Presence of air-filled space in the soil profile. Aeration limitation is defined as the proportion of the year in which anaerobic conditions may prevail in the soil.
Aerial oversowing and topdressing
The application of fertiliser and seed from aircraft.
Afforestation (imaged) [LCDB2 Classification]
Areas of Pinus radiata forest visible in the imagery and located on sites recorded as nonforested in LCDB 1 (1996-97).
Afforestation (not imaged) [LCDB2 Classification]
Areas of Pinus radiata forest not visible in the satellite imagery, but identified during the field-checking phase or because of contextual patterns associated with forest establishment, e.g. roading and firebreaks.
A non-crystalline soil mineral; an oxide of silicon and aluminium with high water content, variable-charge surfaces, and a very high surface area.
Allophanic Soils [NZ Soil Classification]
Soils dominated by allophane (and also imogolite or ferrihydrite) minerals. They have a porous, low-density structure, greasy moistened feel, stable resistant topsoil, low natural fertility and high phosphorus retention.
Sediments such as sand, silt or gravel that have been deposited by streams, rivers and other running waters.
Alluvial soils
Recent soils derived from alluvium, and showing developing marks of soil forming processes, but with distinct topsoil.
Alpine Herbfield [LCDB2 Classification]
Areas of vegetation above the tree line dominated by low growing and mat forming herbs and grasses.
Alpine Rock [LCDB2 Classification]
Scree slopes and glacial debris, as well as rock tors and outcrops mainly in the Southern Alps above an altitude of 1300m.
Absence of air. The condition that pertains when the soil is waterlogged and the supply of oxygen is limited to plant roots.
A dark-coloured volcanic rock intermediate in composition between rhyolite and basalt.
Andesitic ash
Unconsolidated volcanic ash of intermediate silica content, of Recent and Upper Pleistocene age. Occurs as a primary deposit or as rewashed material in river and coastal terraces.
Anthropic Soils [NZ Soil Classification]
Soils substantially disturbed/created by man, e.g. as a result of mining activity.
Capable of being ploughed; fit for tillage.
Arable use
Suitable for cultivation for cropping and capable of growing at least one of the common annual field crops or more per season, with average yields under good management and without permanently degrading soil conditions.
Rocks or substances composed of clay or having a notable proportion of clay in their composition.
A mudstone or siltstone that has undergone hardening by pressure, heat or cementation.
A type of volcanic rock which has a high iron and magnesium content but low silica.
Baserock [LRI]
Baserock is identified using identical codes to rock and toprock and identifies the principal basement lithology.
The solid rock that underlies soil or other loose material.
Beech forest
Evergreen trees of the beech family comprising hard beech, black beech, mountain beech, silver beech, and red beech.
Soft, plastic, porous, light-coloured (often green or red) rock composed essentially of montmorillonite clays. Feels greasy or soapy. Has the ability to absorb water and increase in volume up to eight times leading to the development of deep-seated earthflows.
Berry fields
Growing of shrubby plants, mainly cane plants, for soft fruit production. The term excludes growing of strawberries which is defined as a horticultural activity.
Bog [Wetlands classification]
A peatland that receives its water supply only from precipitation, receiving neither groundwater nor nutrients from adjacent or underlying mineral soils. Bogs are nutrient poor, poorly aerated, and usually markedly acid. Bog peat is poorly drained, having almost no water movement with the water table relatively constant and close to, or above, the ground surface.
Border dyke irrigation
A flood irrigation system restricted to land < 4° where parallel borders 10–20m wide are separated by low levees or 'dykes'. Between the dykes water is flooded from a headrace.
Angular rock fragments in fine-grained material.
Broadleaf–podocarp forest (aka. Podocarp-broadleaved forest)
Forests characterised by podocarps, e.g., rimu, miro, matai, kahikatea, silver pine, totara, and broadleaved or hardwood subcanopy species such as taraire, tawa, puriri, mahoe, hinau, maire and karaka, ngaio and pohutukawa in coastal locations.
Brown Soils [NZ Soil Classification]
Have yellowish brown subsoils, stable and well structured topsoils, are well to imperfectly drained, with low to moderate fertility, and are generally drought free.
Built-up [LCDB2 Classification]
Central business districts, suburban dwellings, commercial and industrial areas, and horticultural sites dominated by structures and sealed surfaces.
Suitability for productive use, after taking into account the various physical limitations the land may have.
Catchment control scheme
A scheme combining river and erosion control works and an improved pattern of land use in a catchment where erosion and flooding have created community problems which have required a co-ordinated effort to resolve.
Catchment Protection (Land)
Class 8 land which has such unfavourable characteristics that it is unsuited for agricultural, pastoral, or forestry use, although it is often well suited for recreational and wildlife use and for water yield.
Soil material which consists of particles less than 0.002 mm in diameter.
Tendency to split along closely spaced planar structures or textures.
Climatic limitations
Limitations for the growth of pasture, crop and tree species, such as rainfall, temperature, wind and frost.
Coastal Sand [LCDB2 Classification]
Coastal strip of land that falls on the landward side of the "coastline" as defined in the NZTopo data.
A general term for weathered soil and rock material mantling slopes which has been transported primarily by gravity and sheet wash.
Community of interest
Problems shared by a group, largely as cause and effect, and which require collective effort to resolve.
Compound slopes
Used in an inventory code when slope patterns cannot be separated at the scale of mapping and are recorded as a complex using double or multiple symbols, e.g. D+E.
A coarse sedimentary rock consisting of pebbles or boulders set in a sand and silt matrix.
Conservation fencing
Fencing designed to enable grazing management to control and prevent soil erosion, e.g. the separation of eroded from non-eroded land, summer from winter grazing country, sunny from shady slopes.
Conservation planning
Based on land inventory and land use capability assessment, a series of one or more five-year programmes are compiled which incorporate two concepts:
  1. The extent of the physical measures required to meet the magnitude of the conservation problems and the degree of financial assistance applicable to combat existing or potential erosion.
  2. The tailoring of these measures to the ability of individual farmers to meet the local share, from money budgeted for the purpose.
Conservation tillage
Seed drilled directly into an undisturbed soil (direct drilling), where the stubble of the previous crop is retained on the surface.
Conservation trees
Tree species used specifically for erosion control, e.g. willows and flame trees.
Conservation works
Consist of the following practices: conservation fencing (including cattle-proofing), tree planting (open, close, windbreaks, pair planting), gully control structures such as debris dams, drop structures and flumes, terraces, water diversion (graded banks, spring tapping, pasture furrows), regulating dams, stock ponds, strategic firebreaks, revegetation including over-sowing and topdressing, sod seeding, bulldozing of tunnel gullies, and retirement from productive use.
Contour furrows
Contoured across-slope plough furrows designed to intercept and slow surface runoff and sheet wash.
Cropland [LCDB2 Classification]
Land used for growing cereal crops, root crops, annual seed crops, annual vegetable crops, hops, strawberry fields, annual flower crops, and open ground nurseries.
Debris avalanche
Rapid slides or flows on long, usually very steep slopes exposing an extended, narrow scar with a long run out. The initial failure is small, the debris scouring a deep but narrow scar down a significant length of slope.
Debris flood
A rapid, hyper-concentrated, channelled flow of water charged with sand and silt sized sediment. They have lower sediment concentrations than debris flows and are less damaging, often extending downstream beyond debris flows. Debris floods can occur in the absence of debris flows, and are not classified as landslides.
Debris flow
A type of landslide triggered by exceptionally heavy rainfall events. They consist of dense fluid mixtures of debris (rock, soil, vegetation) and water. Sediment concentrations are high, with a consistency like wet concrete. They move rapidly down a channel faster than the flow of water.
Debris mantle regolith
Comprises slope debris derived from the underlying and upslope bedrock and bedrock regolith and may contain layers of regionally derived loess, and/or interlaid tephric loess, and/or tephra depending on location.
Deciduous Hardwoods
Typically willow and poplar species growing adjacent to inland water and rivers, this class also includes stands of planted exotic deciduous hardwoods, such as Oak (Quercus), Ash (Fraxinus excelsior) and Elm (Ulmus).
Degree of erosion
Extent of sheet, wind, and scree erosion is recorded on an areal basis as the percent of bare ground or area eroding. However soil slip, slump, debris avalanche, earth flow, rill, gully, tunnel gully, and streambank erosion are recorded in terms of seriousness, which is decided with reference to standard selected sites, parent material, physical loss of land, and cost of repair.
Degree of limitation
Applies to the Land Use Capability Classes, and expresses the relative limitations to sustained use, from Class 1 to Class 8.
See Digital Elevation Model.
Depleted Tussock [LCDB2 Classification]
Very low herbaceous vegetation with grassland/herbfield character: short tussock grassland species are usually less than 10% cover; hieracium species, exotic grasses and bare ground are conspicuous.
Digital Elevation Model (DEM)
A DEM is a digital model or 3-D representation of the terrain surface, also sometimes referred to as a Digital Terrain Model. The most common form of DEM is a raster or Grid DEM (think of this as a grid of squares with each grid square assigned an elevation). The resolution of a DEM refers to the size of the grid squares. Typically, low resolution DEMs have >= 100m grid squares, and modern high resolution DEMs can have grid squares of approximately 1 metre or even less. DEMs are powerful mapping tools from which slope, aspect and other useful datalayers can be derived.
Diversion channel
A channel constructed around the slope or a designed gradient, to intercept and divert water away from highly erodible sites (particularly effective for gully control).
Undulating land; usually an extensive area of gently to strongly rolling land around the margin of a plain.
Drop structures
Structures constructed in gullies to dissipate the energy and erosive power of falling water.
Dump [LCDB2 Classification]
Areas used for the surface disposal of solid waste material.
Slow movement of soil and associated regolith, usually along basal and marginal shear planes, with internal deformation of the moving mass. Movement rates vary from <0.5m/yr to >25m/yr. The original vegetation surface, although often still present, is hummocky and may contain numerous tension cracks. Earthflows may be shallow (< 2m) to deep seated (typically 3-5m but up to 10s of metres deep).
Erosion control forestry
(a) Planting exotic forest species principally for soil conservation and water management purposes but with a variable component of production permitted. (b) Management of indigeneous forests principally for soil conservation and water management purposes but with some selective milling permitted (also see production forestry).
Erosion types
The Land Resource Inventory erosion type codes are:
Da Debris avalanche
Ef Earthflow
Es Earth slip
Mf Mudflow
Ss Soil slip
D Deposition
G Gully
R Rill
Rf Rockfall
Rs Riparian slip
Sb Streambank
Su Slump
T Tunnel gully
Sc Scree
Sh Sheet
W Wind
Non-erosion codes that may occur in the erosion type field are:
estu Estuary
lake Lake
quar Quarry, mine
ice Icefield
rive River
town Urban area, airport
(See also Degree of erosion, Erosion severity, and LRI erosion)
Erosion severity
The Land Resource Inventory describes erosion severity in a six class system:
Class Description Percent area affected (sheeet, wind, scree)
0 negligible negligible
1 slight 1-10%
2 moderate 11-20%
3 severe 21-40%
4 very severe 41-60%
5 extreme >60%
(See also Degree of erosion, Erosion types, and LRI erosion).
Erosion Terrain
Erosion processes vary throughout New Zealand depending on rock type, landform (especially slope angle), and rainfall. Erosion terrains have been derived by amalgamating land use capability units from the New Zealand Land Resource Inventory based on these factors.
Estuary [LCDB2 Classification]
Areas of standing or flowing open water without emerging vegetation, where occasionally or periodically saline waters are diluted by freshwater or freshwater is made saline.
Fans are gently sloping, fan-shaped masses of material formed along the margins of hills and mountain ranges by the streams that drain their slopes. A fan commonly occurs where there is a marked decrease in gradient, for example where a stream meets the gentler floodplain or river terrace.
Fen [Wetlands classification]
A wetland with predominantly peat substrate that receives groundwater and nutrients from adjacent mineral soils. The water table is usually close to the or just below the peat surface and relatively constant. Water flow is slow to moderate and acidity low to moderate.
Fernland [LCDB2 Classification]
Areas of dominant bracken fern (Pteridium esculentum), umbrella fern (Gleichenia), and ring fern (Paesia scaberula).
A non-crystalline iron oxide mineral; has a very large surface area per unit weight.
Ferromagnesian minerals
Minerals containing iron and magnesium.
Field survey
As referred to in land inventory mapping, this is the field observation, measurement and recording of the physical factors of the landscape in symbol form on a suitable base map.
Fine earth fraction
Those particles in a mass of soil less than 2 mm in diameter, i.e., sand (particles between 0.06 and 2.0 mm), silt (particles between 0.002 and 0.06 mm), and clay (particles less than 0.002 mm) in diameter.
Flaxland [LCDB2 Classification]
Areas dominated by lowland flax (Phormium tenax), usually moist and often represent parts of wetland systems.
Flood plain
The surface of relatively flat land adjacent to a river channel; built of alluvium deposited by that river or stream, which in the absence of flood protection works may still be flooded.
Belonging to a river, produced by river action; growing or living in freshwater rivers.
A planar arrangement of textural or structural features, especially that which results from the flattening of the constituent grains of metamorphic rocks.
Forage crops
Supplementary feed crops for livestock. Winter forage crops include hay, silage, turnips, swedes, choumoellier, and kale; summer forage crops include soft turnips, rape, lupins, barley, cereal greenfeeds; autumn forage crops include rape, kale, turnips, lupins, green maize.
Forest Harvested [LCDB2 Classification]
Areas showing evidence of harvesting since LCDB1, e.g. forest canopy openings, skidder tracking, new roading or log landings.
Forestry potential
The potential for establishment of productive exotic forest, based on assessment of the physical factors of the site, but not on a full-scale study of economics, transport, markets, etc.
Fractured rock
Rock in which breaks, cracks or joints occur due to mechanical failure by stress, with or without displacement.
A subsoil horizon which has a high bulk density and which is relatively hard when dry but softens when wet. Fragipans usually impede the downward movement of water. The presence of a fragipan frequently gives rise to impeded drainage and perched water tables.
A soil consistence term relating to the ease of crumbling of soils.
Glacial Drift
Glacial drift is a general term for the coarsely graded and extremely heterogeneous sediments of glacial origin.
Glacial Till
Till or glacial till is unsorted glacial sediment. Glacial till is that part of glacial drift which was deposited directly by the glacier.
Gley Soils [NZ Soil Classification]
Are saturated by water for prolonged periods and have pale greyish subsoils. Many were originally wetlands before being drained.
Absence of oxygen in soil leading to strong reducing conditions that create grey coloured profiles. Usually associated with drainage limitations, perched water tables and severe soil compaction.
Hard coarse-grained metamorphic rock often similar in appearance and composition to granite; usually has some banding.
Gorse and Broom [LCDB2 Classification]
Gorse and Broom are commonly associated with Low Producing Exotic Grassland on hill country, where low site fertility, and disturbance (extensive grazing and fire) facilitate the plants' spread and establishment.
Coarse-grained hard igneous rock that has crystallised deep below the earth's surface. It is rich in crystals of quartz, feldspars and shiny black and white micas.
Granular Soils [NZ Soil Classification]
Clayey soils derived from strongly weathered volcanic rocks or ash, well developed resistant structure, slowly permeable and limited rooting depth.
Rock fragments greater than 2 mm in diameter.
Grazing control
Control of stock numbers and movements to specific areas most commonly by fences.
Greenfeed crops
Special-purpose crops grown to provide succulent nutritious forage, e.g. for flushing ewes, for lambing ewes in August, and for milking cows in August and early spring.
Grey Scrub [LCDB2 Classification]
Small-leaved indigenous shrubs with mainly divaricate growth form. Small-leaved Coprosma are usually dominant and the presence of native climbers such as Muehlenbeckia and Parsonsia is characteristic.
A dark, grey sandstone, flecked with angular fragments of finer rock; formed by the hardening of deposits in ocean basins. The major rock type of central New Zealand.
Water which occurs in the soil or rocks below the ground surface and which is free to flow.
Gullies are formed by the removal of soil, regolith or rock by fluvial incision. They are large permanent features, >60cm deep and >30cm wide. Initially they form through channelised flow of water and involve headward and sideways migration of the channel. Gullies may be linear or amphitheatre in shape, depending on rock type, and usually only carry water during rainstorms. In some cases gullies are formed by a complex process of mass movements, sheet erosion and debris flows in response to over-steepening of gully sides by channel incision.
Gully planting
Gully control and stabilisation involving the establishment of vegetation with extensive rooting systems to reduce the velocity of flow and hence transporting power; to increase the resistance to flow; and to trap debris. This is usually done in conjunction with small structures, diversions, fencing for stock exclusion and perhaps minor bulldozing.
Hard rock
Rocks that have hardness and strength through induration. They ring when struck with a hammer, require a strong blow to fracture and are impractical to dig with a spade.
Gumland [Wetland classification]
Land formerly occupied by forest of Kauri (Agathis australis) in Northern New Zealand, the soils once exploited for kauri gum, prone to waterlogging, and having heathland vegetation.
The danger/risk of erosion and/or flooding.
Herbaceous Freshwater [LCDB2 Classification]
Areas dominated by herbaceous aquatic vegetation as a component of freshwater wetlands.
Herbaceous Saline [LCDB2 Classification]
Areas dominated by herbaceous aquatic vegetation as a component of estuarine or coastal wetlands,
High Producing Grassland [LCDB2 Classification]
Intensively managed exotic grasslands, rotationally grazed for wool, lamb, beef, dairy, and deer production.
Homogenous mapping units
At the scale of mapping the inventory factors (rock type, soil, slope erosion severity and type and vegetation cover) are considered homogeneous within the mapping unit.
Horticultural use
The growing of crops, excluding berry fruit, vines and orchard crops, for the fresh fruit and vegetable market and intended to be consumed fresh.
Hydromorphic features
Mottling or gleying caused by chemical oxidation/reduction reactions associated with changes in oxygen availability.
Rocks that were once molten. If they crystallise deep below the earth.s surface they are plutonic (e.g. granite); if they are erupted they are volcanic (e.g. rhyolite).
Thick sheets of rock formed by the welding together of extremely hot particles of rhyolitic ash during volcanic eruptions.
Imperfectly drained soils
Soils that have 50% or more grey mottles between 30-60 cm of the soil surface (but not within 15 cm of the base of the A horizon), or soils that 2% or more rust-coloured mottles or less than 50% grey mottles within 15 cm of the base of the A horizon, or within 30 cm of the soil surface.
Indigenous Forest [LCDB2 Classification]
Vegetation dominated by indigenous tall forest canopy species e.g., Kauri (Agathis australis), Beech (Nothofagus), Kahikatea (Dacrycarpus dacrydioides), Rata (Metrosideros umbellata), Rimu (Dacrydium cupressinum).
Indigenous Hardwoods [LCDB2 Classification]
Mix of broad-leaved, generally seral hardwood species such as Wineberry (Aristotelia serrata), Mahoe (Melicytus ramiflorus), Pseudopanax, Pittosporum, Fuchsia, Ngaio (Myoporum laetum), and Titoki (Alectryon excelsus), together with Tutu (Coriaria) and tree ferns.
Inland saline
Sites in semi-arid climates in inland basins where localised areas of saline soils are associated with seasonally wet habitats.
Situated between, or surrounded by, mountains or mountain ranges.
Intrusive rock
Rock that consolidated from magma beneath the surface of the earth.
Fracture or parting in a rock without displacement.
Kind of limitation
The single most limiting factor to the use of land for common agricultural purposes. Four kinds of limitation are recognised: erosion (e), excess water (w), root zone limitations (s), and climate (c).
A flow of volcanic material, both ash and coarser products, mixed with water; often caused by the spilling-over of a crater lake.
Lake [LCDB2 Classification]
Areas of permanently or intermittently, standing open fresh water without emerging vegetation (lacustrine systems).
Land cover
A classification of what is covering the lands surface. Generally this will be vegetation classes, but it also includes other types of non-vegetative cover such as water bodies, snow, bare rock and built-up areas. Land cover may often imply something about land use but this is not certain. For example a land cover class might be "high producing grassland" but this does not tell us whether the land use on this pasture is being grazed by sheep, beef, dairy cows, horses, or indeed that it is a golf course or some other non-agricultural land use.
Land Resource Inventory (LRI)
An inventory of the five physical factors considered to be critical for long-term sustainable land use; rock type, soil, slope angle, erosion type and severity, vegetation.
Land Resource Inventory (LRI) map unit
The land contained by a mapping boundary within which each of the physical characteristics recorded in the inventory is uniform at the scale of mapping.
Land Use Capability
A systematic arrangement of different kinds of land according to those properties that determine its capacity for long-term sustained production, after taking into account the physical limitations of the land. Divided into eight classes:
  • 1-4 for arable land,
  • 5-7 for non-arable land, and
  • 8 for normally non-productive land.
These eight classes are divided into 4 subclasses based on the dominant limitation to land use: e – erosion; c – climate; s – soil, w – wetness.
Land Use Capability map unit
The land contained by a mapping boundary within which each of the physical characteristics recorded in the inventory is within the range of those defined for a specific Land Use Capability Unit. An example of a LUC code would be '6e1', where '6' is the LUC class (non-arable), 'e' the subclass suggesting a dominant limitation from erosion, and the '1' denotes the map unit where LUC units are arranged (within subclasses) in order of decreasing verstaility for use and increasing degree of limitation to use.
A generic term covering a wide variety of mass movement types involving the movement of a mass of rock, earth or debris down a slope, under the influence of gravity. Landslides usually involve rapid failure along a slip plane at the contact between a more permeable material and an underlying less permeable material occurring when shear stress forces exceed shear strength. Landslides vary in size and volume from <10 m³ to >1,000,000 m³.
Landslide [LCDB2 Classification]
Areas of subsoil and parent material exposed due to a localised erosion event.
Pebble-sized fragments of tephra.
The molten rock that exudes from a volcano. Also the solid rock formed from cooling the molten material.
Any naturally produced low ridge, but usually built of sand and silt by a stream on its floodplain.
Light summer grazing
Restricted, controlled grazing during summer to encourage flowering and seeding of native and/or introduced pasture: a management technique used in the rehabilitation of depleted and eroded high country areas particularly in the semi-arid and mountainous regions of the South Island.
A rock composed predominantly of calcium carbonate.
Lithic contact
The contact of soil with underlying rock where the rock is hard or very hard, maybe cracked and shattered, is impracticable to dig with a spade, and is impenetrable to plant roots.
The nature and composition of rocks.
A blanket deposit of silt-sized materials; usually carried by wind from dry river beds or outwash plains during glacial and post-glacial periods.
Low Producing Grassland [LCDB2 Classification]
Extensively managed grassland grazed for wool, sheep-meat and beef production.
LRI Erosion

The code recorded in the LRI for erosion should be interpreted as follows:

The first erosion type is the dominant erosion form. Any erosion types which follow are recorded in descending order of prominence.

0 denotes negligible erosion of any form
3G denotes an area with severe gully erosion
2Ss1Ef1Sh denotes an area where moderate soil slip is the dominant erosion form with slight earthflow and 1–10% of the unit area exposed to sheet erosion.

Sheet wind and scree are assessed on the basis of area affected by recognising the percentage of bare ground or eroding area within the map unit. The severity of the remaining erosion types is assessed on a basis of seriousness, taking into account rock type, rate and depth of movement, frequency of erosion events, feasibility and cost of control and economic effect.

In the NZLRI South Island 1st Edition data the first erosion severity record describes the erosion severity for all erosion types in the polygon, not just the type which follows it. So the 2Ss1Ef1Sh example code above might be repesented as 3SsEfSh (depending on the additive area and severity of the three erosion types).

(see also Erosion severity and Erosion types)

LRI Rock (see also Toprock, Baserock)
The code recorded in the LRI for rock type differ a little between the North and South Island and also between Edition 2 mapping in Northland, Gisborne, Wellington and Marlborough regions compared with earlier Edition 1 mapping elsewhere. The following table should assist interpretation of rock codes. For more information refer to the Rock Type Classification booklet.
Weak Igneous Rock Types Ed2 Nth.Is.Ed.1 Sth.Is.Ed.1
Ngauruhoe tephra Ng Ng -
Rotomahana mud Rm Rm -
Tarawera tephra Ta Ta -
Scoria Sc Sc -
Pumiceous lapilli Lp Lp -
Kaharoa and Taupo ashes Kt Kt -
Taupo and Kaharoa breccia and pumiceous alluvium Tp Tp -
Ashes older than Taupo ash Mo Mo -
Quaternary breccias older than Taupo breccia Ft Ft -
Lahar deposits La La -
Extremely weak altered volcanics Vu Vu -
Strong Igneous Rock Types Ed2 Nth.Is.Ed.1 Sth.Is.Ed.1
Lavas and welded ignimbrites Vo Vo Vo
Indurated fine-grained pyroclastics Tb Cg Tb
Indurated volcanic breccias Vb Cg Tb, Vo
Ancient volcanics In Vo In
Plutonics Gn Gn Gn
Ultramafics Um Um Um
Loose Sedimentary Rock Types Ed2 Nth.Is.Ed.1 Sth.Is.Ed.1
Massive mudstone Mm Mm Ms
Bedded mudstone Mb Mb Ms, Fy
Frittered mudstone Mf Mj Ms
Bentonitic mudstone Me Me Ms
Massive mudstone Sm Sm Ss
Bedded sandstone Sb Sb Ss, Fy
Weakly consolidated conglomerate Cw Gr Cw
Sheared mixed lithologies Mx Mj Ms
Crushed argillite Ac Ac,Gw Ar
Strong sedimentary Rock Types Ed2 Nth.Is.Ed.1 Sth.Is.Ed.1
Argillite Ar Ar Ar
Indurate sandstone Si Sm, Gw Hs
Conglomerate and breccia Cg Cg, Gw Cg
Greywacke Gw Gw, Ar Gw, Ar
Limestone Li Li Ls
Metamorphic Rock Types Ed2 Nth.Is.Ed.1 Sth.Is.Ed.1
Semi-schist Sx Gw St1
Schist Sy - St2
Gneiss Gs - Gs
Marble Ma - Ma
Other valid codes that may occur Ed2 Nth.Is.Ed.1 Sth.Is.Ed.1
Estuary estu estu estu
Perenial snow and ice ice ice ice
Lake lake lake lake
River river river river
Quarry quar quar quar
Town town town town
LRI Slope
The code recorded in the LRI for slope should be interpreted as follows:
Code Description Description Landscape
A 0-3° Flat to gently undulating Flats and terraces
B 4-7° Undulating Terraces, fans
C 8-15° Rolling Downlands, fans
D 16-20° Strongly rolling Downlands, hills
E 21-25° Moderately steep Hill country
F 26-35° Steep Hilly and steepland
G >35° Steep Steeplands, cliffs
Molten rock generated within the earth; which, on cooling, forms igneous rocks.
Major Shelerbelts [LCDB2 Classification]
Major Shelterbelts are visible as linear features in the source imagery. No distinction is made between evergreen or deciduous shelterbelts. Shelterbelts longer than 200 m and 2 or more pixels wide.
Mangrove [LCDB2 Classification]
Mangrove (Avicenna officinalis) communities found on estuarine mudflats and tidal creeks in the upper North Island northward of latitude 38°.
Manuka/Kanuka [LCDB2 Classification]
Manuka (Leptospermum scoparium) or kanuka (Kunzea ericoides) indigenous shrubland found throughout New Zealand often associated with lightly grazed hillcountry.
Map unit
The area enclosed by a boundary indicating that within the limitations imposed by the scale of mapping the information mapped is homogeneous within that area i.e. rock type, soil, land use capability etc.
A hard, metamorphic rock consisting predominantly of the calcium carbonate mineral calcite.
Marsh [Wetland classification]
Mainly mineral wetlands with moderate to good drainage, fed by groundwater or surface water of slow to moderate flow, and characterised by moderate to great fluctuations of water table. Marshes are often temporarily inundated and differ from swamps in having better drainage, lower water table, more mineral substrate and higher pH (more alkaline). Usually occur on slight to moderate slopes and alongside water bodies.
Occurring in thick beds, free from minor joints and lamination.
Matagouri [LCDB2 Classification]
Matagouri (Discaria toumatou) is a divaricating, thorny shrub found in open shrubland or thickets restricted to freely drained recent soils, especially on river terraces and outwash fans in montane areas of the South Island.
Melanic Soils [NZ Soil Classification]
High fertility, dark well structured topsoils, associated with lime-rich rocks or dark (basaltic) volcanic rocks.
Metamorphic rocks
Rocks that have been altered by heat and pressure deep below the earth's surface.
Mine [LCDB2 Classification]
Culturally derived bare surfaces such as gravel pits and other open quarries.
Minimum tillage
An alternative to conventional cultivation aimed at minimising disturbance of the soil after spraying with herbicide. The soil is lightly worked with a cultivator before drilling.
Minor Shelterbelts [LCDB2 Classification]
Minor Shelterbelts are visible as linear features in the source imagery. No distinction is made between evergreen or deciduous shelterbelts. Considered shelterbelts if longer than 150 m and 1 pixel in width.
Mixed Exotic Shrub [LCDB2 Classification]
Single-species or mixed communities of introduced shrubs and climbers, such as Boxthorn, Hawthorn (Crataegus), Elderberry (Sambucus), Brier (Rosa rubiginosa), Buddleja (Buddleja davidii), Blackberry (Rubus), and Old man's beard (Clematis vitalba).
Modal classes
When formulating Land Use Capability standards each soil grouping is usually assigned a capability class. Variables such as slope, elevation, or erosion, may then be of significance and warrant placing variants in a higher or lower capability class.
Moderately well drained soils
Soils that have 50% or more grey mottles between 60–90 cm of the soil surface or greater than 2% rust-coloured mottles between 30–90 cm of the soil surface.
Mound or ridge of debris deposited by a glacier. Lateral moraine is deposited at the sides of a glacier; medial between two tongues of ice, and terminal at the front end of the glacier.
Spots or blotches of (often bright) colour different from the predominant soil colour. Very often the mottles are rusty in colour and are due to concentrations of iron oxides. Mottles indicate that there are periods of restricted profile drainage. The severity of the restriction to profile drainage is indicated by the abundance and depth at which mottles and gleying occur.
Soft sedimentary rock formed from material which contains a large proportion of clay. Form may be massive, bedded, frittered or bentonitic. Mudstone comprises much of the Tertiary 'soft rock' hill country. Soils formed from mudstones tend to be naturally fertile, but often carry a severe erosion potential.
Multiple symbols
Denote that, at the scale of mapping, there are two or more inventory factors or land use capability classes present within the mapping unit. The first recorded component is dominant, e.g. rock types Af+Pt; soils 99+90d; slope C+D … land use capability classes 3e4+6e12 etc.
Multiple use concept
Flexible land use and management that meets society's objectives and achieves sustainable yields whilst maintaining the natural resource.
Native pasture
Grasslands dominated by poa tussock, fescue tussock, snowgrass, and red tussock, and native grasses such as danthonia and fescue, and various small herbaceous plants. Extended over considerable areas of New Zealand at the time of European settlement.
New Zealand Land Resource Inventory (NZLRI)
A national land resource inventory survey that used the land use capability method of land evaluation at a nominal scale of 1:50,000 (1:63,360), which was initially completed in the late 1970s (1st Edition), with limited 2nd Edition regional remapping in Northland, part Waikato, Gisborne East Coast, and Marlborough in the 1990s.
New Zealand Land Resource Inventory (NZLRI) Worksheets
The map presentation of NZLRI inventory codes (rock type, soil, slope angle, erosion type and severity, vegetation cover) and land use capability codes.
An alternative to conventional cultivation aimed at minimising disturbance of the soil. After spraying with herbicide to kill weeds, the seed is drilled directly into the undisturbed soil (also known as direct drilling).
Not suitable for ploughing (cultivatable) and hence most suitable for pastoral, forestry or conservation.
Optimum crop production
Maximising sustainable crop production within the environmental limits of a particular soil and site.
Orchard [LCDB2 Classification]
Orchards and areas cultivated less than annually, and used for producing tree crops like pip fruit, stone fruit, nuts, olives, and citrus fruit, as well as crops like berries, kiwifruit, and asparagus.
Organic Soils [NZ Soil Classification]
Formed from partly decomposed plant materials, e.g. peat, are strongly acidic and have high water-tables.
Other Exotic Forest [LCDB2 Classification]
Exotic forest consisting of conifers other than Pinus radiata, such as Douglas fir, macrocarpa, and larch, or evergreen broad-leaved species, such as Acacia and Eucalyptus. Includes wilding pines.
Safe disposal areas for water directed from soil conservation structures such as flumes, diversion banks, etc. Outfalls include natural depressions, sod flumes, road ditches, waste land, concrete channels and tile drains.
Oxidic Soils [NZ Soil Classification]
Clayey soils formed from weathered ash or dark volcanic rock, friable with low plasticity and fine stable structure, limited rooting depth, slow permeability, and moderate or rapid infiltration rates.
Pallic Soils [NZ Soil Classification]
Have pale coloured high bulk density subsoils, weak structure, are slowly permeable and have limited rooting depths. They are dry in summer and wet in winter.
A general term for areas of flat to rolling land found mainly on the South Island's West Coast, having infertile mineral to organic, severely leached soils with poor drainage and a fire-prone vegetation of scrub with ferns, sedges and restiads.
Paralithic contact
The upper surface of rock or regolith that can be cut with difficulty with a spade or easily broken by a hammer, but is impenetrable to plant roots.
Parent material
The unconsolidated material in which soil develops.
Parent rock
The rock from which the parent material is derived by weathering.
Pastoral use
Growing of pasture to be harvested by grazing animals, but in some cases, e.g. lucerne, to be harvested by machine and fed to grazing animals. The term may also embrace the growing of fodder crops for on-farm supplementary feeding of animals.
Partly decomposed plant remains in a water-saturated environment, such as a bog.
Perched water table
A zone in the soil where, due to a slowly permeable layer such as a fragipan, downwards percolation of water is impeded and the water table is said to be 'perched' above the slowly permeable layer of soil.
Perennial vegetation
Vegetation living for more than 2 years, e.g. pasture, forestry, tree crops (walnuts, apples and olives) and vineyards.
Permanent works
Major works such as large scale community based irrigation, flood control or drainage schemes that significantly reduce or permanently remove a limitation to use.
A measure of the rate at which water can flow through the soil.
Phosphate retention
Capacity of a soil to 'lock up' phosphorus and make it plant-unavailable. High P-retention values indicate that plants will give a lower response to the same amount of phosphate fertiliser than on a soil with low P-retention.
Physical limitations
Permanent unalterable features of the environment that determine the potential use of an area, under a given climate, i.e. rock type, soil, slope, climate, erosion, and vegetation.
Pine Forest – Closed canopy [LCDB2 Classification]
Plantations of Pinus radiata where reflectance is dominated by the pine canopy - indicating trees are likely to be older than 15 years.
Pine Forest – Open Canopy [LCDB2 Classification]
Plantations of Pinus radiata showing significant reflectance of understorey land cover - indicating trees in an age class of approximately 6 - 15 years.
Plant-available nutrients
The proportion of soil nutrients available for plant uptake.
Plant-available water capacity
The amount of water a soil can hold that is available for plant uptake.
Once molten rocks that have cooled slowly and crystallized deep below the earth's surface.
Podzols [NZ Soil Classification]
Occur in high rainfall areas, are strongly acidic and strongly leached, with very low fertility. Drainage is variable from well to poorly drained.
A series of points that are combined together topologically to create a two-dimensional enclosed space, equivalent to a map unit.
Poorly drained soils
Soils that have 50% or more grey mottles within 15 cm of the base of the A horizon or within 30 cm of the soil surface, OR soils that lack a topsoil and have 50% or more grey mottles between 10–30 cm depth from the soil surface.
Porosity (soil porosity)
The amount and nature of the voids in a soil. A soil with high porosity allows water and gases to pass through relatively easily.
Potential evapotranspiration
Actual evapotranspiration is the total volume of water removed from land through evaporation and plant transpiration. Potential evapotranspiration represents the evapotranspiration rate of a short green crop, completely shading the ground, of uniform height and with adequate soil water supply.
Production forestry
Forests managed principally for commercial wood production.
Profile available water (PAW)
The amount of water that would be available to a grass/pasture cover within the soil profile to a depth of 1 m when the soil is at field capacity. PAW is expressed in units of millimetres of water where a PAW of 100 mm implies that 10% of the soil volume is water available to plants. PAW takes into account variations in soil horizons, and is calculated by percent area weighted averages using the proportions of the siblings where more than one soil sibling is mapped in a soil polygon.
Profile drainage
Profile drainage provides an indication of how long a soil, or part of a soil, is saturated with water, and how quickly it can rid itself of excess water.
Profile readily available water (PRAW)
The amount of water held in a soil that can be easily extracted by plant roots within the potential rooting depth. Profile readily available water (PRAW) is measured as the water that can be extracted between field capacity (-10kPa) and permanent wilting point (-1500kPa) for topsoils, and between -10kPa and -100kPa for subsoils to 1.0 m depth.
Protection forestry
Forests managed principally for soil conservation and regulation of water (also see erosion control forestry)
Protective blocks
Spaced or close planted blocks of trees, creating strong points to control gully head enlargement and the gradient of the longitudinal gully profile.
A soft, light-coloured, frothy, glassy rock with the appearance of a sponge; usually formed by the trapping of bubbles of volcanic gases in molten rhyolite.
Pumice Soils [NZ Soil Classification]
Sandy or gravelly soils dominated by pumice, or pumice sand with a high content of natural glass, rapid drainage but high water storage capacity, low clay contents, low soil strength, high macroporosity, deep rooting depths, and low macronutrient reserves.
Raw Soils [NZ Soil Classification]
Very young soils lacking distinct topsoil, and developed on sites of active deposition or erosion.
The length of a channel, uniform with respect to discharge, depth, area, and slope.
Recent Soils [NZ Soil Classification]
Soils formed in young sediments. They have distinct topsoil, but weakly developed subsoil, with moderate to high fertility and well to imperfect drainage. They have widely variable rooting depths and water storage capacities.
Recommended land use
A legacy component of early Land Use Capability surveys, whereby a map of recommended land use was prepared to accompany the Land Resource Inventory and the LUC classification. Simply recognises that some land uses are more suited (or less suited) to particular land types and classifications. Similar to potential land use used in NZLRI extended legends.
Reconnaissance surveys
Quick investigative surveys to gain preliminary information for planning more comprehensive surveys.
Redox segregations
Mottles or concretions formed as a result of the reduction and solubilisation of iron and/or manganese, their translocation, concentration, oxidation and precipitation as oxides. They are indicated by the association of low and high chroma colours.
A general term for the layer or mantle of fragmental and unconsolidated rock, whether residual or transported and of highly varied character, that nearly everywhere forms the surface of the land and overlies and covers the bedrock.
Resilient soil
Soils with the ability to recover or maintain essential soil physical qualities such as infiltration, aggregation and aeration from modification such as intensive cultivation.
Closely spaced channels resulting from the uneven removal of surface soil by running water. Rills are < 60cm deep and <30cm wide. They are features that can be removed by cultivation using normal farm equipment. In certain circumstances rills can develop into gullies.
Volcanic rock rich in silica, but poor in iron and magnesium. Molten rhyolite is very stiff and usually gives rise to explosive volcanic eruptions with emissions of large quantities of ash.
River [LCDB2 Classification]
Areas of flowing open freshwater without emerging vegetation (riverine systems).
River and Lakeshore [LCDB2 Classification]
Areas adjacent to rivers, streams and lakes characterised by bare gravel, sand and rock.
Rock [LRI]
The lithology of the map unit beginning with the surface and/or dominant rock type and ending with the basement and/or least prominent rock type.
Rooting barrier
The type of barrier that limits root extension, e.g. very dense soil horizons, pans, densely packed gravels, rock, anoxic conditions and high water tables.
Rooting zone limitations
Limitations to plant growth within the rooting zone such as profile shallowness, stoniness, pans, rock outcrops, low soil water holding capacity, low fertility (where this is difficult to correct), poor soil texture and structural conditions, salinity or toxicity.
Saline soil
Soil that contains enough soluble salts to interfere with the growth of most crop plants.
Material which consists of particles between 0.05 and 2.0 mm in diameter.
Sedimentary rock consisting of compressed or cemented sand-sized particles.
A metamorphic rock that has developed distinct layering (foliation); can be split into slabs or flakes. Mica appears as characteristic shiny flecks in the rock.
Lightweight volcanic rock, usually formed by the trapping of bubbles of volcanic gases in andesitic or basaltic lava; denser and darker than pumice.
The transport and accumulation of coarse, fragmented rock debris on slopes as a result of weathering and gravitational movement.
Seasonal wetness
Seasonal fluctuation of water table depths influencing plant performance through determining soil aeration, e.g. high water table in winter, lower in summer.
Sedimentary rock
Rocks resulting from the consolidation of loose material that has accumulated in layers, usually on the bed of the sea, in lakes or in rivers.
Groundwater emerging at the surface. This commonly takes place at a change of slope, at the junction of permeable and impermeable strata, or where groundwater is perched.
Seepage [Wetlands classification]
An area on a slope which carries a moderate to steady flow of groundwater, often also surface water, but less than would be considered a spring or a stream. Substrate, nutrient status and acidity vary widely. Seepages usually occur at changes in slope or where an impermeable basement raises the water table.
Semiarid Soils [NZ Soil Classification]
Are dry for most of the growing season, have moderate to high natural fertility and are well to imperfectly drained. They are fragile with weak soil structure, and very low organic matter.
Sheet erosion
The removal of surface particles by non-channelised overland flow of water.
Material which consists of particles between 0.05 and 0.002 mm in diameter.
Deep seated failures, usually of large blocks of rock and regolith. Slumps involve rotational slide movements along curved failure plains, resulting in raised lower (toe) slope relative to the upper part of the slope. This often results in the formation of ponds or lakelets at the head of a slump.
Snow and Ice [LCDB2 Classification]
Perennial cover of snow and / or ice.
Soft rock
Weak rocks with minor or insignificant cementation that disaggregate with a mild hammer blow or can be crushed by hand. Soft rock can be cut by hand with a spade.
Soil and water conservation plans (farm plans)
A conservation management plan designed to address soil erosion and water control issues through management, and the installation and maintenance of conservation works. Such a plan includes:
  • An initial land inventory survey and land use capability assessment.
  • The design of a conservation programme based on land use capability, and effective, economic soil and water conservation techniques.
  • An agreement between the regional authority and the farmer to carry out specified works or practices within a prescribed period.
Soil depth
Soils are assigned to one of five depth/stoniness phases according to their depth above gravel, bedrock or stone in the upper 20 cm: Deep (>90 cm), Moderately deep ( 45–90 cm), Shallow (20–45 cm), Very shallow (<20 cm), Stony (5–35% stones in upper 20 cm), and Very stony (>35% stones in upper 20 cm).
Soil erosion
The displacement of sediment, soil, rock and other particles usually by wind, water, or ice, by downward movement in response to gravity, or by living organisms.
Soil phase
Most commonly used as a subdivision of the soil type based on a characteristic or combination of characteristics potentially significant to land use, e.g. depth, physical composition, surface forms, drainage, salinity, erosion, sedimentation, or climatic regime. For example, Oxford silt loam, easy rolling phase; Mata clay, slightly eroded phase; Rukuhia peat, burned phase.
Soil profile
A vertical section of a soil showing all its horizons to 100 cm depth.
Soil salinity
Soils where the electrical conductivity of a saturated soil extract is greater than 0.8 mS cm-1.
Soil series
A soil series is a profile class concept, described by a modal profile with a defined range of values for certain properties, e.g. Templeton series. As a soil mapping unit – a soil-landscape mapping unit will be dominated by the profile classes of one series, BUT may contain other profile classes, for example, the Templeton series with Eyre or Wakanui series.
Soil set
A convenient mapping unit used on general surveys, and is a grouping of soils with like profiles or like assemblages of profiles. Its constituent soils need not be geographically related.
Soil slip erosion
Shallow, rapid slides and flows involving soils and regolith. Movement rates are typically 0.5-5 m/s, or fast walking to running pace. They comprise a scar (source area), and a debris tail (accumulation area).
Soil structure
The way in which soil particles are aggregated into soil peds. Structure is described by ped size (fine, medium, or coarse), shape, and how strongly they are formed (weakly, moderately or strongly). The presence of peds is important because spaces are left between and within them. These spaces are necessary for root growth and the movement of water and air within the soil.
Soil texture/texture class
Soil texture is used to describe the particle size distribution of those particles in a mass of soil that are less than 2 mm in diameter. Particles coarser than 2 mm are described as gravel and are not regarded as a textural component. Soil texture is described as a class determined from a standard texture triangle based on the relative proportions of sand, silt and clay.
Soil type
The basic unit of soil mapping, a unique combination of chemical, physical, biological, and mineralogical characteristics and site features. Often designated by a geographic name and/or a topsoil textural and depth qualifier.
Stony soils
Soils that have 5–35 % stones in the upper 20 cm depth.
Embankments along streams or on floodplains designed to confine river flows to a definite width for the protection of surrounding land from flooding.
Supplementary feed crops
See forage crops and greenfeed crops.
Sub Alpine Shrub [LCDB2 Classification]
A diverse range of shrubland communities (including Hebe, Olearia, Dracophyllum and Cassinia) usually occurring within an altitudinal range of 900–1200m, but also at lower altitudes where they represent secondary vegetation after forest clearance.
Surface runoff
That portion of the precipitation that makes its way towards stream channels, lakes, or oceans as surface flow. The term runoff also includes subsurface and deep seated flows. Runoff will occur only when the rate of precipitation exceeds the rate at which water may infiltrate into the soil.
Sustainability in the context of land use means to manage the land in a way that will permit continued use over the long term without significant degredation to the land and surrounding environment while also maintaining financially viability.
Swamp [Wetland classification]
A wetland that receives a relatively rich supply of nutrients and often also sediment via surface runoff and groundwater from adjacent land. Swamps usually have a combination of mineral and peat substrates and leads of standing water or surface channels with gentle permanent or periodic flow with the water table permanently above some of the ground surface.
Tall Tussock [LCDB2 Classification]
Areas of Chionochloa species, usually accompanied by short tussock grassland species and a number of herbs, in particular, Celmisia species.
A general term for all solid (rather than molten) materials ejected from a volcano during an eruption: boulders, lapilli and ash.
A relatively flat or gently inclined surface (tread) less broad than a plain, bounded one edge by a steeper descending slope (riser) and along the other by a steeper ascending slope (riser), and sufficiently elevated to be beyond the reach of the waterway that formed it.
See soil texture.
Thematic classification
Classification techniques used to define mapped areas based on a classification scheme relevant to a theme or application (e.g., erosion severeity, land cover or land suitability.
Toprock [LRI]
Toprock is first-named entire (i.e. not patchy) rock type in the LRI rock code, irrespective of any succeeding stratigraphy.
A general term for the upper part of a soil with evidence of organic matter accumulation; usually identified as an A horizon.
Transport [LCDB2 Classification]
Artificial surfaces such as roads, railroads, airport runways and skid sites associated with forest logging,
Tree crops
The growing of trees for fruit and/or nut production.
A general term for consolidated volcanic tephra.
Tunnel gully
These are initiated by subsurface concentration and flow of water, resulting in eluviation and scouring, and the formation of narrow conduits, tunnels or pipes. Soluble, dispersive or low strength material is removed, ultimately resulting in collapses, visible either as holes in the hillslope or as gullies when sufficient collapses coalesce to form continuous linear features.
Ultic Soils [NZ Soil Classification]
Strongly weathered soils with a well-structured, clay-enriched subsoil horizon, clay depleted E horizon immediately beneath the topsoil. Ultic Soils are acid and strongly leached with low levels of calcium and other basic cations, are slowly permeable, and have low nutrient reserves.
Relates to igneous rocks with very high contents of dark-coloured minerals containing iron and magnesium and less than 44% silica.
Urban Parkland [LCDB2 Classification]
Open, typically mown, grassed amenity areas within or associated with built-up areas (including scattered trees, playing fields, cemeteries, airports, golf courses, and river berms).
Very poorly drained soils
Soils that have an O horizon (an organic horizon), or lack a distinctive topsoil and have 50% or more grey mottles at less than 10 cm from the soil surface.
Vineyard [LCDB2 Classification]
Land occupied by rows of perennial vines supporting grape crops usually harvested for the production of wine.
Versatility in the context of land use is a measure of whether or not land can be put to many different uses with equal facility. This contrasts with land suitability which usually refers to one specific land use. High suitability with low versatility implies a clear choice of best land use with no conflicting uses, while high suitability and high versatility may imply a conflict of potential land uses.
Volcanic ash
Fine ash-like rock particles ejected from volcanoes during eruptions; may be transported large distances by wind.
Water holding capacity
The storage capacity (or ability) of a soil to hold water.
Periods of soil anaerobic conditions after rain or flooding. Short-term water logging is where anaerobic conditions may occur after heavy rainfall for periods of up to one week; Water logging is where there are sustained anaerobic conditions for periods of greater than one week due to a high groundwater table or perched water table.
Water table
At a depth below the surface, the ground is saturated with water. The upper surface of this zone of saturation is termed the water table.
Well drained soils
Soils that have no evidence of gleying or mottling within 90 cm of the soil surface.
Any type of barrier for protection from winds. Although more commonly associated with vegetative barriers, they also include non-vegetative barriers.