Glossary

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M

M
1,000 units.MBF is 1000 board feet of wood.
M Acre Feet
A unit of measure associated with water volume equal to 1,000 acre-feet of water. One acre-foot is 326,000 gallons of water.
Machine Planting
Mechanical equipment which opens a hole or furrow and closes it again and firms the soil about a tree seedling which is usually inserted by hand.
Macroclimate (Regional Climate)
The general large-scale climate of a large area or country, as distinguished from the mesoclimate and microclimate.
Macroeconomics
Economic studies or statistics that consider aggregates of individuals or groups of commodities; for example, total consumption, employment, or income.
Macroinverts (Macroinvertebrates)
Animals (without backbones) that will not pass through a U.S. Standard #30 sieve (0.595-millimeter mesh opening).
Macrophyte
Any plant that can be seen with the naked, unaided eye; e.g., aquatic mosses, ferns, liverworts, rooted plants, etc.
Macrophyton
Large aquatic plants that can be seen without magnification, including mosses and seed plants.
Maintenance
The personnel and dollars (costs) required to ensure the continued safe operation and/or utility of system capital facilities. The word has been used for personnel as well as for the entire system.
Maintenance Level
A formally established criterion that prescribes the intensity of maintenance necessary for the planned operation of a road.
Maintenance Level 1
This level is basic custodial care as required to protect a road investment and to see that damage to adjacent lands and resources is held to a minimum. Level 1 maintenance often requires an annual inspection to determine work, if any, is needed to keep drainage functional and the road stable. This level is the normal prescription for roads that are not open for traffic. Level 1 is to maintain drainage facilities and runoff patterns.
Maintenance Level 2
Used on roads where management requires that the road be open for a limited passage of traffic; traffic is normally minor, usually consisting of one or a combination of administrative use, permitted use, or specialized traffic. Level 1 maintenance plus logging out, brushing out, and restoring the road prism as necessary to provide passage.
Maintenance Level 3
Action on roads that are opened for public traffic and generally applies when use does not exceed 15 Average Daily Traffic (ADT). ADT should be used as a guide in determining the maintenance level and not as the sole criterion. A road may receive only one or two vehicles a day for most of the year; however, during a brief period, such as hunting season, the road may receive 20 or 30 vehicles a day. Total traffic types and planned land use are important criteria for selecting maintenance level. The road is maintained for safe and moderately convenient travel suitable for passenger cars.
Maintenance Level 4
Actions when a road is between 15 ADT and 100 ADT (see comment concerning ADT under Level 3). At this level, more consideration is given to the comfort of the user. These roads are frequently surfaced with aggregate material, but some routes may be paved to meet economical consideration of the limited aggregate resource and surface-replacement-cost factors.
Maintenance Level 5
Actions for use of 100 ADT and greater (see comment concerning ADT under Level 3). Roads in this category include both paved and aggregate surfaces. Safety and comfort are important considerations. Abrupt changes in maintenance will be posted to warn a traveler until these deficiencies are corrected.
Major Ions
Elements which are (or could be) in fairly high concentration in most natural waters, such as calcium, magnesium, sodium, potassium, bicarbonate, carbonate, sulfate, and chloride.
Major Land Use
A grouping of primary land uses into classes with similar characteristics, e.g., cropland, pasture, and forest.
Major Recreation Facility
Developed recreation facilities with substantial investment in facilities or operation costs or receiving significant recreation use. Examples are campgrounds, picnic areas, swimming areas, boating sites, and interpretive sites.
Majority Determinism
A point of view in resource planning which advocates making resource use and allocation decisions on the basis of a simple expression of the most popular choice of use or mixes of uses. This simple one-person-one-vote approach has severe problems in the land-use-planning context on several grounds. How are the alternative resource use mix choices formulated and presented to the "voters"? How is the planned-for populace defined, located and canvassed? How are the desires of transient resource users (such as campers and hikers who do not belong to organized groups) to be counted, and how are they to be weighed against the needs and desires of permanent residents and users?
Major Vegetation Types
Plant communities, which are typically named after dominant plant species that are characteristic of the macroclimate and geology of the region or subregion.
Management
The action or activities of analyzing, preparing, organizing, and directing environmental and human systems and their relations to achieve specified human objectives; controlling systems toward pre-determined end states.
Management Area
(1) An area of land that has common direction and is operated to achieve a common set of objectives throughout. (2) (USFS 2005) A specifically identified area within the "plan area" to which specific plan components (desired conditions, objectives, identification of suitable and unsuitable land uses, or special Designations) are applied.
Management-by-Objective
A management process whereby managers at various levels in an organization jointly define the organization's goals, define each individual's major responsibilities in terms of measurable results, and use these measures as guides for operating the organization and assessing unit or individual contributions to meeting the identified goals. (See goals vs objectives)
Management Concern
A matter of importance to the management of a land area, an issue or problem needing solution, usually identified internally by an agency or owner.
Management Direction
A statement of goals and objectives and the management prescriptions (see Giles' Objectives Type 6) and the associated standards and guidelines (see Giles' Objectives, Type 4) for governing them.
Management Emphasis
The specific resource outputs or benefits to be featured or enhanced.
Management Information
Data that are classified as neither an output nor an activity but are included in reports to allow managers to monitor progress; e.g., motor vehicle accident frequency used in a status report.
Management Intensity
The extent of a practice or combination of management practices designed to obtain different levels of goods and services.
Management Objective
A concise statement that describes a desired condition or function of the land to be achieved sometime in the future.
Management Opportunity
A statement of general actions, measures or treatments that address the public issue or management concern in a favorable way.
ManagementPlan
A written plan for the operation of a forest property using forestry principles. It usually reconds data and prescribes measures designed to provide for optimum use of all forest resources.
Management Practice
A specific action, measure or treatment.
Management Prescription
Statement of actions to take, and practices selected and scheduled for use in a specific area to attain stated benefits.
Management Program
Includes, but is not limited to, a comprehensive statement in words, maps, illustrations, or other media of communication, prepared and adopted setting forth objectives, policies, and standards to guide public and private uses of lands and waters. It is equivalent to a "plan" in some usage. Also the action itself.
Management Situation
A section of the planning area guide which contains a comprehensive statement of the planning area resources, its history as it may influence planning, past and present uses, and a review of the publics directly concerned with the area. The significance of the information about the area as it relates to national objectives and program targets is also important as it describes how that area is unique in its ability to contribute to satisfying human needs.
Management Type
A forest type that has been selected as the species to manage for timber yields. Normally the species is selected based on the best timber yield but expected present net value may be a more suitable criterion.
Management Unit
The finest delineation of land area, which identifies the area of land or water to which specific management decisions apply.
Management Zone
For planning purposes, areas of land with similar characteristics, whether they are social, economic, or environmental characteristics, may be delineated into management zones. Such stratification is used for planning areas to help delineate the particular area of land on which certain coordinating criteria apply.
Map, Operational
A precise, detailed, large-scale map, usually with small contour intervals but sometimes only planimetric (i.e., representing only the horizontal position of features), constructed for specific uses -- such as administrative site development, road location, bridge sites, dam sites, campground development, ski areas, and geological area maps.
Map Overlay (Overlay Map)
A transparent sheet accompanying a map, on which limited information, coloring, or symbols are entered so that when the sheet is placed on the map, the effect is identical to having entered the overlay information on the map itself. By combining several overlays, it is possible to display a variety of data combinations and classifications that would not be possible otherwise. The map may display physical or computer images. The spatial distribution of data combinations, or more exactly the areas of joint occurrence and dissimilar occurrence, may be seen on physical or computer maps.
Map, Planimetric
A map representing the horizontal position of features, in contrast to a topographic map that shows both the horizontal and vertical position of features.
Marginal Acres
The component of the regulated commercial forest land that includes areas not qualifying as standard or special components primarily because of excessive development costs, low product values, resource protection constraints, and inadequate markets.
Marginal Analysis
A type of analysis in which the only costs and benefits considered are those about which decisions can be made. Fixed benefits and costs are not considered.
Marginal Cost
The addition to total cost caused by producing one or more unit of output.
Marginal Land
Land of questionable economic capabilities for a specific purpose, probably at the financial margin, within one unit of profitability.
Market Value
Quantitative values for resources in public demand which are traded in dollars, e.g., timber, minerals, and some types of recreation.
Market-Valued Outputs
Goods and services valued in terms of what people are willing to pay for them, as evidenced by market transactions (money exchange; these include timber sales and special use permit fees). Non-market-valued outputs are not evidenced by market transactions. Their value has to be estimated by other means. These outputs include dispersed recreation and wilderness use.
Market Place
An hypothetical construct of economic theory representing the place all potential buyers and sellers of all goods and services come together, express their desires and offer their wares, through bargaining establish a price structure and production schedule, and complete their transactions. All locations where economic transactions occur treated as a single whole.
Market Value (Market Price)
A price at which both buyers and sellers are willing to do business; the market or current price. The price at which the perceived supply and demand are equal.
Marking Timber
The process of indicating what trees are to be cut or otherwise treated. Prior to timber sales it is advisable to mark with paint each tree to be harvested. One spot of paint at eye level and one on the stump portion will help determine whether unmarked trees have been cut.
Marsh
A wetland, part of the palustrine system, dominated by emergent, submerged, or floating aquatic vegetation.
Mass-Wasting
A general term for any of the variety of processes by which large masses of earth material are moved downslope by gravitational forces -- either slowly or quickly.
Mass Diagram
A graphical representation of cumulative quantities (e.g., soil or snow) over time. Each point on the curve is the sum of all preceding quantities.
Mass Instability (Slope Stability)
An evaluation of the tendency for the materials on a slope (e.g., rocks, soil, and snow) to move downhill as a large mass.
Mass Movement
Downslope unit movement of a portion of the land's surface, i.e., a single landslide or the gradual simultaneous downhill movement of a whole mass of loose earth material on a slope face.
Mast
Hard mast is the hard-shell fruit or nuts of oaks, beech, walnuts, chinquapins, and hickories. Soft mast includes the fruit and berries of dogwood, viburnums, elderberry, huckleberry, grape, raspberry and blackberry. Mast connotes that animals consume these.
Master Plan
A comprehensive, long-range plan intended to guide the growth and development of a city, town, or region, expressing official contemplations on the course its transportation, housing, and other community facilities should take, and making proposals for industrial settlement, commerce, population distribution, and other aspects of growth and development toward an ultimate state of development. There is no unified agreement on its precise meaning or use in either theory or practice. The term "master" has connotations of grandiose schemes, an ultimate state and inflexible authority. This term has been so loosely, and often incorrectly (or dishonestly), used that it has gained disfavor among planners. They now prefer to instead use the term "general plan" (see Comprehensive Plan) in the titles of their more long-range plans and proposals, because it has connotations of flexibility and thus more accurately reflects the nature of such plans. It is also used to denote a functional class of a comprehensive plan, for example, master plan for highways and thoroughfares, or those for parks and recreation.
Matrix
(1) A rectangular array of rows and columns of mathematical elements that can be combined, for example, to form sums and products. (2) Something resembling a mathematical matrix, such as a list of categories along vertical and horizontal axes with a Designation of the interactions of components at the points of intersection. Matrices may be manipulated in total in a manner similar to the algebraic manipulation of single numbers, but knowledge of special rules, called matrix algebra, is necessary for such manipulation.
Matrix, Flow
A matrix that indicates the existence, magnitude, and direction of flows between the boxes of a box and arrow diagram.
Mature Tree
A tree that has reached the desired size or age for its intended use. Size or age will vary considerably depending on the species and intended use.
Maximax
A method of choosing among alternatives by noting the attribute with the highest value for each alternative, and comparing these attributes across alternatives to choose the alternative with the maximum highest value. In order to determine the attribute with the highest value for each alternative and follow this decision rule, a very high degree of comparability between attributes within each alternative and among alternatives is needed.
Maximin
A method of choosing among alternatives by noting the attribute with the lowest value or quality standard least met for each alternative, and selecting the alternative with the most acceptable lowest valued attribute or standard. In order to determine the lowest valued attribute or worst met standard, and follow this decision rule, a very high degree of comparability between attributes within each alternative and among alternatives is needed.
Maximum Modification
A visual quality objective (VQO) meaning human activity may dominate the characteristic landscape. However, when viewed as background, the visual characteristics must be those of natural appearance within the surrounding area.
MBF (Thousand Board Foot Measure)
A symbol to indicate 1,000 board feet of wood fiber volume either in log form or after conversion into lumber. One board foot is 1 foot x 1 foot x 1 inch or 0.l44 cubic inches.
MBM
Thousand feet board measure.
MCCF -
Thousand Cunits
MCF
Thousand cubic feet. A measure of wood volume.
Meadow
(1) An herb-land used primarily for hay production. (2) Openings in forests and grasslands of exceptional productivity in arid regions, usually resulting from high water content of the soil, as in stream side situations and areas having a perched water table.
Meadow Site Class
Sites of the same dominant species and similar proportions.
Meadow Sites
Areas of relatively homogenous species composition that are visually significantly different from adjacent areas.
Meadow SiteClass
Measow sites of the same dominant species and similar proportions of species.
Mean Annual Increment and Culmination of Mean Annual Increment
(1)The average annual growth of a tree, calculated by dividing the total growth it has accrued over its life by its age in years at the time of measurement; (2) the total increment of increase of volume of a stand (standing crop plus thinnings) up to a given age divided by that age. Culmination of mean annual increment is the age in the growth cycle of an even-aged stand at which the average annual rate of increase of volume is at a maximum. In land management plans, mean annual increment is expressed in cubic measure and is based on the expected growth of stands, according to intensities and utilization guidelines assumed in the plan or its supporting Plan Document or Set of Documents(USFS 2005).
Median Lethal Dose (LD50)
The amount or concentration of a toxic substance which will result in the death of 50 percent of a group of test organisms upon exposure (by ingestion, application, injection or in their surrounding environment) for a specified period of time.
Median Tolerance Limit (TLm)
The concentration of some toxic substance at which just 50 percent of the test animals are able to survive for a specified period of exposure.
Memorandum of Understanding - MOU
An agreement with another state or federal agency making land available for occupancy or use under specified conditions.
Mensuration, Forest
A science dealing with measuring volume, growth and development of individual trees and stands and determining various products obtainable from them.
Merchantable Height
The point on a tree stem at which diameter limit requirements for a centain product are not met. Limits are: the point at which a sawlog tree is less than 5 inches in diameter, measure inside the bark (dib); a pulpwood tree less than 4 inches dib; or the point on any tree at which a defect is found that cannot be processed out.
Merchantable Timber
A tree or stand of trees which may be disposed of at a profit through conversion to salable products.
Mesic
Environmental conditions that are medium in moisture supply.
Metacommunity ecology
Metacommunity ecology is the study of the processes involved in "assembly," the gain and loss of species, and maintenance of patchily distributed communities and populations distributed across a landscape.
Meteorology
Study of the Earth's atmosphere, including its movements and other phenomena, especially as they relate to weather forecasting.
Microclimate
(1) The local climate of a site or habitat varying in size from a tiny crevice to a large land area, but being usually characterized by considerable uniformity of climate over the site involved and relatively local as compared to its enveloping macroclimate from which it differs because of local climatic factors (such as elevation and exposure). (2) A local climatic condition near the ground resulting from modification of relief, exposure, or cover. (3) The fine climatic structure of air space which extends from the very surface of the Earth to a height where the effects of the immediate character of underlying surface no longer can be distinguished from the general local climate (i.e., mesoclimate or microclimate). The microclimate varies with and in turn is superimposed upon the larger-scale conditions. While some rigid limits have been placed on the thickness of the layer concerned, it is realistic to consider variable thicknesses, e.g., the microclimate of a putting-green versus that of a redwood forest. Generally, four times the height of surface growth or structures defines the level where microclimatic overtones disappear. The word has been used to describe the climate of a cave, a plant, and an insect inside of a log.
Microeconomics
Economic studies of particular individuals or single commodities; for example, the demand for wheat or for employment in the auto industry.
Microenvironment (Microhabitat)
A small or restricted set of distinctive environmental conditions that constitute a small habitat, such as a tree stump, a dead animal, or a space between clumps of grass.
Microinverts (Microinvertebrates)
Small animals (without backbones) that will pass through a U.S. Standard #30 sieve (0.595-millimeter mesh opening).
Microrelief (Microtopography)
Minor ground surface irregularities which, when compared from a fixed point of elevation between them, display differences in elevation of not more than 1 foot within a distance of 4 feet.
Mid-range Planning (Middle Term Planning, Mid-term Planning)
Planning that combines elements of both long-range planning and short range planning, typically between 10 and 25 years in the future. Often, however, the planning process is merely divided into the short-range and long-range planning with a single dividing point, and the mid-range classification is not used.
Middle Ground (Visual Distance Zone)
Part of a scene or landscape which extends from the foreground zone 1/4 to 1/2 mile up to 3 to 5 miles from the observer. Texture, shape, and some detail are discernible at that distance. It is within this range that the emergence of shapes and patterns on the landscape can be clearly seen. Consequently this portion of a view often best shows whether human-made changes rest easily or uneasily on the landscape.
Migration Corridor
Situations, usually linked to topography and vegetation, that provide a completely or partially suitable habitat that animals move through during migrations.
Milacre Plot
A sample plot of 1/l00O acre (usually 1/10 chain square) used in reproduction or vegetation surveys.
Millwood
Timber that is used by turning mills and specialty hardwood plants.
Mine Drainage
Any water forming on or discharging from a mining operation.
Mine Drainage, Acid
Any acid water draining or flowing on, or having drained or flowed off, any area of land affected by mining.
Mine Tailings
The waste material or refuse separated and remaining after raw minerals or ore have been processed. Mining waste from open-pit mining is termed "spoils" while "tailings" is usually used for the waste from hard rock mining.
Mineral
A substance is "mineral" under the general U.S. mining laws: (1) if it is scientifically recognized as such, (2) if it is classified commercially as such or (3) if it derives from the Earth and possesses economic value and utility aside from the agricultural purposes of the surface itself. Mineral is a word of common speech and, as such, its interpretation is within the judicial knowledge and therefore a matter of law (Marvel vs. Merritt, 116 U.S. 11). It is an inorganic substance that can he extracted from the Earth for profit, whether it be solid, liquid or gas, e.g., coal, petroleum and natural gas -- even though these materials are not truly inorganic.
Mineral, Common Variety
Earth materials which, although maybe having value for use in trade, manufacture, the sciences, or in the mechanical or ornamental arts, do not possess a distinct, special economic value for such use over and above the normal uses of the general sum of such deposits. For example, sand and gravel are frequently present in abundance in most areas and that makes them a "common variety mineral". Neither mining claims nor mining claim patents can be filed for "common variety mineral" deposits.
Mineral Entry
The filing of a mining claim for public land to obtain the right to any minerals it may contain.
Mineral Entry, Withdrawals
The exclusion of mining locations and mineral development work on areas required for administrative sites by an agency and other areas highly valued by the public.
Mineral, Excepted
Types of minerals that are exempted from the regulations in the general mining laws which authorize prospecting for and development of mineral resources on public lands. The excepted minerals are: oil, gas, oil shale, coal, potassium, sodium and phosphates and in Louisiana and New Mexico, sulfur. Similarly excepted as to mineral locations made after 1955 are the common variety minerals sand, stone, gravel, pumice, pumicite, or cinders.
Mineral, Leasable
Types of minerals, the prospecting and development of which on public lands under permit or lease was authorized by the Mineral Leasing Act of February 25, 1920, as amended and supplemented (41 Stat. 437; 30 U.S.C. 181-287). For example, coal, phosphate, sodium, potassium, oil, oil shale, gas, and in some states sulfur.
Mineral, Locatable
Precious or semi-precious minerals that are not considered to be common variety minerals, i.e., not such materials as sand or gravel. Locatable mineral deposits can be claimed and the mining claim patented, thus converting it to private ownership.
Mineral Rights
The ownership of the minerals under a given surface of ground, with the legal right to enter that area and mine and remove them, including the right to use as much of the land surface as may be reasonably necessary for the conduct of mining operations. "Mineral rights" may be separated from "surface rights" ownership but, if not separated by a distinct conveyance, are included in the latter.
Mineral Soil
A soil consisting predominantly (80% or more) of and having its properties determined predominantly by inorganic matter. The soil may have an organic surface layer up to 30 centimeters thick.
Mineralization
The breakdown of organic compounds to their inorganic (i.e., mineral) forms, e.g., proteins to nitrates, phosphates, etc.
Minimal (Variety Class C)
Refers to little or no visual variety in the landscape. A monotonous or below average variety compared to the common features in the character type.
Minimal Level Management
The management strategy that would meet only the basic statutory requirements of administering unavoidable non-discretionary land uses, preventing damage to adjoining lands of other ownerships, and protecting the life, health, and safety of incidental users.
Minimum Management Requirements
Constraints or activities necessary to maintain viable wildlife populations and to prevent permanent impairment of the productivity of the land.
Minimum Viable Population
For planning purposes, a population having the estimated numbers and distribution of reproducing individuals, to ensure its continued existence throughout its existing range in the planning area.
Mining, Area Surface (Area Strip Mining)
A type of open-pit mining or strip mining that is generally practiced on gently rolling to relatively flat terrain on relatively large tracts of land and is commonly found in the mid- and far-western United States. A trench is first cut through the overburden to expose the deposit of mineral or ore to be removed. The first cut is extended to the limits of the property or deposits. The overburden from the first cut is placed on un-mined land adjacent to the cut. The mineral or ore is then removed. Once the first cut is completed, a second cut is made parallel to the first, and the overburden from the succeeding cuts is deposited in the cut just previously excavated. The final cut leaves an open trench equal in depth to the thickness of the overburden and the mineral bed removed, bounded on one side by the last spoil pile and on the other by the undisturbed highwall. The final cut may be up to a mile or more from the starting point, and the overburden from the cuts, unless graded or leveled, resembles a plowed field or the ridges of a gigantic washboard.
Mining, Auger
A mining method often used by surface mine operators when the amount of material overlying the seam from which a mineral (or ore) is being extracted gets too thick to be removed economically. Large diameter (2 to 7 feet), closely spaced holes are drilled up to 200 feet into the seam using an auger type bit whose head breaks up the deposit and whose screw-like extensions carry the material back out of the bore hole and into the open. Auger mining is usually associated with contour strip mining. It is a common practice used to recover additional tonnage after the coal to overburden ratio has become too small to render further contour strip mining economical. When the slope is too steep for contour mining, augering is often performed directly into the hillside from a narrow bench. Augers are also used to recover coal near an outcrop that cannot be extracted safely by underground mining.
Mining Claim (Claim)
One unit of the public mineral lands which a miner (claimant or association), takes for mining purposes, and holds in accordance with mining laws.
Mining Claim (Patented)
A mining claim to which a patent has been secured from the government by compliance with the laws relating to such claims. The patent is a legal document that conveys the title to the ground (i.e., ownership) to the claim's owner. No further annual assessment work need be done, but property taxes must henceforth be paid.
Mining Claim (Valid)
A claim where there is an actual discovery of valuable minerals in quantities such that it would be profitable to mine.
Mining, Contour Surface (Contour Strip Mining)
A type of strip mining that is practiced in areas of hilly topography when the coal seam is exposed on or approaches the surface at approximately the same elevation along a hill side. The conventional method of mining consists of removing the over burden from the mineral seam, starting at the outcrop and proceeding around the hillside. The cut appears as a contour line, thus, the name. Overburden is cast down the hillside and stacked along the outer edge of the operating bench. After the uncovered seam is removed, successive cuts are made until the depth of the overburden becomes too great for economical recovery of the coal. Physical limitations of equipment reach, capacity, etc., may also determine the strippable limit or cut-off point for mining. Contour mining creates a shelf or bench on the side of the hill. On the inside it is bordered by the highwall, ranging in height from a few feet to more than 100 feet; and on the outer side the pit is bordered by a high ridge of spoil with a precipitous downslope that is subject to severe erosion and landslides. Certain laws require some of these slopes to be stabilized in "return to contour" restoration activities.
Mining Debris, Hot (Hot Waste, Hot Spoils, Hot Tailings)
Refers to materials in the overburden, mining refuse, mine tailings or mining spoils piles that are highly acid and difficult to re-vegetate.
Mining Debris, Sweet (Sweet Waste, Sweet Spoils, Sweet Tailings)
Refers to materials in the overburden, mining refuse, mine tailings or mining spoils that are neutral or slightly alkaline and capable of supporting certain calcium-demanding plants.
Mining Hydraulic
See Mining, Placer.
Mining, Lode
The mining of a valuable mineral which occurs as a tabular deposit between definite, contrasting mineral or rock boundaries. "Lode", as used by miners is nearly synonymous with the term "vein" or "ore body" as employed by geologists. A lode consists of several veins spaced closely enough together so that all of them, together with the intervening rock, can be mined as a unit.
Mining, Open-pit (Opencut Mining, Open Cast Mining)
A form of mining operation which extracts minerals that occur near the surface from an open excavation. Waste materials overlying the minerals are first removed and then the mineral materials are broken up and removed. The mining of metal bearing ores by surface mining methods is commonly termed "open-pit mining" as distinguished from the strip mining of coal and the "quarrying" of other non metallic materials such as limestone, building stone, etc.
Mining, Pit
Surface mining, developing a quarry, or excavating whereby the material of value is removed from below the surrounding land surface.
Mining, Placer
The extraction of valuable heavy minerals from a placer deposit (a mass of sand, gravel or other similar alluvial material) by concentration in running water. When water under pressure is used to break down placer deposits, placer mining is generally termed "hydraulic mining".
Mining Refuse
The solid waste from a mineral preparation or refining plant.
Mining Spoils (Mining Waste)
The overburden non-ore material removed in gaining access to the ore of mineral material in mining. Contrast with "mining refuse" which is the solid waste left by mineral processing operations. Mine "tailings" is also sometimes used in this latter sense.
Mining, Strip
Any operation in connection with prospecting for, excavating, or mining minerals which results in a large-scale surface or stream bottom disturbance from stripping, trenching, dredging, rim cutting or open-pit digging. There are two general types: area and contour mining.
Mining, Surface (Strip Mining, Open Cast Mining, Open-cut Mining, Open-pit Mining)
A very broad term referring to any process of removing the earth, rock, and other strata in order to uncover the underlying mineral or fuel deposit.
Minor Recreation Facility
Developed recreation facilities with minor investment in facilities, minor operating costs, and/or low levels of recreation use. Examples are observation sites, playgrounds, fishing sites, trailheads, and minor interpretive sites.
Minority Groups
A term commonly limited to racial and ethnic minorities, but the meaning is in flux, and, by extension, may be applied to others i.e., American Indians, Oriental Americans, Appalachians, women, the young, the old, homosexuals, the imprisoned, the mentally ill, drug addicts, alcoholics, and rural migrants. trees in the main crown canopy are of a single species. MOLT. To shed the hair, outer skin, or feathers at certain intervals, to be soon replaced by a new growth. MORTALITY. Death or destruction of forest trees as a result Of competition, disease, insect damage, drought, wind, fire, and other factors.
MIS
Management Information Systems.
Mission
A major, continuing national area of concern or responsibility (e.g., of the US Forest Service) that is directed by legislation, order, or regulation. The Forest Service mission represents the basic reason for its existence as a Federal agency and characterizes the agency's role in solving broad, national problems.
Miscellaneous Land Type
A mapping unit for areas of land that have little or no natural soil, or that are too nearly inaccessible for orderly examination, or that occur where, for other reasons, it is not feasible to classify the soil. Examples are alluvial land, bad lands, made land, marsh, mine dump, mine wash, river wash, rock land, rough broken land, rubble land, scoria land, swamp, secure military areas, and urban land.
Mixed Stand
A stand in which less than 80 percent of the trees in the main canopy are of a single species.
Mission
A major problem or concern that programs are designed to address. The basic reasons for the existence of an organization in a governmental agency, a "general" or Type 1 objective, e.g., environmental improvement, rural development, agricultural production efficiency.
Mitigate
To reduce the impact of an action by moderating its force, intensity, or scope.
Mitigation
Actions to avoid, minimize, reduce, eliminate, or rectify the impact of a development or management practice.
Mitigation, Impact
Measures which are taken to minimize the significant potential environmental impacts of a given development alternative on various environmental factors, or the measurable reduction or elimination of an effect.
MM
1,000,000 units.
MMBF (Million Board Foot Measure, MMBM)
A symbol to indicate 1,000,000 board feet of wood fiber volume either in log form or after conversion into lumber.
MMCF
Million cubic feet. A measure of wood volume.
MOA
Memorandum of agreement.
Model
A representation of a thing; sometimes a facsimile. An abstraction from reality, an attempt to present some of the important features of a real thing (system) in a simplified way to aid understanding. Some models use words, pictures, diagrams, and/or mathematical equations to present an idealized representation of reality for purposes of describing, analyzing, understanding, and predicting the behavior of some aspect of it. Applicable to a broad class of representations, ranging from a relatively simple qualitative description of a system or organization, to a physical model, to a highly abstract set of mathematical equations or computer program. It is also used in the sense of a perfect or best case situation which others may try to duplicate.
Model, Conceptual
A mind's-eye perception of what something is; the image conjured up by prompting from both the physical and theoretical aspects of the entity of concern, whether that entity be a simple object, an abstract system, or a multidimensional problem.
Model, Deterministic
A model in which the state of the system results from determining causes, and those causes can be identified and adequately described without considering probabilistic elements. Each aspect or factor of the model is specified. Risk is not included.
Model, Graphical
The graphic portrayal of an idea, thought, or concept e.g., a trophic level diagram of a functional ecosystem.
Model, Mathematical
(1) A conceptual tool which relates the general characterization of a process, object, or concept in terms of mathematics, thus enabling the relatively simple manipulation of variables to be accomplished in order to determine how the process, object, or concept would behave in different situations. (2) A mathematical abstraction of a real system, with the variables in the model behaving, in some sense, as real-world analogs. There are two major values of the model: (i) to provide a framework for organizing and developing a research program and the assessing different facets of field and laboratory investigations; and (ii) to allow inferences to be made about the real system from observation and manipulation of the model, done more easily than with the real system.
Model, Mechanistic
A mechanistic model attempts to represent a biological system in terms of basic well-defined laws or relationships. A basic assumption of such a model is that the natural processes and especially life processes are mechanically determined and capable of complete explanation by the laws of physics and chemistry.
Model, Probabilistic
A model in which most of the key variables may take on more than one value which may be assigned based on probable distributions. It allows randomness to be used or studied. Such models are sometimes called stochastic which means, literally, making a best guess.
Model, Simulation
A dynamic mathematical model that mimics the functioning of a system or process by step-by-step solutions of the equations which describe the system. Such models often allow the consequences of different inputs and processes to be evaluated as to the effects that they may have on the system outputs.
Model, Stochastic (Probabilistic Model)
(1) A mathematical model the variables of which (all or some) are drawn at random from some specified distribution. (2) A model that attempts to include the effects of random variability in driving variables and parameters. (3) A stochastic model is one that does not offer a unique solution but rather a distribution of solutions with the probability of each solution corresponding to some specified probability distribution.
Model, Systems
Conceptual representations of an ecosystem of concern... not all-inclusive but rather, all encompassing. That is, they include abiotic, producer, consumer, decomposer, and nutrient components, but they may not include all of the interesting or important biological processes or parts that are found in the ecosystem. The specific miniaturization, omissions, or substitutions depend upon the objectives for the modeling activity.
Modification (VQO)
A visual quality objective meaning that people's activity may dominate the characteristic landscape but must, at the same time, utilize naturally established form, line, color, and texture, so that its visual characteristics are those of natural occurrence with the surrounding landscape.
Modified Cut Areas
Areas that will require modification of normal timber regeneration methods (leading to even-aged stands) because of landscape management quality standards or filter strip criteria. Depending on conditions in each area, cutting methods will be used which may not result in even-aged management. Variance may range from no cutting to shelterwood, selective cut, or group selection cuts.
Modified Cutting
An even-aged harvest cutting method modified to the extent that it no longer meets the definition of that even-aged harvest cutting method, but will insure the perpetuation of the desired commercial tree species. Use is limited to special management situations where normal mitigating and/or coordinating measures will not provide the desired effects for resource concerns other than timber. The selection of trees or groups of trees to be harvested is determined by a silviculturist through analyzing stand and site conditions in concert with the site specific objective for which the modified cutting is done.
Modulation
Modification of any aspect of a land use plan in order that it more nearly expresses the constituency's interpretation of the relevant goals and objectives. An adjustment of parts in proportion or relative to the whole.
Monitoring
Systematically collecting information to evaluate changes in actions, conditions, and relationships over time and space or progress toward meeting desired conditions or plan objectives.
Monitoring and Evaluation
Evaluating a sample of management practices to determine how well objectives have been met, as well as the effects of those management practices on the land and environment.
Monitoring Program, Environmental
A program for measuring anticipated disturbances in environmental systems to assure that they do not exceed acceptable limits. The program often includes certain aspects of a baseline study program selected for their ability to detect alterations in the ecosystem which are induced by a project.
Morphological Map
A morphological map represents the form of the surface of the land, e.g., a map of occurrence of various slope steepness categories.
Morphology, Land
Land "morphology" is restricted to studies of the surface form of the Earth without any reference to the processes responsible for those forms.
Most Probable Number (MPN)
A statistical evaluation of degree of water pollution based on presence of coliform bacteria. It is not feasible to identify the exact concentration of coliform bacteria in a water sample. The MPN interprets test results in terms of results observed.
Mountain Top Removal
In this mining method, 100% of the overburden covering a coal seam is removed to recover 100% of the mineral. Excess spoil material is hauled to a nearby hollow to create a valley fill.
Muck
Highly decomposed wet organic matter in which the original plant parts are not recognized.
Muck Soil
A wet soil containing between 20% and 50% organic matter.
Muddling Through
See Incrementalism.
Mulching
Providing any loose covering for exposed forest soil, using organic residues, such as grass, straw or wood fibers to protect exposed soil and help control erosion.
Multidisciplinary Team
Two or more people having different training and/or backgrounds all assembled and assembled and assigned responsibilities in the same activity or effort. Each specialist is assigned a portion of the problem and his or her partial individual solutions are linked or combined to provide the complete solution. No one discipline is sufficiently broad to solve adequately the problem. This is different from an "interdisciplinary team" which does not break the problem apart by disciplines, but instead works with frequent interaction so that each discipline may provide insights into any part of the problem and so that disciplines may combine to provide new solutions beyond the scope of any single discipline.
Multiple Use
A term and concept of long-standing debate. At least three different ideas are involved: (1) different uses of adjacent sub-areas which together form a composite multiple-use area, (2) the alternation in time of different uses on the same area, and (3) more than one use of an area at one time. In the first two ideas it is implicit that direct competition between uses is avoided by alternating them in space or in time. The third idea involves simultaneous use of one space and must deal with satisfactory resolution of conflicting activities, and incompatible uses by different groups of different size and economic, social, and political influence.

Where spatially coincident uses are involved at a given time, conflicts between resource users will almost always occur and the concept of such forms of multiple use should be realistically interpreted as a dominant use with secondary uses integrated only in so far as they are compatible with the first. However, where the idea of incompatibility relates to whether the productivity or yield of a single resource has been maximized, multiple use can perhaps be validated in terms other than single-resource production efficiency. To the single purpose resource user, multiple-use may seem inefficient or economically ruinous. Under this concept the aim of resource use allocation is to maximize the national well being, promoting general social and economic prosperity. Social needs are not necessarily best served by maximizing the production of a single resource (or even by maximizing the production of several resources) but by an over-all mix of total national resource uses that brings the greatest social and economic benefits.

In US FS 2005, "Multiple Use" was the management of all the various renewable surface resources of the National Forest System so that they are utilized in the combination (single) that will best meet the needs of the American people. Also making the most judicious use of the land for some or all of these resources or related services over areas large enough to provide sufficient latitude for periodic adjustments in the use to conform to changing needs and conditions; also that some lands will be used for less than all of the resources; and harmonious and coordinated management of the various resources, each with the other, without impairment of the productivity of the land, with consideration being given to the relative values of the various resources, and not necessarily the combination of uses that will give the greatest dollar return or the greatest unit output (Multiple Use-Sustained-Yield Act 1960, U.S.C. 528-531). Consistent with the Federal Land Policy and Management Act of 1976 (FLPMA), multiple-use includes Federal energy and mineral resources underlying National Forest System lands. Exploration and production of those resources is considered one of the "principle or major uses" under FLPMA which, under Sec. 202(e)(1) of that Act, are to be given special consideration in the planning process.


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