Friday, 15 June 2018

Tree Care




TREE NURSERY





When buying stock from nursery outlets, prices for trees vary according to their species and size, with discounts for quantity purchases. A cheaper alternative to purchasing larger plants is to buy seedlings and line them out for a year or two before transplanting. Alternatively, start your own nursery.




SEEDLING AND TRANSPLANTS





A young tree is known as a ‘seedling’ for as long as it is growing where the seed was sown. Once moved, it becomes known as a ‘transplant’. The age of a young tree can be expressed by giving the time spent as a seedling in the seedbed and the time spent when moved to a transplant line. This is indicated by a ‘+’ sign. Thus ‘2 + 1’ means two years in a seedbed and one year in a transplant line giving an age of three years.






TRANSPLANT LINES





The density at which transplants are lined out depends on the size they are expected to be at the time of their next move, ie, a seedling less than 20cm in height with an expected growing rate of 75 – 100cm will have a planting density of 135 – 100 plants per m2. 100 plants per m2 gives a spacing of 20cm between rows and 5cm apart within a row.







UNDERCUTTING






Plants that have been undercut rather than transplanted are known as ‘1 u 1’ or ‘1 u 2’. These plants are left to grow if space or time is lacking for further transplanting. Longer roots are cut and new roots encouraged to develop.


SIZE OF TREE





NAME

OVERALL HEIGHT

PLANTING DISTANCE


SEEDLING (one year old in Rootrainer/Japanese paper pot)


Variable

2 – 3m

TRANSPLANT

20 – 4cm

2 – 3m


WHIP

60 – 90cm

3 – 4m


WHIP or FEATHERED WHIP


90 – 120cm

3 – 4m

FEATHERED WHIP

150 – 180cm

4 – 5m


FEATHERED WHIP


180 – 210cm

6m

LIGHT STANDARD

250 – 275cm

10m +


STANDARD

275 – 300cm

10m +


SELECTED STANDARD


EXTRA HEAVY NURSERY STOCK

300 – 360cm
(180 – 215cm stem)

5m +

10m +


20m +





Feathered trees are well furnished with branches low on the stem. Standard trees have a specified length of clear stem below a crown of branches, ie, standard 275 – 300cm high with 150 – 180cm clear stem.



PLANTING





One year seedlings in Rootrainers are becoming more popular as their use maximises the benefits of using tree shelters.




Planting with the root ball intact from container grown trees results in high survival rates and strong early growth as well as an extended planting season. The risk of root deformation is high as is the cost of purchasing them, however, if planting is delayed heling in is not required.




Small trees survive transplanting better than larger ones of the same species as large plants are slow in establishment. The optimum size for most broadleaved species is 25 – 30cm. More important than the height is the root collar diameter, as thin, spindly plants are more likely to die than shorter but sturdier ones.




WEATHER




Avoid planting in sunny or cold windy drying weather. Choose cloudy, drizzly days. Be sure to firm up trees!




PLANTING SEASON




Between October to March or April. Avoid frosts. Evergreens are best planted in the spring when the soil has begun to warm, but before the first flush of new growth. Always mulch!



CONSIDERATIONS




The origins of the tree – carefully check the provenance or source of the native tree you buy as much native stock is of foreign origin – local seedstock is often best suited to local conditions.



The care with which they are handled before planting – carefully inspect for evidence of any dry and shrivelled roots, broken or scarred stems, fungal growth or insect pests. If you cannot plant on delivery then ‘hele’ them in the pre dug trenches without delay.



The protection and early care they receive – at all times the roots must be protected from drying out. Always keep the roots out of strong sunlight and drying winds. They should not be left exposed a second longer than is necessary.



The planting procedure should be careful and considered. Pit planting is usually the slowest but surest method. Treading in and firming are particularly important, as are stake and tie heights. Other methods include notch planting. Turf planting is used on wet and peaty soils.




CONTAINER GROWN





Advantage




Trees grown singly in containers can be planted out at any time of the year without any damage to the root system. They often have a large amount of top growth for the size of the root ball and if planting is delayed heling in is not required. Evergreens are best planted out in the spring. Careful planting results in high survival rates.



Disadvantage




Root deformation. The lateral roots (which in normal conditions spread outwards) begin to spiral around the sides of the container – weakens the stem and creates instability when planted out – as the new root growth has difficulty in penetrating through the root ball. Frosty sites should be avoided. Keep well watered and weeded. Often more expensive than open ground stock due to extra work and materials needed to grow them plus higher transportation costs.




Planting Out




Container grown in a light compost as this promotes rapid root growth. If planted into heavy soils the roots will have difficulty penetrating the soil and may simply continue to grow around the root ball. This can be avoided by digging a planting hole twice the diameter of the pot and half as deep again. Back fill it with half soil to half well rotted compost.






TREE PROTECTION






CONSIDERATIONS






What are the threats to the tree? Voles, rabbits, deer, livestock, vandalism, etc.





Costs – number of trees being planted that need protection. Either perimeter fencing or individual guards/shelters.





Type of protection is site specific, ie, how long is the protection needed, is the appearance important, does it need to be conspicuous for maintenance or weeding purposes?




It is never worth planting trees unless you can give them adequate protection.




Fences – guards – shelters.




FENCES





The cost of fencing relates to the size and shape of the land enclosed (regardless of the number of trees) and the type of fence protection needed, ie, livestock, rabbits, deer, etc.






GUARDS





Can be spiral, tubular, mesh or timber enclosures depending on the site requirements.






SHELTERS





Come in a range of shapes and sizes. They were designed to promote rapid growth especially in drought conditions. Young trees are protected against damage by animals. They are readily visible to relocate for weeding and maintenance purposes.





AFTER CARE






MULCHING





Keeps the ground surface moist, fairly stable in temperature and suppresses weeds. Organic or bio-degradable mulching is always favourite as these materials will decompose.






VISITS





Visit your tree regularly – firming up around the base due to wind sway or adjustments to tree shelters or tree ties are always needed.






WATERING





Newly planted trees should only need watering at planting time (be sure to soak the mulching material). The exception is drought where constant watering will be needed. Too much water can induce surface rooting making the roots susceptible to scorching when drier weather comes.





WEEDING





Weeds compete with a tree for water, light and nutrients. A weed being the wrong species in the wrong place at the wrong time. A minimum of three years protection from the time of planting is needed. Good mulching will help prevent competition from grasses, bracken, etc, usually at their strongest between April, May and June.






BEATING UP





The replacement of trees that fail is usually considered when more than 20% of the planted trees fail. Always investigate the cause of failure. A change of species may be needed. Causes can be poor plant handling (roots exposed), damaged diseased stock, poor planting procedure, wrong species for site chosen (soil, exposure, etc), mammal, insect or fungal damage, or fire.

Summer drought can take its toll in dry years. Beating up should be done in the autumn or winter after planting. Later than two years and the new trees struggle to catch up with the main crop and are often suppressed by canopy closure.

The replacements should be at least as large as the originals or of a faster growing species.

Weeding must be kept up until the tree is firmly established.

Monday, 5 February 2018

Pollards and Pollarding



History





A pollard is a tree cut 2-3 m above the ground, which develops a crown of branches which can be cropped repeatedly. The height of the boll prevents stock browsing the young shoots.




It was therefore particularly suitable for trees in wood-pasture, parks, commons and Royal forests; and was also used for trees on riverbanks, woodland and district / parish / ownership boundaries. The bark of the lopped branches, and if cut in summer, the foliage of deciduous species, could also provide some food for livestock.




Rotations varied between 10 - 35 years and seemed quite irregular in an area.




Complex systems of rights evolved with pollarding on commons and in Forests. Generally, the landowner owned the unpollarded trees and the bolling (trunk) of the pollard. The commoners sometimes had rights of lopping branches from the pollards - so they wanted to continue to lop and create new pollards, whilst landowners were keen to restrict the establishment of new pollards and removed for their own use bollings which had died.




Which species?





Almost all species of broadleaved trees will pollard - many very readily if started when young and regularly lopped. In wood-pasture the species least palatable to stock predominate; hornbeam, oak and beech. Other species frequently pollarded are ash, willow, field maple, elm, crab apple, hawthorn, whitebeam and black poplar.





Why pollard?





1. Longevity: Repeated, regular pollarding increases a tree's lifespan. It also prevents the crown becoming top heavy which would de-stablilize a riverside tree, causing bank erosion and the build-up of trash behind a fallen trunk. A heavy crown may even split the boll, where rot will invade and kill the tree.




On the other hand, water is often retained in the top of the boll which probably makes the pollards more liable to rot and at younger ages than standard trees of the same species.




2. Historical importance: In terms of perpetuating some features of the wildwood, and in nature conservation interest, wood-pasture complements coppice and high forest in ancient woodland; and maintains environmental conditions intermediate in some ways between high forest and open ground.




3. Wildlife: Pollards are a unique habitat. Different invertebrates are found in standing dead wood when compared to dead wood on the ground. The pollard bolling is a long-lived source of standing dead wood. Epiphytic bryophytes and lichens are found on extremely old bollings in pollution-free areas.




Old crowns and hollow trunks provide roosting and breeding sites for owls, duck, bats and otter bolts.




4. Wood: Willow pollards provide withies (1 year's growth), rods (3-5 years) and all provide firewood (10+ years).




5. Landscape and historical importance: To many these striking trees are very beautiful and give clues to the past system of land and tree management. These old trees carry in their tree rings a record of their treatment superimposed on the changes in climate and other factors affecting their growth.





The current problem





Regular lopping and creation of new pollards declined about 50-100 years ago and can probably be attributed to a general decline in local firewood demand during the Industrial Revolution; and various common lopping rights were extinguished.




The problem now is: (a) no new pollards are being created to replace the old and dying and (b) old, neglected and sometimes dangerous pollards which are unlikely to be re-pollarded without more awareness of the need, and possibly some incentive to do an uneconomic task.




The October 1987 storm damaged recently re-pollarded trees less than unstable, neglected pollards. Storm-damaged trees may well recover through self-pollarding, with or without tree surgery to tidy them up.




Morphology and physiology of pollarding





Pollard branches, coppice regrowth and epicormic shoots all arise from the same stock of long-dormant buds (augmented in the case of pollarding and coppicing by adventitious buds). The difference between these three types of growth depends on the part of the tree involved, the extent of the growth (often slow part of the tree involved, the extent of the growth [often slow or limited in epicormic shoots] and what stimulated growth [ie total loss of crown or shoots, environmental factors]).




Roughness of bark and especially burrs ("bird's eyes") indicate a high density of dormant buds, which tend to be concentrated around present or former branches. Dormant buds appear to be very abundant on oak, hornbeam and sweet chestnut but less so in other broadleaves. The longevity of these buds is variable, but up to 100 years in oak, averaging 60 years in hornbeam and chestnut, less in beech and still less in birch and willow.




Thus the fact that young bark seems better at producing new branches than old bark could be because the initial stock of buds has had less time in which to decline or the thinner bark is easier for buds to break through.




Adventitious buds develop in the callus formed on the rim of the cut surface. Again, there are differences between tree species in the readiness to form adventitious buds.




Most pollard branches come from dormant buds in oak and hornbeam, in beech a high proportion probably arise from adventitious buds and in lineage elm they all do.




Pollarding removes the entire crown while leaving the bolling and roots untouched. Such a severe alteration of the shoot and root balance must be reflected in the physiology of the tree, but little about this is known.




Successful re-growth consists of many shoots arising in a vigorous bushy mass at the top of the bolling. These shoots self-thin so that as the branches become larger there are correspondingly fewer of them.




Pollarding is an extremely traumatic treatment to the physiology of the tree. There must be substantial root death after lopping, thus providing much fungal resource and allowing entry into the heartwood. The cut surfaces and water-holding hollows of the bolling also encourage fungal entry and growth. Subsequent entry of specialised wood-feeding invertebrates can be tolerated for centuries and is not indicative of imminent death.





Responses of tree species





Oak: variable. Hatfield - 90% of trees that had not been pollarded for 15- years died. Killerton (Devon) - 85% re-pollarded well. Response varies according to many factors.




Beech: usually dies. However, Epping Forest - 44% survival.




Ash: responds well.




Hornbeam: considered to be the most successful. Epping Forest - 97% survived.




Lime (small and large leaved): thought to respond well, judging by urban pollarding of hybrids.




Wych and smooth-leaved elm: variable response. In Suffolk, not good.




Willows: excellent response.




Black poplar: good response.




Field maple: good response.




Hawthorn: good response




HINTS, TIPS AND RECOMMENDATIONS FOR RE-POLLARDING NEGLECTED TREES





1. Tree species and genotype





Burry, twiggy trees (oak, hornbeam) respond best to re-pollarding.




Burrs are probably genetic in origin and indicate a local concentration of buds keeping up in growth with the bark. Burry oaks (such as self-pollarded, gale-damaged specimens in Staverton Park) are much more likely to succeed than smooth-barked ones. Smooth-barked ash are less likely to succeed than rougher ones.





2. Age of bolling and branches





It is difficult to say how age of branches or time since last lopped, effect success. There does seem to be a marked decline in the abilities of dormant buds to grow after a certain time - varying with species. As a rough rule, once past the normal rotation age (say about 40 years at the most), for some species the success rate of re-pollarding declines quickly to a low level.




3. Size of bolling





Large oak trees, well over 1 m diameter at breast height, hollow, with branches up to 45 cm in diameter have responded well. Similarly with ash. This factor may not have a great deal of effect.




4. Fungal infection





Variable in different trees and difficult to assess.





5. Time of year to pollard





Lopping for foliage must have taken place in the summer, but is nowadays preferred in the autumn and winter. Better success rates are achieved by lopping in January and February (stopping when the sap starts to rise), than November to December. (This may be because, like winter pruning, negligible callus growth results over winter, allowing more time for fungus, etc., to invade.).





6. Method of pollarding







(a) The need for younger bark from which more buds may grow out and the general toleration of heart-rot, may justify leaving branch stubs 15-60 cm long which seems to result in better re-growth.




(b) Re-growth arises from adventitious buds formed in the callus and from dormant buds in the bark below the cut. Cutting branches on a slant increases the perimeter of cut bark from which at least some shoots arise. Lopping higher up the crown, so that more, smaller branches are removed may increase the amount and vigour of the callus formed. Slanting surfaces shed water and may decrease fungal infection.




(c) Although there may seem little point in using wound dressings to reduce fungal infection, dressings might play a useful role in encouraging callus growth by slowing dehydration of the cut surface, eg Arbrex, or by direct chemical stimulation such as a preparation containing thiophanate methyl.




(d) Clean cuts on the bark may be left by edge tools so that callus formation is easier and there is less risk of the bark being detached. Others believe this does not have any effect.




(e) Leaving one branch only uncut for one year (two or three if re-growth is slow), whilst the others are pollarded, so that this branch will provide some photosynethate during the first year when the new shoots are growing. To preserve the stability of the tree a single, near vertical branch near the centre of the trunk would be preferred (although this would be the most difficult to cut later on).





7. Shade





Although light may not be the main stimulus to the emergence of epicormic shoots, it encourages growth once they have appeared. A re-pollarded tree is in a fairly delicate state for the first year or two and shading by taller, more vigorous neighbouring trees undoubtedly adversely affect re-growth.





8. Other site factors





Soil, wetness and other factors may all affect re-growth success but this is not yet clearly understood.





CREATING NEW POLLARDS





New pollards should be created to replace old, dying pollards not only for landscape and historical reasons, but to minimise the distance for organisms to travel to find a suitable substrate. Start many new pollards to give a balanced age-structure to the population and to allow for failures.




Which trees?





Normally young maiden trees (from natural regeneration or planting) will be available for pollarding, but coppice stems can also be used. Mis-shapen trees, or those with "weak forks" and likely to cause problems later, or storm-damaged trees may be easier to "sacrifice" for those who find it difficult to pollard a lovingly planted tree!




How young?





Create new pollards when young trees are as young as 2 m in height and between 10 - 30 cm diameter breast height:




- "very young" for oak

- younger than 15 years for beech (said to be difficult)

- 15 years for hornbeam

- 12 years for yew




How high?





Pollarding should be done at least 30 cm above the reach of whatever browsing animals are envisaged, ie 1.8 m for fallow deer, 3 m for horses (Giraffe-pollards [4-5 m high] exist at Windsor and Sherwood). At least 30 cm branch stubs should be left.




TAKE EXTREME CARE - POLLARDING CAN BE DANGEROUS!






Thursday, 25 January 2018

Hazel Coppice Restoration

Management Prescriptions






Neglected coppice can be felled at any time of the year with little effect on subsequent growth, but it is inadvisable to cut during spring and early summer when it will disturb nesting birds. The tree must be in its dormant cycle to begin the process of coppicing.


Stools should be cut as close to the ground as possible. Cut the tree above the basal wood, which is the swollen area at the base of the tree trunk. New stems will probably develop closer to, or below, ground level and may develop their own root systems and have greater stability.


Coppice with standards is more complicated to manage than simple coppice. Standards reduce the size and vigour of coppice shoots and stools, and if necessary overstorey canopy cover should be reduced when the understorey is cut.


Allow shoots to grow. A number of shoots will spring up and grow rapidly after cutting. These may be cut during the dormant season, whenever they reach the desired size. Cut each new stem above its basal section. New shoots will continue growing after each cutting. A broad stump, known as a stool, eventually will develop.


New shoots must be protected from deer, until they have grown beyond the height at which browsing damage occurs, for vigorous crops in good growing conditions this will be a minimum of two growing seasons. Temporary plastic fencing erected around a coupe of hazel, should provide adequate protection.


Shoots will grow rapidly during the following spring which is then left until ready for cropping. Once cropped the cycle starts again.


Tools to be used



Small or medium-sized shrubs and small-diameter tree species can be cut with a pruning saw or billhook. Thicker-diameter shrubs or trees may require the use of a bowsaw, axe or chainsaw. Regardless of the tool you choose, remember to follow all necessary safety precautions. Be aware that thicker trees may require undercutting, which can add significantly to the danger of falling material.


The conservation value of coppice



Some butterflies, in particular, require the open conditions of newly cleared woodland which was once provided by coppicing. Several of the woodland butterflies, for example, have become much rarer since the decline in coppicing.


Actively coppiced woodland is very diverse in its structure and is, therefore, attractive to many different plants and animals. Rich communities of birds, for example, can be found in coppiced woods with many stages of growth. Although no birds are confined to coppiced woods, some, such as nightingale and garden warbler, find ideal habitats in coppice. These species and other birds needing open and young woodland were probably far more widespread before the decline in coppicing.


Many invertebrates undoubtedly thrive in young coppice because it provides open ground with a particularly warm microclimate for adults feeding at flowers or hunting for prey and because the highly diverse ground flora. Ground-dwelling species such as ground beetles and wolf spiders occur in these areas, when cutting is done.


Under the shade of a mature coppice canopy the field layer is usually very sparse some species of plant have become dependant on coppice woodland. Their success require regular cutting of the coppice. If cutting become neglected the dense canopy that forms will shade out the woodland floor.


Light reaching the woodland floor is the first step to promote the growth of flowering plant species such as bluebells, ground-ivy and yellow archangel.


Saturday, 20 January 2018

What is Coppicing?


COPPICE WOODLANDS






Coppicing is the act of periodically cutting a small tree so that it produces many shoots rather than one main trunk.


History



The practice of coppicing dates back to Neolithic times and by the middle ages the hazel cycle system had become the standard form of woodland management. In Celtic law, hazel or ‘coll’ were given chieftain status along with Oak, Yew and Ash. The system reached its zenith in the 19th Century by becoming an indispensable part of the rural economy. The isolation of settlements and industries meant that timber had to be procured from the immediate area. This necessitated perpetual management of woodlands in order to produce a constant timber crop. Nearly all indigenous species will sprout readily from the base if cut and this is how the crop of wood was maintained. Rotational cutting over an area of woodland gave a constant supply of wood which was used in every aspect of life. A few standard trees – ones that were never coppiced – were allowed to reach maturity or a size for specific purposes such as building houses, barns or boats.


Decline



By the mid 1800’s the decline in rotational cutting had begun. More and more oak standards were planted to supply the rapidly expanding tanning and ship building industries – ironically both demands collapsed before the felling time. Other factors aiding the decline included the improved transportation which carried the exploitation of coal for fuel, and brick and stone for building to rural settlements and industries. Since then two world wars have decimated the rural communities who managed these rotational systems and, coupled with the march of modernisation in agricultural practices, have caused many ancient woodland sites to be grubbed up and changed to extensive softwood plantations, or to increase productive field sizes for crops or pasture land for grazing stock.


Conservation







The act of coppicing increases the longevity of a tree. By rotational coppicing in coups (the term given to compartments within a woodland as illustrated) it will be highly beneficial to both flora and fauna, ranging from the dense canopy and shaded area of the older coppice to the bare open ground of the cleared coppice with various stages of growth between the two. This creates a constantly recurring cycle and it is important to remember that most of our native flora woodland species and wildlife have evolved under the coppice system. Years 3 - 5 are most suitable for wildlife cover. It is estimated that over 90% of coppice is out of cycle or derelict, even this state in conservation terms is far more favourable than plantation or field systems.


Coppice Working



Ideal conditions for coppicing occur between October and March. This is the period when the sap level is low in the stools. Cutting outside this time can harm the stools and reduce the vigour of the regrowth. It will also produce material full of sap which, in the case of hazel for hurdles, lacks the durability of those made with the sap ‘down’. Other factors include the damage to flowering flora and nesting wildlife.

Just below the bark is the cambium layer – this is the living layer that produces the shoots when cut. Before felling commences the immediate area around the stool should be cleared and the height and lean of the growth assessed for safety reasons. The cutting height should be as close to the ground as possible. This gives a greater yield of produce and also increases root development. In the case of old stools, this may be as high as 0.5m. The angle of the cut should be outwards and clean to prevent water collecting which will cause rotting. The finished cut when felling should leave no damage to the bark and cambium level of the stool.

The size of area cut in any one season is called a coup and its size will depend on the workforce and management objective. Traditionally this was dictated by the ability of one or two men to prepare the produce required in a winter’s season. As a general rule coups should be no smaller than 0.5 hectares (1 acre) and no more than 25% of the wood or 5 ha maximum.

Traditionally, billhooks with various weights were used with handsaws and side axes. This is still the case but with the added help coming from the chainsaw (full safety precautions to be observed). Waste material such as ‘lop and top’ is placed over the cut stool to protect new shoots emerging in the following season from the ravages of deer browsing. Any excess should be burnt, chipped or heaped into habitat piles. Bonfire sites should be kept both in sites and numbers.


Rotation Lengths:


Suggested length of rotation is very much site specific and geared to the end product.


Hazel - Spars and other thatching uses, pea and bean sticks, hurdles (7 to 12 years)


Birch - Horse jumps, besom brooms (4 to 12 years)

Ash, Birch, Field - Firewood (15+ years)

Maple, Hornbeam Turnery poles (15 to 20 years)

Oak - Charcoal cleftwood (30+ years)



Standards



Overstory also needs management. A wide age distribution being the goal, with new saplings coming on to replace the mature trees.

Suggested age range:-

20 saplings – 0 – 25 years                                  

12 young trees – 25 – 50 years

8 semi mature trees – 50 – 80 years

6 mature trees – 80 – 125 years

4 trees ready for felling – 110+ years


Replanting Coppices



Consideration should be given to replanting gaps in the coppice floor which prevent the canopy from suppressing all undesirable species from gaining a foothold. The suggested densities should be aimed for, depending on soil and drainage.

Hazel - 1500/2000 stools per acre

Sweet Chestnut - 800/1000 stools per acre

Ash and Oak - 200/500 stools per acre



Economics



Short rotations such as hazel make favourable income compared to other broadleaved crops. In addition it will provide a livelihood for approximately 10 times as many people as a similar sized wood managed by modern forestry methods. Hazel is used between the years 6 – 12, any older and it fast becomes a liability. Prices paid by coppice workers for standing in-cycle hazel vary widely per acre depending on quality, but a well-stocked acre of 8 year old hazel should produce 10,000 – 12,000 rods of 10 to 15 feet in length. This can be converted into approximately 300 x 6 foot square hurdles, or 75,000 thatching spars. In addition, assorted bean and pea sticks, clothes line props and the occasional oak or ash standard. Other uses include stakes and ethers or hedge laying, charcoal, pulpwood, wood chips, turnery, firewood, garden products, compost bins, tree guards, clothes pegs and tent pegs, walking sticks and rake handles. Other coppice species include Alder, Apple, Aspen, Birch, Sweet Chestnut, Lime, Hornbeam, Ash, Oak, Maple and Willow, all having a multitude of uses and income.







Monday, 15 January 2018

History of UK Forest




13000 BC:





  • Ice Age came to an end – as glaciers and ice receded northward trees began to colonise Britain.



  • Britain was joined to the continent at this time – seed spread northwards from the continent.



  • Early colonisers included species such as Scots Pine (Pinus sylvestris) and Birch (Betula sp.) – these were followed by Oak (Quercus robur), Beech (Fagus sylvatica), Elm (Ulmus sp.), etc.









10000 BC:





  • Land bridge between Britain and continent disappeared.



  • An image of the area known as Doggerland which connected the British Isles and the European continent.



  • Most of Britain was covered in forest – trees that had established themselves by this time are known as Native.








5000 BC:





  • Britain experienced warm moist climate.



  • Most of the country up to 2500 ft. (800 m) was covered in forests of Oak, Elm and Elder (Sambucus nigra).



  • Birch was present in some of the uplands – rarer in the east and south.



  • Highlands of Scotland contained a cover of Pine (Pinus sylvestris).



  • Animals of the forest included Bear, Wolf and Mesolithic man (middle stone age) - these men were hunters and fishers, collected berries in the Wild Wood, as the virgin forest is known.




3000 BC:





  • Neolithic period



  • First farmers appeared introducing stock-keeping.



  • Britain and Ireland were still covered in forest at this time, grassland was rare.



  • Foliage was probably the only fodder available for sheep and cattle.



  • Particularly Elm (Ulmus procera) – elm decline during this period may be due to feeding stock on a large scale.



  • Another theory for elm decline – infection akin to Dutch Elm disease



  • Neolithic man seems to have cleared patches of forest to plant crops, then abandoned clearings as crop yields declined, - didn’t know about crop rotation.



  • Usually re-colonisation of woodland followed, but occasionally the clearance was more lasting.








1700 BC:





Bronze Age:


  • Acceleration of deforestation – man now had metal tools to clear the forest.



  • Chalk hills of eastern and southern England were cleared for arable farming – remained important arable areas throughout the Iron Age and Roman occupation.




Anglo-Saxon Period:


  • Considerable forest clearance and expansion of agriculture on clay lands of Midlands and Weald.



  • Introduction of the eight-ox plough.



  • Farmland abandoned on some of the chalk ridges – gave Beech (Fagus sylvatica) a chance to establish – normally unable to compete with Oak (Quercus robur).



  • Woodland formed in areas such as Chilterns and Cotswolds.



  • Major deforestation around AD300 coincided with the beginning of the Christian era – Celtic monasteries promoted agriculture.



  • Scotland – some forest was destroyed by fire during Viking raids – main deforestation came later than in England.






AD 1086:





  • Doomsday records show greater portion of England was still covered with forest compared to today.



  • Normans designated areas of Royal Forest:-


New Forest

Forest of Arden

Feckenham (Midlands) -.special laws passed to preserve the King’s hunting, particularly boar and deer.


  • Norman woodland was used extensively to provide ‘pannage’ for swine, and they also re-introduced rabbits (previously introduced by the Romans a thousand years earlier).



  • These were two important factors in preventing regeneration.



  • Cistercian monks had considerable impact on the ecological history of the uplands of northern England. They were initially tenacious toilers of the soil, clearing vast tracks of wooded and unpromising countryside for agriculture and industry. As the extent of their holdings outstripped their ability to provide sufficient monks to work the land they recruited vast numbers of ‘lay brothers’ who perpetuated the order’s industrious and entrepreneurial impulse. By the high middle ages, the Cistercian Order was the wealthiest organisation, ecclesiastical or lay, in England.



  • Monasteries owned large tracts of hill country – monks were efficient estate managers.



  • They farmed sheep on a large scale – large areas of woodland were cleared to provide grazing as a consequence, in the 12th and 15th Centuries.






AD 1200:




Oakwoods


  • Woodlands of lowland England began to have scarcity value – began to be managed for profit



  • Coppicing was the usual method, leaving a number of standards of Oak and occasionally Elm.



  • Lower layers of Ash (Fraxinus excelsior), Maple (Acer campestre), and Hazel (Corylus avellana) were regularly cut (coppiced) on a 14 year cycle.



  • Exploitation of timber in 16th Century.



  • Expansion of sheep in 18th Century.



  • Fully grown standards provided large timber for buildings.



  • Coppiced timber was used for firewood, poles, charcoal, tool and weapon handles.



  • Artificial woodland structure developed as ‘coppice with standards’.



  • Old coppice can be identified by a cluster of 4 or 5 slender trunks from one stool.




AD 1800 – 2000




Industrial Revolution


  • Woodland products replaced by fossil fuels



  • Coppicing was abandoned in many places in 19th Century, but persisted locally up to the First World War.



  • Wholesale felling during two world wars.



  • Deaths of skilled woodland workers



  • Setting up of the Forestry Commission (established 1919) to create a supply of home grown timber.



  • Loss of 20 million elms from Dutch Elm disease.



  • Catastrophic storms of October 1987 and January 1990.



  • Succession of debilitating droughts – (1975 and 1976 were particular dry years).



  • Closure of small sawmills means higher costs in transportation to fewer larger automated sawmills.





Conclusion



  • Woodlands are much more a product of past management than they are natural features.



  • Ancient woodlands have survived because they were managed.



  • Management is expensive so income from woodland is crucial.



  • Coppicing now becoming re-established – disturbance of the soil after cutting allows establishment of open-ground plants such as Marsh Thistle (Cirisium palustre), light reaching the ground encourages vigorous growth of species such as Violets (Viola sp.) and Bluebells (Hyacinthoides non-sciptus) as well as the coppice stools themselves.



Wednesday, 10 January 2018

Native Tree Species

Native species are those that have arrived naturally on the island of Britain and have been here since post glacial times. Britain lost most of its flora and fauna during the Ice Age as plants and animals retreated south in the path of the advancing glaciers. When this cold period was eventually over some 10,000 years ago the land was recolonized by species that crossed via land bridges that existed between Britain and the continent. Some species, however, did not arrive in time as the land bridges disappeared under the rising seas from the glacial melt waters. As a result, some common tree species that are native to the continent are not represented in the native flora such as beech and Norway spruce. Beech succeeded in crossing to the south of England.

Most of our native trees are broadleaves such as oak, ash, birch etc while conifers are represented by only three species– Scots pine (Pinus sylvestris L.), yew and juniper – the latter being only a shrub. Conifers form only a very minor part of the native species resource and consequently reference to native species usually means native broadleaves.

Currently, native species form only a small percentage of our forests due to their low productivity in relation to introduced species. Native broadleaves are more difficult to grow requiring sheltered fertile sites and a high degree of silvicultural skill if productive stands of quality timber are to be achieved. Better quality of land is, however, becoming available for afforestation in farm forests and along with attractive grants and premiums, native broadleaf species are being planted in higher numbers than any time since the start of the afforestation programme which began in the 1920s. Scots pine is also being planted but mostly as a nurse species in mixture with broadleaves.

Native species are being planted not only for timber production but also to encourage and enhance biodiversity in our forests. Native trees have a long association with many indigenous animals and plant species and provide rich and diverse habitats that are not seen in stands of introduced species, particularly conifers. Old forests and stands of native species are important islands of native biodiversity and it is from these areas that native plants and animals spread to new habitats. Their conservation and enhancement is therefore an important objective in forest management which today is also concerned with the environmental sustainability of the forest resource.


Elm, wych (Ulmus glabra) - Despite the English elm's name, wych elm is the only elm that is regarded as being truly native to Britain.As a results of Dutch elm disease, wych elm is now found very infrequently.