Glossary

Above-ground biomass

All living plant material from living, or recently living organisms, above the soil including stems, branches, bark, seeds and foliage.

Basal area

The area of the cross-section of tree trunks and stems, measured at 1.3m above the ground, usually expressed in square metres per hectare.

Basal shoots

Shoots (plant stems) arising from below or near the ground surface.

Bell Miner Associated Dieback

Increases in bell miner populations and their distribution, in addition to other factors such as tree stress, psyllid infestation, dense forest understories, forest structure as well as weed invasion, drought, logging, pasture improvement, soil nutrient changes, frost and changing fire and grazing regimes have all been implicated in the spread of dieback.

Biodiversity

The variety of life forms that exist.

Biomass

Matter in living organisms, usually expressed in tonnes of dry matter per hectare.

Biomass accumulation rate

The rate of increase in biomass, usually expressed as tonnes of dry matter per hectare per year.

Blade ploughing

A blade plough is a horizontal cutter-bar that is dragged through the ground to sever tree roots.

Canopy

The above-ground portion of a vegetation type, formed by plant crowns. In a woodland or forest, the canopy is formed by the crowns of trees and sometimes large shrubs. The canopy can be further divided into upper, mid and lower canopy layers. The tallest plants of a vegetation type form the upper canopy layer.

A measure of how much the plant canopy covers the ground.

In these web pages, canopy cover values are for 'approximate crown cover'. This is the percentage of a sample site within the vertical projection of the periphery of the tree crowns. The crowns are treated as 'opaque' (i.e. if there are patches of sky visible within the tree crowns when the observer looks from below, these patches are considered part of the crown, and are included in the cover value).

Another way of estimating canopy cover is to use 'projective foliage cover'. This is the percentage of the sample site occupied by the vertical projection of the foliage only (i.e. if there are patches of sky visible within the tree crowns when the observer looks from below, these patches are not included in the cover value).

Carbon accumulation rate

The rate at which carbon dioxide (CO2) from the atmosphere is absorbed by plants through photosynthesis, and stored as carbon in biomass (tree trunks, branches, foliage and roots). It is expressed as the mass of carbon or carbon dioxide equivalents (tonnes) stored over a period of time (years). Estimates of carbon accumulation rates for vegetation often also include a measure of area (e.g. carbon or carbon dioxide equivalents (tonnes) per area (hectares) stored over a period of time (years)).

Carbon dioxide equivalent

The basic unit for greenhouse gas accounting which allows standardised comparison of gases with differing global warming potentials.

Carrying capacity

The number of cattle, sheep, horses, that can sustainably graze on the land. The maximum stocking rate that is consistent with maintaining or improving vegetation or related resources. It may vary from year to year on the same area due to fluctuating forage production.

Carbon stocks

The amount of carbon held in a specified pool such as biomass in a forest.

Chaining

A method of tree and shrub management involving a large chain dragged between two bulldozers to pull woody plants onto and out of the ground.

Closed forest

Canopy trees are 10-30m high and canopy cover is more than 80%.

Condition state

A description of the structure and composition of vegetation which may refer to the presence and extent of native and exotic plant species and bare ground. A particular vegetation type may exist in a range of different condition states. A site that once supported a particular vegetation type can also be converted into a different condition state.

Coppice

New shoots arising from damaged tree stems.

Crown

The totality of the plant's aboveground parts, including stems, leaves, and reproductive structures. A plant canopy consists of one or more plant crowns growing in a given area.

Crown fires

Fires that get all the way up into the crown (leafy canopy) of the trees in these tall forests.

Dbh

Diameter at breast height - a standard measurement point for trees.

Defoliation

To cause the leaves of (a plant, tree, or forest) to fall off.

Dieback

A condition in trees or woody plants in which peripheral parts are killed, either by parasites or due to conditions like acid rain and drought.

Ecological model

Describes which factors influence the structure and function of a natural system (e.g. a forest) including which factors may result in transitions between condition states.

Edge effects

A range of changes that occur near the edge of a patch of vegetation

Elevated fuels

Fuel above the ground, such as leaves

Emergent tree

A tree that projects above the main canopy of a forest.

Epicormic growth

Sprouting from epicormic buds, which lie dormant beneath the trunk, branches or stem of a tree until triggered by events such as fire.

Eucalypt

A collective term for species of Eucalyptus, Corymbia (bloodwoods) and Angophora.

Gilgai

Gilgai are repeated mounds and depressions formed on shrink-swell and cracking clay soils (or vertosols); water can accumulate seasonally in the depressions to form gilgai wetlands. (A shelf is sometimes found between the depression and the mound, but not always.)

This landform was once common in the Brigalow Belt in Queensland. Gilgai is a word from the Kamilaroi, Wiradhuri and related Aboriginal languages in which it means ‘small waterhole’. Early settlers in Australia used a number of terms for these microrelief features, the commonest being crabhole, melonhole and gilgai.

Grazing pressure

Stress on plant populations due to the grazing of animals. Plants may be lost either directly as a result of animals eating them, or indirectly as a result of damage to the vegetation or ecosystem by animals moving through the area.

Habitat features

Structural and other aspects of an ecosystem that provide resources for species. For example, tree hollows and mistletoe and two important features found in many Australian woodland ecosystem that used by animals for shelter and food.

Herbage

Herbaceous plants such as grasses and forbs

Honeyeaters

A large and diverse group of birds in the family Meliphagidae, including miners, friar birds and wattle birds.

Hot fire

A fire of moderate severity to very high severity. Hot fires can occur whenever humidity and soil moisture levels are low, and they most commonly occur in the late dry season. In Queensland, this tends to be in winter or spring.

Humus layer

The layer of fine organic debris on the soil.

Lignotuber

A lignotuber is a woody growth surrounding the base of the stem that contains substantial food reserves and many dormant buds that can develop into new shoots.

Liverworts

An ancient type of plant, liverworts are flowerless, spore producing plants. See www.anbg.gov.au/bryophyte/what-is-liverwort.html.

Maximum carbon state

The particular condition state that will store the maximum amount of carbon for a given vegetation type.

Maximum diversity

A method of rainforest regeneration that involves planting a diverse suite of species rather than a narrower set

Microclimate

The climate of a small specific place. Microclimate is used in an ecological context to describe climate differences between parts of an ecosystem. For example, the microclimate of a tree canopy differs considerably from that under a log on the soil surface.

Mid stratum

A layer of small trees or shrubs that sit between the canopy (tall) tree layer and the ground layer (grasses) in some forests.

Monocultures

The cultivation or growth of a single species, especially on agricultural or forest land.

Negative feedback loop

A process which tends to reduce change in a system. See http://en.wikipedia.org/wiki/Negative_feedback.

Nutrient cycling

The process by which nutrients are transferred from one pool to another. For example, fungi and other decomposers help cycle nutrients from dead plant material, where they are generally unavailable to living plants, into soil nutrient pools where they are accessible by living plants.

Open forest

Canopy trees are 10–30m high and canopy cover is between 50% and 80%.

Pasture yield

The crop produced from the land.

Predation

A biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked).

Pulling

See chaining

Recruiting

The act of recruitment. Providing new members. In ecology, recruitment typically refers to new individuals in some population or age cohort.

Ringbarking

Girdling, also called ring barking or ring-barking, is the complete removal of a strip of bark (consisting of cork cambium, phloem, cambium and sometimes going into the xylem) from around the entire circumference of either a branch or trunk of a woody plant. Girdling results in the death of wood tissues above the damage. A branch completely girdled will fail and when the main trunk of a tree is girdled, the entire tree will die, if it cannot regrow from above to bridge the wound. Healing can only happen when the xylem is not cut into and damaged. (Wikipedia)

Seedbank

A store of seeds, commonly in the soil but also sometimes within the canopy of trees and shrubs

Soil degradation

When the soil is compacted and/or eroded.

Splatter gun

Gas powered ‘gun’, like a drenching gun, used to apply herbicide in low volume and high concentration, especially to lantana

Staged canopy conversion

A method used to gradually convert a forest of weedy trees into a native system

Stand

A group of trees

Standing carbon stocks

The carbon contained in standing trees, including dead ones.

Stem density

The number of individual plant stems in a specified area.

Sucker

A sucker, basal shoot, root sprout, adventitious shoot or water sprout is a shoot or cane which grows from a bud at the base of a tree or shrub or from its roots.

Suckering

Producing shoots (suckers) from horizontal roots

Topography

Pertaining to the surface of the land and the arrangement of features on it.

Tree density

The number of trees in a given area

Tubestock

Young plant seedlings.

Understorey

Generally the vegetation beneath a forest canopy, particularly the grasses, other herbs and small shrubs.

Water infiltration

Water on the ground surface entering the soil.

Woodland

Canopy trees are 10–30m high and canopy cover is between 20% and 50%.

Woody plant

A plant that produces wood as its structural tissue (secondary xylem), usually either trees, shrubs, or lianas (a type of climbing vine).

Woody thickening

When densities of woody plants increase in a woodland or pasture.