Sharing Knowledge and Traditional Concepts

This glossary is an amalgamation of terms and concepts from various scientific and editorial boards. In addition, readers may find definition variations in other relevant literature. Sources appear at the bottom of the list.


AAHU: Average annual habitat units

Abatement: Refers to reducing the degree or intensity of greenhouse-gas emissions.

Abiotic: Nonliving.

Abiotic Disorder: Plant malady caused by nonliving, environmental, or artificial agents.

ACE: Allowable cut effect.

ACEC: Area of critical environmental concern.

Acid Rain: Rainwater with an acidity content more significant than the postulated natural pH of about 5.6. It is formed when sulfur dioxides and nitrogen oxides, as gases or fine particles in the atmosphere, combine with water vapor and precipitate as sulfuric acid or nitric acid in rain, snow, or fog. The dry forms are acidic gases or particulates.

Acre: An area of land measuring 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.

Adaptability: The genetic ability of plants and other living organisms to adjust or acclimate to different environments.

Adaptation: Adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploit beneficial opportunities.

Advance Regeneration (also called Advance Reproduction or Advance Growth): A seedling or sapling that develops or is present in the understory.

Adventitious Bud: Bud arising from a place other than a leaf axil or shoot tip, usually due to hormonal triggers.

Adventitious Roots: Roots arising from roots or stems have no connection to apical meristems.

Afforestation: Planting of new forests on lands that historically have not contained forests.

Age: Mean age of the trees comprising a forest, crop, or stand. The mean age of dominant (and sometimes codominant) trees is taken in woods. The plantation age is generally taken from the year the plantation was begun, without adding the age of the nursery stock. Of a tree: the time elapsed since the germination of the seed, or the budding of the sprout or cutting from which the tree developed.

Age Class: One of the intervals, commonly 10 or 20 years, into which the age range of tree crops is divided for classification or use. Also pertains to the trees included in such an interval. For example, trees ranging in age from 21 to 40 years fall into a 30-year age class; 30 designates the midpoint of the 20-year interval from 21 to 40 years.

Agroforestry: Collective name for land-use systems and technologies where woody perennials (trees, shrubs, palms, bamboos, etc.) are deliberately used on the same land-management units as agricultural crops and/or animals, in some form of spatial arrangement or temporal sequence. In agroforestry systems there are both ecological and economical interactions between the different components. Agroforestry can also be defined as a dynamic, ecologically based, natural resource management system that, through the integration of trees on farms and in the agricultural landscape, diversifies and sustains production for increased social, economic and environmental benefits for land users at all levels. In particular, agroforestry is crucial to smallholder farmers and other rural people because it can enhance their food supply, income and health.

Alkalinity: Having the properties of a base with a pH of more than 7. A common alkaline is baking soda.

Alley Cropping: Alley cropping is planting rows of trees at wide spacings with a companion crop grown in the alleyways between the rows. Alley cropping can diversify farm income, improve crop production and provide protection and conservation benefits to crops. Common examples of alley cropping plantings include wheat, corn, soybeans or hay planted in between rows of black walnut or pecan trees. Non-traditional or value-added crops may also be incorporated for extra income, including sunflowers or medicinal herbs planted in between rows of nut trees alternated with nursery stock trees. Fine hardwoods like walnut, oak, ash, and pecan are favored tree species in alley cropping systems and can potentially provide high-value lumber or veneer logs while income is derived from a companion crop planted in the alleyways.

AMSL: Above mean sea level.

Anaerobic Decomposition: The breakdown of molecules into simpler molecules or atoms by microorganisms that can survive in the partial or complete absence of oxygen.

Anaerobic: A life or process that occurs in, or is not destroyed by, the absence of oxygen.

Angiosperm: A plant that has true flowers and bears its seeds in fruits. In temperate zones, many angiosperms are deciduous trees, while in tropical zones, many are evergreen trees. Examples include oaks, willows, maples, and birches.

Annual Ring: The combination of one earlywood layer (light colored) and one latewood layer (dark colored) seen in a cross-section of a tree. One annual ring usually represents one year of growth.

Anthracite:  A hard, black, lustrous coal containing a high percentage of fixed carbon and a low percentage of volatile matter. Often referred to as hard coal.

Anthropogenic: Caused by or resulting from people. Usually used to describe emissions produced by human activity.

Appropriate Forest Cover: Vegetation composed of plant communities, which would occur naturally on similar sites depending upon the stage of plant succession. Forbs, grasses, and shrubs in their proper ratios are also elements of forest cover.

Area Regulation: Method of controlling the annual or periodic acreage harvested from a forest, despite fluctuations in fiber-yield volumes. Leads to a managed forest.

Arid: An area where rainfall is insufficient to support large amounts of vegetation. Regions with arid climates are those with persistent high pressure, such as those under subtropical anticyclones, or those with topography that prohibits moisture-bearing systems from entering.

Artificial Regeneration (Reproduction): A group or stand of young trees created by direct seeding or by planting seedlings or cuttings.

Atmosphere:  The mixture of gases surrounding the Earth. he Earth’s atmosphere consists of about 79.1 percent nitrogen (by volume), 20.9 percent oxygen, 0.036 percent carbon dioxide and trace amounts of other gases. The atmosphere can be divided into a number of layers according to its mixing or chemical characteristics, generally determined by its thermal properties (temperature).


Bacteria: One-celled organisms. Many act as decomposers that break down dead organic matter into substances that dissolve in water and are used as nutrients by plants.

Bare-root Seedling: Tree seedling grown in a nursery bed. When large enough for transplanting, the seedling is lifted from the nursery bed and the dirt is removed from the roots before packaging.

Bark: The tough exterior covering of a woody root or stem that protects the tree from injury caused by insects and other animals, by other plants, by disease, and by fire.:

Benefit-Cost Ratio: Ratio obtained by dividing the anticipated benefits of a project by its anticipated costs. Either gross or net benefits may be used as the numerator.

BEST: Biomonitoring of Environmental Status and Trends.

Best Management Practices: Procedures employed during harvesting and/or timber stand improvement activities that reduce erosion and prevent or control water pollution.

Biltmore Stick: Similar to a yardstick, but usually about 25 inches long. The stick is scaled on one side and is held horizontally at arm’s length against the tree at breast height to measure its diameter. This stick features a Merritt hypsometer that measures tree height from 66 feet away from the tree’s base. The stick’s volume table is used to determine the tree’s volume based on these two measurements.

BINGO: Business and industry non-governmental organizations.

Biodegradable:  Material that can be broken down into simpler substances (elements and compounds) by bacteria or other decomposers. Paper and most organic wastes such as animal manure are biodegradable.

Biodiversity: As a term used to describe the variety of living species on Earth, biodiversity refers to the number of plants, animals, bacteria, and fungi.

Biofuel: Gas or liquid fuel made from plant material (biomass). Includes wood, wood waste, wood liquors, peat, railroad ties, wood sludge, spent sulfite liquors, agricultural waste, straw, tires, fish oils, tall oil, sludge waste, waste alcohol, municipal solid waste, landfill gases, other waste, and ethanol blended into motor gasoline.

Biogeochemical Cycle: Natural processes that recycle nutrients in various chemical forms from the environment, to organisms, and then back to  the environment. Examples are the carbon, oxygen, nitrogen, phosphorus, and hydrologic cycles.

Biological Oxygen Demand (BOD): Amount of dissolved oxygen needed by aerobic decomposers to break down the organic materials in a given volume of water at a certain temperature over a specified time period.

Biomass Energy: Energy produced by combusting biomass materials such as wood. The carbon dioxide emitted from burning biomass will not increase total atmospheric carbon dioxide if this consumption is done on a sustainable basis (i.e., if in a given period of time, regrowth of biomass takes up as much carbon dioxide as is released from biomass combustion). Biomass energy is often suggested as a replacement for fossil fuel combustion.

Biomass Fuels or Biofuels: Plant-derived fuel derived from dry organic matter or combustible oils. Firewood, alcohol fermented from sugar, and soy-based combustible oils are renewable fuels as long as the vegetation that produces them is maintained or replanted. Since the plants that are the fuel sources absorb carbon dioxide from the atmosphere, their use reduces greenhouse gas emissions.

Biosphere: The living and dead organisms found near the earth’s surface in parts of the lithosphere, atmosphere, and hydrosphere. The part of the global carbon cycle that includes living organisms and biogenic organic matter.

Biotic: Living. Living organisms make up the biotic parts of ecosystems.

Blue Carbon: Carbon captured by the world’s coastal ecosystems and oceans.

Board FootA unit of measure equal to a board that is 1 inch thick, 12 inches long and 12 inches wide, or 144 cubic inches.

Bole: The main trunk of a tree.

Bonn Agreements: Informal term for a political deal reached at COP-6 in Bonn, Germany, in 2001, by which governments agreed on the most politically controversial issues under the Buenos Aires Plan of Action. The Bonn agreements paved the way for the Marrakech Accords later in the same year.

Broadleaf: A class of trees that have broad, flat leaves of many different shapes; most are deciduous; also called hardwood because most broad-leaved trees have harder wood than do conifers. Examples include oak, hickory, maple and ash.

Buffer Zone: The zone or strip of land around a forest, national park, or any other conservable area where the local community can obtain items that would otherwise be obtained from the forest or where alternative products can be produced. Streamside buffers protect water quality, while visual buffers screen the view along roads. Forest pests can also be controlled with buffers.

Bush Fallow: The natural vegetation that arises when land is left uncultivated for some time. Composed of small trees, shrubs, grasses (and sedges) and herbaceous plants. Bush fallow may be grazed or browsed and firewood collected from it before it is returned to cultivation.


Cambium: Layer of living cells between the wood and the innermost bark of a tree. Each growing season the cambium adds a new layer of cells (by cell division) on the wood already formed, as well as a layer of inner bark on the cambium’s outer face.

Canopy: The “roof” of the forest formed by the crowns of the tallest trees.

Capacity Building: In the context of climate change, the process of developing the technical skills and institutional capability in developing countries and economies in transition to enable them to effectively address the causes and results of climate change.

Carbon Credit: Permit or certificate that allows the emission of one ton of carbon dioxide or the equivalent of another greenhouse gas.

Carbon Cycle: All carbon reservoirs and exchanges of carbon from reservoir to reservoir by various chemical, physical, geological, and biological processes. Usually thought of as a series of the four main reservoirs of carbon interconnected by pathways of exchange. The four reservoirs, regions of the Earth in which carbon behaves in a systematic manner, are the atmosphere, terrestrial biosphere (usually includes freshwater systems), oceans, and sediments (includes fossil fuels). Each of these global reservoirs may be subdivided into smaller pools, ranging in size from individual communities or ecosystems to the total of all living organisms (biota).

Carbon Equivalent: A metric measure used to compare the emissions of the different greenhouse gases based upon their global warming potential (GWP). Greenhouse gas emissions in the United States are most commonly expressed as “million metric tons of carbon equivalents” (MMTCE). Global warming potentials are used to convert greenhouse gases to carbon dioxide equivalents.

Carbon Market: A popular (but misleading) term for a trading system through which countries may buy or sell units of greenhouse-gas emissions in an effort to meet their national limits on emissions, either under the Kyoto Protocol or under other agreements, such as that among member states of the European Union. The term comes from the fact that carbon dioxide is the predominant greenhouse gas, and other gases are measured in units called “carbon-dioxide equivalents.”

Carbon Neutrality: A state in which carbon dioxide emissions are zero (also referred to as net-zero).

Carbon Offsets: Tradeable carbon offsets are certificates or “rights” tied to activities that lower atmospheric carbon dioxide (CO2). An individual or group can purchase carbon offset certificates in place of taking actions to lower their own carbon emissions. As a result, the certificates “offset” the buyer’s CO2 emissions with an equal reduction somewhere else.

Carbon Sequestration: a natural or artificial process by which carbon dioxide is removed from the atmosphere and held in solid or liquid form. It may be contained in a reservoir.

Carbon Trading: A market-based mechanism for helping mitigate the increase of CO2 in the atmosphere. Carbon trading markets are developed that bring buyers and sellers of carbon credits together with standardized rules of trade.

Carrying Capacity: The maximum number of healthy wildlife that a given habitat or area can support without degradation of the habitat.

CCF: One hundred cubic feet.

CFL: Commercial forestland.

Cellulose: The scientific name for wood fiber.

Certified Emission Reductions (CER): A Kyoto Protocol unit equal to 1 metric tonne of CO2 equivalent. CERs are issued for emission reductions from CDM project activities. Two special types of CERs called temporary certified emission reduction (tCERs) and long-term certified emission reductions (lCERs) are issued for emission removals from afforestation and reforestation CDM projects.

Chlorofluorocarbons (CFCs):  Organic compounds made up of atoms of carbon, chlorine, and fluorine. An example is CFC-12 (CCl2F2), used as a refrigerant in refrigerators and air conditioners and as a foam blowing agent.  Gaseous CFCs can deplete the ozone layer when they slowly rise into the stratosphere, are broken down by strong ultraviolet radiation, release chlorine atoms, and then react with ozone molecules.

CH4: Methane.

Clearcut: A harvesting and regeneration method that removes all trees within a given area. Most commonly used in pine and hardwood forests that require full sunlight to regenerate and grow efficiently.

Clearcutting Regeneration Method with Reserves: A clearcutting regeneration method in which varying numbers of reserve trees are retained to achieve goals other than regeneration. This method produces a two-aged stand in which varying numbers of reserve trees are not harvested. If a minor, live component is left for snag replacement, the method is considered a clearcut method rather than clearcut with reserves.

Clearcutting Regeneration Method: The cutting of essentially all trees, producing a fully exposed microclimate for the development of a new age class. Regeneration can be from natural seeding, direct seeding, planted seedlings, coppice, or advance reproduction. Cutting may be done in groups or patches (group or patch clearcutting), or in strips (strip clearcutting). The management unit or stand in which regeneration, growth, and yield are regulated consists of the individual clearcut stand. When the primary source or regeneration is advance reproduction, the preferred term is overstory removal.

Climate Feedback: An atmospheric, oceanic, terrestrial, or other process that is activated by direct climate change induced by changes in radiative forcing. Climate feedbacks may increase (positive feedback) or diminish (negative feedback) the magnitude of the direct climate change.

Climate Lag: The delay that occurs in climate change as a result of some factor that changes very slowly. For example, the effects of releasing more carbon dioxide into the atmosphere may not be known for some time because a large fraction is dissolved in the ocean and only released to the atmosphere many years later.

Climate Sensitivity: The equilibrium response of the climate to a change in radiative forcing; for example, a doubling of the carbon dioxide concentration.

Climate System (or Earth System): The atmosphere, the oceans, the biosphere, the cryosphere, and the geosphere, together make up the climate system.

CO2: Carbon dioxide.

Community Forestry: Forestry developed in areas marginal to agriculture, with many members of the community being landless or small-scale farmers, often characterized by ecological and cultural diversity and the employment of traditional technologies. Communal land development is basic to this type of forestry.

Competition: The struggle between trees to obtain sunlight, nutrients, water and growing space. Every part of the tree, from the roots to the crown, competes for space and food.

Conifer: A class of trees that are evergreen, have needle or scalelike foliage and conelike fruit; often called softwood. Examples include pine, hemlock, cedar and cypress.

Conservation: Planned management and wise use of natural resources for present and future generations.

Coppice Regeneration Method with Reserves: A coppice regeneration method in which varying numbers of reserve trees are retained to achieve goals other than regeneration. This method normally creates a two-aged stand. If a minor, live component is left for snag replacement, the method creates an even-aged stand.

Coppice Regeneration Method: An even-aged method of regenerating a stand in which the trees in the previous stand are cut and the majority of regeneration is from sprouts or root suckers.

Cord: A standard unit of measure equivalent to 128 cubic feet of round or split wood. A standard cord measures 4 feet by 4 feet by 8 feet. A face cord or short cord is 4 feet by 8 feet by any length of wood under 4 feet.

Cover: (a) Any plant that intercepts rain drops before they reach the soil or that holds soil in place; (b) a hiding place or vegetative shelter for wildlife from predators or inclement weather.

Crop Rotation: Planting the same field or areas of fields with different crops from year to year to reduce depletion of soil nutrients. A plant such as corn, tobacco, or cotton, which remove large amounts of nitrogen from the soil, is planted one year. The next year a legume such as soybeans, which add nitrogen to the soil, is planted.

Crown: The branches and foliage at the top of a tree.

Cruise: A survey or inventory of forestland to locate timber and estimate its quantity by species, products, size, quality or other characteristics.

Current Maintenance Reforestation: All acres in need of reforestation that have been deforested by any natural or human cause, such as fire, wind, insects, disease, or timber harvest since July 1, 1975. The National Forest Management Act (NFMA) requirement that all backlog reforestations be completed by September 30, 1985, was accomplished; therefore, all reforestation is now considered current work.

Cyds: Cubic yards, used to measure quantities of sand and gravel.


Deciduous: A group of trees that lose all their leaves every year.

Decomposition: The process by which organic material such as leaves and branches are broken down by bacteria, fungi, protozoans and the many kinds of animals that live in the soil.

Degazettement: The loss of legal protection for an entire protected area.

DEIS: Draft Environmental Impact Statement.

Dendrology: The study of trees; tree identification.

Desertification: Desertification is a phenomenon that ranks among the greatest environmental challenges of our time. Although desertification can include the encroachment of sand dunes on land, it doesn’t refer to the advance of deserts. Rather, it is the persistent degradation of dryland ecosystems by climate change and mainly human activities: unsustainable farming that depletes the nutrients in the soil, mining, overgrazing (animals eat away grasses and erode topsoil with their hooves) and clear-cutting of land, when the tree and plant cover that binds the soil is reDmoved. It occurs when trees and bushes are stripped away for fuelwood and timber, or to clear land for cultivation. Wind and water erosion aggravate the damage, carrying away topsoil and leaving behind a highly infertile mix of dust and sand. It is the combination of these factors that transforms degraded land into desert.

DFC: Desired future condition.

Diameter at Breast Height (DBH)Tree diameter measured at 4.5 feet above ground level.

Direct Seeding: Spreading seed over the forest seedbed by hand or machine. Practice used to assist or supplement natural seed fall to achieve regeneration.

DOG: Designated old growth


Earlywood: Wood cells produced at the beginning of a tree’s growing season that are generally light in color. Also called springwood.

Ecological Succession: The gradual change of plant and animal communities over time.

Ecology: The science or study of the relationships between organisms and their environment.

Ecosystem: The complex system of plant, animal, fungal, and microorganism communities and their associated non-living environment interacting as an ecological unit. Ecosystems have no fixed boundaries; their parameters are set to the scientific, management, or policy question being examined. Depending upon the purpose of analysis, a single lake, a watershed, or an entire region could be considered an ecosystem.

Ecosystem Services: Ecosystem services refer to the benefits humans obtain directly or indirectly from ecosystems. They can be divided into provisioning services (food, water, wood, raw materials), regulating services (pollination of crops, flood and disease control, water purification, prevention of soil erosion, sequestering carbon dioxide), cultural services (recreational, spiritual and educational services) and supporting services (nutrient cycling, maintenance of genetic diversity).

Environmental Credit Trading (ECT): In contrast with command-and-control regulations, ECT represents a market-based approach to comply with regulations that could lead to pollution abatement efforts at a lower cost to society. Regulatory firms can meet their obligations by purchasing p: ollution abatement credits from lower-cost providers through environmental credit trading.

Environmental Impact Statement (EIS): A document intended to provide decision makers and the public with information about the potential impacts of major federal actions and alternatives to them. Federal agencies prepare an EIS if a proposed federal action is determined to significantly affect the quality of the human environment, as required by the National Environmental Policy Act (NEPA).

Edge: The transition between two different types or ages of vegetation.

EITI Standard: The Extractive Industries Transparency Initiative Standard is an international standard for openness around the management of revenue from natural resources. Governments disclose how much they receive from extractive companies operating in their country and these companies disclose how much they pay. Governments sign up to implement the EITI Standard and must meet seven requirements. In 2017, the U.S. withdrew from EITI as an Implementing Country, but remains committed to institutionalizing the EITI principles of transparency and accountability.

Emission Reduction Unit (ERU): A Kyoto Protocol unit equal to 1 metric tonne of CO2 equivalent. ERUs are generated for emission reductions or emission removals from joint implementation projects.

Emissions Trading: One of the three Kyoto mechanisms, by which an Annex I Party may transfer Kyoto Protocol units to, or acquire units from, another Annex I Party. An Annex I Party must meet specific eligibility requirements to participate in emissions trading.

Endangered Species: Any species that has been classified by the U.S. Fish and Wildlife Service or a state wildlife agency as being in danger of extinction throughout all or a significant portion of its range. A species is endangered when the total number of remaining members may not be sufficient to reproduce enough offspring to ensure survival of the species.

Enhanced Greenhouse Effect: The concept that the natural greenhouse effect has been enhanced by anthropogenic emissions of greenhouse gases. Increased concentrations of carbon dioxide, methane, and nitrous oxide, CFCs, HFCs, PFCs, SF6, NF3, and other photochemically important gases caused by human activities such as fossil fuel consumption, trap more infra-red radiation, thereby exerting a warming influence on the climate.

Environment: The sum of all external living and non-living conditions and influences that affect the development and survival of an organism.

Environmental, Social, and Governance Criteria (ESG): Refers to a collection of corporate performance evaluation criteria that assess the robustness of a company’s governance mechanisms and its ability to manage its environmental and social impacts effectively. Examples of ESG data include quantifying a company’s carbon emissions, water consumption or customer privacy breaches. Institutional investors, stock exchanges and boards increasingly use sustainability and social responsibility disclosure information to explore the relationship between a company’s management of ESG risk factors and its business performance. In investing: Measure of greater risk and reward management.

Erosion: The wearing away or removal of land or soil by the action of wind, water, ice, or gravity.

Evapotranspiration: The loss of water from the soil by evaporation and by transpiration from the plants growing in the soil, which rises with air temperature.

Even-Aged Management: Silvicultural system in which the individual trees originate at about the same time and are removed in one or more harvest cuts, after which a new stand is established.

Even-Aged Methods: Regeneration and maintenance of a stand with a single age class.

Even-Aged Silvicultural System: A planned sequence of treatments designed to maintain and regenerate a stand with predominately one age class. The range of tree ages is usually less than 20 percent of the rotation (see also clearcuttingseed-treeshelterwood, and coppice regeneration methods).

Even-Aged Stand: A stand of trees composed of a predominately single age class in which the range of tree ages is usually less than 20 percent of the intended rotation (also clearcuttingseed-treeshelterwood, and coppice regeneration).

Evergreen: A group of trees that do not lose all their leaves every year but go through a gradual replacement by dropping only their oldest leaves each year. Instead of being bare in winter, these trees have leaves all year.

Extractive Industry: Oil, gas, and mining industries that extract natural resources.


FAO: Food and Agriculture Organization of the United Nations.

Fair Market Value: The estimated price for a natural resource lease, based on the government’s analysis and the geological resources on the lands or waters.

Farm Forestry: Growing trees for timber, poles, fuelwood on farmland. This may be done in small woodlots or as boundary plantings.

Farmer Managed Natural Regeneration (FMNR): Low-cost method of restoring land to increase food production and resilience to climate extremes among poor subsistence farmers. FMNR involves regrowing and managing trees and shrubs from stumps, sprouting roots, or seeds after trees are felled. Integrated into crops and grazing pastures, regrowing trees and shrubs reduces soil erosion and soil moisture evaporation, restores springs, and increases biodiversity. Nitrogen is also imparted to the soil by some tree species. By doing so, FMNR increases farmer incomes, provides lumber and firewood for construction, fodder and shade for livestock, and wild foods for nutrition and medicine.

Financial Rotation: Rotation of tree crops determined solely by financial considerations (which are related to biological production potential) to obtain the highest monetary values over time, in terms of optimum net present value or return on investment (ROI).

Foliage: The leaves of a tree or other plant.

Forage: Vegetation such as leaves, stems, buds and some types of bark, that can be eaten for food and energy.

Forb: Any herb other than grass.

Forest: An ecosystem characterized by 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, streams, fish and wildlife.

Forest Bathing: Shinrin-yoku, the Japanese practice of forest bathing, involves immersing yourself mindfully in nature for health purposes on a physical, mental, emotional, and social level. It can be described as a slow, mindful stroll through nature that makes use of your senses (such as sight, smell, hearing, and touch). The goal is not to reach any particular destination, it is to seek out things in nature that bring you peace and happiness. Any safe nature space can be used for forest bathing. Silence and slowness are the main principles.

Forest Floor: The lowest level of the forest that is made up of tree seedlings, dead leaves and

Forest Garden: A land-use form on private lands outside the village in which planted trees and sometimes additional perennial crops occur.

Forest Management: Caring for a forest so that it stays healthy and vigorous and provides the products and values the landowner desires.

Forest Regulation: The technical (in contrast to the administrative and business) aspects of controlling stocking, harvest, growth, and yields to meet management objectives including sustained yield.

Forest Stewardship Plan: A written document listing activities that enhance or improve forest resources (wildlife, timber, soil, water, recreation and aesthetics) on private land over a five-year period.

Forest Type: A designation or name given to a forest based on the most abundant tree type or types in the stand; groups of tree species commonly growing in the same stand because their environmental requirements are similar. Examples of North Carolina forest types include (a) pine; (b) mixed hardwood; (c) cypress, tupelo and black gum; and (d) oak and hickory.

Forest Smart Mining: An approach to mining that recognizes forest growth’s importance across many sectors, including agriculture, energy, infrastructure, and water. Embracing sustainability and inclusion, it emphasizes the fact that forests are part of a broader landscape and that changing forest cover affects other land uses and people.

Forestry: The art and science of managing forests to produce various products and benefits including timber, wildlife habitat, clean water, biodiversity and recreation.

Fuel Loading: A buildup of easily ignited leaves, pine straw, branches and trees on the forest floor.


GATT: General Agreement on Tariffs and Trade.

Geosphere: The soils, sediments, and rock layers of the Earth’s crust, both continental and beneath the ocean floors.

Global Warming Potential (GWP): The index used to translate the level of emissions of various gases into a common measure in order to compare the relative radiative forcing of different gases without directly calculating the changes in atmospheric concentrations. GWPs are calculated as the ratio of the radiative forcing that would result from the emissions of one kilogram of a greenhouse gas to that from the emission of one kilogram of carbon dioxide over a period of time (usually 100 years).

Global Warming: The progressive, gradual rise of the earth’s surface temperature thought to be caused by the greenhouse effect and responsible for changes in global climate patterns.

Grassland: Terrestrial ecosystem (biome) found in regions where moderate annual average precipitation (25 to 76 centimeters or 10 to 30 inches) is enough to support the growth of grass and small plants but not enough to support large stands of trees.

Green Bonds: A bond designed to support projects on climate change and environmental stewardship.

Greenhouse Effect: Trapping and build-up of heat in the atmosphere (troposphere) near the earth’s surface. Some of the heat flowing back toward space from the earth’s surface is absorbed by water vapor, carbon dioxide, ozone, and several other gases in the atmosphere and then reradiated back toward the earth’s surface. If the atmospheric concentrations of these greenhouse gases rise, the average temperature of the lower atmosphere will gradually increase.

Greenhouse Gases (GHGs): The atmospheric gases responsible for causing global warming and climate change. The major GHGs are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N20). Less prevalent –but very powerful — greenhouse gases are hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6).

Group Selection Regeneration Method: A method of regenerating uneven-aged stands in which trees are cut, in small groups, and new age classes are established. The width of groups is commonly approximately twice the height of the mature trees, with small openings providing microenvironments suitable for tolerant regeneration, and the larger openings providing conditions suitable for regeneration that is more intolerant. In the group selection regeneration method, the management unit or stand in which regeneration growth and yield are regulated consists of a landscape containing an aggregation of groups.

Group Selection: (a) The removal of small groups of trees to regenerate shade-intolerant trees in the opening (usually at least 1/4 acre); (b) a specific type of selective cutting.

Growth Rings: See Tree Rings

Gymnosperm: A plant whose seeds are not enclosed in flowers. Most gymnosperms produce their seeds on the surface of the scales of female cones and are pollinated by wind. Conifers are the most common type of gymnosperm.


Habitat: An area in which a specific plant or animal naturally lives, grows and reproduces; the area that provides a plant or animal with adequate food, water, shelter and living space.

Hardwoods: Trees with broad, flat leaves as opposed to coniferous or needled trees. Wood hardness varies among the hardwood species, and some are softer than some softwoods.

Harvest Activity: A reference to a specific type of cut applied under a regeneration method or intermediate treatment.

Heartwood: The central core of a tree, which is made up of dense, dead wood and provides strength to the tree. Also, the supporting pillar of the tree. Although dead, it will not decay or lose strength while the outer layers are intact. A composite of hollow, needlelike cellulose fibers bound together by a chemical glue called lignin, it is in many ways as strong as steel.

Hectare: A unit of area, used in land and sea floor measurement and equal to 10,000 square meters; 2.471 acres; 100 ares; 4,840 square yards; 107,637 square feet.

HFC: Hydrofluorocarbons.

High-Grading: A harvesting technique that removes only the biggest and most valuable trees from a stand and provides high returns at the expense of future growth potential. Poor quality, shade-loving trees tend to dominate in continually high-graded sites.

Hypsometer: Any device used for measuring tree height.


ICAO: International Civil Aviation Organization.

ICCP: International Climate Change Partnership – global coalition of companies and trade associations committed to constructive participation in international policy making on climate change.

ICLEI: International Council of Local Environmental Initiatives.

IEA: International Energy Agency.

IGO: Intergovernmental organization.

IMDA: The Indian Mineral Development Act of 1982, which increased Indian self-governance concerning extraction.

IMO: International Maritime Organization.

Impact Investing: Key objectives are positive social and environmental outcomes, not necessarily shareholder returns.

Improvement Cutting: An intermediate treatment made in a stand, pole-sized or larger, primarily to improve composition and quality by removing less desirable trees of any species.

Increment Borer: A hollow auger-like tool with a screw bit used to remove core samples from trees.

Infrared Radiation: The heat energy that is emitted from all solids, liquids, and gases. In the context of the greenhouse issue, the term refers to the heat energy emitted by the Earth’s surface and its atmosphere. Greenhouse gases strongly absorb this radiation in the Earth’s atmosphere, and re-radiate some of it back towards the surface, creating the greenhouse effect.

Integrated Landscape Management: A way of managing the landscape that involves collaboration among multiple stakeholders, with the purpose of achieving sustainable landscapes. The governance structure, size and scope, and number and type of stakeholders involved (e.g., private sector, civil society, government) can vary. The level of cooperation also varies, from information sharing and consultation, to more formal models with shared decision-making and joint implementation.

Intercropping: The cultivation of two or more crops simultaneously on the same field, with or without a row arrangement (row intercropping or ‘mixed intercropping’). Also, the growing of two or more crops on the same field with the planting of the second crop after the first one has already completed development.

Intermediate Treatment: A collective term for any treatment or tending designed to enhance growth, quality, vigor, and composition of the stand after establishment or regeneration and prior to final harvest.

Intergovernmental Panel on Climate Change (IPCC): The IPCC was founded in 1988 by the UN Environment Programme and the WMO. IPCC assesses information in the scientific and technical literature related to all significant aspects of climate change. Hundreds of scientists from around the world contribute to the IPCC as authors and thousands as reviewers. Over sixty nations’ experts have contributed to the IPCC’s periodic assessments of the scientific underpinnings of global climate change and its effects. Globally, the IPCC serves as an official advisory body to governments on the state of science on climate change and its effects, as well as the viability of adaptation and mitigation measures.

International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA): Often referred to as the International Seed Treaty, this international agreement supports global food security by allowing governments, farmers, research institutes, and agro-industries to pool their genetic resources and share the benefits from their use. Ultimately, it protects and enhances food crops while giving fair recognition to local farmers who have nurtured them for millennia. The UN FAO adopted it in 2001.

Intrinsic Value: Value inherent in something, independent of its value to others.


Jurisdictional Approach: A jurisdictional approach and a landscape approach are often used synonymously. However, the jurisdictional approach is a type of landscape approach that uses government administrative boundaries, primarily sub-national, to define the scope of action and involvement of stakeholders rather than social (e.g., indigenous community) or environmental (e.g., ecosystems, watershed) boundaries.


Keystone Species: A species whose impacts on ecosystem function and diversity are disproportionate to its abundance. Even though all species interact, some species have deeper and more far-reaching interactions, so their removal from an ecosystem often triggers cascades of direct and indirect changes on more than one trophic level, eventually leading to habitat loss and extinction of other species.

Kyoto Protocol: An international agreement standing on its own, and requiring separate ratification by governments, but linked to the UNFCCC. The Kyoto Protocol, among other things, sets binding targets for the reduction of greenhouse-gas emissions by industrialized countries.


Land Management Unit (LMU): Land management unit is a generic term to refer to an area of land that has been identified, mapped, and managed according to its intended use or productive capability, e.g., a logging concession, a private farm, a protected wetland etc. LMUs are components of a landscape. Due to siloed sectoral resource management, LMUs with competing objectives sometimes overlap. For instance, a logging concession may be granted in a protected area.

Land Use, Land-Use Change, and Forestry (LULUCF): A greenhouse gas inventory sector that covers emissions and removals of greenhouse gases resulting from direct human-induced land use, land-use change and forestry activities.

Landscape Approach: A conceptual framework whereby stakeholders in a landscape aim to reconcile competing social, economic and environmental objectives. It seeks to move away from the often-unsustainable sectoral approach to land management. A landscape approach aims to ensure the realization of local level needs and action (i.e., the interests of different stakeholders within the landscape), while also considering goals and outcomes important to stakeholders outside the landscape, such as national governments or the international community. A landscape approach may be undertaken by one or more stakeholders who engage in actions independently, or by multiple actors as part of a collaborative, multi-stakeholder process. This multi-stakeholder process is referred to as integrated landscape management.

Landscape: A landscape is a socio-ecological system that consists of natural and/or human-modified ecosystems, and which is influenced by distinct ecological, historical, economic and socio-cultural processes and activities.

Latewood: Wood cells produced at the end of the growing season that make up the darker section of an annual ring. Also called summerwood.

Leakage: That portion of cuts in greenhouse-gas emissions by developed countries — countries trying to meet mandatory limits under the Kyoto Protocol — that may reappear in other countries not bound by such limits. For example, multinational corporations may shift factories from developed countries to developing countries to escape restrictions on emissions.

Lease: A contract that allows a company to be the exclusive entity that can apply to explore for and extract natural resources within a specific tract of federal lands or waters.

Least Developed Countries (LDCs): The world’s poorest countries. The criteria currently used by the Economic and Social Council (ECOSOC) for designation as an LDC include low income, human resource weakness and economic vulnerability. Currently 48 countries have been designated by the UN General Assembly as LDCs.

Liberation Cut: A intermediate, release treatment made in a stand not past the sapling stage in order to free the favored trees from competition of older, overtopping trees.

Lifetime (Atmospheric): The lifetime of a greenhouse gas refers to the approximate amount of time it would take for the anthropogenic increment to an atmospheric pollutant concentration to return to its natural level (assuming emissions cease) as a result of either being converted to another chemical compound or being taken out of the atmosphere via a sink. This time depends on the pollutant’s sources and sinks as well as its reactivity. The lifetime of a pollutant is often considered in conjunction with the mixing of pollutants in the atmosphere; a long lifetime will allow the pollutant to mix throughout the atmosphere. Average lifetimes can vary from about a week (e.g., sulfate aerosols) to more than a century (e.g., CFCs, carbon dioxide).

Limiting Factor: Any requirement for wildlife survival that is in limited supply.

Location Not Published: Location data is not published for Native American land. It is only available at the national level. This protects private data and personally identifiable information (PII).

Loess: Loess soils are among the most fertile in the world, principally because the abundance of silt particles ensures a good supply of plant-available water, good soil aeration, extensive penetration by plant roots, and easy cultivation and seedbed production. Micaceous minerals in the silt and clay fractions provide an adequate supply of potassium for most crops, and the large amounts of total nitrogen in chernozems can maintain moderate yields of cereals without fertilizer additions. However, loess soils often contain little clay, which leads to loss of organic matter from soil types other than chernozems under arable cultivation; the resulting structural instability of the surface soil causes problems of crusting, poor germination of crops and erosion.


Mangrove: Any of certain shrubs and trees that belong primarily to the families Rhizophoraceae, Acanthaceae, Lythraceae, Combretaceae, and Arecaceae; that grow in dense thickets or forests along tidal estuaries, in salt marshes, and on muddy coasts; and that characteristically have prop roots—i.e., exposed supporting roots. The term mangrove also applies to thickets and forests of such plants. Respiratory or knee roots (pneumatophores) are characteristic of many species; they project above the mud and have small openings (lenticels) through which air enters, passing through the soft spongy tissue to the roots beneath the mud.

Mast: Fruits or nuts used as a food source by wildlife. Soft mast includes most fruits with fleshy coverings, such as persimmon, dogwood seed or black gum seed. Hard mast refers to nuts such as acorns and beech, pecan and hickory nuts.

Meristem: A region of plant tissue, found chiefly at the growing tips of roots and shoots and in the cambium, consisting of actively dividing cells forming new tissue.

Mine in Forested Area (MFA): Formal and regulated activity for extracting and processing valuable ore from the ground in forests over 1km in diameter and with a canopy density greater than 10% using modern industrial technology.

Mineral Acres: Sometimes the land’s surface owner is different from the owner of the minerals in the ground below. For instance, a state might retain mineral rights when it sells or swaps land.

Mineral Resource Potential: According to the U.S. Geological Survey, mineral resource potential is the likelihood for the occurrence of undiscovered mineral resources in a defined area.

Mitigation: In the context of climate change, a human intervention to reduce the sources or enhance the sinks of greenhouse gases. Examples include using fossil fuels more efficiently for industrial processes or electricity generation, switching to solar energy or wind power, improving the insulation of buildings, and expanding forests and other “sinks” to remove greater amounts of carbon dioxide from the atmosphere.

Mixed Stand: A timber stand in which less than 80 percent of the trees in the main canopy are of a single species.

MRV: Measurable, reportable, and verifiable. A process/concept that potentially supports greater transparency in the climate change regime.

Multi-Stakeholder Group (MSG): In the U.S., a cross-sector body comprised of members and alternates from government, industry, and civil society organizations commissioned by the Secretary of the Interior to guide and monitor EITI implementation.

Multiple-Use Management: The management of land or forest for more than one purpose, such as wood production, water quality, wildlife, recreation, aesthetics and clean air.


N2O: Nitrous oxide.

National Adaptation Programmes of Action (NAPAs): Documents prepared by least developed countries (LDCs) identifying urgent and immediate needs for adapting to climate change.

Natural Regeneration: The growth of new trees in one of the following ways without human assistance: (a) from seeds carried by wind or animals, (b) from seeds stored on the forest floor, or (c) from stumps that sprout.

Natural Resource Management: The process of managing the use and development of natural resources, in both urban and rural settings. It covers all activities concerned with the management of land, water and related resources from both an environmental and economic perspective. It can include ecosystem conservation, farming, mineral extraction, infrastructure development, and the physical planning of towns and the countryside. Landscape management is a form of natural resource management, at the landscape scale.

Nature-Based Solutions (NbS): Actions to protect, sustainably manage, and restore natural or modified ecosystems that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits.

Non-Governmental Organizations (NGOs): Organizations that are not part of a governmental structure. They include environmental groups, research institutions, business groups, and associations of urban and local governments. Many NGOs attend climate talks as observers. To be accredited to attend meetings under the Convention, NGOs must be non-profit.


Outer Bark: the tree’s protection from the outside world. Continually renewed from within, it helps keep out moisture in the rain, and prevents the tree from losing moisture when the air is dry. It insulates against cold and heat and wards off insect enemies.

Overstory Removal: The cutting of trees comprising an upper canopy layer to release advance regeneration in an understory. Overstory removal is only applicable to the clearcutting regeneration method and only when the primary source of regeneration is advance reproduction.

Ozone: A colorless gas with a pungent odor, having the molecular form of O3, found in two layers of the atmosphere, the stratosphere and the troposphere. Ozone is a form of oxygen found naturally in the stratosphere that provides a protective layer shielding the Earth from ultraviolet radiation’s harmful health effects on humans and the environment. In the troposphere, ozone is a chemical oxidant and major component of photochemical smog. Ozone can seriously affect the human respiratory system.


Patch (Group) Clearcutting: Under an even-aged method, a modification of the clearcutting method where patches (groups) are clearcut in an individual stand boundary in two or more entries. Under a two-aged method, varying numbers of reserve trees are not harvested in the patches (groups), to attain goals other than regeneration.

Per Hectare Factor: A number used to convert sample plot information to per hectare information (as in converting the plot volume to be a per hectare volume).

Permaculture (Permanent Agriculture): The design and maintenance of sustainable, ecologically favorable, energy efficient agricultural and horticultural systems. The concept includes not only agroforestry but the integration of organic farming principles and intermediate technology, the use of renewable resources and recycling, the exploitation of biodiversity, conservation and habitat protection, as well as social and institutional well-being. It can be applied to urban as well as rural environments.

PFC: Perfluorocarbon.

Phloem: The part of a tree that carries sap from the leaves to the rest of the tree. Also called inner bark.

Photosynthesis: The process by which a plant or tree combines water and carbon dioxide with energy from the sun to make glucose and oxygen.

Phytoremediation: Phytoremediation is the direct use of living plants for in situ remediation of contaminated soil, sludges, sediments, and ground water through contaminant removal, degradation, or containment.

Pioneer Species: Hardy tree and plant species that are able to occupy barren environments or previously diverse ecosystems that have been disrupted through the effects of mining, fire, or natural disasters.

Plant Succession: The progression of plants from bare ground to mature forest.

Policies and measures (PAMs): A frequently used to refer to the steps taken or to be taken by countries to reduce greenhouse-gas emissions under the UNFCCC and the Kyoto Protocol. Some possible policies and measures are listed in the Protocol and could offer opportunities for intergovernmental cooperation.

Pollard: Cutting off the top branches of a tree to encourage new growth.

Preparatory Cut: An optional type of cut that enhances conditions for seed production and establishment applied under the shelterwood regeneration methods.

Prescribed Burning: The practice of using regulated fires to reduce or eliminate material on the forest floor, for seedbed preparation or to control competing vegetation. Prescribed burning simulates one of the most common natural disturbances. Also called controlled burning.

Primary Forest: A forest that has existed since ancient times or that has remained relatively undisturbed by human activity.

Private Lands: Lands owned by citizens or corporations.

Protocol: An international agreement linked to an existing convention, but as a separate and additional agreement which must be signed and ratified by the Parties to the convention concerned. Protocols typically strengthen a convention by adding new, more detailed commitments.

Proved Reserves: Quantities of natural resources that, by analysis of geological and engineering data, can be estimated with reasonable certainty to be commercially recoverable from known reservoirs and under current economic conditions, operating methods, and government regulations.

Public Domain Lands: In the U.S., public domain lands are lands that have belonged to the federal government since they were obtained from the 13 original colonies, from Native American tribes, or through purchases from other countries and have not been dedicated to a specific use.

Pulpwood: Wood used in the manufacture of paper, fiberboard or other wood fiber products. Pulpwood-sized trees are usually a minimum of 4 inches in diameter.


Quantified Emissions Limitation and Reduction Commitments (QELROs): Legally binding targets and timetables under the Kyoto Protocol for the limitation or reduction of greenhouse-gas emissions by developed countries.


Rangeland: Land, mostly grasslands, whose plants can provide food (i.e., forage) for grazing or browsing animals.

Reclamation: The process of restoring the surface environment to acceptable pre-existing conditions, including surface contouring, equipment removal, well plugging, and revegetation.

REDD+:  Reducing Emissions from Deforestation and Forest Degradation. A framework for climate change mitigation that guides activities within the forest sector to reduce greenhouse gas emissions caused by deforestation and forest degradation, as well as ensuring sustainable forest management, and conserving and enhancing forest carbon stocks.

Reforestation Treatment: A reference to a specific reforestation activity used to establish reproduction in a stand. Treatments include planting, direct seeding, coppice or root suckers, site preparation for natural reproduction (regeneration), or natural regeneration without site preparation. These treatments typically start at the beginning phases of a regeneration method just subsequent to the harvest, such as: clearcutting, clearcutting with reserves, overstory removal, seed-tree, seed-tree with reserves, shelterwood, shelterwood with reserves, coppice, coppice with reserves, single-tree selection, and group selection.

Reforestation: Replanting of forests on lands that have previously contained forests but that have been converted to some other use.

Regeneration Method: A cutting procedure by which a new age class is created. The major methods are clearcutting, seed-tree, shelterwood, selection, and coppice. Regeneration methods are grouped into four categories: coppice, even-aged, two-aged, and uneven-aged.

Release: To free a tree from competition with its immediate neighbors by removing the surrounding trees. This occurs naturally and artificially. Also, an intermediate treatment designed to free young trees from undesirable, usually overtopping, competing vegetation.

Renewable Resource: Natural raw materials or forms of energy that can be replenished by ecological cycles and sound management.

Rent: An annual payment for leasing lands or waters, generally before production starts.

Reserve Trees: Live trees, pole-sized or larger, retained in either a dispersed or aggregated manner after the regeneration period under the clearcutting with reserves, seed-tree with reserves, shelterwood with reserves, group selection with reserves, or coppice with reserves regeneration methods. Trees are retained for resource purposes other than regeneration.

Reservoirs: A component or components of the climate system where a greenhouse gas or a precursor of a greenhouse gas is stored. Trees are “reservoirs” for carbon dioxide.

Resin: A group of sticky liquid substances secreted by plants that appear on the plant’s external surface after a wound.

Rewilding: Natural processes drive outcomes. Rewilding seeks to reinstate natural processes – for example, the free movement of rivers, natural grazing, habitat succession and predation. It is not geared to reach any human defined optimal point or end state. It goes where nature takes it.

Riparian: Located on or near a watercourse, typically a river or stream.

Roots: The underground portion of a tree that helps anchor the tree in the ground and absorbs water and nutrients from the soil.

Rotation: The number of years required to establish and grow trees to a specified size, product or condition of maturity. A pine rotation may range from as short as 20 years for pulpwood to more than 60 years for sawtimber.

Royalty: A payment for extracted natural resources, determined by a percentage of the resources’ production value.


Salvage Cut: The harvesting of dead or damaged trees, or the harvesting of trees in danger of being killed by insects, disease, flooding or other factors to save their economic value. Also, Salvage Cutting: The removal of dead trees or trees being damaged or dying due to injurious agents other than competition, to recover value that would otherwise be lost.

Sanitation Cutting: The removal of trees to improve stand health by stopping or reducing actual or anticipated spread of insects and disease.

Sawtimber: Wood of large enough size to be used to produce lumber for construction and furniture.

Sedimentation: The deposition or settling of soil particles suspended in water.

Seed Cut: A type of cut that removes trees except those needed for regeneration and reserve trees. Prepares the seed bed and creates a new age class in an even-aged or two-aged stand under the seed-tree or shelterwood regeneration method. If reserve trees are retained, it is under a two-aged method of seed tree or shelterwood regeneration methods.

Seed Tree Regeneration Method with Reserves: A seed-tree regeneration method in which some or all of the seed trees are retained after regeneration has become established to attain goals other than regeneration. This method creates an even-aged stand or a two-aged stand depending on management goals. Reserve trees may also include those trees that are not expected to provide seed for desirable regeneration.

Seed Tree Removal Cut with Reserves: Under the two-aged method, seed tree regeneration method, the final removal of some of the remaining crop trees (seed trees) after regeneration is established. Some seed trees are retained to attain goals other than regeneration.

Seed-Tree Regeneration Method: An even-aged regeneration method in which a new age class develops from seeds that germinate in fully exposed micro-environments after removal of the previous stand, except for a small number of trees left to provide seed. All trees are cut except for a small number of widely dispersed trees retained for seed production and to produce a new age class in fully exposed microenvironment. Seed trees are usually removed after regeneration is established unless some are retained to meet other resource objectives (snags replacement). Under a two-aged method (seed tree with reserves), some, or all the seed trees are retained after regeneration has become established to attain goals other than regeneration. When the Seed Tree method is employed, the sequence of activities can include 1) seed cut (establishment cut) to establish a new age class and, 2) Steed Tree removal cut.

Selective Cutting: The periodic removal of individual trees or groups of trees to improve or regenerate a stand.

Semi-Arid: A semi-arid climate is also known as a semi-desert climate or a steppe climate. It is found in regions with precipitation below potential evapotranspiration, but not as low as in a desert climate. Different semi-arid climates create different biomes, depending on variables such as temperature.

Sequential Cropping: A pattern of multi-cropping in which one crop follows another on the same land without any break (continuous cropping = continuous land occupancy) or with a break (intermittent cropping = intermittent land occupancy). Also, growing more than one crop on the same piece of land with each seasonal crop component being grown during a different time of the year.

Sequestration: Represents statutory spending limits which are withheld from certain government programs. Some program funds are returned in the following fiscal year.

SF6: Sulphur hexafluoride.

Shade-Intolerant Species: Trees which require full sunlight to thrive and cannot grow under larger trees.

Shade-Tolerant Species: Trees that can grow in shade and compete with other trees.

Shelterbelt: An extended windbreak of living trees and shrubs established and maintained for the protection of farmlands over an area usually larger than a single farm.

Shelterwood Cut: Trees in the harvest area are cut in two or more successive cuttings to provide seedlings with seeds from older trees. The result is an even-aged forest.

Shelterwood Regeneration Method: A method of regenerating an even-aged stand in which a new age class develops beneath the moderated microenvironment provided by the residual trees. When the shelterwood regeneration method is employed, the sequence of treatments can include three distinct types of cuttings: (1) an optional preparatory cut to enhance conditions for seed production; (2) a shelterwood seed cut (establishment cut) to establish a moderated micro-environment, prepare the seed bed, and create a new age class; and (3) a shelterwood removal cut to release established regeneration from competition with the overwood. Cutting may be done uniformly throughout the stand (uniform shelterwood), in groups or patches (group shelterwood), or in strips (strip shelterwood).

Shelterwood Removal Cut with Reserves: A final removal cut that releases established regeneration from competition with shelter trees after they are no longer needed for shelter under the shelterwood with reserves regeneration method. Reserve trees are retained during the final removal cut if it is a sequence of the shelterwood with reserves regeneration method (consistent with ST sequence).

Shelterwood Removal Cut: A final removal cut that releases established regeneration from competition with shelter trees after they are no longer needed for shelter under the shelterwood regeneration method.

Shelterwood with Reserves Regeneration Method: A regeneration method in which some or all the shelter trees are retained to attain goals other than regeneration. This method creates an even-aged stand or a two-aged stand if sufficient trees are reserved.

Shifting Cultivation: Found mainly in humid and subhumid climates. Different types of rotational agriculture exist; for example, those where a settlement is permanent, but certain fields are fallowed and cropped alternately. Other settlements move and clear new land once the old is no longer productive.

SIDS: Small island developing States.

Silvicultural Prescription: A document written or approved by a certified silviculturist that describes management activities needed to implement silvicultural treatment or treatment sequence. The prescription documents the results of an analysis of present and anticipated site conditions and management direction. It also describes the desired future vegetation conditions in measurable terms. It documents a planned series of treatments designed to change current stand structure and composition to one that meets management goals. The prescription normally considers ecological, economic, and societal objectives and constraints.

Silvicultural System: Process of tending, harvesting, and replacing forest trees, which results in the production of forests with distinct compositions. Systems are classified according to the method of harvest cutting used for stand reproduction.

Silviculture: The art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands to meet the diverse needs and values of landowners and society on a sustainable basis.

Single Tree Selection Regeneration Method: An uneven-aged method where individual trees of all size classes are removed uniformly throughout the stand, to promote growth of remaining trees and to provide space for regeneration.

Sink: Any process, activity or mechanism which removes a greenhouse gas, an aerosol or a precursor of a greenhouse gas from the atmosphere. Forests and other vegetation are considered sinks because they remove carbon dioxide through photosynthesis.

Site Index: A relative measure of forest site quality based on the height (in feet) of the dominant trees at a specific age (usually 25 or 50 years, depending on rotation length). Site index information helps estimate future returns and land productivity for timber and wildlife.

Smallholder Farmer: Farming on a small scale is called smallholder farming. In developing countries, smallholder farms operate on up to 10 hectares, or 24 acres, with most cultivating less than 2 hectares. Most smallholder farmers depend on relatives’ labor to meet production needs, and they typically retain a portion of their harvest for household consumption. A smallholder farmer owns or rents his or her land. Also known as a family farmer and small-scale farmer.

Snag: A standing dead or dying tree.

Socially Responsible Investing (SRI): Potential investments are screened according to specific ethical guidelines. May include issues like gambling, tobacco, etc.

Softwood: A tree in the order Coniferales. Usually evergreen, softwood trees have needles or scalelike leaves and bear cones. Among them are pines, spruces, firs, and cedars.

Soil Carbon: A major component of the terrestrial biosphere pool in the carbon cycle. The amount of carbon in the soil is a function of the historical vegetative cover and productivity, which in turn is dependent in part upon climatic variables.

Species: A group of related organisms having common characteristics and capable of interbreeding.

Spill-Over Effects: Reverberations in developing countries caused by actions taken by developed countries to cut greenhouse-gas emissions. For example, emissions reductions in developed countries could lower demand for oil and thus international oil prices, leading to more use of oil and greater emissions in developing nations, partially offsetting the original cuts. Current estimates are that full-scale implementation of the Kyoto Protocol may cause 5 to 20 per cent of emissions reductions in industrialized countries to “leak” into developing countries. Also known as rebound effects and take-back effects.

Springwood: See earlywood.

Stand Clearcutting: A type of clearcutting where removal of essentially all trees in the previous stand, producing a fully exposed microclimate for the development of a new age class. Under a two-aged method, varying numbers of reserve trees are not harvested to attain goals other than regeneration.

Stand Composition: The proportion of each tree species in a stand expressed as a percentage of the total number, basal area, or volume of all tree species in the stand.

Stand: A contiguous group of trees sufficiently uniform in age class distribution, composition, and structure, and growing on a site of sufficiently uniform quality, to be a distinguishable unit, such as mixed, pure, even-aged, and uneven-aged stands. A stand is the fundamental unit of silviculture reporting and record-keeping. Stand may be analogous to Activity Unit.

Streamside Management Zone (SMZ)An area adjacent to a stream in which vegetation is maintained or managed to protect water quality.

Strip Clearcutting: A type of clearcutting involving strip cutting in two or more entries, separated by a few years, resulting in an even-aged or two-aged stand under the clearcutting regeneration method. Reserve trees may or may not be retained. Under an even-aged method, a modification of the clearcutting method where alternate or progressive strips are clearcut in an individual stand boundary in two or more entries. Under a two-aged method, varying numbers of reserve trees are not harvested in the strips, to attain goals other than regeneration.

Strip Mining: Cutting deep trenches to remove minerals such as coal and phosphate found near the earth’s surface in flat or rolling terrain.

Subsurface Rights: A lease holder’s right to use as much of the land beneath the surface as necessary to operate under the lease.
Subsurface Mining: Underground mining, which has different and more labor-intensive techniques than surface mining.
Summerwood: See latewood.

Suppression: The process by which a tree loses its vigor due to inadequate light, water and nutrients.

Surface Mining: Removal of soil, sub-soil, and other strata and then extracting a mineral deposit found fairly close to the earth’s surface.

Surface Rights: A leaseholder’s right to use as much of the surface of the land as necessary to operate under the lease.

Sustainable Development: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Sustainable Land Management (SLM): Sustainable land management refers to the process of managing a land management unit — farms, production forests, protected areas — in a sustainable way. Sustainable land management across a range of different land management units is necessary to achieve sustainable landscapes. However, SLM commonly focuses on the site level and on particular stakeholder groups, rather than on the broader landscape level.

Sustainable Landscape: A sustainable landscape helps to meet the principles of sustainable development as defined in the UN Sustainable Development Goals. These are landscapes that can meet the needs of the present, without compromising the ability of future generations to meet their own needs. Broadly, sustainable development aims to ensure synergies and minimize trade-offs between economic, social and environmental (including climate) goals where these objectives compete.


Taungya System: An agricultural system that combines the cultivation of forest trees with the production of (seasonal) agricultural crops. It is used in the early stages of the establishment of a forest plantation. It can reduce the establishment costs as well as provide some food.

Technology Transfer: A broad set of processes covering the flows of know-how, experience and equipment for mitigating and adapting to climate change among different stakeholders.

Thinning: An intermediate treatment made to reduce stand density of trees primarily to improve growth, enhance forest health, or to recover potential mortality. Includes crown thinning (thinning from above, high thinning), free thinning, low thinning (thinning from below), mechanical thinning (geometric thinning), and selection thinning (dominant thinning).

Threatened Species: Any species that has been classified by the U.S. Fish and Wildlife Service or a state wildlife agency as likely to become endangered within the foreseeable future throughout all or a significant portion of its range. A threatened species has declining or dangerously low populations but still has enough members to maintain or increase numbers.

TPA: Trees per acre.

Transpiration: The loss of water through leaves.

Tree Caliper: A metal or wooden device consisting of an arm and two prongs, one of which is free to slide along a graduated scale on the arm. The prongs are placed against opposite sides of a tree to read its diameter on the scale.

Tree Garden: Planting several different fruit and/or nut trees in a multistoried agroforestry system (that is, for multiple products), sometimes with perennial (e.g., mushrooms, blueberries, lavender) and/or annual crops included.

Tree Rings: Each year, a tree adds to its girth, the new growth being called a tree ring. The most recently formed tree ring is the new wood near the outer part of a tree’s trunk, just beneath the bark.

Troposphere: The lowest layer of the atmosphere and contains about 95 percent of the mass of air in the Earth’s atmosphere. The troposphere extends from the Earth’s surface up to about 10 to 15 kilometers. All weather processes take place in the troposphere. Ozone that is formed in the troposphere plays a significant role in both the greenhouse gas effect and urban smog.

Trust Land: In the U.S., land for which the federal government holds title to the land, but the beneficial interest remains with a Native American individual or tribe.

TUNGO: Trade-related non-governmental organizations.

Turpentine: A distilled chemical produced from tapping into a living pine and harvesting the sap.

Two-Aged Method: Regeneration and maintenance of stands with two age classes. The resulting stand may be two-aged or tend towards and uneven-aged condition as a consequence of both an extended period of regeneration establishment and the retention of reserve trees (green trees) that may represent one or more age classes.

Two-Aged Silvicultural System: A planned sequence of treatments designed to regenerate or maintain a stand with two age classes.

Two-Aged Stand: A growing area with trees of two distinct age classes separated in age by more than plus or minus 20 percent of rotation.


Ultraviolet Radiation (UV): A portion of the electromagnetic spectrum with wavelengths shorted than visible light. The sun produces UV, which is commonly split into three bands of decreasing wavelength. Shorter wavelength radiation has a greater potential to cause biological damage on living organisms. The longer wavelength ultraviolet band, UVA, is not absorbed by ozone in the atmosphere. UVB is mostly absorbed by ozone, although some reaches the Earth. The shortest wavelength band, UVC, is completely absorbed by ozone and normal oxygen in the atmosphere.

Umbrella Species: Species with large habitat needs or other requirements whose conservation results in other species being conserved at the ecosystem or landscape level.

UN: United Nations.

UNCCD: United Nations Convention to Combat Desertification.

UNCED: United Nations Conference on Environment and Development.

UNCTAD: United Nations Conference on Trade and Development.

Understory: The area below the forest canopy that comprises shrubs, snags and small tree. Because the understory receives little light, many of the plants at this level tolerate shade and will remain part of the understory. Others will grow and replace older trees that fall.

UNDP: United Nations Development Programme.

UNECE: United Nations Economic Commission for Europe.

Uneven-Aged Methods: Regeneration and maintenance of stands with a multi-aged structure by removing some trees in all size classes either singly or in groups or in strips.

UNEP: United Nations Environment Programme.

UNFCCC: United Nations Framework Convention on Climate Change.

UNIDO: United Nations Industrial Development Organization.

Uneven-Aged Silvicultural System: A planned sequence of treatments designed to regenerate or maintain a stand with three or more age classes Includes single-tree selection and group selection regeneration methods.

Uneven-Aged Stand: A stand of trees of three or more distinct age classes, either intimately mixed or in groups.

Unorganized Land: In Alaska, over half of land is not contained in any of its 19 organized boroughs. This land (collectively called the Unorganized Borough) is divided into 10 census areas for statistical purposes.


VOCS: Volatile organic compounds.

Volume Table: A table showing the estimated average tree or stand volume based on given tree measurements, usually diameter and height.

Vulnerability: The degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change, including climate variability and extremes. Vulnerability is a function of the character, magnitude, and rate of climate variation to which a system is exposed, its sensitivity, and its adaptive capacity.


 Wastewater: Water that has been used and contains dissolved or suspended waste materials.

Water Vapor: The most abundant greenhouse gas; it is the water present in the atmosphere in gaseous form. Water vapor is an important part of the natural greenhouse effect. While humans are not significantly increasing its concentration, it contributes to the enhanced greenhouse effect because the warming influence of greenhouse gases leads to a positive water vapor feedback. In addition to its role as a natural greenhouse gas, water vapor plays an important role in regulating the temperature of the planet because clouds form when excess water vapor in the atmosphere condenses to form ice and water droplets and precipitation.

Waxes: Solid or semisolid materials derived from petroleum distillates or residues. Light-colored, more or less translucent crystalline masses, slightly greasy to the touch, consisting of a mixture of solid hydrocarbons in which the paraffin series predominates. Included are all marketable waxes, whether crude scale or fully refined. Used primarily as industrial coating for surface protection.

WCC: World Climate Conference.

WHO: World Health Organization.

WMO: World Meteorological Organization.

Weeding: A release treatment in stands not past the sapling stage that eliminates or suppresses undesirable vegetation regardless of crown position.

Wetland: Land that stays flooded all or part of the year with fresh or salt water.

Wetlands: Areas regularly saturated by surface or groundwater and subsequently characterized by a prevalence of vegetation adapted for life in saturated-soil conditions.

Windbreak: Arrangements of trees or shrubs that provide protection from high winds for animals, crops, and/or structures. Arrangements in a long line are called shelterbelts. A timberbelt is sometimes used when it is associated with the possibility of harvesting timber in the future.

Wood: A tree’s solid interior.

Wood Chemicals: Various chemicals found or occurring naturally in trees.

Wood Energy: Wood and wood products used as fuel, including roundwood (i.e., cordwood), limbwood, wood chips, bark, sawdust, forest residues, and charcoal.

WSSD: World Summit on Sustainable Development.

WTO: World Trade Organization.


Xylem: The part of the tree responsible for transporting water and nutrients from its roots to its leaves. As the xylem ages, it becomes part of the heartwood. Often called sapwood.


YOUNGO: Youth non-governmental organization.


ZIP Code: Zone improvement plan



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  14. Harvard, Earth Science Reviews, Volume 54, Issue 1, The Agricultural Importance of Loess
  15. Hectare | Definition of Hectare at
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  18. The Center for Agroforestry, University of Missouri
  19. The Commission of Ecosystem Management
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  23. United Nations Biodiversity A-Z
  24. United Nations Climate Change Glossary
  25. United States Department of the Interior, Natural Resources Revenue Data
  26. USGS, science agency for the U.S. Department of the Interior. Science Explorer (
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