Glossary ofForestry Terms

Contents

H&S/Environment/Quality .........................................1

Tree Species..............................................................3

Plant production........................................................7

New planting and restocking ...................................10

Establishment and protection ...................................14

Thinning .................................................................17

Timber Felling.........................................................18

Timber Haulage......................................................21

Tracks, roads and access .........................................23

Wildlife...................................................................25

Diseases .................................................................29

1

H&S/Environment/Quality Diffuse Pollution: When water is not properlymanaged silt and pollutants can be carried intowatercourses. This is known as diffuse pollution.When this happens the water quality is reduced,aquatic biodiversity compromised anddownstream flooding risks can be increased.The effects of diffuse pollution can be seen fromsource to sea. Environmental regulators areincreasing their activity in Forestry and breachesin the rules can lead to prosecution.

Forestry operations, especially harvesting,mounding and drainage works, need to becarefully managed by operators and duringsupervision visits to ensure that watercourses areprotected and diffuse pollution does not occur.

Diffuse pollution on a forestry site

Emergency procedures: Forestry often involvesharsh and dangerous environments. Reactingquickly and efficiently to emergencies isimportant and can save lives. All operators onTilhill sites receive site specific risk assessments,to highlight potential risks, and emergencyresponse cards providing details of where thenearest medical facilities are located andimportant numbers to have to hand, includingthe mountain rescue. All Tilhill employees andcontractors are kept up-to-date with first aidtraining to ensure everyone’s safety on site.

Emergency procedures

Goal posts: Goal posts are installedunderneath powerlines to help ensure thatmachinery does not come into contact with thepowerline.

Goal posts

Impacts observed downstream

2

Stand down day: Stand down days areimportant to ensure that all those on site areaware and understand current environmentaland health and safety issues and legislation.They also provide an opportunity for all toimprove their technical and operationalknowledge. Events such as ‘Insist on Safetydays’ give employees and contractors achance to discuss issues and queries relatingto specific issues they may face.

Stand down day

Standing deadwood: Standing deadwood isa requirement under certification schemes andis industry good practice to ensure forestbiodiversity and forest ecosystem integrity ismaintained and enhanced. It is an importantpart of the forest habitat at all stages in itsdevelopment.

Deadwood can also provide perch poleswhere raptors can sit, hence helping tomanage vole and rabbit populations.

Standing broadleaf deadwood

Standing conifer deadwood

Supervision: Supervision by forest managersand harvesting managers ensures that anyissues or problems arising during forestryworks are promptly identified and proactivelyresolved to ensure that work standards andlegislation are being met and value for moneyis being maintained for the forest owners. Supervision

3

Tree Species – BroadleafAspen: Aspen is a fast growing broadleaf thatis well suited to poor, damp soils.

Birch: Birch is a hardy pioneer species thatcan easily establish itself on poorer and wetterareas, making it particularly suited to wet,upland sites.

Oak: Easily identifiable by its uniquely shapedleaves, oak can be used to enhancebroadleaved areas.

Oak

Birch

Rowan: Rowan is a fast growing native speciesand is able to establish itself on exposed andwindy sites. Alongside its ability to establishitself on difficult sites it produces flowers andberries at different points throughout the yearmaking it a valuable species for enhancingbiodiversity.

Rowan

Aspen

4

Tree Species – Conifer

Larch: Larch can thrive in a range of conditionsand has historically been incorporated intomany commercial schemes. However, due tothe threat posed by the disease phytophthoraramorum which causes the trees to die, plantingLarch is not currently advised.

Lutz spruce: Lutz spruce is a natural hybrid ofwhite spruce and Sitka spruce. It is thought tohave great potential as an alternative to Sitkaspruce in areas that are marginally too dry forSitka.

Norway spruce: Norway spruce is aparticularly accommodating species and cangrow in almost all parts of the UK, making it agreat alternative conifer to Sitka spruce.

Larch

Douglas Fir: Douglas Fir produces redwood (ascompared to the whitewood of spruce). It growsfast and produces high quality timber. It needsto be planted on the right site as it is ademanding species. It has a soft foliage whichis favoured by browsing animals.

Douglas Fir

Lutz spruce

Norway spruce

5

Tree Species – Conifer (continued)

Scots pine: Scots pine is a native conifer andis a fairly adaptable species. A good speciesfor many wildlife species, such as the redsquirrel.

Scots pine

Cryptomeria Japonica: Japanese cedar isbeing used as an alternative on sites with over1200mm of annual rainfall, are sheltered andhave deep, well-drained, sandy loams likeWales and South-West England. It is a strong,durable timber.

Cryptomeria Japonica

Scots pine

Sitka spruce: Sitka spruce is the most commonspecies used in upland commercial forestrydue to its adaptable nature, particularly on wetand exposed sites, and is reknowned for highproductivity. Its white wood is in high demandby processers.

Sitka spruce

Redwoods: Redwoods are a niche speciessuited to prime sheltered sites, which are fertileand well drained, for example, some of theWelsh valleys. A high volume tree that can growto 50m high.

Redwood

6

Tree Species – Saw logsSaw logs: The bottom part of a felled maturetree is sold to the sawmill as a sawlog and isregarded as the most valuable part of the tree,used in the highest grade products. Sawlogscan be any conifer species and depending onthe qualities and characteristics of each specieshave a number of uses, including being usedby the construction industry.

Oak

Douglas fir saw logs

Larch saw logs

Sitka spruce saw logs

7

Plant production Bare root: Bare root trees arrive with bare,fibrous roots and need to be plantedrelatively quickly. Roots need to be protectedfrom drying out. Ideally, trees come to theforest direct from a cold store so the trees aredormant when they arrive at the planting site.They are supplied in coextruded bags – blackon the inside and white on the outside, andkept in the shade to avoid over-heating.

Cell: Cell trees have a small amount of soilsurrounding their roots and thus are betterprotected. They can be stored on site butneed to be kept moist. They are moreexpensive than bare root trees but can beused to extend the planting season especiallyin September and October.

Bare root

Cell

Controlled pollination: Controlled pollinationis costly and thus the seed arising is bulkedup using vegetative propagation or in someplaces somatic embryogenesis.

Our understanding of genetics ensure the fullsibling material is consistent and of bestquality with traits such as straightness vigourand acoustic velocity (stiffness).

Controlled pollination

8

Full siblings: Full siblings have two identifiedparents that have desired growth and qualitytraits. Such desirable traits are hereditary andwill be seen in the offspring. Pollination iscontrolled to ensure the parents are knownand recorded.

Full siblings

Sitka spruce flowers: The female flowers ofSitka spruce usually grow at the top of thetree and develop into cones in the autumn,which contain the seeds. The male flowersproduce pollen which is then carried by thewind to pollinate the female flowers.

Each individual Sitka tree has both male andfemale flowers. You can tell the differencebetween male and female flowers by theirlooks; male flowers are red, upright and ovalwhereas female flowers are blunt, a paleyellowish colour and oval in shape.

Female flower

Immature male flower

Lining out: Lining out, also referred to astransplanting, is the process of lifting upseedlings and rooted cuttings (part of thevegetative propagation process) from seedbeds/rooting beds and replanting them outsidein transplant beds. Lining out produces treeswhich have more fibrous and compact rootscreating more robust and stronger trees.

Lining out

Somatic embryogenesis: An artificial processto commercially produce a high number ofcloned material from plant tissue in a lab.

Somatic embryogenesis

9

1+1 transplant: The first number indicatesthe time the tree spent growing in the seedbed and the second how long it spent in thetransplant bed. Thus a 1+1 transplant hasspent one year growing in the seed bed andone year in the transplant bed. So this is a 2year old plant with significant juvenile vigourto assist early establishment.

Plants such as 2+2 may be more robust butat the expense of juvenile vigour.

1+1 transplant

Useful link: www.conifercoop.co.uk

Transplant beds: When trees are lined outthey are transported to transport beds. Treesare usually kept in transplant beds for onegrowing season.

Transplant beds

Seed orchard: Such orchards are made up ofcirca 40 clones which cross pollinate eachother producing a first level of improvedstock. The arising seed is sown to createseedlings to be planted directly.

Seed orchard

10

New planting and restocking

Mounding: Mounding is a process which usesexcavators to create small mounds of soil toplant trees on and can be used for newplanting or restocking. Mounding ensures thatthe correct stocking density (number of treesplanted in each hectare) is maintained andcan improve growing conditions for the trees;including improved soil aeration, moistureavailability and reduced weed competition toname a few. Mounding provides fasterestablishment and even crop spacing onrestock ground.

Continuous mounding: An alternative toploughing typically used on new plantingschemes to create a raised planting positionon certain site types.

Mounding

Continuous mounding

Rotary mounding: Also an alternative toploughing typically used on new plantingschemes to create a raised planting positionon certain site types.

Rotary mounding

11

Helicopter leadout: Some areas of the forest,particularly in upland areas, can be difficultto access for essential maintenance works,such as fencing distant boundaries. In suchinstances, helicopters can be used to delivermaterials, in a very cost effective manner, tothat part of the forest before works begin.

Helicopter leadout

Planters: Planters use a small spade to createa notch in the mound/plough ribbon to plantthe tree into, ensuring that all roots are in theground and the tree is left standing straight asthey do so. The average number of trees oneplanter can plant a day is around 1000-1500.

Planters and Planting Planting: Planting usually takes place betweenOctober to May, but this is dependent onweather conditions. The planting season canbe extended due to the changing weather. Thisis facilitated by using cold storage and cellgrown trees.

12

Plotting: Plots are taken at randomised pointsacross compartments to ensure that moundingand planting is being undertaken at the correctdensity for the required stocking.

Plotting

Quad bike: Quad bikes are a useful way toget people and materials, including treesduring planting and fencing materials forboundary repairs, across compartments. Theyare able to access areas which others vehicleswould be unable to get to and have a smallimpact to the ground with regards to damage.

Quad bike

Ploughing: Ploughing is used on new plantingschemes to create raised planting positions,soil cultivation and enhance drainage on site.The ploughs are towed by tractors, fitted withspecial tyres to reduce the amount of pressurethey place on the ground.

Ploughing

Tractor and plough

13

Walking excavator: Walking excavators areused to mound very steep sites that are beyondthe safe working limits of tracked excavators.They can work on new planting sites andrestock areas.

Walking excavator

Scarifier: A scarifier is generally used onrestock sites with light brash and, likeploughing, creates a slightly raised platingposition. Due to Sitka brash retaining itselasticity for long periods scarification isgenerally not used on sites that have had Sitkaon them and is more generally used on pineand larch sites. Good friable soils such asbrown earths are best suited to scarification.

Scarifier

14

Establishment and protection

Deer Management: Today’s forests create afavourable habitat for a wide spectrum ofwildlife. Some can harm trees by browsing,such as deer. To protect vulnerable crops it isimportant to control deer numbers. Damageassessments are carried out to estimatepopulations so managers can take informeddecisions.

Deer fence: To prevent browsing damage,particularly of soft conifers and broadleafspecies, deer fencing can be installed toprevent deer accessing the trees. Althoughdeer fencing is effective it can be expensivemeaning it is only cost effective in someinstances when a larger area is in need ofprotection.

Deer damage to sapling

Deer fence

Pruning: Pruning trees whilst they are youngcan result in better form (straightness andbranching and avoiding double stems) at theend of the rotation, increasing their qualityand subsequently their value.

Pruning

Tree shelters: Tree shelters are plastic tubesthat are used to protect individual trees frombrowsing damage. They also promote rapidgrowth in young trees because they shelterthe tree from the elements creating afavourable microclimate.

Tree shelters

15

Weeding: Weeds surrounding young treescan be controlled by spraying them withherbicides or removing them mechanically orby hand. Weeds compete with the tree formoisture, light and nutrients. Thus byremoving them, there is less competition forsuch resources enabling the tree to grow andestablish itself quickly. Depending on the site,weeding a band or an individual spot is used.

Band Weeding

Spot Weeding

Weevil: Weevils are insects which feed on thephloem of the tree and can cause significantdamage to young trees. When feeding issevere and a significant proportion of thebark is removed (or ringbarked) the tree isunable to transport nutrients and water upfrom the roots and subsequently dies.Spraying an insecticide containingAcetamiprid is currently the most commonand economically viable way of controllingtheir populations and reducing sapling losses.

Weevils are responsible for circa 25% ofrestocking costs. Currently, significantresearch is being carried out to establishviable Integrated Pest Management systems.Our weevil populations are approximately7 times higher than those in Scandinavia andCentral Europe.

Weevil

16

Weevil control trials: Alternatives to chemicalspraying to control weevil populations haveand are being explored through trials byTilhill, under encouragement by the UKWoodland Assurance Scheme (UKWAS) tominimise the amount of chemical use inforestry.

The trials have explored many differentcontrol measures, some of which have beeneffective in Scandinavia where weevilpopulations are lower. Some examples ofphysical barriers trialled to prevent weevildamage have included wax coatings on thestems, paper sleeves, clip stops and tights toname a few!

However, despite these efforts, to dateinsecticide spraying remains the most effectiveand economically viable way to controlweevils.

Tilhill Forestry, together with industry partnersare researching an Integrated PestManagement System that will protect ourcrops irrespective of weevil numbers in asustainable manner.

Full wax coating

Clip stop

17

ThinningThinning: Thinning is a silvicultural operationwhere certain poorer quality trees (in terms ofgrowth or form) are identified in a stand andremoved mid-way through the rotation.Removing a proportion of the trees enablesmore resources to become available for theremaining trees. The remaining trees haveaccess to more nutrients and grow faster,resulting in improved quality and growth. Thisfocuses the potential volume the site cansupport on fewer, larger trees.

Thinning

18

Timber Felling

Brash recovery with a forwarder: On somesites the timber and brash can be recoveredto help feed biomass markets. Forwarderspick up the brash and take it to forest roadswhere it can be chipped. Care must be takento ensure that by removing this material theunderlying soils and site are protected.

Brash recovery with a forwarder

Brash mat: The branch wood is placed infront of the harvester to form a mat protectingthe underlying soil.

Brash mat

Clear fell: When the tree crop is mature areasof the forests are felled and cleared and thenrestocked. This is also called ‘clear cut’. Allthe trees are felled over an area according toa pre determined plan and approval.

Clear fell

Forwarder: The forwarder collects the timbercut by the harvester from the harvesting coupeand stacks it by the roadside ready to bepicked up by timber haulage lorries. Eachdifferent type of timber product picked up bythe forwarder is stacked in individual stacks.

Forwarder

19

Hill Climber: A specialist harvester specificallydesigned to operate on steep ground. Theyhave good traction and the ability to have thecab level despite the gradient.

Hill Climber

T-Winch: A recent innovation. The winch isdesigned to assist forwarders and harvestersto safely work on terrain with steep gradientsthat they would otherwise be unable to access.

T-Winch

Harvester (on steep ground): Harvestersgrasp, cut and process trees to specificpredetermined lengths of timber felling the treein the process. Computer optimisation helpsensure maximum value is achieved.

Harvester (on steep ground)

Harvester head: The harvester head issituated on the end of the boom in front of theharvesters cab. The heads have curved bladesthat grasp the tree. Its chainsaw severs the tree.Rollers then move the tree through the headwith the blades trimming the branches off. Thechainsaw cuts the tree to the required length.The head also contains sophisticated sensorswhich measure diameter, length and form.

Harvester head

20

Windblow: Windblow occurs when the tree isunable to withstand the force of the wind andis blown over at the rootplate. As windblowntimber is more expensive to harvest thanstanding timber it is important to try andreduce the amount of windblow that occurs ina forest. This can be achieved by careful forestmanagement and strategic planning of thetiming and pattern of felling phases.

Windblow

Windsnap: Windsnap occurs when the stem isunable to withstand the force of the wind butthe roots remain anchored but the stemsnaps/breaks. This reduces the value andyield of the crop significantly.

The owner can insure vulnerable cropsagainst windblow/windsnap through GrowingTimber Insurance schemes.

Windsnap

21

Timber Haulage

Low Ground Pressure (LGP) haulage: Forestroads and public roads are an expensiveinvestment and not all roads are designed andbuilt to take the heavy haulage especially withtimber haulage. Some sub-optimum roads canbe used by specialist vehicles. For example,increasing the number of axles and/or addingadditional wheels across the axle can reduce theirfootprint to a point where they can haul economicloads on these sub-optimal roads.

The LGP haulage units are designed to havethe largest possible surface area touching theroad surface in order to reduce the amount ofpressure being placed on the road. The LGPunit will usually transport the timber to astorage area where it will then be collected byconventional timber lorries.

Such systems are particularly useful on softroads or over particularly long haulage routesand, although slightly more expensive thanconventional haulage using timber lorries, canreduce maintenance costs to the road over time.

Low ground pressure (LGP) haulage

LGP tyres

Central Tyre Inflation (CTI): In order toprotect fragile roads and sometimes toincrease traction, some timber lorries have theability to lower and increase the vehicles tyrepressures from within the cab.

Central Tyre Inflation

Landing Craft: This is a specialised ship that hasbeen developed with a flat hull which enablestimber to be shipped from remote areas. Somelimited on-shore infrastructure is required toallow the ship to sit on the shore. The ship isloaded with up to 100t of timber from thenearby fell site and floated off at high tide.Landing Craft

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Shipping and floating pier: In some locationstransporting timber by ship can be costeffective. The timber is taken from theharvesting site to a pier or floating pier andthen loaded into ships. The west coast ofScotland has a number of piers of varyingdesign to facilitate this. Shipping container and floating pier

Timber haulage: Specially designed lorries witha boom and grab arm are used to collect thecut timber from roadside in the forest andtransport it to the sawmill for further processing.

Different axle and tyre configurations allowtimber lorries to be matched to the forest andlocal road conditions and geometry.

In bad weather snow chains can be fitted toensure the timber dispatch can continueallowing mills to continuously process.

Timber haulage

Timber lorry loading timber

Skyline: On particularly steep sites skylining isused to move trees down to roadside forprocessing and stacking. The skylining systemuses a stationary winch and a series of pulleysand wire cables to carry the cut trees and logsto the roadside over obstacles, includingstumps and brash. Skyline

23

Tracks, roads and access

Blasting: Blasting is a process which usesexplosives to break up hard rock in-situ, sothat it can be used to build infrastructureonsite, including roads and turning circles. Byblasting rock onsite, material does not have tobe brought in, significantly reducing the costsof building necessary forest infrastructure.Using hard stone which requires blastingleads to a more durable road.

Bridge: Bridges are necessary for ensuring thatwater quality in the forest is not compromisedby vehicles travelling through watercourses.Bridges need to be carefully engineered so thatthey can support the weight of machinery andtimber lorries during establishment,maintenance and harvesting operations.

Blasting

Access tracks: The creation of tracks throughcompartments are important for operationsduring the planting and establishment phases.They can be used to gain access into the cropduring site visits to check on the crops processand by contractors during establishmentworks, such as weed control and weevilspraying, alongside providing easier accessfor the deer controllers. Track

Bridge

Culvert: Culverts enable water to flowunderneath roads, ensuring that both thestructural integrity of the road and quality ofwater travelling through the forest are notcompromised.

Culvert

24

Road Building: Roads throughout the forestare essential to enable all aspects of forestryoperations and management duringestablishment, maintenance and harvesting tobe undertaken. They have to be carefullyengineered to maintain their structuralintegrity against machinery and have suitabledrainage to ensure water quality on site ismaintained.

Road Building

Quarry and crusher: After rock has beenblasted it is crushed using a crusher to make itsmall enough to be used for road building. Itis usually stored in-situ in the newly createdquarry where it was blasted from. A surfacelayer of finer material is laid to allow regularmaintenance and grading to ensure the roadsurface sheds rainwater and is suitable forheavy traffic.

Forest road

Quarry and crusher

25

Wildlife

Buzzard: Buzzards are large birds of prey,also known as raptors, which can commonlybe seen across the UK. Part of their dietconsists of small mammals, including speciesthat pose threats to saplings like voles.

Maintaining healthy populations of buzzards,and other birds of prey, in forests is importantas they provide a natural form of pest control.The predation of pest species can beenhanced by providing places for such birdsto perch whilst they hunt, such as standingdead wood being retained on restock sitesreferred to as raptor poles.

Buzzard

Black grouse: Black grouse are typically seenin the transitional habitat between forests andmoorland. However, due to declines in suchhabitat type their numbers have significantlydropped and are now regarded as a red listspecies and a priority species in the UKbiodiversity action plan.

Sympathetic forest design, including creating afeathered edge to forest boundaries withshrub species, can help to increasepopulations and aid their conservation.

Black grouse (male)

Raptor poles

26

Fox: Maintaining a healthy fox population inforests can help control certain pest species,such as voles, which they predate on. Thougha level of management is often required whenthe forests are in prime sheep country, and/orwhen they are adjacent to protected areasknown for hen harriers for example.

Fox

Field signs: In order to determine whether acertain species is on site the animal inquestion does not always need to bephysically seen as it leaves behind field signs,such as tracks, droppings and residues fromfeeding. Such field signs can be used todetermine if protected species are on site. Forexample, we can know if red squirrels are onsite by observing the patterns and way a coneleft on a stump has been eaten or whatspecies of deer are on site based on the sizeand pattern of the tracks it leaves behind.

Red squirrel feeding signs

Red deer track

Red squirrel: The native mammal’s populationis under threat from a reduction in theirfavoured habitat, competition from the non-native grey squirrel for food and habitat andthe squirrel pox virus which has resulted inthem becoming a priority species under theSpecies Action Framework. They feed primarilyon pine, spruce and larch cones, makingconifer plantations a prime habitat for them. Red squirrel

27

Red deer: Red deer are native to Britain andare the UK’s largest land mammal. Like otherdeer species they live in forests and causedamage to saplings through browsing,alongside stripping the bark of mature trees.Again management is often required tomanage populations and to protect habitatsand crops.

Red deer

Roe deer: Roe deer are native to Britain andcan commonly be seen in forests but whennumbers are high they will browse saplingscausing significant damage and sometimesdeath, which have serious economicconsequences.

Given that large areas of our forest are firstrotation plantations at restructuring the foresthabitat significantly improves and as aconsequence roe deer populations willincrease rapidly. Deer management is criticalto ensure crops and habitats are protected.

Bark stripping on a mature tree

Roe deer

28

Vole: Voles are small mammals which will eatthe bark around the base of saplings. Whenthey feed on a large proportion of the saplingthey can cause ring barking which preventsthe tree from carrying water and nutrients upfrom the roots and results in the trees death.

Such feeding damage can be reduced byinstalling vole guards around the base ofsaplings, which create a physical barrier,spraying or cutting surrounding vegetationand encouraging strong populations ofnatural predators, including foxes and raptors.

Vole

Sika deer: Sika deer were introduced intoBritain during the 1800s and their favouredhabitats are coniferous forest and acidic soilheathland. Like Roe deer they cause significantdamage to saplings through browsing. Theyare a secretive and shy species and thusdifficult to manage.

Vole guard

Sika deer

29

Diseases

Chalara: Commonly known as Ash dieback,Chalara causes Ash tree branches and crownsto dieback before the tree dies.

Chalara

Phytophthora ramorum: The disease isspread through air and water and isparticularly prolific in Larch. Phytophthoracauses the crown and branches to die back,ultimately resulting in death.

In infected stands the Forestry Commissionmay issue a statutory plant health noticewhich requires the infected trees to be felled,in an effort to reduce the diseases spread. Phytophthora ramorum

Dendroctonus

Dendroctonus micans: A bark beetle thatcame into the UK in the 80s/90s and is slowlyspreading. The beetle lays its eggs in the barkof spruce trees, sometimes causing the tree todie. A natural predator Rhizophagus grandiscan be released to control outbreaks to amanageable level.