The following Arboricultural Associations list, of commonly used terminology/abbreviations and their meaning. May help in understanding some aspects of my reports and on various posts within this website:
AA Arboricultural Association
AAIS Arboricultural Advisory and Information Service.
AIS Arboricultural Implication Study
AMIUG Arboricultural Mortgage and Insurance Users Group
AONB Area of Outstanding Natural Beauty
Appellant A person who appeals to a higher court.
Arisings Product of the tree works. Brushwood, woodchips, logs, debris etc.
Bark Wounds Damaged or missing bark.
Basal Area Area of tree around stem base, including visible buttress roots.
Bifurcated A tree with two main stems.
BLS Better Land Supplement – Forestry Commission
Branch Bark Ridge An external physical feature resembling a raised ridge of bark and located on the upper-side of the branch to stem union. An area where branch and stem vessels are separated.
Branch Collar An external physical feature resembling a raised bulge or thickening of the branch diameter and located at the base of the branch where it meets its parent stem. An area where branch and stem vessels overlap.
BRE Building Research Establishment
BS British Standard
Buttress Roots Angled roots at base of stem.
Cable Brace Aerial branch or stem supporting system designed to reduce mechanical stresses and usually constructed from flexible wire or rope.
Callus Reactive cell growth usually found around bark wounds and old pruning wounds.
Cambium A layer of cells located between the bark and sapwood which are able to divide and thus produce further cells as growth rings.
Cavity Hole located within the branch or stem and extending into the wood beyond the bark layer.
CCF Continuous Cover Forestry.
Clean out Removal process where dead, dying and diseased branches are removed from the trees crown and stem. Can also include the removal of epicormic shoots, Ivy and rubbish.
Clear Services To prune branches clear of services such as street lamps or aerial service cables (i.e. telephone & electricity wires). The actual clearance can be specified as a distance. (e.g. clear aerial service wires by 3m).
Compaction Compacted soil. Soil which has become compressed to leave little or no air gaps between the soil particles. Compacted soil prevents proper root growth due to oxygen and water starvation.
Coppicing Where the tree stem’s are pruned close to ground level to leave a cluster of low stump’s (stool), with each stump being approximately 200mm in height, with the intention being to encourage the production of new growth shoots from these stumps. Final cuts on the stumps should be made with a slight angle to assist the shedding of rain water. A tree which has not been previously coppiced and has only a single stem follows the same procedure.
Cordate Heart shape. Normally used to describe leaf type.
CPO Chief Planning Officer
Crown The part of the tree comprising of limbs, branches and foliage.
Crown clean See Clean out.
Crown Lifting Operation where the branches of the lower crown are either completely removed or pruned to increase the ground to tree clearance. A clearance height is normally specified (e.g. crown lift to 3m over footpath).
Crown Reduction Reduce the overall size of the crown by a given specification. The operation should be carried out by pruning the tips of each branch back to a suitable branch union in a manner to create a balanced shape and outline. The reduction specification can be specified as a percentage (e.g. reduce crown by 30%) or as an absolute amount (e.g. reduce crown by 3m) or as an absolute height & spread specification (e.g. reduce crown to leave the tree with an overall height of 18m and a crown radius of 5.5m).
Crown Shaping To balance the crown by reducing its spread in certain places to achieve a more desirable shape which is more consistent with the trees habit. The reshape specification can be specified as an absolute amount (e.g. reduce eastern crown spread by 3m).
Crown Spread Distance from stem to crown edge. Usually specified as a single averaged distance or as four separate measurements for north, south, east and west.
Crown Thinning To reduce the foliage and outer-branch density of the whole trees crown or just part of the trees crown. This operation would normally be achieved by removing damaged, crossing, rubbing limbs and by removing smaller secondary branches but leaving the main branch structure intact. The thinning specification can be specified as a percentage (e.g. thin crown by 10%).
Cultivar A plant which has been developed (bred) in cultivation rather than in the wild.
CWS Community Woodland Supplement – Forestry Commission
DBH Diameter at Breast Height (DBH). The tree diameter is measured at breast height (approximately 1.3m above ground level).
Dead-wood Dead branches and stubs.
Defendant A person sued or accused in a court of law.
Dismantle Safe and controlled removal of the tree in small sections. The remaining stump would normally be cut as low as practically possible (usually just above ground level).
Epicormic Growth shoot growing from a dormant or adventitious bud located on stem and/or branches.
FASTCo Forestry and Arboriculture Safety Training Council
Fastigiate Conical or tapering outline with upswept branches.
Fell The removal of the tree in one operation. The direction of the fell can be determined and relatively controlled. The remaining stump would normally be cut as low as practically possible (usually just above ground level).
Fluted Used to describe vertical grooves found on some tree trunks.
Formative Pruning Selective pruning of a young tree so as to promote good future shape and habit typical of that tree species. Would normally include the removal of multiple leaders and crossing/rubbing branches.
FSC Forestry Stewardship Council
FWPS Farm Woodland Premium Scheme – Forestry Commission
Glabrous Not pubescent, not hairy.
Heave Expansion and movement of shrinkable clay soil due to rehydration by water.
Honeydew Sugary secretion produced by sap sucking insects such as aphids.
Hybrid The resulting offspring obtained from parents of different species or types of species.
Hyphae Fine threads composing of the actual fungus.
Included Bark Bark which is trapped between a stem union as the two stems press together. In some situations the edges of the two stems fuse together to form a single stem with a single growth ring. However, parts of the stems remain separated inside by the trapped bark.
ISA International Society of Arboriculture
Lenticel A pore on a shoot. Usually visible, elliptical and slightly raised.
LPA Local Planning Authority
Major Dead-wood Dead-wood exceeding 50-75mm in diameter.
Minor Dead-wood Dead-wood up to 50-75mm in diameter.
Multiple stemmed A tree with many main stems.
Mycelium Network of threads (hyphae) which form the normally unseen part of the fungus.
NAA National Arborist Association
Natural Regeneration New young tree stock established by natural means (i.e. seed dispersal).
NGO Non-Governmental Organisation
NHBC National House Building Council
NJUG National Joint Utilities Group
NNR National Nature Reserve
Node Position on a shoot where a leaf or another shoot grows.
NPTC National Proficiency Tests Council
Occlusion Term used to describe a wound which has become closed by callus growth.
Pathogen A disease causing organism.
PAWS Plantation on Ancient Woodland Site
PEFC Pan-European Forest Certification
Petiole The stalk of a leaf but not the shoot that the leaf stalk is fixed.
Pollarding Maintaining a tree by regularly pruning back the whole trees crown to previous pruning points located on its main stem. Similar to the coppicing procedure except that subsequent shoot rejuvenation forms on the trunk. Final cuts should be angled to assist the run-off of rainwater.
Plaintiff A person who brings a case of law against another in court.
PPE Personal Protective Equipment
PPG Planning Policy Guidance
Planting Circle An area located around the trees stem which is clear of other vegetation (competition). Would normally incorporate a form of soil protection such as mulch.
Pubescent Hairy. Normally describes smaller, soft hairs.
Reshape Crown See Crown Shaping
Respondent A defendant (esp. in an appeal case).
RFS Royal Forestry Society
Rhizomorphs Black, root like threads formed from Hyphae and normally associated with Honey Fungus.
Rod Brace Similar operation to Cable Bracing. A non-flexible rod of metal is inserted physically into the tree branch or stem and would incorporate threaded ends so it can be bolted tight. Normally used to reinforce a weak fork or to prevent the movement of crossing/rubbing branches.
Root Plate The base of the tree stem incorporating the major root structure.
SAC Special Areas of Conservation
Saprophyte An organism which feeds on dead plant matter.
Sessile Stalkless. Normally used to describe leaves which have no stalks.
Slime Flux Liquid exudation from the tree, bacterial based.
Soil Compaction See Compaction
Soil Heave See Heave
SNCO Statutory Nature Conservation Organisation
SPA Special Protection Areas
SPG Supplementary Planning Guidelines
SRA Subsidence Risk Assessment
SSSI Site of Special Scientific Interest
SSTS Scottish Skills Testing Service
Stool A stump(s) which has been allowed to produce new shoots. See Coppicing.
Stump The remainder of the trunk which is left in the ground after a tree has been removed. The stump is still attached to the root and is normally cut close to ground level.
Stump Grinding Removal of the stump to a specified depth below soil level by way of a specialised machine.
Sucker Growth Growth from stem base and/or exposed roots.
SULE Safe Useful Life Expectancy
Tomentose Having dense, pubescence.
Topping The indiscriminate reduction of a trees height by removing the upper crown. A poor practice.
TPO Tree Preservation Order
Tree Circle See Planting Circle
Trifurcated A tree with 3 main stems.
TROBI The Tree Register of the British Isles
UDP Unitary Development Plan
UKWAS United Kingdom Woodland Assurance Scheme
VTA Visual Tree Assessment
Weak Fork A stem or branch union which is exhibiting signs of a potential structural weakness through its growth habit (i.e. included bark).
WIG Woodland Improvement Grant – Forestry Commission
Witch’s Broom Foliage disorder resulting in clustered and dense area of twigs.
WGS Woodland Grant Scheme – (Forestry Commission)