Glossary page H - N
Glossary page O - Z

ACID SULPHATE SOILS
Soils containing iron sulphides, found in low lying waterlogged areas, generally less than 5 metres above sea level. When exposed to air, as can occur when drained, these sulphides oxidise to produce sulphuric acid, hence the name acid sulphate soils.Iron sulphide soil is dark grey and wet. Acid sulphate soil is a mottled yellow containing a sulphur mineral called jarosite.

ARMOURED
(referring to road construction and bridging) Use of a surfacing material to prevent erosion by water flow, especially in flood conditions and which is resistant to displacement by machinery or vehicles.

AUSTRALIAN GROUP SELECTION
A silvicultural practice where specific regeneration gaps are created within forest stands.

BASAL AREA
Basal area is the cross-sectional area of a tree at breast height measured over bark. It is measured in m². The stand basal area is the total of the basal areas of all the trees over 10 cm DBHOB in the stand. It is measured in m² per hectare.

BATTER
An earth slope formed from placed fill material or cut into the natural hillside, during road construction.

BATTER DRAIN
A reinforced drain that carries water down a batter without causing erosion.

BATTER STABILISATION
The provision of adequate vegetative, structural or mechanical measures to control erosion from road batters. Measures include provision of catchment drains, topsoiling, seeding or mulching, hydro-mulching and use of geo-fabrics.

BIODIVERSITY
The variety of life forms: different species of plants, animals and micro-organisms, the genes they contain and the ecosystems they form.

BLADING OFF
The removal of surface soil from a snig track or road in wet conditions in order to expose a drier or firmer surface for use by machinery.

BOLE
The trunk of a tree.

BREAST HEIGHT
the standard height at which trunk measurements are made. It is 1.3M above ground level, on the uphill side.

BRIDGE
A structure designed to carry a road over a drainage feature by spanning it.

BUFFER STRIP
See "Drainage Feature Protection Areas".

BUFFER ZONE
A strip of land along each side of a drainage feature or other area in which special land and water protection conditions are applied.

BUSH FIRE DANGER RATING
A method of forecasting forest fire behaviour based on the interaction of recent rainfall, drought factor, relative humidity, air temperature and wind speed.

BUTT LOG
A log cut from the bole immediately above the stump.

CANOPY
The continuous cover formed by tree crowns in a forest.

C.A.R RESERVE SYSTEM
Comprehensive Adequate and Representative Reserve System. Areas under any of the following categories of land tenure - as described in the JANIS Report - Dedicated Reserves, Informal Reserves and other areas on Public Land protected by prescription (eg under Integrated Forestry Operation Approvals), and areas of Private Land where the CAR Values are protected under secure management arrangement by agreement with private landholders. This reserve system is based on the principles of comprehensiveness, adequacy and representativeness.

C.A.R VALUES
The conservation values as described by the JANIS Reserve Criteria.

CATCH DRAIN
A diversion drain excavated outside the normal road width. The drain is located on the high side of the road to intercept and divert surface runoff water before it reaches the road. Catch drains minimise the flow of water down the sides of cut batters and into the road drainage system.

CATCHMENT AREA
The area determined by topographic features where falling rain will contribute to the runoff at a particular point.

CAUSEWAY
a natural or constructed crossing that enables vehicles to ford a drainage feature. The pavement may be of concrete, gravel, bitumen, rock, logs or natural surface.

CLEARWOOD
Knot free timber.

CLINOMETER
A compact hand held level used for approximating angles of elevation or depression and/or percentage slopes.

CO-DOMINANT
Trees with crowns forming the general level of canopy and receiving direct sunlight from above but limited sunlight from the sides.

COMMERCIAL TREATMENTS
Timber stand improvements, such as thinning, that generate income from the sale of the trees removed.

COMPARTMENT
An area of forest, usually defined by physiographical boundaries, designated for forest management purposes.

CONCENTRATED WATER FLOW
A rate and volume of flow of road drainage water which results from a specified rainfall recurrence event.

CONTOUR LINE
Series of points at the same elevation on a surface

CONTOUR
An imaginary line on the surface of the earth connecting points of the same elevation, or such a line drawn on a map.

CONTRACTOR
Any person or organisation who contracts to carry out work for a forest owner.

COVER CROP
A temporary vegetative cover which provides protection for the soil and the establishment of plants, particularly those which are slow to establish.

C.R.A. PROCESS
Means the Comprehensive Regional Assessment of public lands which underpins Regional Forest Agreements between NSW and Commonwealth Governments. The CRA process identifies areas that both governments agree are required for inclusion in a comprehensive, adequate and representative reserve system.

CROSS BANK
A hump of earth constructed across a snig track, outrow, log dump or road to baulk the flow of water so that it is effectively diverted.

CROSSFALL
The fall or slope of a road perpendicular to the centre line constructed to prevent ponding of water on the road surface.

CROSSFALL DRAINAGE
Drainage which occurs when the surface of a road, trail or other access-way has sufficient cross slope to cause water to flow across and off the surface, rather than along it. Where the water flows into the hillside it is termed INFALL, and where flow is away from the hillside it is termed OUTFALL. Where the road surface is convex in shape causing water to flow away from the road centre to both edges it is termed CROWNING. The minimum cross slope required to achieve such crossfall drainage is 1:25. For safety reasons the maximum crossfall used should not generally exceed 1:10.

CROSSING
Structure, including bridges causeways, and culverts, designed to allow the crossing of a drainage feature.

CROWN
Shape of a road formation so that water drains to both sides of the road.

CROWN COVER OR CROWN CLOSURE
The percentage of a given area covered by tree crowns.

CROWN RATIO
The ratio of the diameter of the crown of a tree to the diameter of its trunk at breast height. Contrast with "Live Crown Ratio" below.

CULTURAL HERITAGE
Items or sites with significance for past or existing social history.

CULVERT
One or more adjacent enclosed conduits for conveying a water course or stream underneath a road formation.

CUTTING CYCLE
the period of time between major harvests in a stand.

CUTTING LIMIT
The limit set below which timber is not to be cut. Usually described in terms of centimetres DBHOB (diameter breast height over bark).

DEFECTS
Characteristics of an individual tree that reduce its quality and utility.

DESIGNATED DRAINAGE
A designated drainage feature is one clearly identified on a 'Site FEATURE Map' and in the field to which 'Plantation Establishment Plan' conditions are applied. Designated drainage features include all watercourses, wetlands, swamps, obvious drainage lines and obvious drainage depressions within the property boundary and where applicable adjacent to the plantation area.

DIAMETER AT BREAST HEIGHT
Diameter at breast height or DBH is the diameter of HEIGHT the tree at 1.3 m above ground level measured on the uphill side of the tree.

DISPERSIBLE SOIL
A soil which readily disperses into its constituent particles (clay, silt, sand) in water. Usually associated with high levels of exchangeable sodium in the clay fraction, and low levels of soluble salts in the soil. Highly dispersible soils are normally highly erodible. Typically slushy when wet and very hard setting when dry. Sub-surface tunnels and pipes can form. Exposed subsoils may display a melting, worm like appearance.

DISTURBED AREA
An area which is susceptible to erosion because the vegetative soil cover has been removed or altered. This may be accompanied by mixing or removal of some soil horizons.

DOMINANT CROWN
larger than average trees with well developed crowns extending above the surrounding individuals. Open sunlight is captured from above and from the sides of the crown.

DRAINAGE DEPRESSION
A shallow depression with smoothly concave cross-section that conveys runoff only during or immediately after periods of heavy rainfall. Drainage depressions may be subject to seasonal waterlogging or spring activity and vegetation type often indicates a wetter micro-environment than the surrounding country.

DRAINAGE FEATURE
A drainage depression, drainage line, major water storage, watercourse, wetland or swamp.

DRAINAGE FEATURE PROTECTION AREAS
Strips of retained vegetation along each side of drainage features PROTECTION AREAS to retard sediment movement and reduce the risk of erosion of (DFPA's) banks, channels or depressions as relevant.

DRAINAGE LINE
A channel down which surface water naturally concentrates and flows, conveying water only during or immediately after (hours or days) periods of heavy rainfall. Drainage lines exhibit one or both of the following features which distinguish them from drainage depressions;
(a)evidence of active erosion or deposition - e.g. gravel, pebble, rock or sand bed; or
(b)an incised channel of more than 30 centimetres depth with clearly defined bed and banks.
In some catchments trickle flows may be sustained in the channel by groundwater seepage and become continuous except during periods of drought. Drainage lines may become stable. Stable drainage lines are often used in association with soil conservation programs for water disposal. Drainage lines are often referred to by landholders as a gully.

EARTHWORKS
All operations involved in moving, loosening, depositing, shaping, compacting and stabilising soil and rock.

ECOLOGICALLY SUSTAINABLE FOREST MANAGEMENT
(ESFM). Forest Management and use in accordance with specific objectives and policies for ecologically sustainable development as detailed in the National Forest Policy Statement. Summarised as:

Principle 1:Maintain or increase the full suite of forest values for present and future generations across the NSW native forest estate. Aims for values include biodiversity; the productive capacity and sustainability of forest ecosystems; forest ecosystem health and vitality; soil and water; positive contribution of forests to global geochemical cycles; long term social and economic benefits; natural and cultural heritage values.
Principle 2:Ensure public participation, access to information, accountability and transparency in the delivery of ESFM.
Principle 3:Ensure legislation, policies, institutional framework, codes, standards and practices related to forest management require and provide incentives for ecologically sustainable management of the native forest estate.
Principal 4:Apply precautionary principles for prevention of environmental degradation.
Principal 5:Apply best available knowledge and adaptive management processes.

ENERGY DISSIPATER
A device located in the base of a channel of running water that dissipates the energy of the flow. The dissipater reduces the velocity and depth by spreading the water flow over a larger area and thus mitigates erosion in the channel bed. Energy dissipaters can be constructed in several forms and from different materials including rocks, gabions, logs, steel baffles and concrete blocks.

ENVIRONMENTALLY SENSITIVE AREA
Drainage feature, steep slope, areas of high erosion hazard or landslip prone area.

EPICORMIC BRANCHING
branches that grow out of the main stem of a tree from buds produced under the bark. Severe epicormic branching increases knottiness and reduces sawn wood quality.

EROSION
In this document refers to accelerated erosion due to plantation operations. These guidelines aim at minimising any acceleration of natural erosion.

ERODIBILITY
See Soil Erodibility.

EVEN-AGED STAND
Stands of trees of an identical age having been planted at the same time or germinated within a short period of each other (eg. in response to a fire). Small differences in age may not be of any practical significance and can be ignored.

EXCLUSION ZONES
Areas set aside for environmental protection or conservation purposes

EXISTING ROADS
Roads which were in existence prior to the commencement of a forestry activity.

EXTRACTION
Transport of trees, stems or logs from the point of felling to a processing or roadside loading area (usually a log dump or landing).

EXTRACTION TRACK
A track along which timber extraction occurs.

FELLING
The process of cutting down standing trees.

FILTER STRIP
See "Drainage Feature Protection Areas"

FIRE RISK ASSESSMENT
Determination of fire risk using methodology defined by the Rural Fire Service.

FLOOD EVENT
The maximum flow which occurs during a flood with a specified average recurrence interval.

FOREST
A biological community dominated by trees and other woody plants.

FORESTry
The science of tending forests.

FORESTRY OPERATIONS

• Logging operations, namely, the cutting and removal of timber from land for the purpose of timber production;
• Forest products operations, namely, the harvesting of Forest Products that are of economic value;
• On-going forest management operations, namely, activities relating to the management of land for timber production such as thinning, bush fire hazard reduction and other silvicultural activities; and
• Transport of Forest Products

FREEBOARD
The vertical distance between the top water level and the crest of a bank, dam or similar structure. Freeboard is provided for in designing such structures to prevent overtopping due to surcharge or wave action. In an earth structure, freeboard should include an allowance for settlement.

FRILLING
The method of killing trees by inflicting a series of cuts around the bole and applying an herbicide to the wounds. Frilling or girdling can be used to reduce the density of a stand or to kill individual undesirable trees.

GIRDERS
High quality logs used in two ways. The first use is in a round or flat faced form to support a deck such as in a bridge or wharf. The second use is as large end section, heart free, sawn timber suitable for heavy construction. Girders for the first use need to be of a durable or treatable species, straight, defect free and have a small end diameter of between 30 and 40 cms depending on the order. Girders for the second use generally have similar specifications but need to be larger in diameter (often up to 60 cms) at the small end. They can carry a little centre defect depending on the diameter and timber sizes required to be cut.

GRAVEL
A naturally occurring mixture of coarse mineral particles larger than sand and smaller than 75 mm diameter

GROUP SELECTION
A process of selecting groups of trees for harvest in order to open the forest canopy and encourage the reproduction of mixed age stands

GROUND COVER
Anything which covers the ground surface or topsoil and has the affect of reducing erosion. Preferably this would be a vegetative layer of grasses and/or other low-growing plants but may also include plant residues such as leaf litter and tree debris as well as various forms of rock. Artificial groundcovers may also be established with such materials as straw mulch or jute mesh.

GROWTH STAGE
The growth or development stage of a forest. It recognises the "juvenile", "sapling", "pole", "mature", and "overmature senescent" growth stage of the forest. It should be recognised that at any development stage a tree may enter a "growth restricted" condition due to competition and if it remains in that condition for some time resumption of normal growth may not be possible.

GULLY EROSION
A complex of processes whereby the removal of soil is characterised by large incised channels in the landscape. Processes include concentration of large volumes of surface runoff and dispersion of unstable subsoils.

GULLY STUFFERS
A type of crossing for a road or snig track or extraction track across a drainage feature. It is formed by filling the drainage feature with trees, debris, spoil, soil, rock or other material to the level of the road or track.

Glossary page H - N
Glossary page O - Z