These are both ancient methods of managing trees and woodland that can be safely performed by a tree surgeon. The key to these approaches are that they both keep the tree for future growth, rather than removing a tree completely. It all started off as using timber as a crop, as timber was useful for building homes, structures, tools and weapons. However the trouble is that when you fell a tree and cut it off to ground level it takes a lot of time to replace that tree from a new seed.
Coppicing takes advantage of the natural process by which trees regrow. It involves cutting down a tree to about a foot above the ground and then allowing it to reshoot multiple stems. After this, all the energy that is stored up in the roots is ready for life again and the regrowth of new stems occurs. After seven to 20 years depending on the species, the stems can be cut and the cycle restarted.
Some species lend themselves being coppiced more than others. Oak, Ash, Sweet Chestnut, Hazel and Beech can all be coppiced however soft wood species can be prone to rot after being coppiced so pollarding is recommended.
Obviously gaining new timber from a coppiced tree is a lot quicker than if you fell the tree and replant a new one.
Performing coppicing in a cycle across a woodland area has a number of advantages. It creates a diverse habitat which supports a huge range of our native plants and animals. Additionally a hectare of woodland under a coppice management cycle would produce enough wood to heat an average house.
When performing the coppice cut to the stem or trunk we ensure that the r cuts are clean and angle away from the centre of the stump. This is important so that rainwater runs off to the ground and doesn't pool in the stump and cause rot.
If your woodland has been coppiced in the past, but have not been under active management in decades reestablishing a coppicing cycle is something you may wish to consider.
Trees that grow in a woodland tend to grow high with a slender crown because of the competition of other trees around them
Trees that grow around our homes, towns and cities instead start growing outwards and have these wide canopies which block light and cause obstructions for buildings, overhead cables and roads.
Pollarding is a way of managing these trees without removing the trees and keeping the height of the new growth as pollarding removes the branches to higher point in the tree, which coppicing doesn't do.
It is similar to a crown reduction however all the canopy is removed so you are left with a framework of a tree that encourages fresh regrowth
Pollarding is a serious procedure for a tree as you're removing all the leaves which is removing the trees ability to produce any energy for itself via photosynthesis. This drives the tree to start sprouting and generate quick regrowth and needs the keen eye of a profession tree surgeon to assess what is best for the tree. So whilst a crown reduction is more sympathetic with some leaves retained so you get more natural growth, it is limited in how much shaping of. tree can be performed in comparison to pollarding.