Acidic Soil

A soil in which the pH value of the soil solution is less than 6.7


Agroforestry or agro-sylviculture is a land use management system in which trees or shrubs are grown around or among crops or pastureland. It combines shrubs and trees in agricultural and forestry technologies to create more diverse, productive, profitable, healthy, ecologically sound, and sustainable land-use systems.


A land area of 43,560 square feet (About 209 by 209 feet).


Pertaining to material that is transported and deposited by running water.


The stem or trunk of a tree, excluding its roots and top, or branched crown. The part of the tree from which logs may be cut.

  Breast height

The standard height for determination of tree diameters, defined arbitrarily as 4½ feet above ground level on the upper side of the tree (see DBH).


Diameter at breast height (4½ feet above the ground). Most often expressed in inches, this measure gives an indication of the size and merchantability of trees (see Sapling, Pole and Sawlog). Average DBH of a stand is defined as the diameter at breast


Descriptor of a stand having trees of approximately the same age, usually within a range of ten or twenty years, and normally a simple vertical structure.


A term applied to broad-leafed trees, many of whose wood is harder than the wood of a majority of needle-leafed trees. The term is roughly equivalent to angiosperm and deciduous and is the opposite of gymnosperm, evergreen, and coniferous. Value depend


A logging operation, normally one in which large trees or many trees are removed. Often applied to regeneration cuttings, which remove mature stands and provide for establishment of new one.


A tree of 4" to 10" DBH, not large enough to be considered sawtimber; also, a stand whose trees average this size (as in polestand or poletimber stand).


In forestry usage, the removal of branches from the lower trunk of a tree to allow the stem to continue growing without producing large or loose knots. This is an expensive practice, but if done judiciously, can be a valuable investment in the crop tre


Also called reproduction, refers to seedlings and young growth below pole size, or to the establishment of such growth. Harvests or regeneration cuttings have, as a principal objective, the establishment of adequate regeneration of desirable species.


The period of time an even-aged stand is left to grow or a particular one-in-asequence of such periods (as in the current rotation or the next rotation).


A tree of 2" to 4" DBH, below pole size; or, a stand with trees averaging this diameter.


A regeneration method for even-aged stands, in which the mature over story is removed in a sequence of cuts over a period of years. Its objective is to provide enough light for adequate seed production, ground preparation, and seedling germination with


The practice of establishing, tending, and reproducing stands of trees. Involves prescribing such cultural operations as weedings, thinnings, prunings, and measures to protect the trees from insects, disease, and other natural elements.


A standing dead tree, generally of value for wildlife.


Partial cut made during intermediate stages in the growth of a stand. Its main purpose is to increase the growing space and resources available to the remaining trees. Most thinnings remove merchantable material and provide immediate financial yields,


All of the material making up a tree, or group of trees, or specified tree components such as stem or branches.


The woody material of trees excluding the stem, stump and roots.


The branches and associated foliage of a tree.

  Cubic metre (m3)

Unit of volume, usually used as the unit for measurements of tree stem volumes.

  Growing stock

A term broadly referring to the standing resource of living trees at a point in time.

  Hectare (ha)

Unit of area equivalent to 100 metres x 100 metres = 10,000 square metres. 1 ha = 2.47 acres.

  Increment (volume)

The increase in volume of a tree or a stand over a year or annualized over a specified period measured either in m3 per year or in m3 per hectare per year. See mean annual increment (MAI)

  Mean annual increment (MAI)

Mean annual increment is the average rate of volume production up to a given year, expressed in cubic metres per hectare per year. In even aged stands it is calculated by dividing cumulative volume production by age.

  Farm Forestry

Farm forestry is the name given to programmes which promote commercial tree growing by farmers on their own land. Farm forestry was defined by NCA (1976) as the practice of forestry in all its aspects in and the around the farms or village lands integrate

  Extension Forestry

It is the practice of forestry in areas devoid of tree growth and other vegetation situated in places away from the conventional forest areas with the object of increasing the area under tree growth.

  Mixed forestry

It is the practice of forestry for raising fodder grass with scattered fodder trees, fruit trees and fuel wood trees on suitable wastelands, panchayat lands and village commons


Shelterbelt is defined as a belt of trees and or shrubs maintained for the purpose of shelter from wind, sun, snow drift, etc.

  Linear Strip plantations

These are the plantations of fast growing species on linear strips of land.

  Rehabilitation of Degraded forests

The degraded area under forests needs immediate attention for ecological restoration and for meeting the socio economic needs of the communities living in and around such areas.

  Recreation Forestry

It is the practice of forestry with the object of raising flowering trees and shrubs mainly to serve as recreation forests for the urban and rural population. This type of forestry is also known as Aesthetic forestry which is defined as the practice of fo


A method of propagation by grafting, using a single bud


A destructive fungal disease of plants or an open wound in the stem of a tree or plant


A plant raised/grown in a container or pot, rather than in the ground.


The term used for a plant variety which has been cultivated by a nurseryman or gardener, rather than occurring naturally

  Cutting Back

Vigorous pruning to promote the next season's growth and/or flowering


A method of propagation where a section of plant is completely removed from the mother plant & treated in such a way that it is able to grow roots of its own


A plant that sheds its leaves in autumn


Decay from the tip of a shoot towards the main stem or root of a plant


In a state of suspended growth (as in winter)


A plant that keeps its leaves or foliage all year round


A group of plants having common structural characteristics distinct from those of all other groups


A method of propagation taking part of one plant & joining it to another that already has its own roots system


The organic content of soil formed by the decomposition of plant materials


The result of a cross between two different species, hybridisation in the parentage being indicated by the use of an 'X' in the botanical name after the GENUS


Native, belonging naturally


A method of propagation where a section of shoot or branch is buried while still attached to the whole tree.


Fertile soil comprised of clay, sand & decayed vegetable matter


A layer of material such as bark or compost placed on the soil surface around a plant for the purpose of feeding, weed control &/or insulation.


(Pronounced Mike O'Rizer) A group of mutually beneficial (symbiotic) fungi that colonise a plant's root system and enhance the host's ability to take up water and nutrients from the surrounding soil. Now available as commercially-produced soil additives to boost a new plant's establishment.


Belonging naturally in the environment and not introduced from another region by man or other agent


A young plant raised from seed


A plant that is able to pollinate itself and so will produce fruit without the help of another similar plants in its environs. Bi-sexual plants have male and female flowers on the same plant and can thus be self-fertile.


A perennial plant with several woody stems at ground level


A group subordinate to the genus, containing plants with common attributes


A plant that has been moved from its original location in the nursery as a means of maintaining a compact root system & promoting the production of the fine root hairs responsible for taking up moisture & nutrition from the soil.


A perennial plant with a single woody stem at ground level


Botanically recognised sub-division of a species which occurs naturally, in the wild.


A line or plantation of trees &/or shrubs for the purpose of providing shelter by filtering the wind.


Alluvium is a depositmade by a river or running water. This leads to an ‘alluvial deposit’ forming in the water. Alluvial soils are rich agricultural lands. Glaciers may also deposit sedimentary material, see ‘glacial till’.

  Anaerobic soils

Anaerobic soils have very little oxygen present - for instance the wet, waterlogged, marshy soils in a bog. While anaerobic conditions are important for some processes, such as bacterial reduction of nitrate to nitrogen, these conditions can also produce hydrogen sulphide, methane and other undesirable substances.

  Available soil water

This refers to the total amount of water in the root zone that is available for evapotranspiration, usually expressed in mm.

  Bearing capacity

This is effectively the weight a soil can withstand before severe damage occurs to the structure of the soil. Bearing capacity varies throughout the year, for instance a very heavy tractor that causes no damage on dry soils may cause a lot of damage to the soil structure of wetted soils.

  Buffering capacity

Buffering capacity is the ability of the soil to reduce high alkalinity or acidity levels coming perhaps from pollution (e.g. acid rain). Chalky or limestone soils for instance are very alkaline and can neutralise acids more effectively than acid, peat soils.

  Bulk density

The dry mass of soil per unit bulk volume of soil. Expressed as Kg/m3 or g/cm3.


That mineral fraction of the soil with particles smaller than 0.002 mm in diameter.

  Effective rainfall (or efficient rainfall)

The rainfall useful for meeting plant water requirements. This does not include water percolating down to aquifers, or surface runoff of water.


Erosion is the wearing away of land or soil through one or more processes. The main causes of erosion include the actions of water (rills, inter-rill, gully, snowmelt and river and lake bank erosion), wind (dessication and wind-blow), translocation (tillage, land levelling, harvesting of root crops, trampling and burrowing animals) and geological (internal subterranean erosion by groundwater, coastal erosion and landslides). Erosion can also be increased by poor land management such as overgrazing, deforestation or inappropriate use of mechanisation (e.g. ploughing down a hill slope).


Eutrophication describes the process where a waterbody, such as a lake or a soil solution, becomes loaded with dissolved nutrients. This can be natural, but is often due to pollution. Algal blooms can remove oxygen in the water, harming fishlife.


This is the rate of water loss from liquid to vapour (gaseous) state from an open water, wet soil or plant surface, usually expressed in mm day-1.


The process by which water passes from a liquid to a vapour (gaseous) state through transpiration from vegetation, and evaporation from soil and plant surfaces. The rate of evapotranspiration is usually expressed in mm day-1.

  Field capacity

Field capacity describes soil when it is completely wetted (excepting free drainage), and where there is plenty of water for plant roots. This occurs after ample irrigation or rainfall, when the rate of downward movement of water has substantially decreased, usually 1-3 days after rain or irrigation. It is expressed as a mass or volume fraction of soil water or a depth of water per metre of soil or mm m-1.


Solid material from which most soil is formed, characterised by the horizon symbol ‘R’ for rock. Soil may lie on top of the geology it came from – but not always, such as where ancient glaciers pushed the soil along. Geology is also a scientific field concerning the study of rock.

  Gley soils

Gley (or gleyed) soils are soils developed under conditions of poor drainage, resulting in reduction of iron and other elements and also in a typical grey/blue soil colouring. There are two main types of gley soil: - surface water gleys where water saturating the soil comes from surface drainage and - ground water gleys where saturation is due to fluctuating groundwater levels. A third type, unripened gley soil forms in brackish flooding conditions (tidal creeks).

  Organic material

Organic matter, also called ‘humus’, forms from the decay of leaves, plants and other life.


Peat is a type of soil formed in waterlogged conditions from incompletely decomposed plant material. Peat forms in wetlands or peatlands, also commonly called bogs, moors, mires, swamps and fens.


PH is a measure of acidity; standing for Potenz Hydrogen. It is measured from 1 (acid) through 7 (neutral) to 14 (alkaline) expressed on a logarithmic scale. Most soil is about pH 3 to 8.

  Saline soil

Soil containing sufficient soluble salts to interfere with plant growth.


That mineral fraction of the soil with particles from 0.063 - 2.0 mm in diameter - fine sand: 0.063 - 0.212 mm in diameter - medium sand: 0.212 - 0.6 mm in diameter - coarse sand: 0.6 - 2.0 mm in diameter

  Sodic soil

A soil with sufficient exchangeable sodium (alkali) to interfere with plant growth and cause dispersion and swelling of clay minerals.


Topsoil is the surface layer of soil containing partly decomposed organic debris, and which is usually high in nutrients, containing many seeds, and is rich in fungal mycorrhizae. Topsoil is usually a dark colour due to the ‘organic matter’ present. In arable land, ‘topsoil’ refers to the soil down to plough depth.

  Water holding capacity

Can the soil hold lots of water like a sponge? If so it has a large ‘water holding capacity’. Soil organic matter increases the water holding capacity. Pure running sand has a low water holding capacity.

  Waterlogged soil

A waterlogged soil is wet, with lots of water in the pores of the soil structure. The opposite is a aerated soil.


The process by which materials are broken down into smaller parts and ultimately their constituents. An example is ‘freeze thaw’ expansion and cracking. There are physical, chemical and biological weathering processes.


Establishment of a forest or stand in an area not previously forested.

  Artificial Regeneration

Creation of a new age class by renewal of a tree crop by direct seeding, or by planting seedlings or cuttings.

  Crown Cover

The ground area covered by the crowns of trees or woody vegetation as delimited by the vertical projection of crown perimeters and commonly expressed as a percent of total ground area

  Cutting Cycle

The planned interval between partial harvests in an uneven-aged stand (Thinning Interval).

  Harvesting Method

A cutting method by which a stand is harvested. Emphasis is on meeting logging requirements rather than silvicultural objectives.

  Natural Regeneration

An age class created from natural seeding, sprouting, suckering, or layering.


A method of regenerating a stand in which all trees in the previous stand are harvested and the majority of regeneration is from sprouts or root suckers.

  Site Preparation

A hand or mechanized manipulation of a site designed to enhance the success of regeneration. Treatments may include chopping, discing, bedding, raking, burning, and scarifying. All treatments are designed to modify the soil, litter, vegetation, and to create microclimate conditions conducive to the establishment and growth of desired species.

  Site Quality

The productive capacity of a site, usually expressed as volume production of a given species.


A release treatment in stands not past the sapling stage that eliminates or suppresses undesirable vegetation regardless of crown position.


Mechanical removal of competing vegetation and/or interfering debris, or disturbance of the soil surface, designed to enhance reforestation.


The place where an animal or plant naturally or normally lives and develops.


A term describing the relative capacity of an area to sustain a supply of goods and/or services in the long run.


An area of land with a single drainage network.


Fleshy fruit developed from a single pistil and with no hard layers in the pericarp. The fruit is usually many-seeded, but one-seeded berries occur in e.g. Persea (avocado). See Drupe, Fleshy fruit, Fruit.


Dry, usually many-seeded dehiscent fruit composed of two or more fused carpels that split at maturity to release their seeds, e.g. Swietenia and Eucalyptus. Capsules may have one or more rooms (locules). See Dehiscence, Dry fruits, Fruit, Locules.


Separation of seed from other species and non-seed fragments such as fruit fragments, leaves or stems. Cleaning may be undertaken by sifting, blowing, winnowing, flotation etc. The degree to which seed is cleaned is called purity.


Collective term of the procedures and methods of gathering seeds and fruits. In phenology also referring to the time of collection i.e. maturation of seed.


Death of seeds, germinants or young seedlings in the nursery resulting from attack by certain soil-living fungi. Damping off in seedlings often causes rot of the stem near the surface of the soil.


Extraction of seeds or stones by removal of the fleshy part (pulp) of fruits like berries and drupes. Depulping may be carried out by soaking and fermentation followed by pounding, maceration or mechanical treatment e.g. by coffee depulper.


One of the two sub-classes in angiosperms (the other being monocotyledons) the main distinctive feature of which is the presence of two cotyledons in their embryos. Other characteristics of the group are branching veins of the leaves, persistent primary root and vascular bundles in rings. Dicotyledons comprise both herbs and woody plants.


For seed: the physical removal and displacement of the dispersal unit (diaspore) from the mother tree to some distance away longer than vertical falling. Dispersal in forest trees usually by wind (anemochory) or animals (zoochory). Time of dispersal usually coincides with maturity and hence seed harvest.


Physiological state in which a viable seed fails to germinate when provided with water and environmental conditions normally favourable to germination.

  Dry fruits

Category of fruits which dehydrate or dry during maturation. Drying often causes dehiscence (opening) of the fruit and release of seed. Dry fruits are e.g. capsules, pods, follicles, cones and some aggregate and multiple fruits.


The non-self-supporting immature organism formed from the zygote by cell division and differentiation; the rudimentary plant within the seed.


Inner layer of the pericarp (fruit wall); e.g. the hard part of drupe fruits like in neem, teak and Gmelina.

  Epigeal (or Epigeous) germination

Type of germination in which the cotyledons are forced above the ground by the elongation of the hypocotyl.


Separation of seeds from the fruit. Extraction may be complete or partial, the latter e.g. of drupes in which part of the fruit (endocarp) is normally kept enclosing the seed. For dehiscent dry fruit, extraction is simply carried out by drying. Other fruit types may require mechanical treatment such as threshing (dry fruits) or maceration (fleshy fruits).


The union of the nucleus and other cellular constituents of a male gamete (sperm) with those of a female gamete (egg) to form a zygote. In gymnosperms fertilisation may occur months after pollination. In angiosperms there is a double fertilisation in which one of the two sperm nuclei from the pollen unites with the egg nucleus to form a diploid zygote and the other sperm nucleus unites with two of the nuclei of the embryo sac to form the triploid endosperm.


Angiosperm reproductive structure bearing pistils, stamens, or both, and usually also sepals and petals. So-called flowers in gymnosperms are male and female strobili before and during pollination.


In a strict botanical sense, the mature pistil or pistils of the angiosperm flower, in some types is also included associate structures like receptacle or perianth. In a less strict terminology it includes the mature seed-bearing organs in gymnosperms, e.g. cones, multiple and aggregate fruits. Fruit wall (pericarp) is sometimes divided into three separate layers viz. exocarp, mesocarp and endocarp.


The physiological processes in the first stages of growth of seed (and pollen grain). In seed germination, resumption of active growth in the embryo of a seed is demonstrated by the protrusion of the radicle. In seed testing (ISTA definition), resumption of active growth in an embryo which results in its emergence from the seed and development of those structures essential to normal plant development.

  Germination capacity (= germination percentage)

Proportion of a seed sample that has germinated normally in a specified test period, usually expressed as a percentage. It should be noted that in earlier literature the term ‘germination capacity’ has been used to express viability.


The process of sorting seeds or seedlings into classes, normally according to size. Grading often implies removal of a certain amount (normally the smaller size) of seeds or seedlings from a seed lot or seedling population.

  Gregarious flowering

Mass flowering in a population of trees of a species with pronounced periodicity. Flowering tends to be synchronised within a population or part of a population. Gregarious flowering often results in masting.


Flowering shoot; the assembly of a few or many individual flowers into large clusters from a common axis. Inflorescences are grouped according to the manner of branching.


Generally referring to fruits of the family Leguminosae, here used equivalent to ‘pod’. Some Leguminosae have, however, modified fruit types such as samaras or follicles. The term should be reserved to the prevalent fruit type in Leguminosae viz. a multi-seeded dry fruit that may or may not open at maturity.


Of plants: the stage of individuals after having passed the juvenile stage; often considered synonymous with reproductive age. Of fruits: the stage of the fruit when seeds are ready to be dispersed; usually, but not always, coinciding with germinability of the seeds. Often visible by e.g. colour change, desiccation and opening structures. Of seeds: seeds which are fully germinable after extraction from their fruits and possible breakage of dormancy.


Middle layer of the pericarp; the pulp of berries and drupes.

  Moisture content (m.c.)

The amount of water present in a material, e.g. wood, soil or seed. It is normally expressed on a weight basis, either as the weight of the water in % of the material’s oven-dry weight (‘dry-weight basis’) or, preferably in the case of seeds and fruits, as a % of the material’s fresh weight including water (‘wet-weight’ or ‘fresh-weight basis’).


Subclass of angiosperms characteristic by having only one cotyledon in the embryo. Differ from dicotyledons in a number of morphological characters like leaf, root and stem structure. Woody monocotyledons are e.g. bamboos and palms.