The Great Escape part three

Or how to appease the Three Fates...

Remember those chainsaws and the chipper I heard when writing the last piece? I did wonder if someone in Cyfoeth Naturiol Cymru, Natural Resources Wales (NRW) had actually read my piece on the stands of planted softwoods now grossly overstocked with self-seeded western hemlock; perhaps someone was taking notice and there was a real purpose to my writing! Well, you live in hope...

So I went to have a nosey, as you do, and found that indeed, the young, self-seeded, western hemlock, now about 5 metres tall, was indeed what had been cut down with chainsaws and chipped but they'd only been cleared back from the track sides, revealing the planted crop of over-mature Sitka and Norway spruce and making the dense, dark thickets of young hemlock within the coupé even more obvious.

above: young Western Hemlock felled and chipped to 5 metres depth along the track side, exposing more hemlock, deeper in the stand of mature Norway and Sitka spruce.

I rang Gwion, local NRW forester and decent bloke, to get the low down. “Pluvialis, Chris,” he said. He went on to tell me, speaking in Cymraeg, of course, that the disease, phytophthora pluvialis, which I had already been told was present in Coed Y Brenin, had been spotted in some of the young hemlock on the side of the track (no. R311: probably best to avoid if you have anything to do with trees). The young hemlock is particularly susceptible to pluvialis and a compulsory tree felling order had been applied, requiring felling of the hemlock to a depth of 5 metres from the track on both sides and chipping of all the material on site.

That pluvialis has appeared does not surprise us; Lyn has been pointing out to me signs of disease in western hemlock around us for the last five years, same as she spotted disease in the mature Corsican pine opposite our gate twenty years ago and their very poor growth and even failure in younger stands above us and the larch stand down the road struggling ten years ago. At the moment she is noticing a growing number of ivy leaves showing signs of disease, so this is probably the one to watch next. From our own observations here in the forest and of roadside trees generally along the Mawddach Estuary, we have never seen so many trees clad in ivy, in itself a sign that something is not right.

above: young hemlock cleared on the right, continuing on the left; will pluvialis respect the red paint marking one of the trunks?

Looking at the work on R311, which has been going on for four days solid now with two chainsaws and a chipper and I think has finally finished, it seems like an very limited approach to take. I can understand the concern, but the area that has been cleared stops abruptly, even though the young hemlock trees continue, both into the coupé and along the track side. This track has seen considerable use over the last few months as timber lorries bring out vast quantities of larch, felled because of ramorum. Pluvialis, like its cousin, ramorum, spreads by wind blown rain and can presumably be carried on wet wood, lorries and clothing. I wonder if the spore is going to respect these clear cut boundaries, or the spray paint marking them.

above: a mature tree within the stand of spruce surrounded by young western hemlock. Note the complete lack of any other ground cover. Also, severe damage to the spruce caused by careless thinning twenty years ago.

As I have said before, western hemlock has self-seeded pretty much throughout the Core Block of Mynydd Penrhos and beyond and is one of the main reasons for the grossly overstocked stands. The species has proved extremely tenacious in our mild, wet climate and in some ways is much worse than rhododendron. Rhodi will grow in 90% shade, western hemlock in 95%, meaning it will grow under almost anything except itself. This means it will thrive under all our native trees, outpace them and shade them out.

Stands of commercially over-mature Norway and Sitka spruce border our place, stands that actually have had some management in the past, at least two thinnings, leaving the trees well-spaced to grow. I've watched thousands upon thousands of western hemlock seedlings start off under them, achieving a complete ground cover within just a few years due to their numbers, suppressing any other vegetation that was there, including bilberry and heather.

A mature western hemlock can produce around a million seeds a year. The cones are many and small, opening on the trees to release tiny seed that blow easily and far on the wind. There's a small stand to the north of our place, containing just eighty western hemlock (I counted them recently), planted in 1942, so now in their eighty first year. If we say it takes maybe thirty years for a western hemlock to reach maturity and set good seed (we're being generous here) then in the last fifty years these few trees have produced upwards of four and a half billion wind-blown seeds. No wonder they are now found throughout the forest and beyond! The recent appearance of the updated Plant Atlas [link] shows western hemlock now appears pretty much throughout Britain; no surprise really, considering.

above: just round the corner from where the pluvialis was found, the reason why the young hemlock was there in the first place! 81 year old western hemlock, just 80 trees, producing a million or so wind-blown seeds each, year in year out...

We were awarded a Forestry Commission contract in 1997 to clear conifers from the riparian zones on Mynydd Penrhos, basically, the stream banks (this was due to the foresight of the Forestry Commission's first Conservation Ranger, Doctor Martin Garnett- many thanks Martin!). This meant hand weeding tens of thousands of self-seeded conifers, by far the greatest number being western hemlock. As we were in effect improving our own watershed we did a really good job.

Ironically, for part of the contract, we were weeding out western hemlock from underneath the very same eighty mature hemlock that had generated the bulk of the work in the first place. An extract from our contemporary log gives an idea of the challenge:

25/6/97: 12:25am-2.00pm 1.35 hours total.

Continued upstream both sides approximately 75 metres, weeded out over 2000 plants, approx 90% under 0.5m, approx 10% over 0.5m, 2 greater than 10cm diameter

95% Western hemlock

5% Norway spruce

1 Ragwort, 2nd year West side of stream

We told the Commission, repeatedly, that unless they cleared the mature hemlock, we were wasting our time and their money- to no avail, the trees are still there and much of the good work we did has since been undone.

Over the last 35 years or so we've seen the track sides on R311, even the middle of the track at times, fill up with western hemlock self-seeded form these eighty mature trees to a height of 5 or 6 metres, then be cut down, repeatedly, on about an eight year cycle, for no product whatsoever. Each cycle of cutting, usually by flail mower, was followed by upgrading the track, scraping of the surface and sometimes adding more gravel; it was not unusual for the heavy machinery to damage the mature trees on the track side, probably shocking them into producing even more seed...This latest venture is the fifth of sixth cycle we've witnessed; and the mother trees are still there, gaily releasing their 80 million seeds a year! Duh!

above: mature western hemlock showing severe damage due to track maintenance and probably shocked into producing yet more seed. This is one of the Band of Eighty, parents to probably millions of self-seeded youngsters, now throughout Mynydd Penrhos.

Obviously, cutting down the source of all this pointless effort would save considerable time and money for other things, namely, drastically reducing the huge fuel burden stored up in Coed Y Brenin. Donning my purple cloak of Emperor I would immediately reinstate the old strategy of allowing locals to scavenge timber from specific areas, through purchasing a “ticket”, which used to cost £10 so it was affordable.

These days Health and Safety would scream and shout about it- to get the contract to clear riparian zones with only hand tools, we had to have Public Liability Insurance of £5,000,000 but this need not be difficult- there are voluntary groups, usually linked to charities which provide basic insurance through membership or relatively small additional costs for practical activities such as this. So it ought to be possible to register scavengers with a community group which has some sort of blanket cover and besides, I'm Emperor!

above: buried somewhere in the self-seeded western hemlock is a planted crop of spruce. The hemlock has a floppy top, the spruce top is very upright and pointy- you might be able to spot one or two…

The clearance of hemlock that has been undertaken in an attempt to control this pluvialis outbreak on track R311 measures roughly 150 metres by 10 metres in total, that is 1500 square metres or 0.15 hectares, at a cost of two chainsaws and a chipper for four days. If you consider that the area of Coed Y Brenin where the western hemlock is rife is several thousand hectares, you can see that this is simply not an affordable method of control. However, if I had been given responsibility for managing the under-story of the commercial crop directly around me forty years ago, this situation would never have arisen and even now would be manageable. Another argument for putting dwellings within the forest.

above: a close up of the picture above taken from the track, showing the density of the self-seeded western hemlock. Many of these trees will die or are already dead, shaded out in the vigorous competition for light, ideal conditions for a fire…

Now I know I have been banging on about these ridiculously tall, thin trees resulting from the Forestry Commission's, “do nothing” approach but lets have a think about it. A 35 year old softwood that is only, say 140mm in diameter or less (say 5-6 inches), contains 70 growth rings in total, (I'm keeping the maths simple to make a point). That's 2mm to a growth ring or 50 rings per 100mm, (very roughly 10 rings to the inch in old money); this is not far off the density of a good hardwood. OK, it might be too small to mill into planks but this sort of timber simply requires a rethink and a bit of imagination in terms of how best to use it. Consider its use in pole buildings, tensile structures, or laminates (or indeed poles for a teepee)¹.

above: “Do nothing” approach has led to this tall, skinny stand of softwoods, too small to mill but the wood has interesting properties and, with a bit of imagination, interesting uses, if it can be harvested before it all blows down.

How the phytophthora diseases play out is anyone's guess. It seems that pluvialis could crop up anywhere on the sides of the many tracks that meander throughout the forest. Larch, another good self seeder, appears dotted here, there and everywhere and the browning of its needles is easily visible in the summer, so ramorum is probably also rampant. It remains to be seen how many other species will be similarly affected and if ivy proves to be another vector for transmission then its probably uncontrollable.

I suppose I am saying that in some ways the Three Fates or Fire, Wind and Plague cannot be escaped, that they are in fact, inevitable. Thus all we can do is seek to mitigate their effects and adapt to and take advantage of their occurrence.

As permaculture designers we usually say that “the problem is the solution”. Certainly it will mean that there's going to be plenty of firewood to come and with the cost of energy more likely to keep going up than down, we may need to temporarily move back into wood burning to keep warm until we get our housing stock adequately insulated. Plus there will be plenty of wood for housing- the infected larch does not lose any of its physical properties to begin with and when it does we can always grow fungi on it, lots.

We need to learn which tree species are resistant to these phytophthora diseases, quickly, and discard the idea that we should concentrate on only native species, an idea that, given global warming, is neither possible nor relevant. Let more people live on the land and in forests to explore these options and then perhaps we can begin to develop the recombinant ecologies that have the potential to be far more diverse and productive than the plantations of purely exotic species that make up forests such as Coed Y Brenin.

Many thanks for reading. Please leaves comments; you can help steer where we go next!

1. Rather than fill up space here describing these options try doing image searches for the following- pole construction, timber tensile structures, laminated timber structures etc.