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Wednesday, March 9, 2011

The Case For Coppicing

I'm a big believer in the wonder that is coppicing.  Coppicing, if you're not familiar with the term, is a form of woodland management by harvesting wood from the same tree over and over and over again.  It takes advantage of the fact that some trees will send out shoots and grow again after they have been cut down.  The word 'coppice' refers to both the verb, which is the act of cutting the tree down for the purpose of regrowing it for use again, and the noun that refers to an area of trees managed in this way, i.e., hazel coppice, oak coppice, etc.  The stump of the tree grown for this purpose is called a stool, and there are stools in coppices many meters in diameter, which indicates that particular coppice has been managed for centuries. One of the interesting things about coppicing is that it actually extends the life of the tree, by resetting the growth of the tree.  Hazels, for instance, will live for about 100 years until they die of rot or fall under their own weight.  But a coppiced hazel can live for 1,000 years. Coppicing has been traced back since before the bronze age in Britain, and even as ancient as the art is, it's a sustainable practice that's relevant today.

Depending on the species, trees were coppiced for making poles and posts, like Hazels and Black Locust, or for making withies for basket work, like Willow, or for making firewood, like Ash, Maple and Oak. Frequently the smaller pieces from harvest were burned off by colliers to make charcoal.  Harvesting occurs on a cycle of between seven and twenty-five years, and depending on the tree, can be carried out in the period between late fall and early spring.  The goal is to cut the trees down at the ideal time for them to start growth again the following spring.

Short rotation coppicing is coppice managed as an energy crop for producing biomass. Harvesting occurs on a two to five year rotation, and the principal species for short rotation are willow and poplar, both very fast growing trees.  Eucalyptus, which also grows very quickly and makes a very hard firewood, is also harvested in some countries.  All three are frequently chipped for making pellet wood.

Anyone with a few acres that they don't need for food or forage crops should probably manage a coppice.  Even if you don't burn wood for heat yourself, it could still be a cash crop that you could produce on marginal land. The government and many university agricultural extensions have information on woodlot management.  One of the best reasons I've read recently for growing your own firewood is the prevention of the spread of the emerald ash borer, an invasive species from Asia that is devastating eastern Ash forests in fourteen states and parts of Canada. It is estimated that seventy-five percent of infestations by the emerald ash borer in the midwest were introduced by firewood trucked in from other states.

I don't have several acres, or even one acre.  I have not quite a quarter acre and I am still going to try coppicing in my backyard to supplement my firewood needs.  I don't expect to be able to grow much of the firewood that I need because I don't have enough room, but I can grow some of it.  For a long time, I wanted to grow Black Locust, Robinia pseudoacacia, but I've given up on that idea because it really needs a lot of room. It can also be an invasive species.  My interest in the Black Locust was because it appeared to be the quintessential, ideal tree for coppicing.  It has a fast growth rate, has one of the highest BTU contents per pound, and its fragrant flowers in the spring make great bee forage.  In addition to that, it doesn't seem to rot too easily; posts made of Black Locust used for gate and fence posts set in the ground have been known to last sixty or seventy years.  It is also supposed to have a lovely grain for fine furniture making.  So what's wrong with it?  It suckers freely, and I can't do that to my neighbors, since the only place for a coppice is along my property lines.  Also, nothing grows under it; it's supposed to be a great tree to grow out in the middle of a field for shading livestock.

My attention was recently alerted to the Eucalyptus by my friend, Rae.  We both grew up in different parts of California, and both had Eucalyptus trees at home.  I happen to know they make great firewood; my mother has been burning the prunings from her Eucalyptus trees, which were originally planted as a noise and light barrier from the expressway several blocks away from her house. Some of those prunings are six inches in diameter; I think they were branches that had to come down.  Research into the species has helped me determine that Eucalyptus would be a suitable replacement for my abandoned Black Locust.  Eucalyptus grow very fast, some clocking six feet a year, and some varieties do coppice, most notably the Cider Gum (E. gunnii) and the White Gum (E. dalrympleana).  And another plus: the Cider Gum is hardy down to approximately zero degrees Fahrenheit, and the White Gum to about five degrees, so they should both do quite well in most of Oregon.  Best of all, they can be had locally.

So I hope I've made the case for coppicing.  The right trees can make for a sustainable source of firewood or other lumber that can be grown on marginal land, making that land useful or even profitable if needed.

More than anything, I think coppicing is an idea whose time has come.  Again.


Miriam said...

What an interesting idea. I remember travelling by train in Europe, and seeing that many of the ancient trees lining roadways were coppiced - I needed to have it explained to me, because I'd never seen it before.

The usual trees around here are evergreen, which I don't think can be coppiced, but there are also some big leaf maples and punky alder trees, so it's definitely something to think about.

Marianne said...

I'm a member of a local woodland group here in the UK. We work co-operatively to manage local woodland. The owner of the woods we're managing at the moment is also an active member, but some landowners are just happy for us to work. The deal is - trained volunteers coppice neglected woodland during the winter and are paid in firewood. The owner gets half the firewood and the volunteers split the rest. In the summer we make charcoal from the thinnings. Almost all charcoal sold in Britain at the moment is imported, much of it from the Far East. We're also producing beanpoles and making traditional hazel hurdles. so we have an income to cover our expenses. the waste that can't be used for anything else is piled in the woods as animal habitat piles and will have rotted by the next coppicing. We're also improving the woods for wildlife, opening up glades, letting light in, encouraging native flowers which have died out in the pine forests which were planted in the 60s, and so insects, birds, dormice. we all benefit.

Jennifer Montero said...

Coppicing is still done here in the UK. I have access to a stand of hazel coppice, sadly it's been left unmanaged for awhile, but I cut all my bean poles out of it. Stick makers cut good straight hazel stems out of it too.

There are charcoal makers around here too, taking advantage of the stools. I understand charcoal making is a very laborious process.

The coppicing principle it the same one used in hedgelaying, which is not only practiced here, but there are annual hedgelaying competitions. You can make a living wall from any tree that you can coppice.

I can't wait to see pictures of your coppicing process!

Rae said...

I'm currently working on LJ to let me plant some eucalyptus. I've learned that if I bring an idea up enough times, he gets tired of hearing about it and gives in. :) Or, I could always just plant a few, and they'll grow so fast the he won't be able to do anything once he realizes I planted them! It all comes down to being pushy or being sneaky... Decisions, decisions.

Paula said...

Miriam- you are right; coppicing only works for broad-leafed trees, and not all will coppice. I listed a lot of those that will, but I didn't list all of them. I think probably the Alders will, but I'm not sure you'd want to. Most people in these parts think of them as 'trash trees', presumably because they don't make good firewood. However, they are good for smoking things like salmon...

I think it's cool that you're part of a group managing a forest by coppicing Marianne! I'm glad to know that it's making a comeback in Britain, because it had been practiced for literally thousands of years before falling out of favor in the mid-1800's. Sometimes the wisdom of our elders is just that: wisdom.

Jennifer- don't you have a horticultural background? Could you take over managing the coppice, or would you even want to? I'm familiar with the British practice of hedge laying, having read about how to do it in a couple of different books. I think it's a truly smart way to corral livestock, and had I the need for it, I'd do it in a heartbeat. Finding a billhook on this side of the pond might be problematic though. Did you know that they've figured out that for every ten feet of hedge, they can tell how many hundreds of years old the hedge is by the number of different species of plant that makes up that ten feet? That's for those really huge hedges that surround really old estates. I read that a very long time ago, and thought it interesting enough to remember.

Rae- just remember that if you plant the kind that will coppice, if he cuts them down, they'll just come back! I bet once he sits in front of a fire made with Eucalyptus wood, he'll come around. My vote is for wearing him down, though. That way, you'll finally get his buy in. You could always engineer a negative consent, but that would be really sneaky.

Tamar@StarvingofftheLand said...

Is there no end to the list of things I don't know about?

We have two wooded acres. We heat primarily with wood. And I'm only now learning that there is such a thing as coppicing.

Thank you! I'm going to go read about it right now.

Paula said...

You are welcome, Tamar. If this helps you, then I've done my job.