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Glossary of Terms

Glossy of Terms and Acronyms




abney level - An instrument used to determine slopes, elevations, and heights. Replaced by clinometers.

acre - Area of land containing 43,560 square feet. A square 1-acre plot measures 209 feet by 209 feet; a circular acre has a radius of 117.75 feet.

all-aged (or uneven-aged) forest management - Management of a forest by periodically removing some trees from the stand. (See also even-aged forest management.)

all-aged stand - all, or almost all, age classes of trees represented.

allowable cut - Volume of wood that can be cut during a given period without exceeding the forest’s net growth.

alluvial - Pertaining to material that is transported and deposited by running water.

anadromous fish - Those species of fish which mature in the sea and migrate into streams to spawn. Salmon, steelhead, and shad are examples.

annual - A plant that lives or grows for only one year or one growing season.

annual Seed Mixture - A mixture of soybean, millet, cow pea, sorghum, lespedeza, buckwheat, and other seeds from which single‑season plants are grown to serve primarily as food or protective cover for wildlife.

annual rings - see growth rings.

aspect - the compass direction toward which a slope faces.

association - a collection of plants with ecologically similar requirements, including one or more dominant species from which the group derives a definite character.


basal area (of a tree) - the cross-sectional area of the trunk 4 1/2 feet above the ground; (per acre)the sum of the basal areas of the trees on an acre; used as a measure of forest density.

best management practice (BMP) - A practice or combination of practices that is determined by a state to be the most effective, practicable means of preventing or reducing the amount of pollution generated by point and nonpoint sources (such as forests, farms) to a level compatible with water quality goals.

Biltmore stick - a tool calibrated to measure the diameter of a tree at breast height. Biltmore sticks are calibrated with different scales depending on the users' arm length.

biological diversity or biodiversity - the variety of life in all its forms and all its levels of organization. Biodiversity refers to diversity of genetics, species, ecosystems, and landscapes.

blaze - to mark a tree, usually by painting or cutting the bark. Forest properties often are delineated by blazing trees along the boundary lines.

BLM - see Bureau of Land Management.

blowdown - see windthrow.

BMP - see Best Management Practice.

board foot - a unit for measuring wood volume in a tree, log, or board. A board foot is commonly 1 foot by 1 foot by 1 inch, but any shape containing 144 cubic inches of wood equals one board foot.

bole - the trunk of a tree.

BOF - California State Board of Forestry & Fire Protection. Develops rules and regulations for management on private forestlands.

breast height - 4 1/2 feet above ground level. See diameter at breast height.

browse - parts of woody plants, including twigs, shoots, and leaves, eaten by forest animals.

buck - to cut trees into shorter lengths, such as logs or cordwood.

buffer strip - A visual buffer consisting of trees or other vegetation used to screen a road, streamside, or harvest unit, or to protect a riparian area.

Bureau of Land Management (BLM) - An agency of the US Dept. of Interior. Manages 15 million acres in California for multiple uses, today primarily recreation and watershed/environmental protection but formerly for cattle grazing. Manages some forested land in northern California. Formerly the Grazing Service and the General Land Office, responsible for disbursing public lands under the Homestead Act.

butt log - a log cut from the bole immediately above the stump.

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California Forest Practice Act (Rules) - Also known as the “Z’berg-Nejedly Forest Practice Act of 1973.” This legislation initiated the forest practice rules in California that, when followed, will allow maximum sustained production of timber, while giving consideration to values such as recreation, watershed, wildlife, range and forage, fisheries, and aesthetic enjoyment.

caliper - a tool to measure the diameter of a tree.

cambium - a layer of cell tissue between the inner bark (phloem) and the wood (xylem) that generates new cells annually for the inner bark and wood.

canopy - the continuous cover formed by tree crowns in a forest.

carrying capacity - the maximum number of individuals of a wildlife species that an area can support during the most unfavorable time of the year.

cat ex - categorical exclusion from having to prepare an environmental assessment or an environmental impact statement. See discussion under environmental impact statement.

CDF - California Department of Forestry and Fire Protection. Primary agency responsible for review and approval of THP & NTMP.

CDF & G - California Department of Fish and Game. Reviews timber harvest plans (THPs) for protection of threatened and endangered species.

CEQA - California Environmental Quality Act, the California equivalent of the federal NEPA, National Environmental Policy Act.

CFIP - California Forest Improvement Program. The purpose of the California Forest Improvement Program (CFIP) program is to encourage private and public investment in, and improved management of, California forest lands and resources. This focus is to ensure adequate high quality timber supplies, related employment and other economic benefits, and the protection, maintenance, and enhancement of a productive and stable forest resource system for the benefit of present and future generations. More details: http://www.calfire.ca.gov/resource_mgt/resource_mgt_forestryassistance_cfip.php.

certification - An evaluation provided by a third party organization that confirms forests are managed sustainably, based on the implementation of a written plan that meets established standards.

choker - a short length of wire cable or chain that forms a noose around the end of a log to be skidded or yarded.

choker setter - A person whose job is to wrap a choker around the end of the log so that the yarder or skidder can drag the log to the landing.

clearcut - the harvest of all the trees in an area. Clearcutting is used to aid species whose seedlings require full sunlight to grow well.

climax community - A relatively stable, undisturbed plant community that has evolved through stages and adapted to its environment.

clinometer - an instrument used to determine the height of a tree.

codominant tree - a tree that extends its crown into the canopy and receives direct sunlight from above but limited sunlight from the sides. One or more sides of a codominant tree are crowded by the crowns of dominant trees.

commercial clearcut - a harvest cut that removes all merchantable timber from the area.

commercial cut - A cutting on a forested property that yields a net income (when product sale receipts exceed cutting cost).

commercial forestland - any area capable of producing 20 cubic feet of timber per acre per year that has not been protected from such use by law or statute.

commercial treatments - timber stand improvements, such as thinning, that generate income from the sale of the trees removed.

community - A collection of living organisms thriving in an organized system through which water, energy, and nutrients cycle.

competition - The struggle between trees and other plant life to obtain sunlight, nutrients, water, and growing space.

conifer - any tree that produces seeds in cones. See softwood.

consulting forester - an independent professional who manages forests and markets forest products for private woodland owners. Consulting foresters do not have direct connections with firms that buy wood products, but are retained by woodland owners as their agents.

Cooperative Extension Service (CES) - the educational arm of the USDA that links university research to people who can benefit from it.

coppice - A stand of forest produced from sprouts from stumps or roots of trees previously cut. Many hardwood species sprout and readily coppice when young. Few conifers will sprout from the stump, with coast redwood being a notable exception.

cord - a unit of wood cut for fuel that is equal to a stack 4 x 4 by 8 feet or 128 cubic feet.

cordwood - small diameter or low quality wood suitable for firewood, pulp, or chips. Cordwood is not suitable for sawlogs.

conservation- The protection, improvement, and wise use of natural resources for present and future generations.

conservation easement - A legally enforceable transfer of usage rights for the purposes of conserving land and prohibiting real estate development.

controlled burn - (See Prescribed Burn.)

cord - A stack of round or split wood containing 128 cubic feet. A standard cord measures 4 feet by 4 feet by 8 feet. A face or short cord is 4 feet by 8 feet of any length wood less than 4 feet. A cord contains about 85 to 90 cubic feet of actual wood and is roughly equivalent to 500 board feet of wood.

cost-share assistance - An assistance program offered by various state and federal agencies that pays a fixed rate or percentage of the total cost necessary to implement some forestry or agricultural practice.

cover— Any plant that intercepts rain drops before they reach the soil or that holds soil in place.

crook - a tree defect characterized by a sharp bend in the main stem.

crop tree - a young tree of a desirable species with certain characteristics desired for timber value, water quality enhancement, or wildlife or aesthetic uses. Tree selected for quality, species, size, timber potential, or wildlife value that is favored for growing to final harvest.

crown - the uppermost branches and foliage of a tree.

crown class - A tree classification system based on the tree's relative height, foliage density, and ability to intercept light. Classifications include dominant, co-dominant, intermediate, and suppressed. A category of tree based upon its crown position relative to those of adjacent and competing trees.

dominant - Trees with crowns that extend above the average of the tree crowns and receives light from directly above and some from the sides. The most competitive trees.

co-dominant - Trees with crowns that form the general level of the crown cover and receive full light from the top, but very little from the sides. Less competitive than the dominant trees.

intermediate - Trees that are shorter than the two preceding classes but with some branches extending into the general crown cover. Receives little light from above and none from the sides.

suppressed - Trees with crown entirely below the general crown level and receiving no direct light either from above or below. The least competitive trees in a forest.

crown classes - see codominant, dominant, intermediate, overtopped, and suppressed.

crown cover or crown closure - the percentage of a given area covered by tree crowns.

crown fire - a fire that spreads across the tops of trees or shrubs independently of a surface fire. Crown fires cannot be effectively or safely fought until the fire drops to the ground.

crown ratio or live-crown ratio - the ratio of the leaved portion of a tree's height to its total height.

cruise - a forest survey used to obtain inventory information and develop a management plan.

cubic foot - A unit of measure for wood volume containing 1,728 cubic inches - for example, a piece of wood measuring 1 foot on a side. A cubic foot of wood contains approximately 6 usable board feet of lumber rather than 12 board feet because wood is lost as sawdust and shavings during processing.

cull - a sawtimber sized tree that has no timber value as a result of poor shape or damage from injury, insects or disease.

cutting contract - A written, legally binding document used in the sale of standing timber specifying the provisions covering the expectations and desires of both buyer and seller.

cutting cycle - the period of time between major harvests in a stand.

cut to length - A system in which harvested trees are cut into log lengths at the stump before they are yarded to the landing; an alternative whole-tree logging.

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DBH - Diameter of a tree at breast height or 4 ½ feet above ground. The standard tree diameter measure.

daylighting— A practice in which trees shading an access road are removed to increase the sunlight on the roadway and along its periphery.

deciduous - shedding or losing leaves annually; the opposite of evergreen. Trees such as maple, ash, cherry, and larch are deciduous.

deck - Stack of logs - either in the mill or on a landing. Usually sorted by species and size.

defects - characteristics of an individual tree that reduce its quality and utility.

defensible fuel profile zone (DFPZ) - A shaded fuelbreak from a few hundred feet to a ¼ mile wide, where the canopy and cover of the larger trees has been retained but the ladder and ground fuels have been removed or treated; defensible in the sense that firefighters can safely take a stand in the DFPZ to fight an oncoming fire.

DFPZ - see defensible fuel profile zone.

den tree - a tree with cavities suitable for birds or mammals to nest in.

diameter at breast height (dbh) - standard measurement of a tree's diameter, usually taken at 4 1/2 feet above the ground.

diameter-limit scale - a timber sale in which all trees over a specified dbh may be cut. Diameter-limit sales often result in high grading.

dimension lumber - hardwood dimension lumber is processed to be used whole in the manufacture of furniture or other products. Softwood dimension lumber consists of boards more than 2 inches thick but less than 5 inches thick. This wood is used in construction and is sold as 2 by 4s, 4 by 8s, or 2 by 10s.

direct seeding - Sowing seed for broad coverage from the air or on the ground.

DMG - Division of Mines & Geology (Department of Conservation). Participates in review of THPs for landslides, debris flows, and other geological hazards

dominant trees - trees that extend above surrounding individuals and capture sunlight from above and around the crown.

drip torch - Firefighters use these torches, that drip a flaming liquid mixture of diesel fuel and gasoline, to ignite fires in burnout operations.

drum chopping - A site preparation technique in which logging debris is leveled by a bulldozer pulling a large drum filled with water.

duff - the partially decomposed organic matter of the forest floor beneath the litter of freshly fallen twigs, needles, and leaves.

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EA - Environmental assessment. See discussion under environmental impact statement.

ecology - the study of interactions between organisms and their environment.

ecosystem - organisms and the physical factors that make up their environment.

ecosystem services - Indirect benefits provided by the forest ecosystem that help ensure the integrity of critical structure, functions and processes.

ecotone - a transition area between two distinct, but adjoining, communities.

edge - the boundary between two ecological communities, for example, field and woodland. Edges provide wildlife habitat. Consideration of an edge can reduce the impact of a timber harvest.

EIS - Environmental impact statement. (see environmental impact statement).

endangered species - any species or subspecies in immediate danger of becoming extinct throughout all or a significant portion of its range.

endangered species - any species of plant or animal defined through the Endangered Species Act of 1976 as being in danger of extinction throughout all or a significant portion of its range, and published in the Federal Register.

environmental impact statement (EIS) - a detailed statement of a federal project’s environmental consequences, including adverse environmental effects that cannot be avoided, alternatives to the proposed action, the relationship between local short-term uses and long-term productivity, and any irreversible or irretrievable commitment of resources. An EIS is one of four classes of documentation under the National Environmental Policy Act of 1969 (NEPA). An environmental assessment (EA) is a concise, public document containing a federal agency’s analysis of the significance of potential environmental consequences of an action, used to determine whether the more comprehensive EIS is required or a “finding of no significant impact” is warranted. A categorical exclusion (Cat Ex) is an exemption for federal agencies from requirements to prepare an EIS or EA for categories of action that have been determined not to involve significant environmental impacts. A conformance determination record exempts federal agencies from having to prepare an EIS or EA for actions that have already been covered in existing EISs or EAs. A programmatic EIS is a document that discloses the environmental consequences of a program or plan of actions rather than disclosure of the environmental consequences of every site-specific project of that program or plan.

Environmental Quality Incentives Program (EQIP) - The Environmental Quality Incentives Program (EQIP) is reauthorized by the 2014 Farm Bill to promote agricultural production, forest management, and environmental quality as compatible national goals and to optimize environmental benefits on eligible land with farmers and non-industrial private forest landowners on a voluntary basis. Through EQIP, agricultural producers receive financial and technical assistance to implement structural and management conservation practices that optimize environmental benefits on working agricultural land. More details: http://www.nrcs.usda.gov/wps/portal/nrcs/main/ct/programs/financial/eqip/.

ephemeral stream - Water that flows in natural channels only during significant rainfall.

epicormic branching - branches that grow out of the main stem of a tree from buds produced under the bark. Severe epicormic branching increases knottiness and reduces lumber quality.

ESA - Endangered Species Act.

evapotranspiration - The evaporation of water from the soil and the transpiration of water from the plants that live in that soil.

Even-aged forest - A forest of trees all essentially the same age (within 10-20 years).

even-age management— A forest management method in which all trees in an area are harvested at one time or in several cuttings over a short time to produce stands that are all at or near the same age.

even-aged stand - a stand in which the age difference between the oldest and youngest trees is minimal, usually no greater than 10 to 20 years. Even-aged stands are perpetuated by cutting all the trees within a relatively short period of time.

evergreens - plants that retain foliage year round.

extension forester - a Cooperative Extension Service professional who educates woodland owners on how they can effectively manage their forests.

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Farm Services Agency (FSA) - The branch of the U.S. Department of Agriculture (USDA) that administers cost-sharing programs for such forestry practices as tree planting and timber stand improvement.

feller-buncher - A harvesting machine that cuts a tree with a shear or saw, gathering one or more cut trees in hydraulic arms before placing them on the ground. Usually limited to 24 in. DBH or smaller trees. Bunching facilitates efficient handling of small, low value trees.

felling - the cutting of standing trees.

felling crew - One or more tree fallers and falling boss. They do the felling, limbing, and bucking (cut logs to specific length). Fellers are also referred to as “cutters” or “choppers.”

firebreak - Any nonflammable barrier such as mineral soil or slow‑burning vegetation used to slow or stop the spread of fire.

fire shelter - Firefighters use this personal protection as a last resort if a wildfire traps them and they cannot escape. Firefighters can get into the tent-like shelter, made of heat reflective material, in about 25 seconds.

fire shovel - shovels, specifically designed for constructing a fireline, feature a tapered blade with both edges sharpened for scraping, digging, grubbing, cutting, and throwing dirt.

forest - a biological community dominated by trees and other woody plants. An ecosystem characterized by a more or less dense and extensive tree cover, often consisting of stands varying in characteristics such as species composition, structure, age class, and associated processes, and commonly including meadows, steams, fish, and wildlife. Forests include special kinds such as industrial forests, non-industrial private forests, public forests, urban forests, and parks and wilderness. Forests differ in their biological composition, management goals and objectives, and the laws and regulations governing them.

forest fragmentation - the subdivision of large natural landscapes into smaller, more isolated fragments. Fragmentation affects the viability of wildlife populations and ecosystems.

forest management - Proper care and control of wooded land to maintain health, vigor, product flow, and other values such as soil condition, water quality, wildlife preservation and beauty, and to accomplish specific objectives.

forest management plan - Written guidelines for current and future management practices needed to meet an owner's objectives.

Forest Practice Act (FPA) - The law that governs private forest management in California. Division 4, Section 8, of the Public Resources Code that declares the policy of the state “to encourage prudent and responsible forest management”. Authorized by the Z’Berg-Nejedly Forest Practice Act of 1973.

forest practice rules - Rules and regulations developed and promulgated by the State Board of Forestry pursuant to the Forest Practice Act. Most rules address protection of water quality, wildlife habitat, and archaeological sites and artifacts.

forest resources - means those uses and values associated with, attainable from, or closely tied to, forested landscapes, and includes but is not limited to aesthetics, fish, forage, recreation, soil, timber, water and watersheds, wilderness, and wildlife.

Forest Service - An agency of the Dept. of Agriculture (USDA). The Forest Service manages 20 million acres in 18 national forests in California, for watershed and wildlife habitat protection, recreation, and timber and grazing.

forest stewardship plan - A written document emphasizing long-term, forest sustainability and activities that enhance or improve wildlife, timber, soil, water, recreation, and aesthetics.

forest stewardship program - A cooperative, technical‑assistance program designed to encourage multiple resource management.

forest types - associations of tree species that have similar ecological requirements. Some California forest types include subalpine conifer, true fir, mixed conifer, Douglas-fir, Jeffrey pine, lodgepole pine, ponderosa pine, eastside pine, redwood, juniper, aspen, blue oak woodland, blue oak-foothill pine, valley oak woodland, and coastal oak woodland.

forested wetland - an area characterized by woody vegetation taller than 20 feet where soil is at least periodically saturated or covered by water.

forester - a degreed professional trained in forestry and forest management. In California, all RPFs (see Registered Professional Forester) must be licensed by the state.

forestry - the science of tending woodlands.

Forestry Incentives Program (F.I.P.) - a Federal cost-sharing program that reimburse part of the costs landowners incur in completing certain forestry practices. The F.I.P. is administered by the NRCS.

fork - a tree defect characterized by the division of a bole or main stem into two or more stems.

FPA - see forest practice act.

frilling - the method of killing trees by inflicting a series of cuts around the bole and applying an herbicide to the wounds. Frilling or girdling can be used to reduce the density of a stand or to kill individual undesirable trees.

fuelbreak - a generally wide (60 to 1000 ft.) strip of land on which native vegetation has been permanently modified so that a fire burning into it can be more readily controlled. See shaded fuel break, DFPZ.

fuel loading - A buildup of easily ignited, fast‑burning fuels such as pinestraw, small branches, and other highly flammable, woody material.

fusee - Firefighters also use these colored flares to ignite fires in burnout operations.

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geotextile - A synthetic material placed beneath road fill and used to confine the road aggregate and to distribute the weight of the load.

girdling - a method of killing trees by cutting through the stem, thus interrupting the flow of water and nutrients. To make continuous incisions around a living stem, through the bark and cambium, generally with the object of killing the tree to thin the forest and/or create snags for wildlife habitat.

GIS - Geographic Information System.

GPS - Global Positioning System.

group selection - a process of harvesting patches of trees to open the forest canopy and encourage the reproduction of unevenaged stands and shade intolerant species.

growth rings - the layers of wood a tree adds each season; also called annual rings. These rings frequently are visible when a tree is cut and can be used to estimate its age and growth rate.

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habitat - the ecosystem in which a plant or animal lives and obtains food and water.

habitat diversity— A variety of food or cover for wildlife that is often critical to the survival of a species.

hardwoods - a general term encompassing broadleaf, deciduous trees.

hardwoods (deciduous trees) - Trees with broad, flat leaves shed on an annual basis whose wood hardness varies among individual species.

harvest - the cutting, felling, and gathering of forest timber.

HCP - Habitat Conservation Plan; an agreement between the Secretary of Interior and either a private party or state, specifying the conservation measures that will be implemented in exchange for a permit that would allow taking (harassing or killing) of a threatened or endangered species.

headlamp - Firefighters who work on the fireline at night wear these flashlights on the front of their helmets.

helicopter logging- using a helicopter to yard or move logs from the harvest area to a landing. Used where landscape sensitivity, steepness, or landslides, precludes the use of ground-based yarding equipment or where no access roads are available.

herbaceous vegetation - low-growing, non-woody plants, including wildflowers and ferns, in a forest understory.

high grading - to remove all mature, good quality trees from a stand and leave inferior species and individuals. High grading should be distinguished from even-aged management in which mature and immature trees are removed to aid regeneration.

hypsometer - any of several tools or instruments designed to measure the height of trees. The clinometer is such a tool.

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IHV - (Immediate Harvest Value). Stumpage values determined by the State Board of Equalization from many timber sales in each timber value area andinfluenced by species, age, logging method, and volume harvest.

improvement cut - a weeding done in stands of pole-size or larger trees.

industrial forester - a professional employed by a wood-using industry, usually a sawmill, who purchases timber from private woodland owners. Many industrial foresters offer free forest management or marketing services to the landowners who sell timber to the forester's employer.

increment borer - an augerlike tool with a hollow bit designed to extract cores from tree stems to remove a cylindrical cross section of the tree’s growth rings for the determination of age and growth rate.

intermediate crown class - trees with crowns that extend into the canopy with dominant and codominate trees. These trees receive little direct sunlight from above and none from the sides. Crowns generally are small and crowded on all sides.

intermediate cut - Removal of immature trees from the forest sometime between establishment and major harvest to improve quality of the remaining forest stand. Contrast with harvest cut. An intermediate cut may generate income (commercial cutting), or may cost the forest landowner more than income realized (a pre-commercial cutting).

intermediate tolerance - a characteristic of certain tree species that allows them to survive, though not necessarily thrive, in relatively low light conditions.

intolerance - a characteristic of certain tree species that does not permit them to survive in the shade of other trees.

introduced species - a nonnative species that was intentionally or unintentionally brought into an area by humans.

inventory - Quantitative method used to estimate the actual volume, composition, and market value of standing timber.

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joe poke - a small tree that has been damage by timber harvesting operations so severely that it is not likely to survive. These trees are often cut off with a chainsaw to improve the aesthetics and reduce fire danger.

jack straw - trees that have been felled in a chaotic fashion as a result of natural events.


k-tag - a thin metallic tag that is nailed to trees to aid in the identification of survey lines or corners in the forest.

kerf - a slit or notch made by a saw or cutting torch; the width of a cut made by a saw or cutting torch.

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landing - a cleared area within a timber harvest where harvested logs are processed, piled, and loaded for transport to a sawmill or other facility.

landing crew- Loader operator, may have landing person or knot bumper who trims knots off the logs before loading.

late succession forest stands - means stands of dominant and predominant trees that meet the criteria of WHR class 5M, 5D, or 6 with an open, moderate or dense canopy closure classification, often with multiple canopy layers, and are at least 20 acres in size. Functional characteristics of late succession forests include large decadent trees, snags, and large down logs.

ladder fuel - configuration of brush and suppressed trees, both live and dead, that provide a continuity of fuels such that fires can burn from the ground into the upper crowns of forest.

legacy trees - Usually large trees left to be examples of the size and characteristics of trees in the original stand. They also fulfill the role of future wildlife trees and snags.log- the stem of a felled tree, trimmed of limbs, cut to preferred lengths for final products. e.g. 16.5 ft or 33 ft for lumber that will eventually be sold in 8 ft lengths. The extra 0.5 or 1.0 ft is called trim allowance and compensates for log end damage and sawmill processing.

log decks at the mill - May be watered to reduce both fire hazard and checking (surface cracks or splits) on the ends of logs which results in loss of valuable material.

logger - an individual who harvests timber for a living.

log rule - a method for calculating wood volume in a tree or log by using its diameter and length. Two widely used log rules include Scribner Decimal C and the International 1/4-inch rule.

lopping - cutting tree tops to a maximum specified height above the ground after a tree is felled.

LTO - Licensed Timber Operator, licensed by the state of California.

lump-sum sale - a timber sale in which an agreed-on price for marked standing trees is set before the wood is removed (as opposed to a unit sale).

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marginal land - Land that does not consistently produce a profitable crop because of infertility, drought, or other physical limitations such as shallow soils.

marking timber - indicating by paint or other means which trees are to be cut or otherwise treated. It is advisable to mark trees to be harvested twice-once at eye level and once on the stump.

mast - nuts and seeds, such as acorns, beechnuts, and chestnuts, of trees that serve as food for wildlife.

MBF - Abbreviation denoting one thousand board feet that is a typical unit of volume for saw logs and manufactured wood products.

McCleod - Firefighters also use this combination hoe, rake, and scraping tool to remove plants and shrubs when building a fireline.

mensuration - The measurement and calculation of volume, growth, and development of individual trees or stands.

merchantable height - the point on a tree stem to which the stem is salable. Limits are: the point at which a sawlog tree is less than 8 inches in diameter, measured inside the bark (dib); the point at which a pulpwood tree is less than 4 inches dib; or the point on any tree where a defect is found that cannot be processed out.

merchantable top diameter- the inside-bark diameter above which a stem is considered nonmerchantable for a particular product. Usually 6 to 10 inches dib, diameter inside bark.

mixed stand - A timber stand in which less than 80 percent of the trees in the main canopy are of a single species.

MOU- memorandum of understanding, a formal, written agreement between two or more organizations or agencies that presents the relationship between the entities for purposes of planning and management.

multiple-age stand - A forest stand composed of trees of different ages and sizes.

multiple land use –the management of land and forests for timber , wildlife, water, and recreation in an integrated and comprehensive program.

multiple-use management- Management of land or forest for more than one purpose.

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national forest - a federal forest, range, or wildland reserve, managed by the US Department of Agriculture, Forest Service, for multiple uses - timber, water, wildlife, recreation, and grazing . National forests differ from 5 National Parks in that recreation is not their only use. Recreation may be a primary use in some part of the national forest. For example, there are more acres of wilderness areas in national forests than national parks. Nationwide, the national forest system administers 154 forests and 19 grasslands.

National Park Service - an agency of the Dept. of Interior (USDI). Manages national parks to conserve the scenery and natural and historical objects and wildlife, and to provide recreation in and enjoyment of the parks.

natural regeneration - A stand of trees grown from natural seed fall or sprouting.

Natural Resources Conservation Service (NRCS) - the branch of the USDA that coordinates and implements soil conservation practices on private lands. The NRCS can provide woodland owners with detailed information on his or her soil.

NEPA- National Environmental Policy Act of 1969. See environmental impact statement.

niche - the physical and functional "address" of an organism within an ecosystem; or, where a living thing is found and what it does there.

NIPF - Non-industrial private forest.NMFS- National Marine Fisheries Service, an agency of the National Oceanic and Atmospheric Administration (NOAA). Pronounced “nymphs”. Responsible for the protection of endangered fish like the coho salmon.

NOAA - National Oceanic and Atmospheric Administration.

nongame wildlife - wildlife species that are protected by state wildlife laws and can not be hunted. Examples include songbirds, eagles, etc.

Nonindustrial timberlands - means timberland owned by a nonindustrial tree farmer.

nonindustrial timber management plan (NTMP) - means a management plan for nonindustrial timberlands with an objective of an uneven aged managed timber stand and sustained yield for each parcel or group of contiguous parcels meeting the requirements of California Public Resources Code Section 4593.3.

nonindustrial tree farmer - means an owner of timberland with less than 2,500 acres who has an approved nonindustrial management plan and is not primarily engaged in the manufacture of forest products.

nontidal wetlands - wetlands not affected by ocean tides. Nontidal wetlands are subject to special regulations.

northern hardwood forest type - an association of tree species common to the Northeastern United States that includes sugar maple, red maple, yellow birch, hemlock, and American beech.

NRCS - see Natural Resources Conservation Service

NTMP - see nonindustrial timber management plan

nursery log- A fallen tree that provides habitat for fern, fungi, insects, etc.

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oak-gum-cypress forest type - an association of tree species common to the bottom lands of the Southeastern United States.

oak-hickory forest type - an association of tree species common to the Northeastern United States that includes oak, hickory, yellow poplar, and red maple.

oak-pine forest type - an association of tree species common to the Southeastern United States that includes loblolly pine, Virginia pine, northern red oak, and white ash.

old-growth forest - a wooded area, usually greater than 200 years of age, that has not been substantially altered or harvested by humans. An old-growth forest often has large individual trees, a multi-layered crown canopy, and a significant accumulation of coarse woody debris including snags and fallen logs.

overmature - a quality exhibited by trees that have declined in growth rate because of old age and loss of vigor.

overstocked - the situation in which trees are so closely spaced that they compete for resources and do not reach full growth potential.

overstory - the level of forest canopy that includes the crowns of dominant, codominant, and intermediate trees.

overtopped - the situation in which a tree cannot sufficiently extend its crown into the overstory and receive direct sunlight. Overtopped trees that lack shade tolerance lose vigor and die.

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partial cut - removal of only part of a stand for purposes other than regenerating a new age class of trees.

patch cut - a clearcut on a small area.plane surface- lumber that has a smooth surface from being run through a planer or surfacing machine. Surfaced lumber is lumber that has been planed. It can be either green (undried) or dried. Dried lumber is often air dried for a while then placed in a kiln to bring lumber moisture down to a specified amount and thus stabilizing its shrinkage and twisting.

plantation - Trees planted artificially in an ordered configuration such as equally spaced rows.

pole stand - a stand of trees whose average dbh is between 4 and 10 inches.

pole timber - trees 4 to 10 inches dbh.

precommercial operations - cutting in forest stands to remove wood too small to be marketed. Precommercial operations improve species composition and increase the quality, growth, and vigor of remaining trees.

precommercial treatments - forestry operations that require landowner investment, such as cleaning or weeding stands to remove trees that have little or no cash value. See commercial treatments.

prescribed burn or controlled burn - to deliberately burn wildland fuels under specified environmental conditions (a burn prescription), which insures the fire will be confined to a predetermined area and intensity. Air temperature, humidity, wind speed and direction, fuel moisture, and soil moisture are taken into consideration. The use of fire under specific environmental conditions to achieve forest management objectives such as reducing hazardous fuels or controlling unwanted vegetation.

preservation- to protect an area from treatment or management. The meaning stems from 19th century land reserves wherein areas and resources were set aside for limited or restricted use and development. Preservation often restricts land uses to recreation or scientific study.

processor head - A saw and delimbing machine mounted on a tractor or boom that cuts the tree stem, delimbs and cuts it into logs, leaving slash at the stump.

prospectus - a document that describes the location of a property, indicates trees marked for cutting, and states that the timber will be sold in accordance with a suitable contact. A prospectus includes the number of trees marked, their diameter classes, and a volume estimate for each species.

pruning - the act of sawing or cutting branches from a living tree. In forest management, pruning is done to promote the growth of clear, valuable wood on the tree bole.

PSW - Pacific Southwest Research Station. The research branch of the Forest Service for California, Hawaii, and the Pacific Islands.public trust resources- natural resources which the public owns. Air, water, wildlife. Protection of public trust resources is often a control or limitation on private property rights and activities, and is the basis of our environmental protection laws and regulations.

pulaski - Firefighters use this tool, which combines a single-bitted axe blade for chopping with a narrow blade for trenching, to clear vegetation when constructing a fireline.

pulpwood - wood suitable for use in paper manufacturing.

pure stand - A timber stand in which at least 75 percent of the trees in the main crown canopy are of a single species.

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QLG - Quincy Library Group, Plumas county, which developed and proposed a shaded fuel break program to protect communities from wildfire, improve the condition of the forest, produce economic return to the community, and minimize the extent and intensity of wildfire. See DFPZ.

quadratic mean diameter - The diameter of the tree of average basal area. For fixed area plots this is the same as the quadratic mean of the sampled tree diameters, QMD = d2/n.


RCD - Resource Conservation District.

reforestation - Reestablishing a forest by planting or seeding an area from which forest vegetation has been removed.

regeneration - the process by which a forest is reseeded and renewed. Advanced regeneration refers to regeneration that is established before the existing forest stand is removed.

regeneration cut - a timber harvest designed to promote natural establishment of trees.

release - to remove overtopping trees that compete with understory or suppressed trees.

Registered Professional Forester (RPF) - a person who holds a valid license as a professional forester licensed to practice forestry in California.

removal cut- The removal of the last seed bearers or shelter trees after regeneration is established.

reproduction - The process by which young trees grow to become the older trees of the future forest that occurs through natural sprouting or seeding, or by the planting of seedlings. Tree seedlings or sprouts 0-1” DBH.

residual stand - the trees remaining intact following any cutting operation.

riparian forest or riparian buffers - Vegetative areas along a body of water containing a complex assemblage of vegetation, typical of a riparian system.

root collar - The transition zone between stem and root at the ground line of a tree or seedling.

rot - a tree defect characterized by woody decay in a standing tree or log.

rotation - the number of years required to grow a stand to a desired size or maturity.

RPF - see Registered Professional Forester

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salvage cut - the removal of dead, damaged, or diseased trees to recover maximum value prior to deterioration.

sanitation cutting –the removal of dead, damaged or insect and disease susceptible trees; essentially to prevent the spread of pests or pathogens and so promote forest health.

sapling - a tree at least 4 1/2 feet tall and up to 4 inches in diameter.

sapling stand - a stand of trees whose average dbh is between 1 and 4 inches.

sawlog - a log large enough to be sawed economically on a sawmill. Sawlogs are usually at least 8 inches in diameter at the small end.

sawlog tree - a tree at least 11 inches dbh and suitable for conversion to lumber. Sometimes, trees 11 to 14 inches dbh are called small sawlog trees, and trees larger than 18 inches dbh are called large sawlog trees.

sawtimber - trees from which sawlogs can be made.

sawtimber stand - a stand of trees whose average dbh is greater than 11 inches.

scale stick - a calibrated stick used to estimate wood volume in a log.

scarifying— The removal of the top litter layer of soil in order to prepare a site for planting.

scribner’s rule - A diagrammatic log rule developed over 100 years ago to estimate the volume of a log assuming a ¼ inch saw kerf and no definite slab allowance. However, the Rule more accurately estimates product output rather than log volume.

sealed-bid sale - a timber sale, usually offered through a consulting forester, in which buyers submit secret bids.

second growth - A loose term for a young stand, or smaller trees, left after cutting. Also, residual trees available for another logging on the same area.

sedimentation— The deposition or settling of soil particles suspended in water.

seedling - (A) A tree, usually less than 2 inches DBH, that has growth from a seed not a sprout. (B) Nursery-grown trees that have not been lifted and replanted in the nursery.

seed tree - a mature tree left uncut to provide seed for regeneration of a harvested stand.

seed-tree harvest - the felling of all the trees in an area except for a few desirable individuals that provide seed for the next forest.

seed year - A year in which a given species produces a large seed crop over a sizable area.

selection harvest - the harvest of all individual trees or small groups at regular intervals to maintain an uneven-aged forest. Selection harvests are used to manage species that do not need sunlight to survive.

selective cutting - The periodic removal of individual trees or groups of trees to improve or regenerate a stand.

seral - A biotic community which is a developmental transitory stage in an ecologic succession.

service forester - a professional forester employed by the California Department of Forestry & Fire Protection (Cal Fire). Service foresters help private woodland owners develop and implement forest management plans.

shelterwood harvest - the harvest of all mature trees in an area in a series of two or more cuts, leaving enough trees of other sizes to provide shade and protection for forest seedlings.

short logger - a log truck with a specially designed trailer used to haul logs that are too short for standard length trailer.

silviculture - the art and science of growing forest trees.

silvicultural system - A process, following accepted silvicultural principles, whereby the crops constituting forests are tended, harvested, and replaced, resulting in the production of crops of distinctive form. Systems are conveniently classified (for example, clearcut) according to the method of carrying out the fellings that remove the mature crop with a view to regeneration and according to the type of crop produced.

site - the combination of biotic, climatic, topographic, and soil conditions of an area.

site class- a classification of site quality and productivity, usually expressed as dominant tree heights at a standard reference age (50 or 100 years) or annual wood production.

site index - a measure of the quality of a site based on the height of dominate trees at a specified age (usually 25 or 50 years), depending on the species.

site preparation - treatment of an area prior to reestablishment of a forest stand. Site preparation can include mechanical clearing, burning, or chemical (herbicide) vegetation control.

skidder - a rubber-tired machine with a cable winch or grapple used to drag logs out of the forest.

skidding - the act of moving trees from the site of felling to a leading area or landing. Tractors, horses, or specialized logging equipment can be used for skidding. Skidding methods vary in their impact on soils and the remaining stands.

slash - branches and other woody material left on a site after logging.

slope position- A particular location on a slope as upper, middle, or lower slope; ridge top; or bottom land. A specific topographic location.

snag - a dead tree that is still standing. Snags provide important food and cover for a wide variety of wildlife species.

softwood - any tree in the gymnosperm group, including pines, hemlocks, larches, spruces, firs, and junipers. Softwoods often are called conifers although some, such as junipers and yews do not produce cones.

soil texture - The feel or composition of the soil (sand, silt, or clay) as determined by the size of the soil particles.

soil type - Soils that are alike in all characteristics, including texture of the topsoil.

sprout - a tree growing from a cut stump or previously established root system.

sustained yield - means the yield of commercial wood that an area of commercial timberland can produce continuously at a given intensity of management consistent with required environmental protection and which is professionally planned to achieve over time a balance between growth and removal.

stand - a group of forest trees of sufficiently uniform species composition, age, and condition to be considered a homogeneous unit for management purposes.

Stand (timber types) - A community of trees of sufficient uniformity, with respect to composition, age spatial arrangement or condition, to be distinguished from adjacent communities, so forming a management entity. Fully stocked: A forest stand with all growing space effectively occupied but have ample room for crop development. Mixed: A stand having less than 80 percent of the trees in the main crown canopy of a single species. Overstocked: Overcrowding in a stand leading to retarded growth. Pole-timber: A stand with most trees from 4 to 8 or 12 inches in diameter. Pure: A stand with at least 80 percent of the trees in the main crown canopy of a single species. Sawtimber: A stand with most trees large enough in diameter (usually 10 to 12 inches DBH or larger) to be sawn into lumber. Understocked: A stand with the growing space not effectively occupied by potential crop trees.

stand density - the quantity of trees per unit area, usually evaluated in terms of basal area, crown cover and stocking.

stocking - the number and density of trees in a forest stand. Stands are often classified as understocked, well-stocked or overstocked.

Stocking level - Number of trees in a forest stand. Often, stocking level is the term used for the desirable number of trees at a given age for best growth and management against which comparisons can be made, such as partially-stocked, well-stocked, or over-stocked.

stratification - division of a forest, or any ecosystem, into separate layers of vegetation that provide distinct niches for wildlife. See canopy, understory, and herbaceous vegetation.

stream classes- California state classification for regulatory purposes.

Class 1 - Fish always or seasonally present in streams that flow year round. Includes habitat to sustain fish migration spawning.

Class 2 - Within 1,000 feet up stream from a class one stream. Aquatic habitat for non-fish species - amphibians. May be a seasonal stream.

Class 3 - No aquatic life present. Capable of sediment transport to a class 1 or 2 under normal water flow conditions. Usually flows only in response to storms.

Class 4 - Man-made water course, ditch, diversion.

streamside management zone (SMZ) - A strip of land adjacent to a water body or stream channel where soils, organic matter and vegetation are managed to protect the physical, chemical and biological integrity of surface water adjacent to and downstream from forestry operations. An SMZ also may be called a “filter strip “ or “buffer zone.”

stumpage - the value of standing trees in a forest.

stumpage price - the price paid for standing forest trees.

stump height - the distance from the ground to the top of the stump. Good logging practice dictates that stumps be as low as possible (preferably as low as 12 inches) to reduce waste, to minimize visual impact on the logging site, and to promote resprouting of trees.

succession - the natural replacement of one plant (or animal) community by another over time in the absence of disturbance.

suppressed - a tree condition characterized by low growth rate and low vigor as a result of competition with overtopping trees. See overtopped.

surface fuels- The loose surface litter on the soil surface, e.g., fallen leaves or needles, twigs, bark, cones, branches, grasses, shrub and tree reproduction, downed logs, stumps, seedlings, and forbs interspersed with or partially replacing the litter.

sustainable forestry - A holistic, conservation ethic based on environmental balance and health that helps ensure forests will be managed in ways that have the potential to meet the social, physical and economic needs of the present while ensuring similar options for the future.

Sustainable Forestry Initiative (SFI)- A comprehensive set of forestry and conservation practices designed to ensure that future generations of Americans will have the same abundant forests and wildlife that we enjoy today. SFI is sponsored by the American Forest & Paper Association (AF&PA). AF&PA member companies have agreed to use sustainable forestry practices on the forestland they manage and to promote sustainable forestry of the forestlands of others from whom they buy timber.

sustainably managed forest - A forest that is managed using sustainable forestry principles and criteria. Such management can be confirmed through certification.

sustained yield - an ideal forest management objective in which the volume of wood removed equals growth within the total forest.

sweep - a tree defect characterized by a gradual curve in the main stem.

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thinning - a partial cut in an immature, overstocked stand of trees used to increase the stand's value growth by concentrating on individuals with the best potential.

timber harvest plan (THP) –An environmental review document required by the California Forest Practices Act, laying out the conditions of a logging operation. The functional equivalent of a CEQA environmental impact statement. As a result of Article 7 of the “Z’berg-Nejedly Forest Practice Act” of 1973, a THP is required for timber operation to take place on land other than federal land within the State of California. Timber operations include the cutting or removal of both timber and other solid wood products from timberlands for commercial purposes. Intent of the legislation is to restore, enhance, and maintain the productivity of California’s timber, watershed, range and forage, fisheries,and aesthetic enjoyment.

THP - see timber harvest plan

threatened species - a species or subspecies whose population is so small or is declining so rapidly that it may become endangered in all or a significant portion of its range.

timberland - means land, other than land owned by the federal government and land designated by the board as experimental forest land, which is available for, and capable of, growing a crop of trees of any commercial species used to produce lumber and other forest products, including Christmas trees. Commercial species shall be determined by the board on a district basis after consultation with the district committees and others

timber cruise - see cruise.

timber stand improvement (t.s.i.) - any practice that increases the value or rate of value growth in a stand of potential sawtimber trees. Pruning and thinning are considered t.s.i.

TMDL- Total Maximum Daily Load of pollutants in a watercourse, including sediment and water temperature.

tolerance - a tree species' capacity to grow in shade.

TPZ (Timberland Production Zone) - Created by the “California Taxation Reform Act” of 1976, TPZs were established so that forest landowners would not pay property tax on the basis of the land’s “highest and best use.” TPZ land is restricted to the growing and harvesting of timber and compatible uses. Lands qualify on the basis of size (minimum sizes are determined by the county in which the land is located) and productivity, as determined annually by the State Board of Equalization for different forest types and sites.

tree farm - a privately owned forest managed on a multiple use basis with timber production as an important management goal.

tree spacing - The distance between trees, which is most often regulated at the time of planting or during a harvest or thinning operation.

trim allowance - the extra 2 or 3 inched left on a bucked log to allow logs with end checks, pulls, or slanting buck cuts to be trimmed to standard lumber lengths.

t.s.i - see timber stand improvement

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understocked - a stand of trees so widely spaced, that even with full growth potential realized, crown closure will not occur.

understory - the level of forest vegetation beneath the canopy.

uneven aged management - means the management of a specific forest, with the goal of establishing a well stocked stand of various age classes and which permits the periodic harvest of individual or small groups of trees to realize the yield and continually establish a new crop.

uneven-aged stand - Three or more age classes of trees represented.

unit sale - a timber sale in which the buyer makes regular (weekly, monthly) payments based on mill receipts. Unit sales are useful when the amount of timber sold is so large that a preharvest, lump-sum payment would be prohibitive.

USDA- U.S. Department of Agriculture, administers the Forest Service, Natural Resources Conservation Service.

USDI - U.S. Department of the Interior, administers the National Park Service, Bureau of Land Management, Bureau of Indian Affairs, US Fish and Wildlife Service.

US Fish and Wildlife Service (USFWS) - An agency of the Dept. of Interior, it develops rules for protection of federally listed threatened and endangered species. e.g. northern spotted owl, bald eagle.

USFS - Forest Service.

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veneer log - a high-quality log of a desirable species suitable for conversion to veneer. Veneer logs must be large, straight, of minimum taper, and free from defects.

virgin forest - an area of old-growth trees that never has been harvested by humans.

volume table - A table estimating volume of wood in a standing tree based on measurements of the tree, most commonly DBH and merchantable height.


Wain - The corners or edge of the board that are missing due to the curvature of the log.

water bar - A diagonal ditch or hump in a trail that diverts surface water runoff to minimize soil erosion.

water control - Management of water to maintain plant growth, water quality, wildlife habitat, and fire control.Water Quality Control Board (WQCB)- Reviews timber harvest plans for compliance with the Clean Water Act, Porter-Cologne Water Act.

watershed - a region defined by patterns of stream drainage. A watershed includes all the land that contributes water to a particular stream or river.

well-stocked - the situation in which a forest stand contains trees spaced widely enough to prevent competition yet closely enough to utilize the entire site.

WHR- Wildlife Habitat Relationship system. lists species likely to be found in specific vegetation types. Can be used to determine the effects of timber harvest and other actions on wildlife habitat.

wildlife habitat - the native environment of an animal. Habitats ideally provide all the elements needed for life and growth: food, water, cover and space.

wildfire- Fires burning out of control regardless of how or why they were started

windrow - A long, narrow row of vegetation, debris, and some soil created during site preparation and clearing operations.

Windthrow, windfall, (blowdown) - a tree felled by wind. Windthrows, also known as blowdowns, are common among shallow-rooted species and in areas where cutting has reduced stand density.

wolf tree - a large older tree with a spreading crown and little or no timber value, but often great value for wildlife.A dominant tree with a broad, spreading crown, that occupies more growing space than its more desirable neighbors.

woodland - see forest.

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yarder - A machine equipped with a tower and cable wound on winches which is used to drag (yard) logs from felling site to the landing. The tower provides lift, which makes the log easier to move with less damage to the soil. It is like an “old fashion” clothes line, which was on a pulley and went around in a circle. The operator is directed by the “choker setter” in the woods using a signal system called a talkie-tooter. The choker setter can blow a whistle on the yarder by pushing a button on a radio control signal device. The number and length of toots signals the yarder operator to pull the line in, slack the line, or stop the line.

yarding crew- Two or more choker setters, yarder operator, and/or skidder operator(s). Depending on the crew size, there may be a separate side rod or crew foreman.

Yield table - A tabulation of volume, basal area, and DBH for forest stands of specified site and age, showing its growth pattern.

Yield tax - Created by the “Forest Taxation Reform Act” of 1976, yield tax is a one-time tax on timber when it is harvested. The tax rate is applied to the value per volume harvested in different timber value areas throughout the state. For example, if the tax rate is 2.9 percent for each 1,000 board feet (MBF) of timber harvested and valued at $500 per thousand board feet on the stump, the yield tax would by $14.50. The tax is based on the IHV.

young growth - a tree or trees that exhibit characteristics of immature trees such as pointed tops, deeply furrowed bark, dense foliage, and rapid growth.


Z’berg-Nejedly Forest Practice Act of 1973 - see California Forest Practice Act (Rules).

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