Coppicing – A Lost Art Revisited
Coppicing has always been interesting to me as a wood production system (fuel, timber) because it uses trees that can be cut perpetually. In other words, the tree is cut and grows back. This is quite different from the type of forestry we practice here in Canada with spruce, fir, and pine trees. These conifers are cut once and then die. As mentioned in my wood gasification article, if we all moved over to burning wood for heat and power, we would deforest the planet in a matter of years. Setting up these types of systems within our cities and farms would be a way of preventing this as well as providing bee fodder, bird habitat and windbreaks.
Here is a great Wikipedia definition on coppicing:
“Coppicing is a traditional method of woodland management which takes advantage of the fact that many trees make new growth from the stump or roots if cut down. In a coppiced wood, young tree stems are repeatedly cut down to near ground level. In subsequent growth years, many new shoots will emerge, and, after a number of years the coppiced tree, or stool, is ready to be harvested, and the cycle begins again.
Typically a coppiced woodland is harvested in sections or coups on a rotation. In this way, a crop is available each year somewhere in the woodland. Coppicing has the effect of providing a rich variety of habitats, as the woodland always has a range of different-aged coppice growing in it, which is beneficial for biodiversity. The cycle length depends upon the species cut, the local custom, and the use to which the product is put. Birch can be coppiced for faggots (bundles of brushwood) on a three- or four-year cycle, whereas oak can be coppiced over a fifty-year cycle for poles or firewood.
Coppicing maintains trees at a juvenile stage, and a regularly coppiced tree will never die of old age—some coppice stools may therefore reach immense ages. The age of a stool may be estimated from its diameter, and some are so large—perhaps as much as 5.4 metres (18 ft) across—that they are thought to have been continuously coppiced for centuries.
Coppiced stems are characteristically curved at the base. This curve occurs as the competing stems grow out from the stool in the early stages of the cycle, then up towards the sky as the canopy closes. The curve may allow the identification of coppice timber in archaeological sites—timber in the Sweet Track in Somerset (built in the winter of 3807 and 3806 BC) has been identified as coppiced lime.”
In Canada we can grow a number of different trees that can be cut and grow back. They include Caragana, Manitoba maple, Green Ash, Willow (105 species) and Elm. Not too long ago, I was speaking at the Organic Connections conference and there was a representative from the Canadian Agroforestry Research Farm at Indian Head, Saskatchewan. I had a great chat with her and she mentioned that they had a ton of resources on coppice agroforestry that they had produced. I tracked them down and have placed them below for folks to download. The articles are loaded with information on yield, energy content, rotation and species. Upon further inquiry it turns out that this research centre was heating all of their buildings with wood chips from their on farm research projects. I believe that the centre has been shut down, like most of the other gems in our country over the last 6 years. This research is much needed and it is going to have to be continued by individuals and universities.
- Breeding willow for bio-energy and agroforestry_ADC Research Review 2009…
- Journal_2009_SchroederKort_Biomass Harvest from Natural Willow Rings
- EcoBuffers-an alternative agroforestry design_ADC Research Review 2009
- Buffer strips for biomass production and riparian protection_Schroeder_A…
- Willow Rings for Biomass Production_ADC Research Review 2009
- Unconventional woody species for agroforestry biomass_ADC Research Review 2009
- Managing_willow_rings_for_biomass_Mushanski-Schroeder_ 2012FINAL – e
- Life cycle analysis of willow biomass production_ADC Research Review 2009
Here is a great video on Coppicing from Britain. This guy makes wooden bowls, heats his home all from his coppice patch. As he states “most of the broad leaf trees in Britain can be coppiced: apple, alder, oak, ash, sycamore, chestnut, hazel, willow.”
In addition to fuel and timber coppice systems can be used for basketry, propagation, mulch and fodder. In Alberta we can grow 105 varieties of willow and this is a high value crop for bioremediation used within the oil and gas and mining industries.
In Ohaton in Camrose County, Alberta, they are using willow to clean up their waste water from a lagoon while growing a feed stock for producing heat for the municipality. Waste to resource!
Dave Jake and Mark Krawczyk are currently working on a book on Coppice Agroforestry which, if it is anything like his last book Edible Forest Gardens Vols I & II, will be amazing! Check out his site, there are a ton of great resources.