What does it mean?

As with so many other aspects in life, we are constantly bombarded with terminology and names that is foreign to us, but that is used in discussions and documents that are relevant to us!

This section maintains an alphabetical list of some of these terminologies – together with an easy to understand explanation.

Please use the “Contact Us” page on this web site to send us any relevant term or name that is unclear and we will get and publish the explanation thereof on this list.

"On-Track" Basic Terminology

Aeolian environments: The erosion, transport, and deposition of material by wind, and commonly associated with dry environments where vegetation cover is sparse, or absent.

Aggregated soils: An aggregate is a mass of rock particles, mineral grains or both.  An aggregated soil is a soil that generally contains a combination of the above, frequently referred to as a fine-grained aggregate or coarse-grained aggregate, depending on the size grains of the aggregate material.

Alien species: Plant and animal species that occur in a given place, area, or region as the result of direct or indirect, deliberate or accidental introduction of the species by humans, and for which introduction has permitted the species to cross a natural barrier to dispersal.  Rooikrans is a good example of alien species in the Western Cape.

Alignment: The configuration of the route in a horizontal plane, i.e. the bends, curves and tangents of the path.

Alternative: Different means of meeting the general purpose and need of a proposed activity.  Feasible alternatives are those which are considered to be technically, economically and environmentally feasible.

Archaeological site: (a) material remains resulting from human activity which are in a state of disuse and are in or on land and which are older than 100 years, including artefacts, human and hominid remains and artificial features and structures; (b) rock art, being any form of painting, engraving or other graphic representation on a fixed rock surface or loose rock or stone, which was executed by human agency and which is older than 100 years, including any area within 10m of such representation; and (c) features, structures and artefacts associated with military history which are older than 75 years and the sites on which they are found.

Aspect: The particular direction a site faces and the amount of solar radiation it is subjected to.

Backslope: The angle of the back wall of a route excavated into a hillside.

Basic Assessment: A process contemplated in regulation 22 of the Environmental Impact Assessment (EIA) Regulations published under the National Environmental Management Act (NEMA).

Bedrock: The solid rock (in situ or residual) that lies under the soil or that is exposed at the surface.

Bench construction:  a bench is a section of tread cut across the side or contour of a hill/slope.  A full bench is constructed by cutting the full width of the tread into the hillside.  On a partial bench, only part of the hill/slope is cut away and the removed soil is placed at the lower edge of the tread to establish the desired tread width.

Berm: A low earth ridge constructed at the side of a route to divert the direction of flowing water.

Best Management Practices (BMPs): Best management practices are those practices that, when correctly applied in the establishment of off-road routes, provide the most effective, practicable means of preventing or reducing the likelihood of negative environmental impacts, and reduce the need for extensive on-going route maintenance.  BMPs address the key planning, location, design, construction, and maintenance requirements of routes.

Biodiversity: The variety of life and its processes; including the variety of living organisms, the genetic differences among them, the communities and ecosystems in which they occur, and the ecological and evolutionary processes that keep them functioning, yet ever changing and adapting.

Borrow Pit: An area where excavation takes place to produce materials for earthwork, such as a fill material for embankments.  It is typically a small area used to mine sand, gravel, rock, or soil without further processing.

Carrying capacity: The number of users that can be supported by a resource in a specific area based on ecological, physical, facility, and/or social factors.

Catchment: Area of land that collects rain water into a river or stream, which then carries the water to a waterbody or the sea.

Channel: A waterway that contains moving water either periodically or continuously.  A channel has a definite bed and banks that confine the water.

Clearing: The corridor from which vegetation is cleared.  Within limits, wider clearing provides for easier travel.

Climbing turn: A turn of approximately 180 degrees resulting in a change of direction of the route.  This feature is intended to lessen the grade of a route travelling up or down a steep slope.

Cohesive soils: A sticky soil, such as clay or silt where its shear strength equals about half its unconfined compressive strength.  Cohesive soils are also frequently referred to as soils that are made up of particles bound together by clay minerals.  Sands and gravels are granular soil and generally considered as non-cohesive soil, whereas silt and clay are fine grained and are classified as cohesive soil.

Compaction: A result of the downward force of vehicles on the route surface.  As a result, the route surface hardens and sinks relative to adjacent untravelled areas.  Compaction hardens the surface by pressing particles into tighter contact and firmer bonding, reducing space for air and water

Consolidated material: Material which has been compressed under a static load.  Consolidated soils are usually formed when water is driven out of voids.  Under these conditions the soil becomes firm or coherent.

Contour: Lines drawn on a plan that connect points having the same elevation.  Contour lines represent an even value, with the contour interval being selected consistent with terrain, scale, and intended use of the plan/map. 

Cross slope: The slope of a route perpendicular to the gradient of the route, either insloped towards the cutbank, or outsloped towards the fillslope.

Culvert: A drainage pipe (usually made of metal, concrete, or plastic) set beneath the travel surface to move water from the inside to the outside of the route, or under the route.  Culverts are used to drain ditches, springs, and streams that cross the travel surface. 

Cumulative impacts: Impacts which can arise from one or more activity.  A cumulative impact may result in an additive impact (i.e. where it adds to the impact which is caused by other similar impacts), or an interactive impact (i.e. where a cumulative impact is caused by different impacts that combine to form a new kind of impact).  Interactive impacts may be either countervailing (the net adverse cumulative impact is less than the sum of the individual impacts) or synergistic (the net adverse cumulative impact is greater than the sum of the individual impacts).

Cut Slope: The artificial face or slope cut into soil or rock along the ‘inside’ edge of the route.

Cut-and-fill: A method of road construction in which a travel surface is built by cutting into the hillside and spreading the spoil materials in adjacent low spots and as compacted fill slope material along the route.  A “balanced cut-and-fill” utilises all of the “cut” material to generate the “fill”, resulting in no residual or excess waste material and no need for hauling additional fill material.

Decommissioning: Permanently closing a route to terminate the function of the travel surface and mitigate the adverse environmental impacts of the route.  Use of techniques that include blocking the entrance, replanting vegetation, adding waterbars, removing fills and culverts, or re-establishing natural drainage patterns.  However, the basic shape of the route will still be in place. 

Disturbance: A discrete event, either natural or human-induced, that causes a change in the condition of an ecological system.

Displacement: Human-caused horizontal movement of route tread material (soil, gravel, stones, etc.).  Displacement invariably deepens the tread over time.

Drainage structure: A structure installed to control, divert, or to move water off or across a travel surface, including but not limited to culverts, bridges, and rolling dips.

Ecological corridor: Narrow continuous areas of favourable habitat that allow the movement of animals, birds and plants along them.

Ecosystem: A system formed by the interaction of living organisms, including people, with their environment.  Spatially, ecosystems are described for areas in which it is meaningful to talk about these relationships.

Ecotourism: Planning and managing tourism in a way that is sensitive to the natural environment.  Ecotourism also involves helping the natural environment to be sustained by the economic benefits of tourist activities.

Edge effects: Tendency to have greater variety and density of organisms in the boundary zone between communities.

Endemic / localised species: A taxon limited in its range to a specific geographical area.  This confinement may be due to historical (e.g. dispersal, evolution and longevity of taxon), ecological (e.g. a particular substrate or environmental modification resulting from competition with other plants or animals), or physiological (e.g. ability to tolerate aridity, excessive moisture or habitat alteration) reasons.

Energy / flow dissipater: Rock or other non-erodible material placed where water is concentrated to prevent erosion by dissipating the energy of the flowing water.

Endangered species: Taxa in danger of extinction and whose survival is unlikely if the causal factors continue operating.  Included here are taxa whose numbers of individuals have been reduced to a critical level or whose habitats have been so drastically reduced that they are deemed to be in immediate danger of extinction.

Endangered wild animal: A wild animal of any species which is in danger of extinction and is specified in Schedule I or Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, Washington, 1973, provided that it shall not include a wild animal of any species specified in such Appendix and Schedule 2.

Environment: the surroundings within which humans exist and that are made up of:

i.                    the land, water and atmosphere of the earth;

ii.                   micro-organisms, plant and animal life;

iii.                 any part or combination of (i) and (ii) and the interrelationships among and between them; and

iv.                the physical, chemical, aesthetic and cultural properties and conditions of the foregoing that influence human health and well-being.

Environmental Impact: An action or series of actions that have an effect on the environment. 

Environmental impact assessment: A study which predicts and assesses/evaluates environmental impacts of specified, proposed activities, both positive and negative.  The conclusions of the EIA report are used as a tool in planning and decision-making.

Environmental management: Ensuring that environmental concerns are included in all stages of development, so that development is sustainable and does not exceed the carrying capacity of the environment.

Environmental management plan: An operational plan that organises and co-ordinates mitigation, rehabilitation and monitoring measures in order to guide the implementation of a proposal and its ongoing maintenance after implementation.

Erosive Soils: Soils that are relatively prone to erosion and movement by rain drop impact and surface runoff.  Fine granular, non-cohesive soils, such as fine sandy sand derived from decomposed granite, silts, or fine sands, are known to be very erosive.  Cohesive soils can also be very erosive, especially if they are dispersive in nature.

Erosion: The process by which the surface of the earth is worn away and soil moved by the actions of wind, water or gravity.

Erosion Control: The act of reducing or eliminating on-going erosion caused by natural or man-made processes.

Erosion Prevention: Preventing erosion before it occurs.  Erosion prevention is typically less expensive and more effective than erosion control.  Erosion prevention is intended to protect a route, including its drainage structures, cut and fill slopes, and disturbed areas, and protect water quality.

Extinct species: Taxa which are no longer known to exist in the wild after repeated searches of their type localities and other known or likely places.  This category is used for a taxon which no longer occurs in the wild but survives in at least some form in cultivation or in a seed bank, but is probably so genetically impoverished or altered as to make it impossible  to return it to a natural habitat. A plant may be listed as Extinct in one country while surviving in another (e.g. Protea gaguedi). It is important to note that extinction can never be regarded as more than a probability, and rediscoveries are occasionally made, hence this category is sometimes referred to in the literature as "Presumed Extinct".

Fill Slope: The inclined slope extending from the outside edge of the travel surface shoulder to the toe (bottom) of the fill.  This is the surface formed where material is deposited to build the route.

Floodplain: A level or gently sloping area on either side of a river or stream active (main) channel that is submerged at times during high water or periods of flooding.  Silt and sand are deposited and accumulate in this area along the main channel.

Flora: Endangered flora, protected flora or indigenous unprotected flora and includes the whole or any part of the plant, whether live, dead or dried.

Fynbos: Low-growing and evergreen vegetation found mainly in the Western Cape. Fynbos is known for its rich biodiversity.

Gabions: Woven baskets (usually made of wire) filled with about 10 to 20 cm. size rock (or broken pieces of concrete), used for building erosion control structures, weirs, bank protection, or retaining structures.

Global positioning system (GPS): A system to map route locations using orbital satellites and portable equipment.  Digital data gathered can be placed directly into geographic information system (GIS) database systems.

Grade: The slope of the route in the direction of travel.  The steeper the grade the more difficult the route is to drive.

Guideline: A broad plan or explanation of information to guide in setting standards or determining a course of action.

Habitat: A dynamic system of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit.

Habitat fragmentation: A process by which habitats are increasingly subdivided into smaller units, resulting in their increased restriction as well as an overall loss of habitat area and biodiversity.

Hardening: The manual, mechanical, or chemical compaction of the route tread resulting in a hard, flat surface that sheets water effectively and resists the indentations that are created by use.

Heritage resource: Any place or object of cultural significance

Hydric Soil: Soil that is saturated or flooded during a sufficient portion of the growing season to develop anaerobic conditions in the upper soil layers.

Hydrologic soil groups: soils grouped according to their runoff-producing characteristics.  The chief consideration is the inherent capacity of soil bare of vegetation to permit infiltration.

Hydrology: The science dealing with the properties, distribution, and circulation of water on the surface of the land, in the soil, and below the ground surface in the underlying rocks, and in the atmosphere.  Commonly used to describe the distribution and circulation of water in a particular area.

Hydrophylic vegetation: Plants which are adapted to growing in saturated, poorly, or very poorly drained soils.

Indeterminate species: Taxa known to be Extinct, Endangered, Vulnerable or Rare, but for which information is insufficient to decide which of the four categories is appropriate.

Indigenous flora: Any plant, shrub or tree or part thereof that occurs naturally in an area, excluding declared invasive and alien plants.

Indigenous species: Any species of flora or fauna that naturally occurs in an area.

In situ: Being in the original location; not having been moved.

Inslope: The inside cross-slope of a route surface.  Inslope is used to facilitate the draining of water from a route surface to an inside ditch.  An insloped route has the highest point on the outside edge of the route and slopes downward to the ditch at the toe of the cut slope, along the inside edge.

Instream habitat: The physical structure of a watercourse and the associated vegetation in relation to the bed of the watercourse.

Insufficiently known species: Taxa that are suspected but not definitely known to belong to any of the above categories, because of the lack of information (Note, most of South African literature has used the term "Uncertain (U) for this category).

Invader plant: A kind of plant which has under section 2(3) of the Conservation of Agricultural Resources Act been declared an invader plant, and includes the seed of such plant and any vegetative part of such plant which reproduces asexually.

Landscape: A uniform land area composed of a cluster of interacting ecosystems that is repeated in similar form throughout.

Limits of acceptable change (LAC): A planning framework that establishes explicit measures of the acceptable and appropriate resource and social conditions usually but not only in wilderness settings as well as the appropriate management strategies for maintaining or achieving those desired conditions.

Low-level crossings: These are constructed at a narrow stream location and are in an area of bedrock or coarse soil for good founding conditions.

“Middle mannetjie”: Vegetation naturally occurring in the centre of the route, such that the route appears as a narrow two spoor track.

Mitigation: Actions or a specific item used to avoid, minimise, reduce, eliminate, or rectify the adverse impact of a management practice.

Monitoring: The collection of information to determine the effects of environmental management and to identify changing environmental conditions or needs.

Mulch: Material (including cut vegetation, grasses, wood chips) placed or spread on the surface of the ground to protect it from raindrop, rill, and gully erosion, and retain moisture to promote growth of vegetation. 

NEMA: National Environmental Management Act, 1998 (Act No. 107 of 1998).

Not threatened: This is used for taxa which are no longer in one of the above categories due to an increase in population sizes or to subsequent discovery of more individuals or populations.

Noxious weed: Plant that is invasive, displacing indigenous species.

Obstacles: Physical objects large enough to significantly impede travel, including logs or large rocks.

Off-road route: any road, route or track, other than proclaimed roads, which can be used by motorised vehicles, including 4x4s, 2x4s, all terrain vehicles, quadbikes and off-road trailbikes for recreation or any other use. 

Outslope: The outside cross-slope of a route surface.  Outslope is used to facilitate the draining of water from a route directly off the outside edge.  An outsloped route has the highest point on the uphill or inside of the route and slopes down to the outside edge of the route and the fill slope.

Parallel and/or braided tracks: A parallel route occurs when two routes run alongside each other.  A braided route occurs when a new route is created and veers from the designated route for a short period of time (usually to avoid an obstacle) and then returns to join the original route.

Precautionary principle: Where the risk is unknown, provision will be made for the worst case scenario.

Principle: A principle addresses environmental, social and economic aspects through governing what must be achieved in order for a route to be sustainable in the long-term.  Principles are supported by Best Management Practices (BMPs), which practically guide how the governing Principles can be achieved. 

Protected flora: Any species of flora specified in Schedule 4 or Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, Washington, 1973; provided that it shall not include any species of flora specified in such Appendix and
Schedule 3.

Protected wild animal: Any species of wild animal specified in Schedule 2 or Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, Washington, 1973; provided that it shall not include any species of wild animal specified in such Appendix and Schedule 1.

Public road: A public road as defined in section 1 of the Road Traffic Act (Act No. 29 of 1989).

Rare species: Taxa with small world populations that are not at present Endangered or Vulnerable, but are at risk as some unexpected threat could easily cause a critical decline.  These taxa are usually localised within restricted geographical areas or habitats or are thinly scattered over a more extensive range.  This category was termed Critically Rare by Hall and Veldhuis (1985) to distinguish it from the more generally used word "rare".

Red data species: Species listed in terms of the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species, and/or in terms of the South African Red Data list.  In terms of the South African Red Data list, species are classified as being extinct, endangered, vulnerable, rare, indeterminate, insufficiently known or not threatened (see other definitions within this glossary).

Rehabilitation / Reclamation: Activities that reclaim, repair or improve part or all of an existing travel surface or disturbed area, and restore it to its original or some desired final condition.

Retaining Structure: A structure designed to resist the lateral displacement of soil, water, or any other type of material.  It is commonly used to support a travel surface, or gain width on steep terrain.  They are often constructed of gabions, reinforced concrete, timber, or mechanically stabilised earth.

Riparian habitat: The physical structure and associated vegetation of the areas associated with a watercourse which are commonly characterised by alluvial soils, and which are inundated or flooded to an extent and with a frequency sufficient to support vegetation of species with a composition and physical structure distinct from those of adjacent land areas.

Riverine: Living in rivers.

Rolling Dip: A surface drainage structure with a constructed break in the route grade, specifically designed to drain water from an inside ditch or across the travel surface, while also serving to reduce vehicle travel speed.

Route Tread: The actual surface portion of a trail upon which users travel excluding backslope, ditch, and shoulder.  Common tread surfaces are native material, soil, or crushed rock.

Runoff: The part of precipitation that reaches streams by flowing over the ground surface.

Sheet erosion: The removal of a fairly uniform layer of soil material from the land surface by the action of rainfall and runoff.

Single-track route: A route wide enough only for one user to travel and requires moving off the route to allow another user to pass.

Sideslope: The slope of the ground at its extreme angle, usually perpendicular to the direction of travel.  As the sideslope becomes steeper, the perception of difficulty and exposure increases.

Stewardship: The wise use, management and protection of that which has been entrusted to somebody or is rightfully theirs.  Within the context of conservation, stewardship means protecting important ecosystems, effectively managing invasive alien species and fires, and grazing or harvesting without damaging the veld.

Sustainable development: Development that is planned to meet the needs of present and future generations, e.g. the need for basic environmental, social and economic services.  Sustainable development includes using and maintaining resources responsibly.

Swale: Open channel used to collect and convey runoff (i.e. drainage system). 

Switchback: A turn of approximately 180 degrees resulting in a change of direction of the route.  This feature is intended to lessen the grade of a route travelling up or down a steep slope.

Temporary Route Closure: Closing vehicular access to a route through the use of barricades such as gates, barriers, earthen mounds, or other temporary structures.  The end result is to restrict the use of the route for some period of time.

Trailbike: A motorcycle constructed primarily for off-road use.  Trailbikes can be distinguished from the street-legal motorcycle by their high-mounted mudguard and exhaust system and tyres with aggressive tread.

Tread surface: The physical condition of the travelled portion of the route.  A tread becomes more difficult to ride as it becomes loose, rough, slippery, etc.

Tread width: The width of the travelled portion of the route.  Wider tread provides for easier travel.

Unconsolidated material: Materials which have not been exposed to compressive loads and can be considered loosely arranged or unstratified.  This material is occasionally described as a loosely aggregated soil.

Underdrain: A buried trench, filled with coarse aggregate, coarse sand, or gravel, and typically placed in the ditch line along the route, which acts to drain subsurface water from a wet area and discharge it a safe and stable location.  Underdrains may use a uniform size of rock, be wrapped in geotextile, and have a perforated drainpipe in the bottom of the trench.

Vegetation: The different types of plants occurring in an area.

Vulnerable species: Taxa believed likely to move into the Endangered category in the near future if the factors causing decline continue operating.  Included here are taxa of which most or all of the populations are decreasing because of over-exploitation, extensive destruction of habitat or other environmental disturbance; taxa with populations that have bee seriously depleted and those whose ultimate security is not yet assured; and taxa with populations that are still abundant but are under threat from serious adverse factors throughout their range.

Waterbar: A low barrier, sometimes accompanied by a ditch, designed to divert water off a route surface.  Usually installed after a route is already established.

Watercourse: A natural or manmade channel through which water flows, and includes:

(a)              a river or spring;

(b)              a natural channel in which water flows regularly or intermittently;

(c)               a wetland, lake or dam into which, or from which, water flows; and

(d)              any collection of water which the Minister may, by notice in the Gazette, declare to be a watercourse,

and a reference to a watercourse includes, where relevant, its bed and banks.

Watershed: The entire area that contributes water to a drainage system or stream/river.

Weed: Any kind of plant which has under section 2(3) of the Conservation of Agricultural Resources Act been declared a weed, and includes the seed of such plant and any vegetative part of such plant which reproduces asexually.

Wetland: Land which is transitional between terrestrial and aquatic systems where the watertable is usually at or near the surface, or the land is periodically covered with shallow water, and which land in normal circumstances supports or would support vegetation typically adapted to life in saturated soil.

Zone of influence: The area influenced by a route, determined by many variables in a complex interaction.