Trees.
There is no botanical definition of a "tree". The word tree is just a handy way of describing a big woody thing that provides shade. If only trees had all evolved from a single common ancestor then it would be nice and simple to produce a one-page guide showing how to grow and coppice them. Unfortunately, trees are an example of many different species alighting on a common solution to a shared problem: how to get enough light to grow and survive.
The distinction between trees and other, merely herbacious, plants lies in their method of growing. Herbacious perennials grow taller and longer from a growth point at the tip (primary growth). Trees on the other hand also get fatter (secondary growth). This fattening is due to a layer of tissue (Cambium) which is formed all over the tree between the bark and the wood, which subsequently grows sideways. Newly created cells from the Cambium move inwards to form new wood (Xylem) and outwards to form new bark (phloem).
Shrubs.
Many books give the definition of a shrub as a "multi-stemmed, woody perennial under 6m in height". This is alright for tree-huggers and gardeners but is pretty meaningless in our sutuation; to us a shrub is just another tree.
Plantations.
Swepstone Coppice is a plantation of mixed broadleaved trees and shrubs.
Plantations are areas of trees created by man with the intention of either growing a timber crop or of providing some amenity/wildlife value. The sites occupied by plantations are usually either redundant farmland or some kind of reclaimed industrial land. The soils are always completely unnatural and therefore never contain the “ideal” communities of flora, fauna and microbes that ecologists regard as essential for natural woodland.
They should not be confused with naturally occurring ancient semi-natural woodlands. Woodland began to develop in the British Isles around 550 years after the end of the last glaciation (this is what is meant as ancient). There are no areas of completely natural woodland left in England; all woodland has been managed by people at some stage in the past (this is what is meant by semi-natural).
Ancient semi-natural woodland contains a complete, interdependent community of trees, shrubs, flowers, herbs, microbes and associated fauna that have evolved together. A plantation can only ever be an attempt at a starting point for the evolution of the planted environment into woodland.
Coppice.
The term "coppice" derives from the french verb "couper" (to cut) and is essentially a form of aggressive pruning.
Coppicing is simply the process of cutting back Hazel, or any other hardwood tree, to a low stump on a regular basis: to provide a supply of wood (timber is obtained from full-sized trees).
Softwood species, mainly conifers, do not regrow from cut stumps. This is because conifers, unlike most hardwood trees, do not store food reserves. Instead they rely on excess food being produced by their mature needles in spring to support new growth: no mature needles, no growth. We have some Pines and Spruces as winter cover for birds, etc. Several of these have been blown down in winter storms and I have had to make a clean "coppice" cut at the base to remove the fallen tree. All have died subsequently.
Coppicing is possible because many broadleaved trees produce far more buds than they need for normal growth. These surplus buds are maintained in a dormant state (stored or epicormic). Other "adventitious" buds can also grow on scar tissue as an insurance policy against damage to their trunk or branches.
These buds are normally suppressed by hormones produced by the buds at the tip of the main stem and branches. When these growing points are removed the dormant buds are released and adventitious buds are stimulated.
New coppice regrowth tends to have a longer growing season than that of standard trees. There are two main reasons for this. Firstly, hardwood species store most of their food reserves in the roots and at the base of the trunk; secondly, a large amount of energy has to go into supporting older growth through respiration. The removal of some or all of the older growth frees the coppiced tree to concentrate entirely on the new shoots.
Provided that their roots are not damaged and no infection gets into the felling wound, hardwood trees can be cut repeatedly: providing a regular supply of wood.
Silviculture.
The process by which the crops making up a wood are tended, removed and replaced by new crops, resulting in the production of stands of distinctive form. Coppicing is not a recognised system for growing quality timber.
Wood Properties.
Density
Kilograms/m-3 at 15% moisture.
Durability
The averabe life of a 5cm x cm section of heartwood in ground contact:
Durable 15 - 25 years
Moderate 10 - 15 years
Non-durable 5 - 10 years
Perishable <5 years.
Permeability
The ease with which timbers can be penetrated with preservative
in normal conditions (heartwood and sapwood usually differ in permeability).
Permeable easily absorbed;
Moderately resistant 6-18 mm penetration in 2-3 hours;
Restitant difficult to penetrate more than 3-6 mm;
Extremely resistant absorbs only a small amount.
(Forestry Commission Handbook no. 9)