Paper GLOSSARY

Adsorbable organic halogens (AOX): Measure of the total amount of halogens (chlorine, bromine and iodine) bound to dissolved or suspended organic matter in a wastewater sample. For pulp, paper and paperboard wastewaters, essentially all of the organic substances measured as AOX are chlorinated compounds that result from the bleaching of pulps with chlorine and chlorinated compounds such as chlorine dioxide and hypochlorite. AOX provides information about the quantity of chlorinated organic compounds in wastewater, and thus contains a broad mix of compounds that have different chemical properties. The actual composition of AOX in pulp mill effluent varies from mill to mill, depending on the wood species used and the process parameters.

Artificial regeneration: Method for producing a new stand of trees following harvesting, in which tree seedlings (or more rarely, seeds) are planted. Most often used in even-aged silvicultural systems.

Bedding: Site-preparation technique in which soil is raised from a few inches to a few feet high to provide an elevated planting or seed bed; used primarily in wet areas to improve drainage and aeration for seeding.

Best Management Practices or BMPs: In this report, forestry practices specified in state-level forest management guidelines or legislation. BMPs encompass the practices required by the mandatory forest practice acts in some states as well as the voluntary or quasi-regulatory BMP programs in other states.

Biochemical oxygen demand (BOD): Amount of oxygen required by aerobic (oxygen-requiring) organisms to carry out normal oxidative metabolism or the amount required by oxidation of metabolic by-product from anaerobic organisms in water containing organic matter. Thus, BOD measures the amount of dissolved organic material that is degraded naturally once it enters a mill’s receiving waters. For regulatory purposes, BOD is most often measured over a five-day period in the United States. The BOD in a test bottle can consume oxygen well in excess of 100 days, and the five-day test may capture only 50-75% of the total BOD.

Biodiversity: Most broadly, biodiversity encompasses the diversity of life on the planet. Biodiversity includes genetic diversity, the diversity of information encoded in genes within a species; species diversity, the diversity and relative abundance of species; and community/ecosystem diversity, the diversity of natural communities.

Biomass: Mass of organic matter. E.g., the “biomass removed in harvesting” refers to the amount of organic matter — mostly wood in trees, but also twigs and leaves — removed at harvest.

Buffer strip: See streamside management zone.

Cable logging: System of transporting logs from stump to landing by means of steel cables and winch. This method is usually preferred on steep slopes, in wet areas, and for erodible soils where tractor logging cannot be carried out effectively.

Carbon dioxide (CO2): Greenhouse gas associated with global climate change that results from the complete combustion of biomass and fossil fuels.

Chemical oxygen demand (COD): Amount of oxidizable compounds (composed of carbon and hydrogen) present in the water. Since an effluent-treatment system removes most of the organic material that would be degraded naturally in the receiving waters, the COD of the final effluent provides information about the quantity of more persistent substances discharged into the receiving water.

Chlorine dioxide (ClO2): Powerful oxidizing agent used to delignify and remove colored substances from pulp. The oxygen in chlorine dioxide initially reacts with lignin. This initial reaction produces substances that can chlorinate the remaining organic material.

Chloroform: A hazardous air pollutant, is classified as a probable human carcinogen. The units of measure are pounds per oven-dried ton of pulp.

Clean Air Act: Federal statute that gives the U.S. Environmental Protection Agency the authority to regulate emissions of air pollutants from all sources in the United States. The purpose of the statute is to protect and enhance the quality of the nation’s air resources. 42 U.S.C. §§ 7401 to 7642.

Clean Water Act: Federal statute that gives the U.S. Environmental Protection Agency the authority to regulate discharges of pollutants from all sources into waters of the United States. The purpose of the statute is to restore and maintain the chemical, physical and biological integrity of the nation’s waters. 33 U.S.C. §§ 1251 to 1387.

Clearcutting: Harvesting/regeneration method in which all merchantable trees (commercial clearcutting) or all trees (silvicultural clearcutting) in a stand are harvested in one operation. Clearcutting is also used in even-aged silviculture to regenerate an even-aged stand of desired shade-intolerant trees. In practice, most clearcuts are commercial clearcuts.

Coarse woody debris: Also called large woody debris. Downed large wood on the forest floor, such as fallen trees and limbs. When such debris falls into streams, it creates waterfalls and pools — important physical structures for fish habitat and other stream functions. In natural forests of some regions (e.g., the Pacific Northwest), coarse woody debris on the forest floor also provides important functions as it slowly decays, returning nutrients to the soil, storing water for use in dry periods, and providing animal habitat. Coarse woody debris develops naturally in unmanaged forests, as trees die and decay, and may also be created by forest management (see also Logging debris).

Coastal Zone Management Act: Federal statute that requires states to formulate programs to reduce water pollution from nonpoint sources impacting coastal waters, including forestry activities. State management measures can include land use management restrictions and control measures similar to the Best Management Practices developed under the authority of the Clean Water Act. 16 U.S.C. 1451 et seq.

Commercial thinning: Silvicultural practice performed in even-aged forests in which some merchantable trees are harvested, usually for pulpwood, to provide greater light, soil moisture and nutrients to the remaining stand.

Compost: (1) Nutrient-rich mulch of organic soil produced through aerobic digestion of mixtures of food, wood, manure and/or other organic material. (2) The process of producing compost.

Cumulative effect: Impact on the environment that results from the incremental impact of an action when added to other past, present and reasonably foreseeable future actions.

Deinked market pulp (DMP): Pulp made from recovered paper by mills that receive high-grade recovered papers and remove the ink and contaminants. DMP is produced in sheets as wet-lap pulp (about 50% moisture) or air-dried form and is sold to paper producers who blend it with virgin pulp for use on existing paper machines.

Deinking: Separation and removal prior to paper formation of ink and other contaminants from wastepaper slurry by screening, washing, flotation, chemical treatment and bleaching.

Dioxins: A group of persistent, toxic substances, including furans that are produced in trace amounts when unbleached pulp is exposed to elemental chlorine. Term used to describe the families of chemicals known as chlorinated dibenzo-p-dioxins and dibenzo-p-furans. These families consist of 75 different chlorinated dibenzo-p-dioxins and 135 different chlorinated dibenzo-p-furans. These molecules can have from one to eight chlorine atoms attached to a planar carbon skeleton. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-tetrachlorodibenzo-p-furan (TCDF) are two of the most toxic members of this family of compounds. If dioxins are detected in the releases from bleaching processes that expose unbleached pulp to elemental chlorine, the dioxins are most likely to be TCDD and TCDF.

Ecosystem: Ecosystems encompass plant and animal communities and also include nonliving components, both structural (soil types) and functional (processes such as disturbance patterns and energy flows in and out of the ecosystem).

Effluent: Wastewater that has been discharged either to a sewer or to a stream or other body of water.

Elemental chlorine: Chlorine gas (Cl2).

Elemental chlorine-free (ECF): Bleaching processes that substitute chlorine dioxide for elemental chlorine and sodium hypochlorite in the bleaching process.

Endangered Species Act: Federal statute that seeks to protect plants and animals in danger of extinction (endangered species) or likely to become so (threatened species). It requires all federal agencies, including federal forestland managers, to ensure that their actions not jeopardize the continued existence of any endangered or threatened species. It also prohibits all persons (including public and private land owners) from “taking” any protected species, either directly or indirectly by destroying the habitat upon which the species depends. 16 U.S.C. 1531 et seq.

Fertilizer: Plant nutrients applied to forest soils, usually in chemical forms that are readily taken up by plants (e.g., phosphorus is applied as phosphate).

Flotation deinking: In a paper recycling system, removal of ink by a process of adding surfactants to the pulp and pumping bubbles of air through the mixture. The hydrophobic ink particles attach to the air bubbles, float to the surface of the pulp and are skimmed off.

Forest canopy: Topmost layer of tree vegetation, also called the overstory.

Fuelwood: Wood used for conversion to some form of energy, primarily residential use.

Furans: See dioxins.

Growing stock: Classification of timber inventory that includes live trees of commercial species meeting specified standards of quality or vigor; cull trees are excluded. When associated with volume, includes only trees 5.0” in diameter at breast height (d.b.h.) and larger.

Hardwood: Technically, a dicotyledonous tree. Hardwoods typically have broad leaves and are often deciduous (they lose their leaves during winter); e.g., maple, oak, aspen, cherry and ash.

Harvesting: The process of felling trees for removal and use. More broadly, may also be used to include related activities, such as the skidding, processing, loading and transporting of forest products.

Hazardous air pollutant (HAP): One of 189 toxic substances as defined by the 1990 Clean Air Act amendments.

Herbicide: One of a group of chemicals used to kill or suppress unwanted vegetation, usually hardwood competition or brush.

Insecticide: One of a group of chemicals used to kill or control populations of unwanted insects.

Intensive management: While forests can be intensively managed for any of a number of objectives, including wildlife habitat or recreation (e.g., hunting), “intensity” in the context of wood production relates to the extent to which specific yield-enhancing practices are employed. Intensity can characterize use of a particular practice, as well as the combination of practices that comprise the overall management system. It spans a spectrum from essentially unmanaged to highly intensive. At the latter end of the spectrum are softwood plantations, which employ even-aged management and a suite of site preparation, artificial regeneration and stand-tending practices. Uneven-aged management systems may also vary in intensity with respect to, for example, the frequency of entries and the extent of removal of biomass at each entry.

Intermittent stream: Watercourse that flows in a well-defined channel only in direct response to precipitation; such a stream is dry for a large part of the year.

Leaching: Downward movement of a soluble material through the soil as a result of water movement.

Logging debris: Also called slash. Accumulation of woody material, such as large limbs, tops, cull logs and stumps, that remains as forest residue after stem-only timber harvesting (as opposed to whole-tree harvesting). Logging debris is typically removed, displaced into piles, chopped, or burned during site preparation.

Logging residues: In this report, the portion of logging debris that is merchantable and that is removed from the site to be chipped for pulpwood or other uses. Logging residues typically make up a small fraction of total pulpwood supply.

Materials recovery facility (MRF): Facility that upgrades recyclable materials for resale to manufacturers by separating, cleaning and baling incoming materials.

Mature forest: Stage in forest development in which the original dominant trees in the forest canopy begin to die and fall, creating canopy gaps that allow understory trees to grow, and providing coarse woody debris on the forest floor. Corresponds roughly to understory regeneration stage. Sometimes used more broadly to include old-growth forest.

Mineral soil: Soil free of organic matter that contains rock less than 2” in maximum dimension.

Municipal solid waste (MSW): Includes durable goods, nondurable goods and containers and packaging that have served their useful life and have been discarded, plus food scraps and yard trimmings from residential, commercial and institutional sources. Strictly defined, MSW does not include construction and demolition debris, sludge, combustion ash and industrial process wastes.

Natural community: Discrete assemblage of interacting plants and animals, often referred to by their dominant plant associations: e.g., longleaf pine-wiregrass savanna; oak-hickory forest; beech-maple forest.

Natural disturbance: Naturally occurring events that disturb the forest by killing or felling one or more trees. Natural disturbance regimes — the typical natural disturbance patterns in a given region and forest type — vary by scale (individual tree mortality vs. wildfire over hundreds of acres), severity (light disturbance of the forest soil in a low-intensity fire vs. landslides that remove massive amounts of soil and organic matter, along with trees and vegetation), and frequency. Natural disturbance regimes typically determine the dominant forest types (which in turn help determine natural disturbance regimes): e.g., longleaf pine-wiregrass savannas in the southeast are maintained by and help to propagate frequent low-intensity ground fires.

Natural regeneration: Method for replacing trees removed through harvesting, in which new trees sprout from cut stumps or roots, or germinate from seeds present in the upper soil layer. May be used in both even-aged and uneven-aged silvicultural systems.

Non-commercial species: Tree species typically of small size, poor form or inferior quality that normally do not develop into trees suitable for industrial wood products.

Non-industrial private landowners: Private timberland owners other than forest-products companies and their subsidiaries.

Nutrients: Chemical elements required by plants for their growth and existence. Various nutrients are used for countless basic functions, such as manufacturing proteins and plant cells. The best-known plant nutrients include nitrogen and phosphorus. Low levels of key nutrients in soils can substantially limit plant growth and productivity. Nutrients may be added to soils in fertilizer to make up for inherent soil deficiencies.

Old-growth forest: The fourth and final stage of stand development, following mature forest, in which the forest canopy is generally composed of scattered remaining trees that assumed dominance following natural disturbance along with newly dominant, shade-tolerant trees. Other characteristics of old-growth forests may include accumulated coarse woody debris, snags and canopy gaps created by fallen trees. Because of these features, and the presence of an understory, old-growth forests generally exhibit complex stand vegetation, and provide habitat for many species. Development of old-growth forest generally takes from 100 to 200 years, with variation depending on forest type. The last remaining sizable area of old-growth forest in the contiguous United States lies in the Pacific Northwest; only a few small and isolated patches of old-growth remain in eastern forests. However, as a stage in stand development, old-growth forest could also develop in eastern forests (and was present in presettlement forests).

OMG: Old magazines.

ONP: Old newspapers.

Overstory: See forest canopy.

Perennial stream: Watercourse that flows throughout most of the year in a well-defined channel.

Pesticides: Chemicals used in silviculture to control unwanted insects (insecticides) or unwanted vegetation (herbicides).

Plantation: Planted stand of trees.

Pocosin: Freshwater evergreen shrub or forested bog found in the Atlantic coastal plain of the southeastern United States, primarily in the Carolinas. The term is taken from the Algonquin Indian word meaning “swamp on a hill.” Pocosins are generally found on flat, slightly elevated and very poorly drained areas between rivers, with either organic or acidic mineral soils.

Post-consumer fiber: Finished paper products that have been sold in commerce and have served their original purpose. As contained in the Resource Conservation and Recovery Act (RCRA), post-consumer material is “paper, paperboard and fibrous wastes from retail stores, office buildings, homes and so forth after they have passed through their end-usage as a consumer item, including used corrugated boxes, old newspapers, old magazines, mixed waste paper, tabulating cards and used cordage; and all paper, paperboard and fibrous wastes that enter and are collected from municipal solid waste.”

Precommercial thinning: Stand-tending method, performed relatively early in the rotation, in which a stand is thinned by cutting down poor-quality trees and unwanted species (usually left in the forest). Precommercial thinning is done to reduce competition among trees for soil moisture, nutrients, light and space.

Preconsumer fiber: Defined by the U.S. Environmental Protection Agency as “materials generated during any step of production of a product, and that have been recovered from or otherwise diverted from the solid waste stream for the purpose of recycling, but does not include those scrap materials, virgin content of a material or by-products generated from, and commonly used within, an original manufacturing process.” For paper recycling, includes trim from converting envelopes, paper plates and cups, boxes and cartons and printing runs, and over-issue publications and forms.

Purchased energy consumption: Amount of purchased electricity and fossil fuels that mills use to run the equipment and to generate process steam. Cogeneration and more efficient combustion of lignin and other wood waste decreases the purchased energy consumption of the mill.

Recycled-content paper: Paper that contains some recycled fiber.

Recycling: The process by which materials that would otherwise be destined for disposal are used to manufacture products. In basic terms, successful recycling requires that four things happen in sequence: (1) collection of recyclable materials; (2) intermediate processing to remove contaminants and to sort and compact materials for shipment; (3) manufacturing of new products; and (4) the purchase of products containing recovered materials by business and individual consumers.

Regeneration: Establishment and early development of new tree seedlings. In unmanaged forests, regeneration takes place on a variety of scales — from individual trees to large areas of forest leveled by large-scale natural disturbance, such as wildfire. In managed forests, regeneration may be natural or “artificial” (performed through planting), and may occur at the level of an individual tree or small group of trees (following selection harvests in uneven-aged silviculture) or at the level of a stand (following clearcutting or other harvesting methods in even-aged silviculture).

Residues: Bark and woody materials that are generated in primary wood-using mills when roundwood products are converted to other products. Examples are slabs, edgings, trimmings, miscuts, sawdust, shavings, veneer cores and clippings and pulp screenings; includes mill residues from bark and wood (both coarse and fine material), but excludes logging residues, which are included in roundwood.

Resource Conservation Recovery Act (RCRA): Federal hazardous and solid waste statute enacted in 1976 and amended several times, most significantly in the Hazardous and Solid Waste Amendments of 1984. Codified as Title 42 of the United States Code, Sections 6901-6987.

Riparian zone: See streamside management zone.

Rotation: In even-aged silviculture, the period of time between harvests. (Related terms: rotation age, referring to the age at which a stand is harvested, and rotation length, the length in years of the rotation.) Where production of solid wood or fiber is the management objective, the rotation age is generally timed to maximize the net economic return from the stand, allowing for considerations such as mill supply and demand. Rotation ages for pulpwood management are significantly shorter than for saw timber (although pulpwood may also be harvested from forests managed on sawtimber rotations, in the form of logs too small or otherwise unsuitable for use as sawtimber). Rotation lengths vary depending on tree species, desired product, site quality and region.

Roundwood products: Logs, bolts and other round timber generated from harvesting trees for industrial or consumer use. In this volume, which follows the conventions of the USDA Forest Service and other federal agencies, roundwood includes so-called logging residues, which are wood chips made from wood that would otherwise be left on-site.

Sawtimber: Classification of timber inventory that is composed of sawlog-sized trees of commercial species. Sawlogs are logs meeting minimum standards of diameter, length and defect; they include logs at least 8 feet long that are sound and straight, and with a minimum diameter inside the bark of 6” for softwoods and 8” for hardwoods; other combinations of size and defect may be specified by regional standards.

Secondary fiber: Recovered paper.

Sedimentation: Deposition of eroded soil into streams or bodies of water. Depending on stream flow and other site conditions, deposited sediment can settle on the stream floor, burying gravels in the streambed and degrading spawning habitat for fish. Elevated sediment concentrations in water can also harm filter-feeding organisms and may interfere with the functioning of the gills of some organisms.

Seed-tree method: Even-aged harvesting/regeneration method in which all of the merchantable timber in a stand is removed in one cutting, except for a limited number of seed trees left singly or in small groups as a seed source to facilitate natural regeneration. These trees typically are harvested after the stand has successfully regenerated.

Selection method: Harvesting/regeneration method used in uneven-aged silviculture in which mature trees are removed, individually (single-tree selection) or in small groups (group selection), from a given tract of forestland over regular intervals of time.

Shade-intolerant species: Tree species (or, more broadly, plant species) that are generally out-competed in shaded conditions but grow vigorously in full sunlight. Many commercially valuable species, such as loblolly pine and Douglas fir, are shade-intolerant. Because of their preference for light, shade-intolerant species are usually managed using even-aged systems.

Shearing: Site preparation method that involves the cutting of brush, trees or other vegetation at ground level using tractors equipped with angles or V-shaped cutting blades.

Shelterwood method: Removal of the mature timber from a stand in a series of cuttings (usually two) that extend over a relatively short portion of the rotation, in order to encourage the establishment of essentially even-aged reproduction under the shelter of a partial canopy. In irregular shelterwood, the period between the first and second cutting is extended to allow the development of a two-aged stand.

Silviculture: The art and science of establishing, tending, protecting and harvesting a stand of trees.

Single-tree selection: Method of harvesting in which individual merchantable trees are removed periodically. Natural regeneration is typically relied on to fill in the resulting gaps.

Site preparation: Silvicultural activity to remove unwanted vegetation and other material, and to cultivate or prepare the soil for regeneration.

Skid trail: Temporary, non-structural pathway over forest soil used to drag felled trees or logs to the landing.

Skidding: Short-distance moving of logs or felled trees from the stump to a point of loading.

Slash: See logging debris.

Snags: Dead but still standing trees. Snags are important habitat for many species of wildlife: an abundance of invertebrates; birds that construct or nest in cavities and/or feed on the invertebrates; and small mammals that live in the cavities.

Softwood: Coniferous, usually evergreen, tree that has needles or scale-like leaves; e.g., pine, Douglas fir and spruce.

Species diversity: Measure of the abundance and relative frequency of species in a specified area. Species diversity is often used with respect to animal or plant populations in a single stand, but can also be thought of on regional and global scales. For the purposes of biodiversity conservation, spatial scales of species diversity are hierarchical: global diversity is a higher conservation priority than regional diversity, and both are more important than local or stand-level diversity.

Stand: Contiguous group of trees sufficiently uniform in species composition, arrangement of age classes and condition to be a homogenous and distinguishable unit; also the area defined by the extent of those trees.

Streamside management zone (SMZ): May also be called buffers trips or riparian management areas. Zone of forest along a forest stream where management practices that might affect water quality, fish or other aquatic resources are modified. Properly designed SMZs effectively filter and absorb sediments, maintain shade, protect aquatic and terrestrial riparian habitats, protect channels and streambanks and promote floodplain stability. State Best Management Practices generally recommend SMZs, although restrictions and key parameters (e.g., SMZ width) vary.

Stumpage: Trees “on the stump.” Landowners sell these trees to loggers for which they are paid a given price (stumpage price).

Sulfur dioxide (SO2): Chemical compound produced when boilers burn fuel that contains sulfur. Of the fuels used in the paper industry, oil and coal generally contain the highest quantities of sulfur.

Tip fees: Solid waste disposal charges; a refuse collection truck empties or “tips” its load at a landfill, transfer station or incinerator.

Total reduced sulfur compounds (TRS): Mix of organic compound that cause the odor associated with kraft pulp mills. These compounds include hydrogen sulfide, dimethyl sulfide, dimethyl disulfide and methyl mercaptan.

Total suspended solids (TSS): Amount of solids in the effluent. They can eventually settle on the bottom of a mill’s receiving water and affect the habitat of bottom-living organisms. Well-operated treatment systems remove most of these solids. Concern remains, however, because heavy metals, dioxins and other unchlorinated compounds can be adsorbed onto the remaining suspended solids.

Toxic equivalence (TEQ): The EPA uses toxic equivalence factors (TEFs) to estimate the relative toxicity of different members of the dioxin and furan families, because they produce similar toxic effects, but at different doses. E.g., TCDD is the most toxic member of the dioxin and furan family and is assigned a toxic equivalence factor of 1.0, while the less toxic TCDF is assigned a toxic equivalence factor of 0.10. Using these factors, the sum of the toxicity of one gram of TCDD and one gram of TCDF would be equal to 1.1 grams TEQ of TCDD.

Understory: Level of vegetation between the ground and the forest canopy, or overstory.

Uneven-aged management: Class of silvicultural systems that maintain several age classes of trees simultaneously in a forest. In a managed uneven-aged forest, the objective of management is to create and maintain a certain distribution of trees: many more trees are in small size (age) classes than in large ones. The selection method, either single-tree or group selection, is the harvesting/regeneration method used in uneven-aged management.

Volatile organic compounds (VOCs): Broad class of organic gases, such as vapors from solvents and gasoline that react with nitrogen oxides in the atmosphere to form low-level atmospheric ozone.

Wetlands: Areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs and similar areas. (This definition is taken verbatim from regulations of the Environmental Protection Agency, published in the Code of Federal Regulations, Volume 40, Part 230.3(t). The U.S. Army Corps of Engineers, which shares authority over wetlands with EPA, uses the identical definition. Code of Federal Regulations, Volume 33, Part 323.2 (c).)

Whole-tree harvesting: Practice of removing entire trees at harvest, including tops, limbs, branches, twigs and leaves. In many cases, these trees are chipped whole on site to produce whole-tree chips.

Wind rowing: Silvicultural activity, associated with intensive site preparation that removes logging debris and unmerchantable woody vegetation into rows or piles to decompose or be burned.

Yarding: Method of transport from harvest area to storage landing.