Thursday 17 November 2011

Could Foresters Relax and Let England's Forests Manage Themselves (for less subsidy)?

The transformation of the Forestry Commission over the years from enemy of the environment to valued national institution has been fascinating. The consultation on future “ownership” has been abandoned; the challenge now is to address the ecological future of our woodland, not its administration.

Sometimes the key to the future lies in the past. Trees are the natural vegetation of England. It almost seems that the trees have not forgotten this, even if many foresters have. Trees spring up anywhere we leave to nature. You see young trees in abandoned railway sidings, the margins of arable fields, and poking out of bracken banks in the hills, even sometimes the chimneys of old buildings. These “wild trees” are the advance guard of the “wildwood” which would eventually return with half a chance. The most striking proof of this is seen at Rothamsted agricultural research station. Agricultural fields were “abandoned” in 1882, and gradually became, over some thirty years, dense woodland. This is slow, almost unnoticed. Man, in the shape of the forester, cannot resist intervening, planting and managing.

The forest ecologist George Peterken draws attention to two competing approaches to nature. The “Imperialist”, seeking to dominate, and the “Arcadian” who likes to see nature taking its course. “The Great Spruce Project” of the last century was redolent with such “imperialism”. “I like to see the hand of man on the landscape” remarked a fellow forester once to me. We were on a flight from Edinburgh, looking down on some great angular plantations in Northern England. The same forester loved to see neat rows of genetically improved spruce trees, exactly two metres apart, on little mounds made by an excavator.

Perhaps the great idea for the future of England’s forests is that nature should be given her head? We could do this in the great conifer forests, the ancient woodlands planted in the last century with conifers, and the fragmented ancient native woodlands. We could even use nature to create great areas of new woodland.

Seventy two percent of the Forestry Commission forests in England are composed of exotic conifers, and, in 2010 eighty percent of the replanting of felled areas was with another “rotation” of conifers. During the “sell off” story recently, I passed these facts to someone. She asked where I got my figures from, “the website is all about broadleaves and recreation”. If you set off to really explore a forest, what will you find? You may find “clearfelling” and large temporarily deforested areas sometimes reminiscent of the battle of the Somme. These areas are often cultivated by machines and replanted with trees from hi-tech nurseries. You may find conifers expensively planted where naturally seeded spruce and birch could be. This all costs money, perhaps nature could be allowed to do restore the forest for free? When conifers were felled (and sold), we could cheaply scatter birch seed and look for a riot of secondary native woodland, and restored open habitats? To achieve this you will have to deal with the challenge posed by deer, they will frustrate any attempt to introduce broadleaved trees.

There is also a great argument for diversity. It is not long since the climate experts, and all credit to them for trying to give advice, told us they were fairly sure that Corsican pine would grow better almost all over England. Now there is a moratorium on its planting because it is being attacked and killed by a newly virulent fungus called Red Band Needle Blight. The larches are also under sudden attack from another fungus. The lesson is that we really cannot have all our eggs in one basket and must stop replanting with pure stands of spruce, there are two or three insect enemies half lined up. Put simply, if the species in a monoculture dies, then the forest dies. In a mixed forest, then only the trees of one species die, and the forest lives on.

What of jobs and industry? We would have to recognise that there would be less softwood timber thirty or forty years in the future. Should we be forever committed to subsidising and supporting a particular level of timber production from the forests created to supply the nation in the world wars of the last century? Timber prices have been generally falling for many years, the National Audit Office concluded long ago that the cost of replanting was not justified. This is not a disaster for industry, a forestry contractor once said to me, “you can replace the spruce with birch if you like, every tree I will ever fell has already been planted”. If we fell the trees and leave the sites to nature, short-term timber supply might increase (and income), but without the cost to the public of another generation of the same sort of forest.

But do we have to fell mature forest anyway? In the 1980s a handful of foresters started making contact with European colleagues practicing “close to nature silviculture”. Essentially this means thinning out the forest so that timber is produced, but the forest environment is maintained as a “continuous cover” of forest. Young trees regenerate from seed in glades below the larger trees, and usually new species colonise, for instance broadleaves under old conifers. Clearfelling has been challenged by these silvicultural pilgrims, returning from their tours of European “forestry countries” like France, Germany, and Slovenia (the latter made clearfelling anywhere illegal in 1947!). The approach has been adopted for management of broadleaves, you would have trouble getting a felling licence to clearfell an oak wood in England, but clearfelling approaches have continued to dominate in large scale in conifer forests managed by the Forestry Commission. Interestingly, the new methods have been pioneered by private owners keen to escape replanting costs.

“Continuous cover” certainly has a role in the 35,000 hectares of “planted ancient woods” managed by the Forestry Commission in England. These are places where past foresters and nature are working against us, planted conifers are year by year smothering the last surviving native trees and ground flora in darkness. There’s no commitment yet to restoring all of these, there should be. Do not believe those who say this will cost a great deal though! At its simplest it means that the conifers are gradually felled, and some income generated, leaving nature to restore the ground flora, and the native trees to colonise the glades created. This only works if we manage the deer!

What of the sixty-eight percent of England’s woodlands which are broadleaved, the vast majority in private hands and “unmanaged”? If you talk to foresters, there is a sort of yearning that they be brought “into management”. It often sounds a nice idea, a future of small scale harvesting of wood fuel and coppice, helping to reduce carbon emissions and opening up the neglected woodland so that there is light for the ground flora. But, is this really the right future?

A study in 2005 for Natural England revisited a survey of woodland in 1971, the conclusion most publicised suggested we need to “get in and open these woods up” as a forester might say. But the report also notes that we may be looking at “juvenile” woodlands still, (forestry is slow) recovering from felling for the Second World War. These woods may be naturally on their way to being dark “old growth” woods, full of fungi and deadwood-living creepy crawlies. Perhaps we should keep the interfering foresters out of them?

The appetite for management (it’s what foresters do), also leads to calls, for instance in a recent Forestry Commission study, for greater management of broadleaved woodland for wood fuel and other timber. The theory is that thinning the trees out provides wood which can be burnt instead of fossil fuels. The thinning allows light into the wood and the remaining trees grow more, neatly removing the CO2 from the atmosphere again. But what if burning wood emits more CO2 per unit of heat than say natural gas, and what if the woodland is growing so slowly that it takes a very long time to take the carbon back out of the atmosphere? It can be argued, with evidence in the Commission’s study, that it is better to leave such woodland to its own devices, quietly growing and sequestering CO2 at its own pace.

Woodland really does sequester CO2, and there really is a case for more native woodland for many reasons. Many of England’s native woods are small and isolated. That means they are vulnerable, for instance species of both plants and animals can become “extinct” in a small wood when a population in a larger wood, connected to others might stand a chance. Many woods also lack natural “scrubby” edges, providing a range of habitats for birds and other wildlife. If we need more native woodland to extend, link and enhance existing woods, how can this best be done? Let’s think “natural” again. Trees colonise less-used agricultural land, you see this on bracken banks in the hills and less often where, for whatever reason, farmland is left alone. Sometimes this is on the urban margin, visible from the commuter train. In the rest of Europe whole areas of forest have established themselves on abandoned farmland. In England this is rarer, and in a strange quirk of the Common Agricultural Policy, if a farmer has a marginal field, not really worth cultivating, and scrub develops on it, he could lose his grant. No matter that in the next field, on a similar site, he has a special grant to establish a new woodland! Perhaps the natural approach would be to find ways of relaxing these requirements to “clear scrub” so that in the right places (and at little extra cost to the taxpayer) the market itself will allow the least useful agricultural land to re-wild? Very neatly, this will often happen next to existing woodland, that is where the tree seed will come from.

The agricultural grants also have an impact on grazed woods in the uplands, without a shrub layer they are dying. Time to change the grants to reduce the number of grazing animals, or fence them out. Then, leave it to nature.

So, let’s change the very heart of the approach to English forests. Let’s make it a central principle that we follow nature, nudging it if really necessary, rather than forever fighting it.

We can make this happen through the Forestry Commission, it has won people’s trust. It may have persuaded people, and perhaps itself, that it has changed more than it really has, but it is a committed and effective institution. It just needs a new and more radically different mission as it approaches its hundredth year. It could engage better with communities from the great Royal Forests, to the smallest parish, but it seems to have secured its status in the public’s eye.

What would this vision look like? The scattered native woodlands will be gently getting older, and yes, for some decades perhaps darker, while the flora and fauna of wildwood return, undisturbed by chainsaw and tractor. On the edges of such woodland, trees will gradually poke their heads out of natural scrub and gorse as the woodlands spread onto land unimportant for food production, some of these also on the margins of great urban areas. In the now less-grazed woodland of the uplands, young trees and scrub will year by year be more evident. Great spruce forests like Kielder in Northumberland are being transformed, all of them, into great new “wilderness” mosaics of naturally regenerating spruce, birch, willow, rowan, heather and bog, not a plough or planted tree in sight. In lowland conifer forests, clearfelling would be rare in the landscape, with multi-structured, varied forests quietly developing, and all planted native woodlands being restored.

Let’s make it such that people can be confident that all over our crowded landscape, in the right places, in many different shapes and forms, the ancient wildwood of England is quietly reviving itself. 

Some Sources

Forestry Commission Statistics
http://www.forestry.gov.uk/pdf/planting1976-2010.pdf/$FILE/planting1976-2010.pdf 

Kirby, K., 2005. Long term ecological change in British woodland (1971-2001): A re-survey and analysis of change based on the 103 sites in the Nature Conservancy “Bunce 1971” woodland survey, Peterborough: English Nature.

Conclusions and implications: “Given the generally young nature of most of the stands, then without deliberate management intervention broadleaved woods are, on average, likely to become older and darker in the next twenty years. This could benefit some species and communities – those of fallen dead wood and shade-loving conditions - but may lead to continuing decline in much of the ground flora and also other groups associated with open space and young growth.” 

Read, D., National Assessment of UK Forestry and Climate Change Steering Group, 2009. Combating climate change : a role for UK forests : an assessment of the potential of the UK’s trees and woodlands to mitigate and adapt to climate change, Edinburgh: TSO.

Chapter 8: “Bringing unmanaged woodlands back into management (FMS-D) leads to significant net emissions (up to 5.5 MtCO2 year–1) from forest biomass and soils relative to the BAU scenario. However, this impact is reduced when total abatement is considered, with the result that over the full course of the simulation to 2150 (Table 8.2), FMS-D provides a small amount of additional abatement (0.3 MtCO2 year–1).”

2 comments:

  1. You're favouring biodiversity over timber production? Is that the tradeoff?

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  2. Yes, in effect, but based on what I am suggesting is a lack of evidence to support publicly subsidising timber production.

    Current policy involves:

    1. Public funding of intensive coniferous replanting. The "close to nature" low cost alternative I suggest would produce less timber.

    2. Expenditure and effort to support timber production on the basis of biodiversity and biomass energy benefits. I am questioning the strength of the evidence that this will be beneficial from a carbon or biodiversity point of view.

    Note of course that one of the arguments for managing native woodlands is to favour biodiversity. I have selectively quoted the Keith Kirby reference. I should make it clear that I believe Keith, who is a very well respected woodland ecologist (which I am definitely not) would NOT agree with my questioning line and rather selective quote. I am trying to give the alternative position some airing, and challenge some accepted wisdoms, which I believe deserve questioning.

    ReplyDelete