Knapp

This link will help you estimate timber volume http://www.forestry.gov.uk/pdf/timbervolume.pdf/$FILE/timbervolume.pdf

This in Harrow highlights the dilemma of pleasing the public Leaf it alone! anger at butchered trees - Harrow Observer I am intrigued by the quote right at the bottom "Pollarding is really common on forest-type trees on clay soils." Do trees only pollard well on clay soils?

It's awkward getting a thorn out with a needle and at the same time trying to hold a hand lens. What I do to leave both hands free is to wear my reading glasses, then put my spare pair over them and sometimes even my wifes glasses, to make 3 pair! It looks odd but it's amazing how close you can focus on the thorn and extraction is much easier when you can see what you're doing.

Birch is a pioneer on bare open ground but it won't germinate where there is any ground cover. I find that in dense self sown birch stands, Oaks struggle to get away. I always thought Oak was a climax tree and it can behave that way; I suppose it depends which part of the woodland cycle you are in. Oak has a specific relationship with Jays which always bury acorns on the woodland edge or in large clearings; often well away from the existing woodland and often in grassland, so creating new woods. The large acorn enables the oak seedling to grow through grass and even has the stored reserves to recover from a nibble or two from animals. Oaks are a very light demanding tree and ideally need lots of space, unless they are grown for timber. I often wonder why they are such prolific growers from epicormic shoots, after being released from shade, if they are traditionally considered a woodland tree. Interesting subject and still lots to discover I'm sure.

Yes Wild Service is a neglected tree. I planted two of them 15 years ago and now they are spreading by suckers and will create a copse of their own eventually. Grey Alder, although not a native tree, will also repay planting by its spreading suckers. Aspen can cover an acre in no time from just one tree. Don't forget, Oak is a pioneer tree and doesn't need as much bother mulching or weeding to get it established. Good luck.

Ben90; your'e right I did mean branch collar. What made me think about this was seeing the work done by British Waterways on the canal. A lot of the overhanging branches from set back trees were cut back only as far as the canal boundary, which meant a lot of long stubs were left. This set me wondering about how rot enters a tree and what happens when occlusion is prevented by the presence of a stub. Thanks for your interesting replies everyone.

It is looked on as bad practice to leave a long stub when removing a branch. To do so invites rot into the trunk because occlusion cannot occur. When a tree looses a branch naturally it will often leave a long stub and if that branch has a large diameter then umpteen years could pass before occlusion can even begin. Does rot pass into the trunk or does it depend on the species? Is it just neatness to trim back to the branch bark ridge or is the tree not worried either way? A conventional neat cut would be unknown in tree evolution. Maybe the long decaying branch gives a tree time to set up decay barriers and very large diameter branches that will never be occluded, may get decay into the trunk quicker when cut back to the bark ridge than if left long. Any thoughts on this?

Good pollard imo. No reason why it shouldn't respond well. Sometimes it helps to keep the side branches on, particularly the swept up ones which then help shelter the bolling from drying winds and sun and keeps the trunk alive.

Alnus incarna, the Grey Alder, is a good tree for covering the ground as it produces suckers from its roots and you will soon have a forest from just one tree. It also produces catkins and leaves weeks before the native alder and so is a welcome bit of early greenery. The stems of the suckers can be harvested yearly for long 'wands' to make hurdles or screens.

Old woodmen said Alder attracts and retains the moisture around it. The is because its roots are chiefly composed of a huge mass of small fibres, whose capillary attraction prevents the escape of redundant water. They also say a plantation of alders has the property of creating swamps and bogs from land that was previously tolerably sound and dry.

As I see it the public have no idea of the skills involved and the danger. It is classed on a par with gardening but done off the ground. Some advertise as tree surgeons some as arbs; no one knows the difference (is there one)? Public say they like trees but not when they are nearby. Then they are just a nuisance and all trees should be in a wood and not outside their property. The easy bought chainsaw doesn't help because everyone then thinks it is easy. Should chainsaws only be available under licence after training in usage? Builders don't need certificates and neither do cowboy arbs. Should the whole industry be illegal without demonstrating competence by licence? Otherwise everyone will want the job as cheapo as poss and that means the transit guys. I don't use a chainsaw and employ a qualified Arb when needed. I am posting these questions as an amateur in this.

No pictures yet, hope to get some. Lime tree left as a lonely, totally shaved 50 foot stick 2 years ago has now new growth all down the trunk and a new crown is forming. Copper beech next to it is still just half a tree with large branches away from railway and nothing on t'other side.

Railway land comes under a special act of parliament and is exempt from usual rules of trees in conservation areas and TPO's. I wonder if the tree contractors also, do not have to abide by the usual standards of arboriculture? Track side clearance is done via the tape measure, which often means one half the tree is shaved of all growth and the other side untouched. Or tall trees left with no growth on of any sort. It's an education to look at some of the results and how the trees respond.

That's odd, the clocks right now, it must have been them butties I ate early that's alterred the time paradigm.

I wonder what evolutionary advantage there is in the forum clock still on British summer time. I am at a loss when to eat my jam butties.