![]() This can be less of a problem with billets owing to improved air flow through the pile. Direct chip harvesting can cause problems for storage with rapid composting (and hence loss of energy content) and mould formation (and attendant health risks) owing to the high moisture content of freshly harvested willow. Harvesting may be as rods (up to 8 m length), billets (5-15 cm lengths) or as direct chip harvesting. Typically the first harvest may be expected to be somewhat lower than subsequent ones, and figures from 7 to 12 oven dried tonnes per hectare per annum can be expected on reasonably good sites. Yield is dependent on many factors, including: In fertile sites growth can be very strong during the first two years after coppicing, giving rapid site capture, reducing thereafter and so a 2 year cutting cycle may be more appropriate. The first harvest is in winter, typically three years after cut back, again using specialist equipment, however a cycle of 2 or 4 to 5 years is also common. Growthĭuring the first year it can grow up to 4m in height, and is then cut back to ground level in its first winter to encourage it to grow multiple stems. Information and advice is available from the Forest Research Yield models for energy coppice of poplar and willow website. The willow stools readily develop multiple shoots when coppiced and several varieties have been specifically bred with characteristics well suited for use as energy crops. Willow ( Salix spp.) is planted as rods or cuttings in spring using specialist equipment at a density of 15,000 per hectare. In the UK many different species have been coppiced in the past, however the principal species currently used for SRC for biomass for energy are: SRC willow Varieties Suitable speciesĪ number of different species are suitable for coppicing, with different optimum cycle periods. This practice is well established in the UK and Europe, having been a traditional method of woodland management over several hundred years for a variety of purposes including charcoal, fencing and shipbuilding. Sometimes you may find it necessary to cut higher first, then trim back.Some fast growing tree species can be cut down to a low stump (or stool) when they are dormantin winter andgo on to produce many new stems in the following growing season. Angle the cut 15 to 20 degrees from the horizontal, with the low point facing out from the stool center. ![]() Make one cut about 2 inches (5 cm.) above the point the branch grows out of the stool. Then, you work from one side of the stool to the center, cutting the most accessible poles. The next step in coppicing techniques is to prune away dead or damaged shoots. ![]() The procedure for coppicing first requires you to clear out foliage around the base of the stool. The smaller wood pieces were also used for firewood, charcoal, furniture, fencing, tool handles, and brooms. Usually, the coppiced trees grow more in their second year, then growth slows dramatically in their third.Ĭoppice products used to include ship planking. Oak and lime grow sprouts that reach 3 feet (1 m.) in their first year, while the best coppicing trees – ash and willow – grow much more. The weakest are beech, wild cherry, and poplar. The strongest broad leaves to coppice are: Generally, broadleaf trees coppice well but most conifers do not. Not all trees are plants suitable for coppicing. ![]() This can be carried out over and over again for several hundred years. The sprouts that arise are allowed to grow until they are of the correct size, and then are harvested and the stools allowed to grow again. Sprouts grow from dormant buds on the cut stump, known as a stool. Coppicing trees provided a constant supply of logs of a size that could be easily handled.Įssentially, coppicing is a way of providing a sustainable harvest of tree shoots. The practice of coppicing pruning was particularly important before humans had machinery for cutting and transporting large trees. What is Coppicing?Ĭoppicing pruning has been around since Neolithic times, according to archaeologists. Read on for more information about coppicing trees and coppicing techniques. The shoots are left to grow for a certain number of years and then are cut, starting the entire cycle again. It is often done to create renewable wood harvests. The word ‘coppice’ comes from the French word ‘couper’ which means ‘to cut.’ What is coppicing? Coppicing pruning is trimming trees or shrubs in a way that encourages them to sprout back from the roots, suckers, or stumps. ![]()
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