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.
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.
#Science #Woodlands #WoodlandManagement #Conservation #Nature #Trees #Coppice #Coppicing #Ecology #Environment #Habitat #Leaves #Countryside #Guide
Monday, 25 February 2019
Proper Tree Pruning
Improperly pruning a tree can be fatal as it encourages decay organisms to enter the wood. Luckily, the correct position to make a pruning cut is often clearly visible from features of the tree.
At the upper side of the branch is a slightly raised ridge of bark – the branch bark ridge. This marks the end of branch tissue and the beginning of trunk tissue.
As a branch begins to wane the tree forms a protective layer in the wood at the base of the branch – the branch collar.
Pruning cuts should always be just to the branch side of the branch bark ridge and branch collar (when one exists), downwards and slightly outwards. If the branch bark ridge or branch collar are damaged or removed, for instance by cutting flush to the trunk, not only is the main stem damaged, but the tree’s internal chemical protective layer is also removed. This allows disease and decay organisms to enter the wood.
Flush cuts may also result in cracking of the timber.
Long stubs should not be left as decay infecting them will easily find its way into the heartwood.
The best time to prune is at the end of the dormant period (late winter/early spring) so that a callus will start to form almost immediately, leaving less time for infection. Avoid pruning when the leaves are expanding.
Exceptions are:
- Hornbeam, birch, maple – prune October/November
- Walnut – prune in summer
- Cherry – prune June/July
Painting the wound will have little beneficial effect and may even encourage the spread of infection. If painting is desirable for cosmetic reasons a thin coat of commercial material is best. Household paints should not be used.
All these points apply to broadleaves and conifers, to live, dying or dead branches. The same procedures should be used for removing small branches from larger ones.
In brief:
- Never damage the branch bark ridge or branch collar
- Don’t cut flush to the trunk
- Don’t leave stubs
- Prune at the end of the dormant season
- Avoid painting the wound
At the upper side of the branch is a slightly raised ridge of bark – the branch bark ridge. This marks the end of branch tissue and the beginning of trunk tissue.
As a branch begins to wane the tree forms a protective layer in the wood at the base of the branch – the branch collar.
Pruning cuts should always be just to the branch side of the branch bark ridge and branch collar (when one exists), downwards and slightly outwards. If the branch bark ridge or branch collar are damaged or removed, for instance by cutting flush to the trunk, not only is the main stem damaged, but the tree’s internal chemical protective layer is also removed. This allows disease and decay organisms to enter the wood.
Flush cuts may also result in cracking of the timber.
Long stubs should not be left as decay infecting them will easily find its way into the heartwood.
The best time to prune is at the end of the dormant period (late winter/early spring) so that a callus will start to form almost immediately, leaving less time for infection. Avoid pruning when the leaves are expanding.
Exceptions are:
- Hornbeam, birch, maple – prune October/November
- Walnut – prune in summer
- Cherry – prune June/July
Painting the wound will have little beneficial effect and may even encourage the spread of infection. If painting is desirable for cosmetic reasons a thin coat of commercial material is best. Household paints should not be used.
All these points apply to broadleaves and conifers, to live, dying or dead branches. The same procedures should be used for removing small branches from larger ones.
In brief:
- Never damage the branch bark ridge or branch collar
- Don’t cut flush to the trunk
- Don’t leave stubs
- Prune at the end of the dormant season
- Avoid painting the wound
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