AgroForestryTree Database
Glossary C
caducous
Tending to drop off, as leaves deciduous.
calcareous soil
Soil containing sufficient calcium carbonate (CaC03), often with magnesium carbonate (MgCO3), to effervesce visibly when treated with cold dilute hydrochloric acid (HCl).
calorific value
Strictly, the heat released from a substance in total combustion. Measured in kcal/kg (1 calorie = 4.187 joules). Individual tree species vary in calorific value from 3 000 to 5 600 kcal/kg of air-dry wood.
cambium
A lateral meristem in a shoot.
canopy See also crown
The assemblage or volume of leaves of all ages supported by branched stems that form the phyotosynthetic layers of a tree or crop.
capitate
Head-like.
capitulum
An inflorescence consisting of a head of closely packed stalkless flowers.
capsule
A dry fruit which normally splits open to release its seeds.
carpel
One of the flower's female reproductive organs, comprising an ovary and a stigma, and containing one or more ovules.
carrying capacity
1. Amount of animal life, human life or industry that can be supported indefinitely with available resources on a given area.
2. In wildlife management, the optimum population density that a given environment or range is capable of sustaining permanently.
catchment area
The land surface on which rain falls. Sometimes called a 'water catchment'. When referring to particular streams or rivers, it is the land surface from which water (rain) flows into them, sometimes through tributaries (feeder streams).
catkin
A pendulous inflorescence of simple, usually unisexual flowers.
chamaeophyte
A self-supporting woody plant or herbaceous evergreen perennial whose mature branch or shoot system remains perennially within 25-50 cm above ground level, or a plant that grows taller but whose shoots die back periodically to that height limit.
chitted seed
1. A general term for pre-germinated seeds.
2. A method of storing and dispatching seed of short viability (such as Quercus and Castanopsis spp). The acorns or chestnuts are placed in trays between layers of leaf litter or peat moss and kept moist.
chlorosis
1. Pathological condition of a plant caused by a deficiency of chlorophyll, shown by yellowing.
2. A condition in which the leaves are yellow and small and plant growth and vigour
chromosome
A small, elongated, deeply staining body found within the nucleus, consisting primarily of DNA and a protein sheath, and containing the genes or factors responsible for most hereditary traits.
ciliate
With a protective fringe of cilia, or minute hairs.
cladode
A flat stem that looks like a leaf and is photosynthetic, for example, as found in Australian acacias.
clay
A mineral soil separate consisting of particles <0.002 mm diameter. Clayey soils have the highest water retention capacity relative to sandy or loamy soils
clay pan
A horizon of accumulation of a stratum of dense, compact and relatively impervious clay. A clay pan is not cemented but is hard when dry and plastic or stiff when wet. Its presence, like that of a true hardpan, may interfere with water movement or root development.
clear cutting
1. Strictly, the removal of an entire standing crop of trees. In practice, may refer to exploitation that leaves much unsaleable material standing. Also termed 'clear felling'.
2. An area from which the entire timber stand has been cut. Removal of the entire stand in one cut.
clearing
[noun] A relatively small area within a forest that has no trees.
[verb] To dispose of undergrowth and vegetational debris (slash) left after trees have been felled and trimmed. Sometimes done by a burn. Clearing is also done by removal or controlled burning around forests, villages, homes or trees to act as a firebreak.
cleistogamic, cleistogamous (of flowers)
Self-pollinating, without the flower ever opening.
climax (of plant communities)
The final stage of succession that continues to occupy an area as long as climate and soil conditions remain unchanged. A plant community that has reached a relatively stable condition in which it is able to reproduce itself indefinitely and under existing conditions. A mature plant community.
climax species See also pioneer, tree temperament
Tree species that will regenerate in shade so is often large seeded.
cline
1. A geographic gradient exhibited by plants usually assumed to be genetically controlled.
2. Continuous character variations (genetically based) that are related to environmental gradients. However, the term cline is not a taxonomic category.
clone
A group of plants that have arisen by vegetative reproduction from a single parent, and which therefore all have identical genetic material.
closed community See also community
A plant community whose components so completely utilize the site as to exclude further entrants. An 'open community' is therefore one not excluding further entrants.
closed forest
Forest where trees are the dominant life form and the canopy is closed.
clumpwood
A plant community dominated by woody clumps.
codominant trees
Trees with crowns forming the general level of the crown cover and receiving full light from above but comparatively little from the sides, usually with medium-sized crowns and more or less crowded on the sides.
collar
The transition zone between stem and root, sometimes recognizable in trees and seedlings by the presence of a slight swelling.
community
1. Any assembly of organisms living together in a common area, no particular ecological status being implied; also closed community.
2. A group of plants growing together, or all of the plants and animals of an area.
community forestry
Forestry developed in areas marginal to agriculture, with many members of the community being landless or small-scale farmers, often characterized by ecological and cultural diversity and the employment of traditional technologies. Communal land development is basic to this type of forestry.
companion crop
A crop grown with another crop. Usually applied to small grain crops with which forage crops are sown. The small grain crop may also be known as a 'nurse crop', but companion crop is the term preferred by agronomists. It may also apply to others such as maize and soybeans when grown together.
complementarity
In intercropping, a net positive outcome for a crop mixture of the interactions such as competition and facilitation that occur between plant components growing simultaneously (spatial complementarity) or a mixture whose components, growing at different times, improve the capture of environmental resources (temporal complementarity).
compost
1. In plant nursery work, a mixture of inorganic and organic materials, perhaps with some soil of a particular suitable kind, in which seeds can be readily germinated or seedlings or young plants grown. Particular composts are made for particular purposes, and fertilizers are often added.
2. A pile of decomposing organic matter of plant or animal origin. Soil and other amendments such as lime, nitrogen and phosphorus may be mixed with the organic matter.
3. Organic residues, or a mixture of organic residues and soil that have been made into a pile and allowed to undergo biological decomposition.
compound
Consisting of several parts, for example, a leaf with several leaflets or an inflorescence with more than one group of flowers.
compound bud See also simple bud
A bud containing both vegetative and floral primordia; also called a 'mixed bud', as distinct from a simple bud.
concomitant cropping
A cropping sequence where 2 or more species, 1 of which has a shorter crop duration than the other(s), are grown together on the same unit of land.
conifers
Trees that usually but not always have needle leaves or scale leaves and that bear separate male and female cones. They are usually, but not always, evergreen. Some, for example, larch, are deciduous. Conifers belong to the class Gymnospermae.
connate See also adnate
Joined or attached to; applied to similar organs fused during development, for example, stamens fused into a tube.
contact herbicide
A herbicide that affects only that part of the plant with which it comes into contact, as opposed to a systemic (that is, translocated) herbicide.
continuous
The growing of crops in succession without a seasonal fallow.
contorted (of sepals and petals)
Twisted in the bud so that they overlap on one side only; spirally twisted.
contour
Linear demarcation of the land surface that indicates places of equal elevation; the lines on a map that connect these points.
contour cropping
Sowing a crop in rows or strips so that these follow along a contour.
contour furrow
A furrow ploughed on the contour on pasture or rangeland to prevent soil loss and so as to allow water to penetrate the soil; sometimes used in planting trees and shrubs on the contour.
contour tillage
The cultivation of land along the lines of uniform elevation, or contour lines, to reduce erosion.
convolute
Rolled together.
coppice See also woodlot
1. A method of cutting certain species of trees to encourage them to regrow from the remaining stump. A tree that coppices readily does not require frequent replanting and is, therefore, useful for producing fuel and poles.
2. Shoot developed from a dormant bud on a main trunk.
3. A small wood regularly cut over for regrowth. Also called a ‘copse’.
coppice stand
A crop of coppice shoots.
cordate (of leaves)
Heart-shaped.
coriaceous
With the texture or consistency of leather, as of certain leaves.
corm
A specialized part of a stem; a short, enlarged base of a stem where food is stored. May be used as a propagule.
corolla
All the petals of a flower; it is normally coloured.
corona
A series of petal-like structures in a flower, either outgrowths from the petals, or modified from the stamens, for example, a daffodil trumpet.
cotyledon
A seed leaf which is borne on a plant embryo.
cover crop
1. A crop grown to reduce soil erosion, conserve nutrients and provide organic matter. Cover crops are grown between the rows of a main crop or during the season when a cash crop is not being grown.
2. In experimentation, a crop grown before an experiment to reduce soil variability.
creeper
1) A trailing shoot that takes root mostly through its length.
2) Sometimes applied to a tight-clinging vine.
crenate (of leaf margins)
Round-toothed.
crenulate
Finely crenate.
crop rooting zone
Depth of soil in which crop roots are found.
crop rotation
The growing of different crops in recurring succession on the same land.
cross-pollination
See pollination.
crown
A tree canopy, the upper part of a tree or other woody plant carrying the main branch system and foliage, and surmounting at the crown base a more or less clean stem.
crude fibre See also crude protein
The components remaining after protein, soluble and easily decomposable carbohydrates, and fats have been chemically removed from a sample of plant material by appropriate methods. May be used in animal feed.
crude protein
The estimated protein content of plant material. Obtained by analysing the nitrogen content of feed, assuming that all nitrogen is present as protein and that all proteins contain 16% nitrogen. Hence it is obtained by multiplying the percentage of the nitrogen content by 6.25.
cultivar
1. An assemblage of cultivated plants, clearly distinguished by some characters (morphological, physiological, cytological, and so forth) and which when reproduced either sexually or asexually retains its distinguishing characteristics.
2. A cultivated variety. It is given a non-Latin name, and designated 'cv' (as distinct from 'var.' for a variety). A cultivar is any clone, race or product of breeding deemed worthy of cultivation and of a separate name.
cultural practices
Crop care practices including land preparation, seed selection, weed control, fertilizer and insecticide application, and water control in the field.
cupule (adj. cupulate)
A cup-shaped sheath, surrounding some fruits.
cutting See also propagule
A detached part of a plant (for example, stem, root or leaf) placed in suitable conditions to promote rooting and the subsequent production of a new leafy shoot. Stem cuttings can be 'hardwood' (secondarily thickened from previous seasons' tissue), 'semi-hard-wood' (mature current or last season's tissue) or 'softwood' (young tissue from the current season). They can be cut nodally or internodally.
cyme (adj. cymose)
An inflorescence in which each terminal growing point produces a flower. Subsequent growth is therefore from a lateral growing point, the oldest flowers being at the apex, or centre, if flat.
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