Glossary

A B C D E F G H I K L M N P R S T V W X

A

Absorbing roots

Fine fibrous roots which take up water and minerals from the ground. Most of the absorbing roots are within the top 30 centimetres (12 inches) of soil.

Arboriculture/Arborist

Arboriculture is the management and cultivation of individual trees or arboreal (woody plants). Arborists are people trained in arboriculture and conduct a variety of tasks such as selection, planting, training, pruning, removal & risk management. Arborists also consider legal & aesthetic issues and can identify pests and pathogens.

B

Barber chair

A dangerous condition which can occur in leaning trees. As the tree is cut it can split vertically from the cut upwards with explosive force. This can result in a dead or severely wounded operative.

Bore cut

Where the saw tip is plunged into the tree to form a hinge before the saw is moved towards the back of the tree to leave a peg. The peg secures the tree from falling until the hinge is correctly formed and can reduce the risk of ‘barber chair’.

Bowline

A knot used to form a secure loop in a rope to which items can be attached.

C

Cambium

Cambium cells are located inside many trees and plants. They are meristematic (can divide to produce new cells) which gives rise to phloem cells (on the outside of the cambium layer) and xylem cells (on the inside of the cambium layer)

Conservation Area

The local planning department can create a conservation area to protect the trees within the area. This can be used to protect the look and feel of an area or to protect a small area where generating a large number of TPOs would be to onerous to introduce. We will check if you are in a conservation area and take the appropriate action. This check is provided to our clients for free.

Coppice

Coppicing is a traditional metod of woodland management. Some trees will regrow if cut down. The new growth is often vigorous as the already has a developed root network the sustain and allow for the rapid growth. This takes advantage of the trees coping mechanism allowing it to regrow quickly after storm damage in the natural environment

D

Deciduous

A deciduous tree or plant is one which sheds all its leaves during the autumn in preparation for winter. Compare to evergreen

E

Epicormic Growth

Epicormic growth (or epicormic shoot) is a shoot which grows from an bud beneath the bark of tree. The buds are prevented from growing until a certain condition is met. Growth may be triggered by the removal of a neighbouring tree or the removal or a branch. Epicormic soots grow vigorously and can be induced by the removal of a branch or if the tree is coppiced or pollarded

Evergreen

A tree which continuously sheds its leaves as a process of renewal but does not shed all of its foliage annually. Compare to deciduous

F

False Crotch

A false crotch (also known as a cambium saver) is installed when there is no natural crotch for the ropes to run over, to protect the natural crotch from damage or to reduce wear on ropes.

G

Girdling root

A root that encircles all or part of the trunk of a tree or other roots. As the girdling root grows it constricts the vascular tissue, inhibits growth and  hinders the movement of water, minerals and photosynthates.

Growth rings

Rings which are formed in the xylem and visible in a cross section of the stem, branch and sometimes root of trees and some plants. In temperate zones one ring usually represents one year of growth and are sometimes called annual rings. The darker thin rings develop when the tree shuts down for the winter and the lighter (and usually thicker) rings develop through the growing season. By looking at the thickness of the lines you can identify periods of good and poor tree growth, overall poor vitality and how fast species grow.

H

Heartwood

The inner, non functional core of the xylem that provides structural strength and chemical defence against decay.

I

Included bark

Bark that becomes embedded within the tree. It is usually formed when a limb and the trunk form an acute angle (V union) or in-between codominant stems. Included bark creates a weak structure

K

Kickback

Kickback occurs when the upper tip of the saw is used to cut. This results in sudden and sometimes violent movement of the saw in an upwards and backwards motion

L

Lignin/Lignification

During lignification Xylem cells deposit lignin, a complex chemical compound, in their cell walls. This strengthens the cells and turns them into wood. Lignin plays an important role in the carbon cycle, it is a good fuel and highly lignified wood is durable. Lignin is the reason why newspapers turn yellow over time and must be removed before higher quality paper can be made.

Lion tailing (lion’s tailing)

Lion tailing is a poor pruning process in which an excessive amount of branches are removed from the inside of the crown. The tree is left with clumps of foliage on the extremities of the limbs. This can weaken the branches and can lead to sunburnt bark tissue.

M

Mutualistic

A type of symbiotic relationship in which two organisms live closely together. Each organism provide a benefit to the other.

Mycorrhizae

A symbiotic and often mutualistic association between certain fungi and the roots of a plant. The fungi is provided with access to carbohydrates, such as glucose and sucrose, while the plant benefits from the fungi’s greater ability to absorb water and some nutrients. Plants with mycorrhizae have a greater resistance to soil-borne pathogens and the effects of drought.

N

NPTC – National Proficiency Tests Council

The UK body responsible for providing proficiency tests for the use of chainsaws, forestry and many related tests. The NPTC website can be found here – http://www.nptc.org.uk

P

Phloem

Phloem is vascular tissue that moves photosynthates and growth regulators around the tree or plant. It is situated on the inside of the bark and just outside of the cambium. Compare to xylem

Pioneer species

These are species which are first to populate an abandoned site, where a ecosystem has been damaged or destroyed or where newly formed soil appears beginning the chain of ecological succession. Pioneer species are capable of growing in poor soil (polluted, poor nutrient availability, waterlogged, shallow soil, heavily compacted) which other species would find difficult to grow in. Birch and alder are two pioneer species, alder is particularly good at growing in waterlogged soil. Over time the pioneers make the site more favourable for other secondary species which, given an opportunity, start to grow and populate the site. Eventually the site will populated by a climatic species.

Pollard

Pollarding is the process of removing the branches from a tree to induce epicormic growth. The new growth is vigorous, its a coping mechanism, allowing the tree to regenerate quickly after storm damage. This is an old technique to encourage regrowth above ground level, they are away from passing animals (opposed to a ground level coppice). Not all tress can be pollarded but many street trees are successfully pollarded for numerous reasons. Pollarding is different from coppicing (which also induces epicormic growth) in that only the lateral limbs are removed and not the main trunk.

R

Reduction

Pruning a tree to decrease height, density and/or spread of a branch or crown

Root crown

The area where the main roots join the stem. This is usually near ground level

S

Sapwood

The outer part of the xylem that transports water and minerals. Compare to heartwood

Soil

Soil is made of organic material (decaying plants or animals), inorganic material (rocks, minerals, sand, silt clay etc), water, air and organisms (fungi, bacteria). All of which are needed for a healthy soil.

Symbiotic

A close and long standing relationship between two organisms. The relationship may be mutualistic (beneficial to both organisms),competitive (both organisms suffer), commensalistic (beneficial to one while the other is not affected) or parasitic (one organism benefits while the other one is harmed)

T

TPO

A Tree Preservation Order (TPO) can be placed on any tree to protect. If a tree is covered by a TPO then you cannot conduct any work upon the tree without written consent from the local planning department. We conduct TPO searches for our clients free of charge.

V

Vascular system

The vascular system consist of Xylemphloem – the parts of the tree that move nutrients or water around the tree or plant

W

Waterlogging

Waterlogging occurs when more water arrives on an area (usually by rain) than can be absorbed by the soil. It happens when soil is saturated with water and more water arrives faster than it can soak away. The water replaces the air in the soil (held in tiny air pockets) and creates an anaerobic environment. Tree (and plant) roots need oxygen in the soil to respire but which is not possible when the soil is waterlogged. This inability to respire is why many trees and plants are unable to survive (for long) in waterlogged areas

X

Xylem

Tissue which transports water and minerals in trees and other plants. It is unidirectional (moves materials away from the roots) and also provides structural support. Xylem cell become wood after they go through the process of lignification. Compare to phloem