Glossary of Forestry Terms - N - O

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Natural boundary the visible high water mark of any lake, stream, or other body of water where the presence and action of the water are so common and usual and so long continued in all ordinary years as to mark upon the soil of the bed of the lake, river stream, or other body of water a character distinct from that of the banks, both in vegetation and in the nature of the soil itself.
Natural disturbance regimes the historic patterns (frequency and extent) of fire, insects, wind, landslides and other natural processes in an area.
Natural justice a set of procedures designed to ensure that decisions are made fairly.
Natural range barrier a river, rock face, dense timber or any other naturally occurring feature that stops or significantly impedes livestock movement to and from an adjacent area.
Natural regeneration the renewal of a forest stand by natural seeding, sprouting, suckering, or layering seeds may be deposited by wind, birds or mammals.
Natural resource land, water and atmosphere, their mineral, vegetable and other components, and includes flora and fauna on or in them.
Naturally resistant seed sources tree species or provenances that have been shown to exhibit increased resistance to some specific pest, over that of the species or provenance that would normally be used in artificial regeneration in a particular situation.
Net down procedure The process of identifying the net land base, which is the number of hectares of forest land which actually contribute to the allowable annual cut. The process involves "netting down" the TSA gross area to the TSA gross forest area then to the TSA net forest area. Areas and/or volumes are sequentially deleted or reduced from the gross land base for a number of considerations, including: private ownership, non- forest or non-productive, environmentally sensitive, unmerchantible and inaccessible.
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Net land base See Net down procedure.
Net present value (NPV) a stand's present worth before harvesting once costs associated with its establishment and tending have been subtracted.
Net volume volume of the main stem excluding stump and top as well as the defective and decayed wood of trees or stands.
New forestry a philosophy or approach to forest management that has as its basic premise the protection and maintenance of ecological systems. In new forestry the ecological processes of natural forests are used as a model to guide the design of the managed forest.
Non-designated wilderness Areas within the provincial forest that have been zoned as wilderness through approved integrated resource management plans including regional land-use plans and Land and Resource Management Plans (LRMPs).
Non-forest land land not primarily intended for growing or supporting a forest.
Non-timber resource values values within the forest other than timber which include but are not limited to biological diversity, fisheries, wildlife, minerals, water quality and quantity, recreation and tourism, cultural and heritage values, and wilderness and aesthetic values.
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Non-timber resources a stand's present worth before harvesting once costs associated with its establishment and tending have been subtracted.
Normal forest an outdated concept, drawing on the idea of a norm or standard forest structure against which existing forest structures can be compared. A normal forest is a forest composed of even-aged fully-stocked stands representing a balance of age classes such that for a specified rotation period, one age class can be harvested in each year. At the end of the rotation, the stands that were harvested first in the cycle would be ready for harvesting again.
Not Satisfactorily Restocked (NSR) productive forest land that has been denuded and has failed, partially or completely, to regenerate either naturally or by planting or seeding to the specified or desired free growing standards for the site.
No-work zones areas in which equipment and people are not allowed during forestry operations, usually for safety or ecological reasons.
Noxious weeds any weed so designated by the Weed Control Regulations and identified on a regional district noxious weed control list.
Nurse log a larger and decomposing fallen log which acts as a germination substrate for tree species establishing in the understorey. Such logs provide moisture, nutrients and often some degree of elevation above other potentially competing vegetation on the forest floor.
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Objective the end result(s) that must be achieved through management at any given administrative level. Objectives are quantified and indicate time and agency responsibility.
Old growth old growth is a forest that contains live and dead trees of various sizes, species, composition, and age class structure. Old-growth forests, as part of a slowly changing but dynamic ecosystem, include climax forests but not sub-climax or mid-seral forests. The age and structure of old growth varies significantly by forest type and from one biogeoclimatic zone to another.
Old-growth attributes structural features and other characteristics of old-growth forests, including: large trees for the species and site; wide variation in tree sizes and spacing; accumulations of large dead standing and fallen trees; multiple canopy layers; canopy gaps and understory patchiness; elements of decay such as broken or deformed tops or trunks and root decay; and the presence of species characteristic of old growth.
Old-growth management areas areas which contain, or are managed to replace, specific structural old-growth attributes and which are mapped out and treated as special management areas.
Operable forest that portion of the production forest that, under current market conditions, can be harvested at a profit.
Operable land all lands that are not considered inoperable lands. See Inoperable lands.
Operable timber see also Timber operability. Available timber that can be economically logged with present harvesting methods after consideration of access, timber quality and market price.
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Operability line a line drawn on a map to differentiate between areas that are operable and those that are not, given status quo harvesting and reforestation technology. Inoperable areas are not economically viable to harvest without seriously impairing the site or other resource values. The operability line is used to determine the operable land base in long-run, sustained yield calculations.
Operating area geographic sub-units of timber supply areas that have been assigned to individual major licensees for the purposes of long-term planning. The boundaries are subject to change as the timber profile within a timber supply area changes over time.
Operational cruise an estimate, to a specified degree of accuracy, of the volume of timber on an area to be harvested.
Operational plans within the context of area-specific management guidelines, operational plans detail the logistics for development. Methods, schedules, and responsibilities for accessing, harvesting, renewing, and protecting the resource are set out to enable site-specific operations to proceed. Operational plans include a forest development plan, logging plan, access management plan, range use plan, silviculture prescription, stand management prescription and 5 year silviculture plan.
Option a set of assumptions representing a possible management direction. Options are constructed as a normal part of a planning process in order to provide a framework for analysis and to facilitate management decision-making.
Organic soil soil containing a high proportion (greater than 20 or 30 percent) of organic matter.
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Orthophoto a completely rectified copy of an original photograph. All variations in scale and displacements, due to relief, have been eliminated, hence the name ortho (correct) photography. Orthorphoto and orthophoto map are synonymous, an orthophoto is, very simply, a photo map.
Outslope to shape the road surface to direct water away from the cut slope side of the road.
Overlanding placing road construction fill over organic soil, stumps and other plant materials, corduroy or geotextiles, any of which is required to support the fill.
Overlay a transparent sheet (either clear or mylar matte film material) accompanying a map, on which information, colouring, or symbols are entered so that when the overlay is placed on the map the effect is identical to having entered the overlay information on the map, itself.
Overmature in even-aged management, those trees or stands past the mature stage.
Overstorey that portion of the trees in a forest of more than one storey forming the upper or uppermost canopy layer.
Overtopped trees with crowns entirely below the general level of the crown cover receiving little or no direct light from above or from the sides.
Overtopping vegetation higher than the favored species, as in brush or deciduous species shading and suppressing more desirable coniferous trees.
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