Tree Planting and Carbon Offsetting.

Sounds easy, doesn't it? But is it...

So you wanna fly to the United States for a holiday but worry about burning all that fossil fuel? So just plant some trees to offset it.

It used to be quite easy, planting trees, here in Cymru, to the north of Cader Idris, in Once Wet Wales. I started a small tree nursery on our place in 1986, grew and planted over a thousand before I stopped bothering to count. I still plant some every year, not that I've flown; I just like trees.

The main competitor to tree saplings is grass, particularly in shallow soils where grass roots can occupy all the available space, so anything that suppresses the grass, benefits the trees. I used squares of corrugated cardboard from boxes, weighed down with stable muck. I used to renew the cardboard and muck two or three times if I wanted to give the trees a good start.

I also mimicked nature, what I'd observed on the rough patch (Argel) and close-planted, very close-planted, often inter-spacing with soft fruit cuttings. The trees and shrubs form a closed canopy quite early, after three or four years, which shades out the grasses and then there's a real acceleration of growth. You have to take on the role of nature though and be prepared to cull back as they grow, to cull back hard, like nature; of the many thousands of trees that started on the rough patch, only a few hundred made it to maturity.

Commercial plantings used squares of plastic and plastic tree tubes, in theory re-usable, thought they were often just left. Even if they were collected when they'd done the job, they would surely bleed micro-plastics continually into the soils. If I went to have a nosey in the tubes to see what had been planted, it wasn't unusual to find moulds or pests had taken up residence in the sheltered micro-climate within.

There's also a tendency to plant larger saplings, in the desire to see rapid change but the smaller the better is usually the case and from seed is probably the ideal. A container grown tree, in effect uprooted and stuck in a fresh hole finds itself in a totally new environment and aspect (which way round is it now in relation to the sun?) is shocked, baffled, stressed.

Natural re-vegetation is best, of course; a seed immediately begins to establish connections with a whole range of overlapping systems and supportive species such as fungi. I remember carefully planting a two foot Rowan sapling from my nursery (that's about 60cms, Euro-buddies), in a hole with a short stake for support and a tree guard and watching it struggle to come to terms with its new environment- it never really did. Meanwhile a bird, probably a blackbird, having recently feasted on local Rowan berries and using the stake as a perch, deposited a neat package of nutrients (poo) which included a seed.

Within three years the Rowan the Blackbird had planted had surpassed my own, (which, non-local as it was, never thrived), and went on to be a fine example of the species that shaded out the other and no doubt provided much feasting for whole families of blackbirds. Lesson learnt. Everything gardens.

Interestingly, if you see a mature Rowan and the conditions are right, you can often spot scores of young Rowan spreading out from the mother tree, where countless birds have deposited seeds neatly packaged in nutrients. Rowan seems to be one of the few trees that will grow in heather (the south side of the Talyllyn Pass is a fine example) and even at times in bracken. So maybe plant one Rowan in the right place, tend it well and let the Blackbirds do the rest of the work

Here in Coed Y Brenin, Natural Resources Wales use the same method that the Forestry Commission had employed for several decades. First, clear felling with Harvesters; these joystick driven, computer controlled, tree cutting machines come in two flavours, 60 tons or 80 tons; that's ten tons per wheel. They are followed by Forwarders of similar size and weight to collect the cut lengths of tree and stack at track-side for collection by timber wagons. A forester speaking on Radio 4 said that the compression of the soils caused by these machines is so great that only another ice age can deal with it. I don't think that's looking very likely now.

So to compensate the next step is to drive something like a Hi-Mac (think extremely large, tracked, mechanical excavator) all over the site, roughly scraping the considerable amount of tree bits that are left into wind-rows running in random directions, often straight up and down slopes and scooping out holes and depositing the soil in mounds on a roughly six foot grid (ok, two metres then; I must switch over at some point as the term for feet and inches- Imperial- does stick in my throat, but they're just such handy, or footy, measurements!).

The resulting landscape closely resembles the bombed and shelled out wreckage of trench warfare with huge amounts of shattered stumps, roots and branches, the bare soil of the mounds and deep ruts from all the machinery.

Combine this with another FC and NRW habit of just clearing windblown timber from paths, tracks and roads and leaving the cut timber where it is as its too expensive to collect all the bits and pieces up. When I asked NRW about a growing accumulation of felled, diseased pine just opposite to us, lying higgledy piggledy wherever they'd been dropped, the trees a good 25 metres in height and up to a metre in diameter at the butt end (there, I can do it..what you say? Ok, eighty feet and a yard across!) I was told it was”habitat”. Habitat for what? You have the ideal conditions both for fire (which I will treat separately as it is so critical and immanent) and fungi!

Would that NRW include spores of useful fungi in the chainsaw oil (as recommended by Paul Stamets of “Mycelium Running” fame; I have suggested it to them) and we might see a host of beneficial species that prepare the way for tree regrowth, or edibles like the pluerotus species, the oyster mushroom family (I grow lots!) flourishing in all this rotting material.

But no, the coupé of clear felled larch just down the road from us was quite literally rampant with honey fungus this year and our place is now practically surrounded by it. When I pointed this out to NRW, I was told that they don't do anything about it, unless especial veteran trees are threatened. Oh well, at least it's edible...

Anyway, to continue with this trashed landscape, at a later date, when the pits and mounds have weathered a bit, bags of trees will appear- still, almost unbelievably, largely Norway and Sitka spruce- and people (no, they haven't got a machine to do this just yet!) will work their way over the site, sticking the bare-rooted trees into the mounds, their boots picking up countless spores of honey fungus to carry with them to wherever they're working next. Job done. Or is it?

Back to offsetting and tree planting. Several hundred thousands of trees have already been planted as part of the HS2 project, as partial offsetting for the vast amount of fossil fuels that are being and will be burned to complete this mammoth (or should that be white elephant?) task. Unfortunately, the dry spring and early summer of 2020 killed a few hundred thousand- apparently it was cheaper to let them die and replant the following year, rather than water them. Then 2021 was even drier that 2020 and 2022 saw the most severe drought for a long time. I wonder what happened to all those re-planted trees? I wonder if they are re-planting every year, a regular, annual routine that becomes so much of a habit it becomes normal, just something to do and they forget the purpose entirely?

From a permaculture design perspective, the obvious thing to do is to apply the types of rain harvesting strategies that have long been practised in arid landscapes, such as swales and pitting, combined with mulches (chip and shred material from roadside tree management for example) to trap and conserve whatever rainfall is available, inoculated with beneficial fungi of course, to take up the spaces honey fungus could otherwise occupy But we can be pretty sure it is not going to get any easier.

Cyngor Cefn Gwlad Cymru (the Countryside Council for Wales) estimated that it took between twelve to fifteen years before planted trees began to capture sufficient quantities of carbon to be genuinely useful, which they estimated as about three tons per acre per year for broad-leafed trees (that's about 6.6 tons per hectare). And that doesn't take into account the likelihood of regular, serious droughts or the possibility that wildfire will burn the lot at the thicket stage and we'll have to start again, again. Fifteen years is a long time- have we got that long? Probably better to pack in the flying, along with all the other fossil fuels and just grow the trees because we like them.

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