Planting trees is promoted as a key response to climate change, but it is important not to overlook the storage capacity of UK peatlands, says Lindsay Waddell in Shooting Times
It’s rather difficult to know quite where to start with the carbon debate, when, according to my research, we have been losing carbon into the atmosphere from our soils since the dawn of agriculture some 12,000 years ago, when we began tillage. The figure I saw was an eye-watering 133 billion tons of carbon over the world as a whole.
That disturbance allows particles of soil, or carbon, to leach into watercourses and blow into the atmosphere. In short, it’s no longer locked up, it’s gone. Like everything else humans have done, they became more efficient, so more and more carbon was lost in an increasingly short timescale. Now we have melting ice sheets and increasingly erratic weather systems bearing down on us. So what can we do to mitigate the losses, or more to the point, what should we do?
Carbon stored in peat
The moorlands of the UK store some 138 million tons of carbon. Simply put, it’s peat. It’s also fair to say that our peatlands are not all in great shape, but moorland managers have been doing their level best to keep them in decent nick for a very long time. They have not always succeeded, with summer fires and severe overgrazing being two of the main culprits for damage.
It’s the summer fire issue we must address as a priority because not burning at all increases the amount of material available for a fire. A huge volume of material available for a fire to burn can lead to disastrous damage to the peat layer if the fire burns down into it, which it often does.
One of the other main losses in the uplands was excessive run-off caused by large-scale open drainage, which was put in to increase agricultural production after World War II. In the 1980s, the Raby Estate blocked almost the whole of the open drainage system on the moors in Teesdale at the behest of John Barrett, a far-sighted English Nature (now Natural England) officer.
Some 30 to 40 years on, you can still see where some of the drains were, but they are no longer pouring water full of carbon or peat down the hillsides. Despite some worries in the early days about large-scale heather loss, the technique has been employed on the vast majority of moorland managed for grouse shooting. It may, in places, lead to water stress on some heather, but the greater good is the lack of chick and lamb losses in the large, open drainage system.
There is an almost mad stampede to plant trees at the moment. I have planted thousands in my lifetime, but mine were for wildlife, both cover and food. From what I see day to day, the black grouse and many other birds are enjoying the fruits of my labours and those of my keepers.
It is interesting to note that the mad dash to plant the grouse moors of Scotland with trees, with the aim of capturing carbon, may not be quite what it seems.
A very interesting report from the Faculty of Natural Sciences at the University of Stirling seems to have had little impact on the politicians’ desire to plant, plant, plant.
The team from the faculty studied four sites where trees had been planted on moorland nearly 40 years ago. Silver birch was the chosen tree and with good reason, as it is in many cases the most common tree found in Scotland. Years of painstaking work found that the trees and the land had not captured more carbon. So, why then is there such a mad rush to plant so many more trees on the basis that it’s going to save the planet? Indeed, the bacterial breakdown of the leaves from these additional trees can lead to an increase in the amount of carbon dioxide going into the atmosphere.
Trees can even be a backward step if they are the wrong sort. Huge blanket spruce forests with no ground flora are even worse. These are often planted using a plough or a machine to create a bed in which to plant the tree root. This is poor practice. There can be a net loss of carbon from the root site and that, coupled with the loss of ground vegetation — which would have helped hold carbon — when the trees mature means you end up with a lose-lose situation.
The GWCT calculated that if you planted trees at 20m spacings in 58% of England’s hedgerows, it would go a long way to meeting the Government’s total of 14 million trees by 2025, without using up one single square metre of arable land.
Expand that and you could then pretty much meet a tree-planting target without the loss of any arable land in the lowlands or wader breeding sites in the uplands.
The North Pennines Area of Outstanding Natural Beauty is engaged with some 24 other bodies in a huge project called Peatscapes. This is a multimillion pound scheme that aims to reduce the amount of carbon lost from eroding peat hags.
It requires a large-scale mechanised effort, including hundreds of hours of helicopter work, plus thousands of tons of heather and other moorland vegetation being cut to ‘brash’ over the exposed peat. In many cases, the peat has been profiled with a machine to reduce the slope of the open peat hag, in order to reduce run-off.
More heather and grass seed is often added to the brash mix, along with a small amount of lime in some cases to aid growth in the early stages. The brash is then spread mainly by hand, so it is a very labour-intensive job. Dams are constructed in the base of the hags, which slows down the surface water and catches peat sediment.
All this is being done to catch the carbon in our uplands, while at the same time thousands of acres of what is essentially peat-based soil is still being farmed in the lowlands for root crops. The loss of soil is well documented here, but what is being done to mitigate that loss?
Though it is being phased out, peat is still being used in horticulture. If we are in dire straits with our climate — and we are constantly being told that we are — why is it still allowed to happen?
Unfortunately, there is still a lack of willingness from some to pay heed to the science that has shown that doing X, Y and Z may not produce the outcome you are expecting. If you decide to ignore the science, which is what many are doing simply because they do not like what it’s telling them, it is a sad day — and one for which we may all pay a price in the decades to come.
Chris Packham and company please take note: destroying whole communities in the glens of Scotland and other rural areas of the UK may well suit your political bent, but it may have no impact on the planet. So, stop trying to convince us and the general public that it will and tackle some of the real polluters instead. But then, it seems we are an easy target.