Glossary page A - G
Glossary page H - N

OLD GROWTH FOREST
Forest that has a significant proportion of the oldest discernible growth stage(s) in it's overstory and negligible structural evidence of disturbances.

OUTFALL DRAINAGE
Drainage which occurs when the surface of a road or track has sufficient cross slope to cause water to flow across and off the surface, rather than along it. This flow of water is away from and not into the hillside. To ensure the effectiveness of outfall drainage, any earth windrow which develops on the downslope side of the road should be removed.

OUTLET
The point at which water discharges from a river, creek or other flowline; lake; tidal basin or drainage depression; or pipe, channel, dam or other hydrologic structure.

OVERSTOCKED
The situation in which trees are so closely spaced that they compete for resources and do not reach full growth potential. Individual trees become suppressed.

OVERSTOREY
The level of forest canopy that includes the crowns of dominant, co-dominant, and intermediate trees.

OVERTOPPED CROWN
The situation in which a tree cannot sufficiently extend its crown into the overstorey to receive any direct sunlight. Overtopped trees that lack shade tolerance lose vigour and die.

PASTURE
Grasses, legumes and/or other herbage used or suitable for the grazing of animals. The term also includes the land covered by such herbage and used or suitable for grazing.

PEAK FLOW
Highest flow rate of a stream during or following a rainfall event. Usually related to a specific event recurrence interval (eg. a 1 in 10 year runoff event).

PILES
Piles are like poles except that the top of the log is driven into the soil. Specifications are similar to poles but piles are usually of larger diameter.

POLES
Logs used to support power lines and so need to be of durable species (Ironbarks, Tallowwood, Grey Box, Grey Gum etc) or species suitable for preservation treatment such as Blackbutt and Spotted Gum. The log needs to meet strict pole specifications for straightness and be generally defect free. Poles need to be of specific sizes with most of the demand for very restrictive size classes. Logs suitable for poles but outside these sizes are often not saleable as a pole.

POLLUTION
Environmentally damaging sediment, dispersed soil or manufactured chemical products in soil, water or the air.

PRESCRIBED STREAM
A prescribed stream is a river, creek, effluent or lake within the meaning of Section 21B(1) of the Soil Conservation Act, 1938. Restrictions apply to the clearing of vegetation within 20 metres of, the bed or bank of any part of a prescribed stream.

PRIVATE LAND
Land other than Public Land or land owned or leased by the Commonwealth

PRUNING
The act of removing unwanted limbs to produce trees with clearwood.

PUBLIC LAND
Lands of the New South Wales Crown.

PULPWOOD
Logs cut and prepared primarily for the manufacture of wood pulp.

RAINFOREST
Any contiguous area of woody native vegetation dominated by rainforest species and with a rainforest structure (inclusive of but not limited to Integrated Forestry Operations Approvals rainforest definition).

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

REGENERATION CUT
A timber harvest designed to promote natural re-establishment of trees.

REGIONAL FOREST AGREEMENTS
Agreements which identify and commit certain obligations on both the NSW and Commonwealth Governments to "ensure effective conservation, forest management and forest industry outcomes" for the region. They have application for both public and private lands.

REGIONAL VEGETATION MANAGEMENT PLAN
Plans prepared at a region level specifying species and vegetation communities under threat or in need of specific protection. Refer to Department of Land and Water Conservation regional offices for details.

REHABILITATE
To return an area of land or a road or track surface to an original, proper and stable condition. This may involve reshaping, spreading topsoil, construction of banks and revegetation.

RELASCOPE
A relascope is an instrument which is used for the rapid measurement of basal area at any location within a forest stand.

RELEASE
To remove overtopping trees that compete with understory or suppressed trees.

RELIC
(related to European heritage) An item of 50 years of age or more not being Aboriginal in origin relating to the settlement of the area. (related to non-European habitation) Any deposit, object or material evidence (not being a handicraft made for sale)

RELIEF PIPE (CULVERTS)
A pipe used to direct water from a table drain and under the road.

RESIDUAL STAND
The trees remaining intact following any cutting operation.

REVEGETATE
The establishment of an effective vegetative ground cover by either natural regeneration or sowing with a seed and fertiliser mixture, to prevent soil erosion. It is preferable to use sterile hybrids if using exotic species.

RILL EROSION
The removal of soil by runoff from the land surface whereby numerous small channels, generally up to 30cms deep are formed.

ROAD
Any route used for the vehicular access to, and the transport of logs from the point of loading (log dump) within the plantation area.

ROAD CONSTRUCTION
The construction of a road where no previous road existed.

ROCKY OUTCROP
An area where rocks or exposed boulders cover more than 70% of any 0.1 hectare area (30 metres by 30 metres); OR areas with skeletal soils (areas with shallow soils where rocks are exposed), supporting heath or scrub (sometimes with occasional emergent trees); OR a combination of both.

ROLLOVER CROSS BANK
A cross bank constructed with a smooth cross section, gentle batters, and well compacted to allow permanent vehicular trafficability (also Rollover Drain).

ROOST TREE
Where the roost relates to a microchiropteran bat roost tree, "roost' includes: a tree or stag where there is clear evidence that such a bat has roosted, such as a tree with a hollow at its base within which there is an accumulation of bat excreta; OR a tree where such a bat has been seen flying into or out of a hollow, crevice or other hole in the tree. Where the roost relates to a threatened owl roost, "roost" includes a site where an owl has been observed roosting (that is sheltering or resting during the day); OR a site where there is clear evidence that an owl has roosted such as where there are owl pellets, remains of prey, or owl excreta: OR both.

RURAL FIRES ACT
This Act deals with all aspects of bush fire control and prevention in NSW. In certain circumstances, this Act can take precedence over other acts in relation to soil disturbance and water pollution where fire prevention or control measures are undertaken.

ROT
A tree defect characterised by woody decay in a standing tree or log.

ROTATION
The number of years required to grow a stand to a desired size or maturity.

RUNOFF
That portion of the precipitation falling on a catchment area that flows from the catchment past a specified point.

SALINE SOIL
A soil which contains sufficient soluble salts to adversely affect plant growth or land use.

SALVAGE CUT
The removal of dead, damaged, or diseased trees to recover maximum value prior to deterioration to unsaleability.

SALVAGE LOGS
Logs or sections of logs that do not make the specifications for other products but still contain sufficient recoverable timber to cover the harvesting and milling costs. Generally sizes and species have little relevance but individual millers often have preferences. The quality of logs taken as salvage varies with market conditions (especially for pallet timbers) and with harvesting and haulage costs.

SAP FEED TREE
A tree with recent V-notch incisions or other incisions made by a Yellow-bellied Glider or Squirrel Glider. Recent incisions are incisions less than two years old as evidenced by non-occlusion of the incision (ie where the incision has not closed).

SEDIMENT
Particles of soil material that have been transported or deposited by water flow.

SEDIMENT TRAP
A structure or vegetative barrier designed to collect soil material transported in run-off and also to reduce water flow velocity and therefore scouring and erosion. Sediment traps mitigate siltation of natural drainage features.

SEEPAGE
The process by which water percolates downwards and/or laterally through the soil, often emerging at ground level lower down the slope.

SEEPAGE AREA
A depression in the ground where water collects, on or below the surface; a place where water oozes slowly out of the ground; or a place where the ground is wet or spongy.

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

SHEET EROSION
The removal of a fairly uniform layer of soil from the land surface by raindrop splash and/or runoff. No perceptible channels are formed.

SILVICULTURE
Silviculture is the art and science of growing and maintaining trees. It is an inexact science and its practice is based on experience, intuition, research, examination of the published literature and observations made in the forest.

SLASH
Tree debris left following the felling, processing and extraction of logs

SMALL SAWLOGS
Sawlogs having a centre diameter under bark of less than 40 cm.

SNIG TRACK
An extraction track used by snigging or skidding equipment while pulling logs.

SNIGGING
The pulling of logs, either wholly or partly supported on the ground, from the point of felling to the log dump.

SOIL EROSION HAZARD
Refers to the susceptibility of an area of land to soil erosion as a result of rainfall erosivity, slope, soil erodibility and cover. Soil erosion hazard classes are Low, Moderate, High and Extreme.

SOIL ERODIBILITY
A term applied to classify a soil on the basis of its susceptibility to erosion through rainfall and surface runoff of water. Soil erodibility classes are Low, Moderate and High.

STABILISATION
The provision of adequate measures, vegetative, structural and/or mechanical, to prevent or control erosion.

STABLE
The condition of a parcel of land or flowline which experiences no appreciable soil erosion or sedimentation and is thus, under current management, adequately protected from erosive agents. The term is also used to describe a soil conservation or hydraulic structure which is functioning effectively and is not adversely affected by erosive agents.

STABLE OUTLET
An outlet which is adequately protected form erosion and is stable under current conditions.

STAG
A standing dead and dry tree greater than 30 centimetres diameter at breast height, and greater than three metres in height.

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

STAND DENSITY
The quantity of trees per unit area, usually evaluated in terms of basal area, crown cover and stocking.

STANDING TIMBER
The volume of standing wood assessed (usually by sampling)

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

SUPPRESSED CROWN
Crown the situation in which a tree cannot sufficiently extend its crown into the overstorey to receive any direct sunlight. Overtopped trees that lack shade tolerance lose vigour and die.

SWEEP
A tree defect characterised by a gradual curve in the main stem.

STATUTORY BUSH FIRE DANGER PERIOD
The period of the year during which restrictions on lighting and maintaining fires in the open are enforced through proclamation under the Bush Fires Act. The Bush Fire Danger Period is normally proclaimed from 1 October to 31 March but may be varied by local government authorities to meet specific seasonal requirements in any particular year.

STRAHLER SYSTEM
Is a system of ordering watercourses.

• Starting at the top of a catchment, any watercourse which has no other watercourses flowing into it is classed as a 1st order watercourse.
• Where two 1st order watercourses join, the watercourse becomes a 2nd order watercourse.
• If a 2nd order watercourse is joined by a 1st order watercourse, it remains a 2nd order watercourse.
• When two or more 2nd order watercourses join they form a 3rd order watercourse.
• A 3rd order watercourse does not become a 4th order watercourse until it is joined by another 3rd order watercourse.
• And so on.

STREAMBANK EROSION
The removal of soil from streambanks by the direct action of stream flow and/or wind/wave action. Typically occurs during periods of high flow.

STREAM PRESCRIBED
A prescribed stream is a river, creek, effluent or lake within the meaning of Section 21B(1) of the Soil Conservation Act, 1938.

STUMPAGE
Stumpage or royalty rates represent net sale proceeds after harvesting, cartage, on-site roading and selling costs are taken into account.

SURFACE RUNOFF
That portion of rainfall that is not immediately absorbed into the soil and becomes overland flow

SUSTAINABLE YIELD
The long term estimated wood yield from forests that can be maintained from a given area in perpetuity under a given management strategy and suite of sustainable use objectives

SWAMP
A vegetated depression with a seasonal or permanent water table at or slightly above the floor of the depression.

TABLE DRAIN
The side drain of a road adjacent to the shoulders and comprising part of the road formation.

THINNING
The cutting and removal of trees to increase distance between trees that have the potential to yield high quality timber, for the purpose of promoting their growth by:

• Removing poorer quality trees, and
• If removing poorer quality trees does not result in sufficient distance between trees, removing other trees

THREATENED SPECIES
Any species of plant or animal listed in Schedule 1 Part 1 (endangered species), Part 4 (presumed extinct) and Schedule 2 (vulnerable species) of the Threatened Species Conservation Act 1995.

TOLERANCE
A tree species' capacity to grow in shade.

TOPSOIL
That part of the soil profile, typically the A1 horizon, containing material which is usually more fertile and better structured than underlying layers. When the A2 horizon also meets these criteria, it may be included. Topsoil is the most important part of the soil with respect to growth of crops and pastures and its loss or degradation represents the most serious aspect of soil erosion. Its retention is particularly important in the revegetation of exposed batters or earthworks.

TOPSOILING
The application of topsoil to exposed or eroded areas, including batters and earthworks, to encourage the rapid growth of vegetation over them, for the purpose of stabilisation against erosion. On disturbed sites the topsoil may be derived from a borrow area or may be the original topsoil, stripped and stockpiled before disturbance.

TREE
A perennial plant having a self-supporting woody main stem or trunk which usually develops woody branches. A tree, under the Soil Conservation Act, 1938, includes sapling, shrub and scrub in this definition.

TRICKLE FLOW
The extended low flow which occurs in many catchments following major runoff events. In some catchments, depending on their hydrologic characteristics, such flows may be sustained by groundwater seepage and thus become continuous except during periods of drought. This is known as base flow and is particularly relevant in upland environments during the winter months, when rainfall intensities and evapotranspiration are typically low, and there is a marked increase in the proportion of precipitation contributing to groundwater seepage.

UNDERSTOCKED
A stand of trees so widely spaced, that even with full growth potential realised, crown closure will not occur.

UNDERSTOREY
The level of forest vegetation beneath the canopy.

UNEVEN-AGED STAND
A group of trees of a variety of ages and sizes growing on a uniform site; also called all-aged stand.

VENEER LOGS
High quality logs that are rotary peeled to produce sheets of veneer. The species suitable are mainly Blackbutt, Spotted Gum and Flooded Gum. Sizes required are upwards of 30 cms diameter and logs need to be of multiples of peeling lengths. Logs need to be round, straight, free of most defects and have a solid heart. Large veneer logs have a centre diameter under bark of at least 40 cm.

VOLUME
in a defined forest area. The timber volume being assessed should be defined, such as gross commercial volume poles, sawlogs, chipwood or some other criteria. Each product has market specifications by which the assessment is made. The timber volume of an individual log standing as a tree can be calculated from measurements of the diameter at breast height over bark (DBHOB) of the tree, the length of the log in the tree, and by applying a taper function for that particular timber species.

VOLUME TO BASAL AREA RATIO
For a given forest area this is the ratio of the standing volume of timber in cubic metres per hectare to the basal area in square metres per hectare.

WALK-OVER
Timber extraction or snigging without removing or unduly disturbing the existing natural groundcover, that is, where no snig track construction or blading is required.

WATERCOURSE
A channel, having defined bed and banks, down which surface water flows on a permanent or semi-permanent basis or at least, under natural conditions, for a substantial time after periods of heavy rainfall within its catchment. It is a general term including:~

• River
  A watercourse that conveys relatively large flows. Under average coastal and tableland condition, rivers typically have continuous flows.
• Creek (Stream)
  A smaller watercourse than a river which usually forms the link between a drainage line and a river in a natural catchment flow path.

WATER MARK
A mark left at the normal inundation level in the stream. It's location is shown by the edge of the terrestrial grasses etc., which cannot tolerate more frequent inundation, or by an area of erosion, or the boundary between different types of sediment on the bank.

WATERWAY
The cross-sectional area provided for the passage of water under the bridge, through a culvert or over a causeway.

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

WINDROW
Timber which is pushed into lines for burning during a clearing operation; or a mound of soil that is formed at the end of a bulldozer or grader blade.

WINDTHROW
A tree felled by wind, are common among shallow-rooted species and in areas where cutting has reduced stand density.