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Articles (36)
Dinefwr Historical Renovation Project
Arwyn Morgan discovers how easy it is to change people’s minds.
I have to admit that I have always been quick to criticise the National Trust, especially when they let mature trees just rot and disintegrate instead of harvesting them so that they can be used. But recently, through my work, I saw the other side of the coin where the National Trust needs to keep many facets of the public happy.
Some time back I had bought some Poplar from the National Trust. It was only 30 odd trees, but it was a clearfell that was not to be replanted. They had been planted some time in the late 60s, like much of the Poplar in the UK. Some of the butts were up to 30" in diameter, but others were hollow, with rot.
They all grew within Dinefwr Park which, with its nearby castle, forms part of the earliest written records in Wales. With this historical background it was decided to renovate the whole park, including the mansion house and adjoining properties. This renovation includes transforming the landscape, returning it to the way it was in the eighteenth and early nineteenth centuries.
Thus the reason for the removal of the Poplar, but it was not to be a simple matter: first of all there were the public meetings, with their many complaints, and the meetings with various agencies and groups. Some people were very opposed to the proposed fellings. A letter was even printed in the local newspaper with a stunning picture of the Poplars in winter. The writer compared the Poplars to Swedish pop stars with legs up to their armpits etc, and so on.
Due to the obvious public interest, it was decided to fell all the trees in one go. I was to do the felling, and as there was a footpath near the Poplars, my father was to act as banksman. Technically the public had no right to be beneath the trees, but sadly people easily forget common sense at times of emotion, and the last thing you need when putting in a back-cut is somebody tapping you on your shoulder and asking you what you’re doing.
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| The evidence which persuaded the public that the Poplars did need felling. |
It was a quick job to get the Poplar on the deck. Needless to say a few people walked by and voiced their disgust that the Trust was having the Poplars felled, especially as they were “several hundred years old”! My father informed them of the Poplars’ true age. That in itself was a revelation. They couldn’t get over how fast trees could grow, but still they thought it was a shame to fell them.
After I had finished felling, we decided that it was more prudent to exit the scene. I returned the next day to sned them. This time I was prepared for any comments. Several people appeared and expressed their disgust at what the Trust had sanctioned. At this point I would direct them to an exceptionally badly butt-rotted stem, and await the look of surprise on their faces. It was funny how easily their attitudes could be changed. From disparaging the Trust, they turned to praising it, and commenting on how the National Trust really knew what they were doing !
As it happens, at Dinefwr Park there are many other wooded areas, some of pure broadleaves, whilst others planted in the sixties or later are made up of a mixture of conifers and broadleaves. Some of these areas were to be clearfelled, apart from the few broadleaves, whilst others were thinned.
One of the areas consisted of two rows of Beech, two of Japanese Larch etc. Some of the Larch were of fine form, but some could act as giant corkscrews or propellers. The Beech had grown through the Larch, with the end result that the old double act – “wedge ‘n’ sledge” – was needed to drive the Larch through the Beech branches.
Sadly the Beech had been barked at their bases by the local deer, and upstairs they had considerable squirrel damage. In fact every other Larch tree had a squirrel dray in it, so next winter some of the woodlands won’t be as hospitable for the greys. The difficulty with such woodland is that even if you just touch the upper branches, because of their brittle semi rotten nature, they tend to snap and, as it were, explode. The long term hope is that the Beech will be under planted with Oak. The Beech will be left as a nurse, and when more light is needed by the Oak, the Beech will be removed for firewood.
One of the other areas had Norway and Sitka Spruce, Douglas Fir, Corsican Pine, Japanese Larch with a few Oak, Beech, Cherry, Ash, and Willow dotted about – quite a mixture.
As all the land was being rented out to local farmers, extreme care had to be taken to avoid messing the fields, and to top it all there were many badger sets. Not only does the Countryside Council for Wales watch all activities in the park very closely, but also a badger group keeps an eye on the badger population.
So many people and organisations watch how the National Trust manages a property. I dread to think about how much in the way of unproductive wages are spent on all these staff from their various organisations.
Unfortunately my machinery isn’t what could be called ideal for this type of timber, as we generally cut larger softwoods or hardwoods. I used the County skidder with its Boughton to pull all the stems out to the edge of the woodland, then cross cut and used the other County with its Botex to stack the sawlogs and pulp. All the brash was bladed by the County and burnt on the site of the clearfell, or on narrow racks, it was bladed up to the base of the Beech trees to dissuade the deer from barking them further.
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| The 35 year old County 1004 that bladed the brash to make a bonfire |
Perhaps you are wondering what was to be done
with all the timber ? Well, anything over 12” butt
diameter is to be milled into boards and planks to be
used on National Trust property whilst all coarser
sawlogs and pulp will be allowed to season for a few
months and then will be chipped. All of the chips
will be stored on site and used as fuel for the estate
buildings, so nothing will be wasted.
With all this timber being utilised on the estate that
grew it, it is encouraging to see that this sort of local
woodland usage is alive and kicking and being
encouraged by the National Trust.
Arwyn Morgan
Forest Machine Journal 11-06
Right Tree – Right Place – Right Reason
Dr Gabriel E Hemery and Dr Peter Savill
We have always thought that the old mantra “The right tree in the right place” needs an extra qualification: “For the Right Reason”. The additional qualification ensures that any tree planting or management is appropriate. For example, we should not advocate planting trees that have been genetically selected for timber production in ancient semi-natural woodland, or equally plant “locally native” when you want quality timber. Although not mutually exclusive, local provenances only very rarely include tested and improved material.
The decision about which species to plant is one of the most important of all in forestry because of the long cycles involved.
An incorrect choice can result in poor health or growth, and even the failure of a crop, and certainly failing to fulfil the objectives of the planting scheme. The stresses imposed by droughts, gales, frosts, and fires, some of which will inevitably occur over a rotation of up to 150 years, could lead to serious diseases or pest outbreaks or even death if species are not well matched to the site. The one or more species selected for planting must therefore be those whose requirements throughout life are likely to be satisfied by the site and climate in question. They must also fulfil the objectives of the planting scheme. The process of species selection is done in three stages:
- The Right Place: determining the characteristics of the planting site in terms of climate, soil, and other factors such as risks of browsing by deer as well as any legal and financial constraints. These characteristics are then matched to:
- The Right Tree: deciding which species are likely to thrive in such conditions. Care should be taken to consider the quality of the planting stock and its origin. For example, a hybrid Walnut (non-native and genetically selected) would not be an appropriate choice in some locations, despite admirably meeting a final objective of growing a valuable timber. From among suitable species, those selected for planting must be chosen for:
- The Right Reason: deciding which of one or more species satisfy the objectives of the planting scheme. Often the reasons why trees are planted are manifold. For example, you might, perhaps, be planting a landscape screen as well as providing game cover, and simultaneously growing a valuable timber crop.
The considerations
to be taken into
account are
summarised in the
diagram:
The process of selecting species for planting entails matching possible species to the characteristics of the site. Then, from among possible species, choosing those that fulfil the objectives of the planting scheme.
Marcus Wallenberg Prize 2006
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| Dr Antoine Kremer – recipient of the 2006 Marcus Wallenberg Prize |
The value of the prize is two million Swedish crowns and it was presented to Dr Kremer by the King of Sweden, at a ceremony in Stockholm on Thursday 28 September 2006.
The annual Prize was established in 1980 to acknowledge the lifetime activities and the memory of Marcus Wallenberg, the late Chairman of Stora Kopparbergs Bergslags AB (now Stora Enso). Each year the Prize recognizes a single breakthrough research achievement of one scientist or a small group of collaborating scientists. For the past few years the Chairman of the selection committee has been Professor Jeff Burley, the immediate past Chairman of BIHIP.
Antoine Kremer has worked for 28 years with the French national research organization, INRA, and has been a leader in both national and international research groups. His breakthrough is in the combination of information from a number of different sciences at their current state-of-the-art level (from molecular genetics to the evolutionary history of forests) to develop new knowledge about Oaks on a continental scale. This knowledge provides a major platform to facilitate decisions about the conservation and management of forests. It also allows prediction of likely future changes under the impact of climate and other environmental changes.
Dr Kremer’s individual researches and synthesis may be applicable to other tree species. The techniques will also have relevance to the introduction, management, improvement and use of exotic species elsewhere.
by Dr Peter SavillOffsetting CO2 Emissions
Woodland Heritage is often asked how much carbon dioxide (CO2) might be sequestered, or “locked up”, offset or “fixed” in the wood of trees as they grow.
The accepted international methodology is given in the Draft Guidelines for National Greenhouse Gas Inventories, published in 1994 by the Scientific Assessment Working Group of the Intergovernmental Panel on Climate Change (IPCC), a joint programme of UNEP and the World Meterological Programme. Assumptions for a typical broadleaved woodland in Britain might be:
- the forest grows at an average annual rate of 5 m³/ha/year for 150 years, and thereafter there is no net increase at all, because any additional growth of some trees is offset by the death and decay of others (and consequent release of CO2 into the atmosphere again)
- that one cubic metre of wood, when dry, weighs half a tonne and that the material which makes up wood is approximately 40 per cent carbon
- thus, the average rate of carbon fixation for the first 150 years would be approximately 1 tonne/ha/year (i.e. 40% of 5/2)
As an example, if the woodland occupies an area of 15 hectares it therefore likely to be able to fix (i.e. “offset”) about 15 tonnes of carbon per year for 150 years, or a total of 2250 tonnes. A concern has always been what happens to the fixed carbon once the trees are mature. There are two possibilities:
- If the forest, having built up a biomass of some 750 m³/ha of wood over 150 years – or 150 tonnes of carbon/ha – is left undisturbed, the carbon is likely to remain more or less fixed, with any deaths of trees being offset by the natural establishment of new ones. The new growth and fixation of carbon will balance that released by the decay of dead trees. However, there would be no fixation of additional carbon. To do this, more previously unforested land would have to be planted.
- If the forest is felled, one must remember that the half-life of timber is very short, at about nine months. Most of the fixed carbon returns to the atmosphere quickly because the wood is converted into ephemeral products such as paper and pallets, much of which is subsequently burnt. Only a very small proportion survives in furniture and other high quality products for long periods. To remove fixed carbon permanently from circulation again, it should be stored somewhere where it will not decay, such as redundant coal mines.
WORKING IN THE WOODS
Words of wisdom from Jack Tenison
| MIND YOUR HEAD! |
A tree fell on my head yesterday. Just a little tree, of course; more like a branch. But I was doing the usual forester’s thing of never looking up and whizzing along the rows without a thought to what was above my head. It is the first rule in forestry; always look up. The butt of a tree can be as smooth as silk, the stem well formed and straight. But if the top is forked, the leader suppressed, other trees too close or if, towering above the precocious sapling is a forest of mature trees blocking out the light and preventing proper formation, then all will be for nothing. Always look up; that is where the tree is going. (And of course, never plant under overhead lines. It is amazing how many people do. I do.)
| WEAR THE RIGHT KIT |
I am thinning a 17-year old plantation of Larch and Beech, alternate lines. The Larch are forty feet tall, worthy of respect and given it. The Beech are miserable stunted bushes, half the size at most, easy to treat casually; but they land with a thunk on my pate even so. So that is the second rule: wear the right kit. Helmet, earplugs, goggles, gloves, trousers and boots may seem over the top for a small wood of adolescent trees, but accidents happen because they are unexpected. My neighbour swallowed his tongue while felling an Apple tree, and I lost sight in one eye for several days when whipped by a raspberry cane. Even the meanest tree can hurt; respect it. And think.
| TEDIUM CAN BE USEFUL IF YOU USE THE TIME TO THINK |
So much of forestry is dangerous, sweaty and boring. Going up and down those lines of trees, weeding, pruning or thinning, is drudgery, physically demanding and mentally dead. I should be learning sonnets or practicing my Greek irregular verbs; instead I nurse historic grievances. At least farmers, once a month, have to shave, and brush their shoes, to go to market. For a forester, years can pass without human contact. I would go mad from loneliness and boredom if I did not reflect on why I do things, and how to get it right.
Over the last twenty years, we have planted or replanted about 100 acres with an even mixture of species: sitka, Larch, Norway, Douglas, Scots, Oak and Beech. I have not planted Ash, Sycamore, Spanish Chestnut and Birch, but they have grown themselves and been managed. I have put time into early and repeated weeding and shaping, particularly the broadleaves. But the cycle has moved on, and I am now doing more thinning, and (in between the grudges and groans) thinking more about species mix, and management.
| IDEAS ON SPECIES MIXES |
First, species mix. Obviously, Larch and Beech do not go, the Beech having been suppressed from the start. But I believe in putting Beech with most things, if only because it helps suppress the weeds and give a balance of light and shade. I would never put Beech with Sitka, where it would add nothing. Nor to a mix of small native trees (Crab Apple, Birch, Mountain Ash etc) which would be my choice, if I were planting only for the grant or for amenity. But with Oak or Douglas, or anything in between, bung in the Beech.
It is a matter of taste whether you plant the different species in rows, or blocks, or discrete compartments. I prefer adjacent rows of alternate species (perhaps a double row if the tree is a relatively slow grower). It spreads the propagation risk across the field, and provides a more intimate mix in the end. I am not normally worried about differential growth rates of two different adjacent species. If you thin to favour the best stem, you are likely to cut enough spaces to give most secondary species a chance.
And you must of course thin to leave the best stems. I get apoplectic when I read forest management plans stating “thin to favour x”, as if one species is so morally superior to deserve preference even if it is manifestly unsuited to a site. Equally, if your sitka plantation has failed and is sprouting birch, do not grub them up at vast expense. Simply grow birch. But only manage them; make sure that they are the best Birch you could grow. Otherwise you are wasting the land. Leave what is growing well, cut out the rubbish, and do not worry about gaps. There is no point in leaving a poor specimen just to make up numbers.
| MANAGEMENT |
Secondly, management. And again, personal preference must decide. In an ideal world, thin little and often, allowing the selected final stems (it is all a bit Brave New World) incremental growth to fill their given space, by judicious removal of adjacent stems and branches, but avoiding excessive light which encourages lateral growth, epicormis and weeds. In practice, we have all got other things to do. I need to gear myself up to do something, happily finding dozens of other jobs around the place, just to put off That Which Must Be Done. And then the right saw needs mending, the chain is blunt, and the oil and mix have run out. So that, once I am into the job, I do not want to stop until it is finished and mentally ticked off for the next five or twenty years. When I thin, I thin hard. But you will have your own ideas.
| DECISIONS ABOUT THINNING |
Next, do you thin to individual stems, or rack, removing all trees in a row? It depends on circumstances. If you grow conifers you may be lucky and get a machine to rack (take out entirely) every third, fifth or seventh row, allowing you to get a tractor into the wood and pull the intervening trees to the rack by hand. But you will have to pay. Around here, I could neither give away my first thinnings nor even pay somebody to do it. I have to do it myself. And I have an instinctive dislike of wasting one third, fifth or seventh of my best trees. So I do everything selectively, and shape all the good trees and cut out the rest, wherever they are. I do not mind the resultant clumps and gaps.
Finally, how to use the thinned trees ? Cutting them is easy: whizz, whizz (thunk, ouch) whizz. But these are likely to be the worst stems, and many will be useless for firewood, timber or stakes. Fifty years ago, first thinnings had some value; now they are a cost. How do you get rid of them? On those many private estates in Britain, where forestry is still practiced as an art, all thinnings are taken from the wood for disposal. Alas; not here. Full marks, if you can get them out. But if your living is from forestry, you may want to consider other ways. I have two suggestions; but any forestry visit will offer others.
If the thinnings are reasonably light (Larch, Oak, Beech etc), I cut down, chop up small and stack tidily in the wood. This provides good habitat, particularly if the tree species prevents much undergrowth. The stacks will rot over time, but they will be a nuisance until then. So the job must be done right first time. Another way is to try to kill the tree standing, perhaps by cutting through much of the base, but not all, or spraying weedkiller into a wound. This leaves the tree standing, preserving the shade of the adjacent trees. But it is difficult to get right (too much, and the tree dies and fall over; not enough, and it keeps on growing).
However you do it, it is all work, and no short cuts. The first step (aged 15-20) is to cut off all the lower branches with a small foot-long chain saw, and single any forked stems which are common among hardwoods (particularly Ash). You must do this first, and do every tree. First, it clears all the brambles; second, it allows you to see the wood properly. I brash (cut off the lower branches) of all trees, even if they are due to be thinned. It makes felling easier and whether you remove the poles or chop them up to rot on the ground, the branches have to come off some time anyway. So do it right first time.
| YOU HAVE TO THINK ABOUT THE NEXT TIME |
And then, whether or not you use a quad or a tractor, and clear the thinnings or leave them to rot, you still have to chop up the lop and top. You must be able to get back into that wood when the time comes, five years later or twenty. Because the next thin, the second thin, is the crucial one: then, you might make some money and, most importantly, you will determine the future of the wood.
CRANN
Ireland’s tree magazine – Spring issue 2006
www.crann.ie
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Jack Tenison is very much a “hands on” forester and woodland owner in South Wales and Lough Bawn, Co. Monahan, Ireland. He writes regular articles for Crann Magazine and has helped Irish timber growers by hosting visits and demonstrating his successes and failures on his wooded estate. Jack was an early member of Woodland Heritage and is a great supporter of the European Squirrel Initiative. We featured his work in Woodland Heritage Journal No. 8 – 2003, page 17. |
Woodland Heritage OakSeed Provenance 2006/7
For our seed this year we chose the BIHIP Selected Oak (Quercus robur) growing in Hindolveston Wood, Norfolk
This tree stands in compartment 2A at the western end of Hindolveston Wood. It was planted in 1951 and in 2007 stands 15.75 m high with a BH diameter of 40.5 cm and contains approx 0.43 m³.
It is free of epicormic shoots and has a bole of 9 m of knot-free timber. It has light branching, with no forks and good apical dominance. It was selected by BIHIP in 1998. Acorns have been collected from it twice, in 2000 and 2006, the latter being a prolific year.
Hindolveston Wood, on the southern half of the Melton Constable Estate was purchased by the Duke of Westminster in 1949 and his woodlands department employed Pulford Estates Ltd to carry out all its forestry activity. It is now owned by the Brun family.
It was decided that Hindolveston Wood, which had been clear-felled in 1939-45, should be totally replanted with one year Oak seedlings. The planting was contracted out to Messrs Longhirsts who at that time had a nursery and contract gang at Sheringham. A forester (Jack Archer) who worked for Longhirsts has told me that at that time he organised a collection of over 10 tonnes of acorns by schoolboys from an avenue in Colby near Gunton in Norfolk. These were sent to Scotland for sowing and the trees returned to Norfolk for planting in Hindolveston Wood. The spacing was 5 feet x 1 ½ feet.
Compartment 2A consists of 1.7ha and has a yield class 8 for the Oak. Amongst the trees growing, it contains 108 selected final crop trees, 63/ha at 12.5m spacing. This is slightly under the 65/ha, which is considered the ideal density of a final crop of a pure Oak stand on a 120-150 year rotation.
Edward Brun
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Planting out the Hindolveston Acorns in the Polytunnel
Using a good quality mulching compost and cell-growing trays, the acorns were set in November 2006, raised on trestles – to defy the mice who fancy tasty acorns.
Mousetraps were set immediately, although we knew that there was no way the mice could climb up the trestles and onto the overhanging aluminium supporting plates.
We were wrong! So far (March 2007) the mice have played havoc with our precious seeds and we are desperate to find out how they managed to reach the trays...
(Someone has suggested paragliding)
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| 4,200 seeds Quercus Robur seed from BIHIP selected trees in Compartment 2A Hindolveston Wood, Norfolk Planted in 1951 |
4,550 seeds Quercus Robur seed from trees in Compartment 2A Hindolveston Wood, Norfolk Planted in 1950 |
In the days before hard hats, safety boots and Risk Assessments, we used to call it
“JUST ONE OF THOSE DAYS”
A Suffolk Tale of Woe in 1990
Characters involved: John; the sawmill manager. Vastly experienced, never wrong and possessing an embarrassing vocabulary when roused. Dave; the harmless, willing, but highly accident-prone driver of the Landrover.
John had bought a Walnut tree from a lady who ran a riding centre 10 miles away. He was under pressure to remove it. John had checked out the location once, but in order to be completely confident, he returned to measure the width of the field gateway for access by the mobile crane. All was well.
The plan was for John to drive the mobile crane and to load the butt onto a 3-ton trailer pulled by the Landrover. I was to bring my Range Rover with a second trailer so that we could collect another Walnut nearby. It would make an impressive convoy.
In case of problems, we decided to take our winch in its heavy canvas bag. Dave went to put this in the back of his Landrover, but as he lifted it forward he caught his shin a painful blow on the trailer drawbar – he said that he hadn’t seen it. (John said later that we should have abandoned the whole trip at this juncture.)
Unaware of events which were to befall us later, the convoy rolled out of the yard onto the main road. I was leading the way and checked my rear view mirror, only to see the mobile crane belching clouds of dense white smoke as it just made the brow of the hill. This smoke did not bother Dave in the following vehicle – he knew the road well. Not so aware was the elderly driver of a Mini Metro coming from the other direction, who saw a white wall confronting him and turned on his headlights. I never did learn what befell them, but his wife looked very scared when they passed me.
The smoke eventually cleared and the convoy proceeded without further incident to the farm. The trailers were parked to one side to allow John to drive through the gateway. Dave went forward to open the gate catch and caught his finger in the spring mechanism. No problem. But from my perspective there was a problem – when I looked up I could see that there was no way that the crane was going to fit through, because not only was there an overhanging Holly tree, with a bushy and venomous top, which would obscure John’s view of the gatepost, but it was also a greasy surface in the heavy rain. But I assured myself that John knew what he was doing.
John squeezed the offside bumper through and instantly realised that the other one was not going to fit – and was liable to demolish the gatepost. He braked hard and the crane slid backwards, hooking itself neatly onto the post. (See photo)
He turned off the engine and we could hear the diabolical language coming from the cab. John needed to get out to see what had to be done, but he could not extricate himself because the Holly tree had enveloped his window and door – and the other door was very temperamental. Just at this critical moment, the owner’s husband arrived on the scene and began haranguing us about compensation for his gate etc. I glared at John and we bit our tongues.
I grabbed a chainsaw and cut away the top of the prickly Holly tree and released the fuming John who was clearly embarrassed at his misjudgement of the width of the gate. The obvious remedy was to detach the rails from the main post. So whilst Dave hammered them off, I vaulted over the gate to view the situation from the other side.
But on that day my gymnastic skills fell short of perfect and I landed heavily on the lower rail which cracked loudly. The owner went daft. He now wanted new rails as well as posts. I gently explained that we were doing our best – and that we would get on better without his presence. He departed and we got on with the job.
Clearly we would have to dig out the main post even though the ground was rock hard. After half an hour of hot, hard work we finally succeeded and John triumphantly drove the crane into the field and over to the fallen Walnut. We unloaded our chainsaws and prepared to reduce the tree in length for transportation. John selected his best saw and began the cut in a pretty innocuous place when he hit a bunch of nails under the bark, ruining the chain. The language was not good, but at least the owners were out of earshot.
Using a second chainsaw, I then made a cut in a different place, only to hit more nails and spoil that chain. John took the saws away to replace the chains and burned his hand on the hot metal. I took an axe to ensure that the bark was clean and free of nails for the next cut, only to hit the tree a glancing blow which directed the axe into my shin. I joined Dave in The Limping Parade.
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| Well and truly hooked! |
After a great deal of cursing, the wire was freed from the pulley wheel and the log dropped violently, bouncing and hitting Dave in the legs. The second piece was at a better angle and lifted well. Dave was told to be on the alert this time. When the log was in position, I released the wire and its heavy hook. This swung back and hit the non-attentive Landrover driver with a pronounced “clang” on the side of the head. I enquired if he was alright and he muttered something about his woolly hat saving him.
With the log correctly suspended from the crane jib, John began reversing the machine across the bumpy meadow towards the gate where the trailer awaited. Dave ambled slowly in front, unaware of the swinging log – which proceeded to hit him in the back knocking him to the ground. John’s comments from inside the cab could not be considered constructive...
Eventually John manoeuvred the log over the trailer whilst Dave directed him to drop the load onto the bearers which he had positioned. When it was down, he reached forward to disconnect the wire, but found that the log was indeed resting on the bearers – but the self-same bearers were resting upon the tops of his shoes – and because his feet were jammed tight in his winkle-pickers, he couldn’t move an inch. I came to his rescue with a crowbar – and ended up jamming my gloves in precisely the same way as Dave had achieved with his size 10s. John climbed down from his cab and released my hands without a word being spoken...
All the timber was now loaded and it was time to drive through the gateway and then reposition the posts and rails. As a precaution, I took photographs of everything “before and after” because I had visions of a High Court judge listening to the proceedings...
Dave bent down to dig some spoil from the post hole, unaware of the post dangling from the crane above him. (You can guess the outcome, but suffice to say that his woolly hat came to his rescue again.) Surprisingly, the owners expressed satisfaction at our repairs and we were allowed to leave without further ado.
The plan had been to collect another Walnut log from a site a few miles away, but I simply couldn’t face another disaster, so I bade farewell to John and Dave and watched them head back to the sawmill – all the while thinking that the Landrover would probably drive into a ditch and John would land up on top of it with the mobile crane...
When I returned to my office an hour later, I thought it prudent to phone John to see if everything had gone to plan. His reply was guarded – although he admitted that they had arrived back without incident. When pressed, he explained that, after a cup of tea in the canteen, they unloaded the trailer and prepared to take a pile of Oak boards back to the cabinet workshops. Apparently, Dave had selected the wrong gear and backed the empty trailer straight into the canteen wall, ripping out all the boarding and hooking the water pipes onto his bumper as he drove off.
John was just getting out his hydraulic jack to replace the broken gate post when my call came through – and, oh yes, could I phone for a plumber ?
Horse Chestnut (Aesculus hippocastanum)
The Bleeding Cankers and Dying Trees
Stem bleeding on Horse Chestnut in the UK was first reported in the 1970s, when the cause was found to be a fungal pathogen known as Phytophthora (Brasier and Strouts,1976). The same disorder had also been recognised in the USA much earlier in the 1930s (Caroselli, 1953).
| Incidence of the disease |
Until recently, such Phytophthora bleeding cankers were only seen in the south of England (Strouts and Winter, 2000). However, over the past four or five years, the number of reports of Horse Chestnut trees (Aesculus hippocastanum) with ‘bleeding cankers’ has increased markedly.
Symptoms visible on affected trees include bleeding areas on their stems and sometimes on their scaffold branches. The increased incidence of stem bleeding on Horse Chestnut is not just limited to the UK; the Netherlands, France and Germany are also experiencing a similar upsurge.
Closer investigation of the bleeding cankers on Horse Chestnut has revealed that Phytophthora is no longer the primary causal agent. Instead there is accumulating evidence that a different pathogen is responsible for the increase in these symptoms on Horse Chestnut.
In 2003 the Disease Diagnostic Advisory Service (DDAS) of Forest Research received more than 60 reports of stem bleeding in Horse Chestnut, while in 2004 a further 90 reports were received. So far 70 reports have been collated for 2005. Affected trees have been recorded as far north as Lancashire and Glasgow.
| What trees are affected? |
Trees of all ages have been affected by the recent disease upsurge. Young trees with a stem diameter of only 10cm (4 inches) have been found with advanced symptoms. However, the impact on the environment can be particularly profound when large, mature trees are infected and disfigured by the disease. If the disease is severe and the areas of bark which are killed are extensive, large trees can undoubtedly be killed. However, younger trees (10- 30 years old) are at greater risk and can succumb to the disease in just a few years (3-5) as the smaller diameter of their trunks means that they can be girdled more quickly.
| Detailed information |
- Extent of the problem
- Reasons for increased incidence?
- Symptoms and casual agent
- Diseases with similar symptoms
- Advice on disease management
- About Horse Chestnuts
- Other common pest and disease problems of Horse Chestnut
- Photo gallery
- Bibliography
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Horse Chestnut Leaf MinerCameraria ohridella This is now firmly established throughout the country. It is continuing to spread and wherever it becomes established, numbers quickly build up and cause extensive damage to the foliage. While it is very disfiguring and the cause of premature leaf fall, C.ohridella is not known to kill otherwise healthy trees. The Forestry Commission are not advising the removal of trees on the grounds that they are infested with this pest, although they do not yet know what the long-term effect on tree health will be following repeated defoliation, year after year. There are no recommended methods for management of the pest on the tree itself. Chemical insecticides are difficult to apply safely and efficiently to large trees. They are also expensive and pose environmental hazards. A much safer and more practical means of control is to remove and destroy fallen leaves during the autumn and early winter. Collected leaves should either be burned or composted thoroughly to destroy the over-wintering pupae residing inside. |
For further information contact:
Dr Joan Webber, Forest Research, Alice Holt Lodge,
Farnham, Surrey GU10 4LH
Tel: +44 (0) 1420 22255, Fax: +44 (0) 1420 23653,
Email:
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or the Tree
Disease Diagnostic and Advisory Service.
Horse Chestnutu (Aesculus hippocastanum)
How to Use This Difficult Timber
by Richard Chapman
"Fell it quick - dry it quick - work it quick"
As a woodturner producing pieces mainly for the decorative art market, I look for different qualities in timber compared to other users. Thus, Spalted Beech, crotch figure, burrs, holes and cracks loom large in my requirements, to catch the eye of art gallery loiterers. My working practice is to chainsaw billets as big as possible. Then rough turn them, leaving sufficient thickness to turn out distortion when dry. Thereby, a 20 inch cube will result in a finished work in 6 weeks. Otherwise wet timber can be turned very thin and finished wet in one session, resulting in an asymmetrical object, after the usual distortion has taken place whilst drying.
Horse Chestnut has very positive as well as negative features.
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| Conclusion |
I would suggest that, as well as use by specialised turners, this timber would make excellent veneers.
Get your potential seed stands registered
John Fennessy (COFORD,Tree Improvement Programme Manager), Jason Hubert (Forest Research, Improvement of Broadleaves), Sam Samuel (Forest Research, Genetics), Peter Savill (Chairman of BIHIP)
There are three ways of improving the genetic quality and productivity of your broadleaved forest:
- by using seed from the most appropriate provenances
- by collecting seed from registered selected superior stands
- by breeding improved trees from individually selected ‘elite’ or ‘plus’ trees
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| A potenial seed stand of Oak (Quercus petraea), in Normandy, France |
Considerable progress has also been made with the third (tree breeding) in recent years, but quantities of seed currently available are still very small because breeding programmes are at such an early stage of development. As genetically superior seed becomes available from seed orchards, the need for seed stands will decline and may eventually vanish.
| Gains achieved by using seed from selected stands |
Selected seed stands need to contain trees with superior and desirable visible characteristics. Before they can be used for seed collection, the forestry authorities responsible for the Forest Reproductive Material Regulations will inspect the stand to confirm its acceptability for inclusion into the National Register. All seed collectors must also be certified by the forestry authority. (See Stop Press)
The progeny derived from an excellent stand of trees will generally out-perform unselected stock. This has been clearly demonstrated for Oak in field trials. The advantages of raising plants from seed collected from selected stands are that it is cheap and can be applied immediately while more intensive methods of breeding usually require a much longer time and are carried out in parallel.
The gains achieved by using seed from such stands are not particularly well documented because they are rarely progeny-tested. For any individual character, they are probably in the region of 2 to 5% compared with unselected seed from a suitable provenance.
Though these improvements may appear modest individually, improving several characteristics simultaneously in the same generation can have much larger additive economic effects so they can result in significant returns as a consequence of increases in recoverable timber per tree. This can be particularly important for broadleaved trees where a small increase in overall quality of the stand can result in a very large increase in value.
There are also advantages to the owners of selected seed stands. In 2006, for example, unselected Ash seed was selling for about £12/kg, while £35/kg was paid for seed from selected stands; for Birch the prices were £85-90/kg for unselected, and £130- £150/kg for selected seed.
| Management of seed stands |
Seed stands are usually managed to produce large quantities of healthy seed by, for example, thinning to favour the best potential parents, and removing nearby sources of genetically inferior pollen. This procedure leaves only the good trees to interbreed. Seed stands are registered by the forestry authority. The seed from them generally has the following characteristics:
- it produces plants with better genetic qualities than seed from unselected stands in terms of adaptability, vigour, stem and crown characteristics and pest resistance
- the geographical locations of the parent trees are known, and information is available to the grower about the soil and climate of the parent stand
- selected seed provides a reliable source of welladapted plants at a modest cost
Though the cost of seed from selected stands may be several times that of unclassified seed, it is modest compared with the advantages to be gained from using it. Seed costs are only a minute proportion of the total establishment costs and should not be the determining factor when deciding between different seed sources.
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| Straightness and branching are heritable characteristics as these two roadside stands in the Netherlands illustrate | |
Ideally a potential seed stand should be fully stocked, and, for broadleaves, contain 50-75 trees ha. They should be of an age to produce seed. The trees should be:
- well-grown dominant or co-dominant trees of above average quality, with large uniform crowns
- vigorous
- straight stemmed with little taper, no spiral grain or significant buttressing, or fluting
- have a desirable branch form (fine and at a flat angle), with good natural pruning
- free from insect and disease attack
The minimum area should be about 2 ha (a population of at least 200 trees is preferred) to minimise contamination from outside pollen, though smaller areas are sometimes acceptable.
To maximise seed production, it is important that the crowns of seed trees are released to full sunlight on at least three sides. Selective thinning of the poorest phenotypes is the recommended form of management for selected seed stands, even if this results in gaps.
In Great Britain, owners, or their agents, can apply to have a stand considered for inclusion in the National Register. Details can be obtained either by writing to Cathleen Baldwin at Forest Research, Northern Research Station, Roslin, Midlothian, EH25 9SY, or from the Forestry Commission website. If using the website search for “national register”, the first link under general information provides details of the register and a FRM1A form can be downloaded to make an application. The second page of this form gives fuller guidance on the requirements for registration. The full National Register is now available from the website as a pdf file and is an essential source of information for growers when considering what to buy.
In Ireland to have a stand registered the owner should contact the Forest Protection and Forest Reproductive Material Section of the Forest Service who will then arrange for the stand to be inspected. If the stand meets the selection criteria it will be issued with a Stand Number and be added to the National Register.
STOP PRESS
The Forestry Commission announced in late February 2007 that charges for inspecting and registering potential seed stands will be abolished. There has never been a charge in Ireland.
The Wild Service Tree (Sorbus torminalis)
The Wild Service Tree (Sorbus torminalis)
Keep Your eyes open!
Swiss Pear is the trade name used on the continent for this species. The majority of mature trees today come from France, but it also occurs in Germany, Switzerland and Austria.
Due to the strong demand early in the 1990s and because of the low occurrence of this species, prices for logs have exploded so that Swiss Pear is now one of the most expensive species in the world. It is used for bedroom furniture, panelling and office furniture.
It is often treated with little respect in Britain because we do not seem to realise how valuable the species can become when it reaches the kind of girth and length as shown in the photograph.
This particular tree was only allowed to be felled from a Suffolk woodland because a storm had snapped the top and it had damaged nearby young Oaks. The size of the butt length was 9 1/2 ft x 21 ins = 29.09 cu ft. When offered to a renowned continental veneer cutter, much interest was expressed, but because it was a single tree, the veneer merchant could not justify the transportation costs.
It was therefore cut into 1 inch and 2 inch planking (right) and sold to North Heigham Sawmills in Norwich – where it was much appreciated.
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