metabolism, when there is incomplete breakdown of glucose. It rapidly produces muscle fatigue and pain.
Lagoon: A shallow area of water separated from the ocean by a sandbank or by a strip of low land.
Lake: Large inland body of water.
Land: The total natural and cultural environment of the solid surface of the earth.
Land, Private: Land owned by a farmer, corporation, or individual (private landowner).
Land, Public: Federal, state, or municipal land in trust for the governed populace (public landowner).
Land and Water Conservation Fund (LWCF): A federal matching assistance program that provides grants for 50%of the cost for the acquisition and/or development of outdoor recreation sites and facilities.
Land Ethic: The desire humans have to conserve, protect, and respect the native landscape and other natural resources because their own well being is dependent upon the proper functioning of the ecosystem.
Land Management Agency: Any agency or organization that manages lands—many managed as recreation and/or wilderness areas. Examples include federal agencies such as the USDA Forest Service, the USDI National Park Service, and the USDI Bureau of Land Management, as well as state, county, and local park system agencies: as well as organizations such as The Nature Conservancy.
Land Manager: Any person who makes decisions regarding land use.
Land Transfer: The sale, exchange, or other conveyance of land from one owner to another, especially under the authority of land disposal laws such as the Desert Land Act, Carey Act, Recreation and Public Purposes Act, FLPMA, etc.
Land Trust: A private, nonprofit conservation organization formed to protect natural resources such as forestland, natural areas, and recreational areas. Land trusts purchase and accept donations of conservation easements.
Land Use: The way a section or parcel of land is used. Examples of land uses include industrial, agricultural, and residential.
Landform: Any physical, recognizable form or feature on the earth’s surface, having a characteristic shape and produced by natural causes. Examples would include but not be limited to beaches, various types of dune systems, plains, swamps, marshes, and mountain with various types of geological process origins.
Landing: The transition area on a switchback.
Landing (Log Landing, Log Deck): A place in or near the timber harvest site in a forest where logs are gathered for further processing or transport.
Landmark: Any monument or material mark or fixed object used to designate the location of a land boundary on the ground. Any prominent object on land which can be used in determining a location or a direction.
Landscape: The sum total of the characteristics that distinguish a certain kind of area on the earth’s surface and give it a distinguishing pattern in contrast to other kinds of areas. Any one kind of soil is said to have a characteristic natural landscape, and under different uses it has one or more characteristic cultural landscapes.
Landscape Block: A specific landscape unit used in analysis (for example, a drainage).
Landscape Character: The arrangement of a particular landscape as formed by the variety and intensity of the landscape features and the four basic elements of form, line, color, and texture. These factors give the area a distinctive quality which distinguishes it from its immediate surroundings.
Landscape Diversity: The size, shape, and connectivity of different ecosystems across a large area.
Landscape Ecology: The study of native landscape structure, function, and change at the scale of entire landscapes, as well as the application of the results to the design and management of both natural and human-dominated areas.
Landscape Features: The land and water form, vegetation, and structures which compose the characteristic landscape.
Landscape Linkage: Large linear protected areas connecting ecosystems and landscapes that provide sufficient space for native flora and fauna to safely live, reproduce, and move, and that may result in the protection of historic sites.
Landslide: Dislodged rock or earth that has slipped downhill under the influence of gravity and obstructs passage on a trail.
Laser: An acronym for “Light Amplification by Stimulated Emission of Radiation,” a device producing coherent energy beams in the spectrum of light or near-light frequencies.
Latitude: The angular distance north or south of the equator, measured in degrees, minutes, and seconds.
Leaching: The loss of soil minerals from upper layers of the soil to lower layers by water drainage.
Leadership in Energy and Environmental Design (LEED): A green building rating system for the design, construction, and operation of high-performance green buildings. LEED recognizes performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality.
Lease: The temporary grant of an interest in land upon payment of a determined fee. The fee does not have to be monetary, but some consideration must be given for the right to use the land, or the lease will not be legally binding.
Leave No Trace (LNT): Educational program designed to instill behaviors in the outdoors that leave minimum impact of human activities or occupation (www.LNT.org).
Ledger: A horizontal piece of wood attached to, and supported by, piles or concrete or stone masonry piers. Ledgers support stringers or tread timbers.
Legend: A listing that shows symbols and other information about a map.
Legislation: Written and approved laws. Also known as “statutes” or “acts.”
Leisure: The free or discretionary time available for people to use as they choose after meeting the biological and subsistence requirements of existence.
Length: Dimension of a feature measured parallel to the direction of travel.
Less-Than-Fee-Simple: Land acquisition technique that obtains only certain land use rights from the landowners, such as conservation easements, management agreements, or leases.
Level(s): A device for establishing a true horizontal line or plane by means of a bubble in a liquid that shows adjustment to the horizontal by movement to the center of a slightly bowed glass tube. Carpentry and construction levels, line levels, and laser levels are different types of levels that can be used for construction of fencing, stone walls, boardwalks, and bridges. Levels also help to determine the slope of trail tread.
Liability (Liable): In law, a broad term including almost every type of duty, obligation, debt, responsibility, or hazard arising by way of contract, tort, or statute. To say a landowner or person is “liable” for an injury or wrongful act is to indicate that they are the person responsible for compensating for the injury or wrongful act.
License: Allows the licensed party to enter the land of the licensor without being deemed a trespasser.
Licensee: Person using a property for their benefit (i.e. hunting, hiking, etc.) with the implied or stated consent of the owner, but not for the benefit of the owner.
Life Jacket (Life Vest, PFD (Personal Flotation Device)): Life preserver consisting of a sleeveless jacket of buoyant or inflatable design.
Life Preserver: A buoyant device, usually in the shape of a ring, belt, or jacket, designed to keep a person afloat in the water.
Lifts: Layers of loose soil. Used to specify how much loose soil should be laid down at a time before it must be compacted or wrapped in geotextile fabric.
Lighting, Back: A situation where the light source is coming from behind the object being viewed. Objects are generally in shadow with highlighted edge
Lighting, Front: A situation where the light source is coming from behind the observer and shining directly upon the area being viewed.
Lighting, Side: A situation where the light source is coming from the side of a scene or object being viewed. It is usually the most critical for revealing contrast.
Limits of Acceptable Change (LAC): A planning framework that establishes explicit measures of the acceptable and appropriate resource and social conditions in recreation settings as well as the appropriate management strategies for maintaining or achieving those desired conditions.
Line: The path, real or imagined, that the eye follows when perceiving abrupt differences in form, color, or texture. Within landscapes, lines may be found as ridges, skylines, structures, changes in vegetative types, or individual trees and branches.
Linear Disturbances: Human-made linear features that are not part of BLMs transportation system. May include engineered (planned) as well as unplanned single- and two-track linear features that are not designated as part of BLMs transportation system.
Linear Event: A specific characteristic of a road/trail that has a beginning measure and an ending measure where the characteristic is constant.
Linear Features: Represent the broadest category of physical disturbance (planned and unplanned). Transportation-related linear features include engineered roads and trails, as well as user-defined, nonengineered roads and trails created as a result of public use.
Linkage(s): Connections that enable trails and greenway systems to function and multiply the utility of existing components by connecting them together like beads on a string.
Litter: The uppermost layer of decaying matter in any plant community (leaf matter), or carelessly discarded trash on the trail.
Livestock: Domestic animals kept or raised for food, by-products, work, transportation, or recreation.
Load, Dead: The total physical weight of a bridge or structure, equal to the combined weight of all structural components.
Load, Design: The maximum weight a trail tread or structure can carry at any point along its length. Service and emergency vehicles need to be considered when determining the design load of trails and structures.
Load, Live: The active forces and weights that a bridge or structure is designed to support, including people, service vehicles, flood waters, floating debris contained within flood waters, wind, snow, and ice.
Loam: An easily crumbled soil consisting of a mixture of clay, silt, and sand.
Loess: A deposit of windblown sand and clay weakly cemented by calcite.
Loft: The upper floor of a shelter, often accessed via a ladder. Or, the degree of fluffiness in the fill of a sleeping bag.
Log, Trail: An inventory of physical features along or adjacent to a trail. An item-by-item, foot-by-foot record of trail features and structures and the improvements needed on a specific trail.
Log Dogs: Metal braces that are used to temporarily hold two logs at right angles to each other.
Log Ride (Logride): A log that provides a challenging bicycling experience while mitigating risks to sensitive areas, wet areas, or areas prone to erosion or heavy maintenance. The log used to create log rides must have the riding surface improved either by flattening the top and cross-hatching via chainsaw, or covering the surface with a traction-improving material such as rubber tracking. This is a natural type of skinny
Logged Out Tree: Down tree across the trail with sections already removed to permit passage.
Logo: A distinctive emblem, symbol or trademark that identifies a product or service.
Loitering: Crime of lingering idly or prowling about on a trail or greenway, especially for the purpose of begging, dealing drugs, or soliciting for prostitution.
Longitude: The angular distance east or west of the prime meridian, measured in degrees.
Loppers (Lopping or Pruning Shears): A long-handled tool with two opposing blades (by-pass or anvil) used for cutting heavy vegetation (limbs of 1 to 1¾ inches in diameter).
Lumber: Wood that has been sawn into a square or rectangular cross section that is two inches thick or less.
Lyme Disease: An infection caused by a spiral-shaped bacterium called a spirochete carried by deer ticks. Symptoms associated with the early stages—fever, headache, stiffness, lethargy, and myriad other mild complaints—are often dismissed as the flu. If left untreated, Lyme disease can produce lifelong impairment of muscular and nervous systems. See a doctor immediately if you suspect you have the disease.