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)