Shades of Green - An Environmental and Cultural History of Sitka Spruce
By Ruth Tittensor, Windgather Press/Oxbow Books 2016, 375 pages.
I’ve felled it, milled it, built my cabin home of it, lived in its dark shade, walked amongst it almost every day for a quarter of a century. In stormy nights the big spruce trunks nudged the eaves of my cabin. Some trees were left coming up through the deck and we had to widen the holes every few years as they grew. Today I see the lorries piled high with spruce logs passing the road end on the way to the mills over east supplying the factory from which I buy it back, processed into neat, flat rectangles of OSB (orientated strand board) which provide my own building business with one of its main materials. You might think I’d love it, but my long and close relationship with Sitka spruce has been a tough one - like the tree - kind of spiky.
The plantation was 35 years old when we bought it, abandoned to its own devices by the state forestry service soon after planting - like a great many in the farther reaches of the Scottish Highlands. Never thinned, it must have quite quickly killed out most other ground flora and shrub species. A handful of large birches survived 40-50 years but are now over-topped and in their death throes. A couple of small gullies retain a fragment of the original woodland flora that covered the site before the arrival of the spruce. Some large, heavily branched logs still lie on the ground, just the tops of the huge oaks that were felled to make room for ‘commercial’ conifers.
When we bought the plantation, the tallest trees stood at about 20 metres. Now it’s nearly 60 years old and 30 metres tall. Trees are starting to snap and others to uproot and fall, parts of the plantation will soon be chaos. Each storm causes more to fall and our own equipment is too small to cope with wind throw on this scale. The mills making OSB, MDF and paper don’t want logs of this size even if we were able to extract them economically. In practice we carry out small fellings to create tracks and landings, cabin and garden sites and this yields what is to us a huge amount of timber. Enough to heat all five ‘cabin-holds’ in our forest as well as to produce all the rough sawn timber that we need for building our own buildings and that we need in construction for concrete shuttering and temporary works. We also make some into cladding for our own buildings.
I’m relating all this to put in context my particular take on Sitka spruce and the industry that has grown up around it in Scotland because as Shades of Green makes very clear, there has been considerable debate and controversy around not so much this one species but the whole silviculture and forest management regimes that dominate what we call ‘forestry’ or ‘the forest industry’ in the UK and Ireland. I need to make it crystal clear here however that most of what I am about to say relates to Scotland and that it also has a Highland bias because that is where I have lived and worked for 38 years since I was 25, then a recent graduate of the Department of Forestry and Natural Resources of Edinburgh University. It may also be worth mentioning that my director of studies was none other than Douglas Malcolm who gets more than one mention in Shades of Green as the leading academic on Sitka spruce silviculture in the UK in the latter part of the 20th century.
It is not surprising therefore that I read this monograph on Sitka spruce with great attention and thoroughly enjoyed about 70% of it. It is full of excellent detail on the ways in which the species was ‘discovered’ and brought to the UK, how it became by far the dominant commercial forest tree. I particularly expanded my knowledge on its uses in its home territories of the Pacific coasts and islands of Canada and USA. Its’ role in providing vitamin C to British sailors on their globe trotting expeditions is fascinating.
About half way through the book we start to get an explanation as to why the public and professional scientists started a debate about the place of large-scale conifer-dominated plantations in the uplands of the UK. The author of Shades of Green conveys a sense of frustration, common amongst foresters of the time, at the level of debate and focus on critiques that were indeed somewhat naive or highly subjective, notably in terms of landscape or habitat impact. I find this rather irritating because many involved in the critique (at least in Scotland) were trained in forestry and/or were respected land-use ecologists. Some were also leading figures in land rights and rural development. To be labelled as “conservationists, visitors and diversity experts” comes across as rather demeaning and some of what follows in the book seems to attempt to undermine the critique of conifer forestry that played a critical role at the end of last century in, amongst other things, halting the appalling and senseless ecological damage of grubbing out and/or underplanting the last remnants of native woodlands in Scotland with (largely) Sitka spruce (a somewhat under-recorded act of ecocide in Shades of Green!).
The forest industry was in drastic need of reform and the Scottish Government acknowledged this. The result of some 40 years of critique from largely outside the industry has been some undoubted improvements in practice and Shades of Green focuses on a small number of ‘best case examples’ of conifer plantations such as Kielder Forest and the way in which they offer facilities for human recreation and habitats for wildlife. This is all very well but deflects attention from the vast majority of plantation forests in Scotland and the realities of our silviculture which can still be very easily argued as unsophisticated and lacking in diversity compared with many other parts of both the ‘developed’ and ‘less developed’ world.
Taking as just one example, Shades of Green cites a wildlife study of a conifer plantation to expound the virtues of afforestation of moorland and nothing in the analysis is factually incorrect, it’s just that the ecological complexities are drastically simplified and fail to explain the ongoing effects of plant-clearfell-restock silviculture in meaningful detail. Yes, various bird and mammal species can indeed take advantage of the different short phases of this cycle but each is quickly replaced by another set. And here is one of the ecological nubs of the problem. Everything about our current industrial conifer model is, unsurprisingly, about speed and efficiency and the book does not own up to the fact that rotation lengths are in fact getting shorter and shorter as the factories, chipping and pulping the vast majority of our conifer plantations are able to process and indeed encourage smaller logs. Also as (forecast) supplies are getting tighter to meet growing demands, a faster turnaround (rotation length) is required. This bodes very badly indeed for the environment in several respects. Soils are torn up far more frequently along with all their mycorrhizal associations and other soil-forming biota as well as that little ground flora as remains after a no-thin, all conifer regime has eliminated the light and therefore most other photosynthesising plants. This whole tendency threatens to undermine some of the progress that has been made in the re-structuring (diversifying of age structure and creating smaller felling coupe sizes) of forests over the last 20 years.
Artificial fertilization, increased nitrogen deposition and climate change may all offset or obscure the effects of soil and nutrient loss in future generation’s growth but perhaps we are yet to see a fall-off in nutrient supplies. Certainly it is becoming more expensive to source rock phosphates and perhaps less acceptable.
The account the author gives of life colonising new conifer plantations is not inaccurate but neither is it the whole story as it is clear that plantations on rotations of 30-40 years never develop anywhere near as much associated wildlife as rotations that in the past may have reached 50-60 years. The fairer picture is that much of the life of a conifer plantation inhabits the rides, the edges and the few bits of open land or remaining native trees that happen to be there. The bulk of a 30 year old, no-thin Sitka spruce forest is a barren place by any ecological standard. As I said, I live in one.
made out of the Sitka spruce felled and milled by chainsaw mill on site in Highland
Scotland - Photo Bernard Planterose
Yes, we have siskins, crossbills and great flocks of goldcrests and tits passing through - but many of them are en route either from or to the native Norway spruce and Scots pine forests of Scandinavia. Even after 60 years, the forest floor under Sitka spruce is mostly a dead zone with a thin, acidic, needle-formed humus. We do have pine martens and some introduced red squirrels but the former have their dens in the next door birch woodland and the red squirrels probably forage there too judging by the number of flat ones in the road. The wildlife story is all relative and if you compare conifer plantation with the average over-grazed and burnt piece of upland moorland you can create a reasonably flattering case for the conifers (as the author does). But a more illuminating comparison would be between the exotic conifer plantation and a native species based forest where natural regeneration is the restocking method and a mix of nutrient-mining broadleaves such as birch or nitrogen fixing alder are intermixed with a conifer component including native Scots pine.
Another rather dubious comparison in the book is one between the 17-21 yr old Sitka spruces which are said to fix 7 tonnes of carbon/yr/ha with the hectare of 72-80 yr old deciduous forest which takes up 4.9 tonnes. This comparison is simplistic and potentially misleading because the rate of CO2 sequestration will also drop off in the spruce plantation with age and this says nothing of the relative soil building (Carbon fixing) potential of the soils under the two types. Most of all it fails to account for the fact that the spruce will most likely be felled at 30-40 years releasing significant quantities of CO2 from the soils whereas the deciduous forest might be managed on a continuous cover regime to yield a sustained flow of equally carbon rich and probably longer enduring products without soil disruption. (Paper products are rapidly rotted and burnt releasing their carbon, thus largely negating their sequestration value). Furthermore the calorific value of the hardwood, if use as fuelwood, is also higher per unit volume in any calculation of fossil fuel substitution. Ultimately it all depends on management, final use and durability of products. It's a complex picture but if you want to see a truer picture of upland conifer management in the UK take a look at the photo below which is entirely typical of my home area.The final section of Shades of Green asks the question ‘where now for Sitka spruce?’. There is interesting information here on propagation and cloning (which doesn’t exactly comfort in an age of disease.) There is little doubt that Sitka is here to stay and the significant industry that has grown around its use and which supports large construction and paper industries.
Scots pine woodland with severe soil and drainage disruption. This site is being returned to native
woodland – Photo Jamie McIntyre
But if short rotation, plant - no thin - clearfell - restock forestry constitutes the “New Temperate Rainforest” of the 21st century (the title of the last section of the book) then we will have failed dismally as both foresters and ecologists. There is another vision out there of the future of forests if not of forestry, at least in Scotland, with which the book does not engage at all. To be fair it has little to do with Sitka spruce specifically but everything to do with the part woodlands and forestry can play in a broader, more socially and ecologically enlightened approach to upland land use as a whole.
It is about trying to innovatively broaden and diversify forestry and upland land-use beyond the narrow focus that Shades of Green describes - a focus on what grows fastest and produces the largest quantity of cellulose on the poorest soils and peats. There is no doubt that Scottish and Irish forestry mastered a particular challenge in that respect and Shades of Green explains that very well. However, what was the opportunity cost of that singular development? What was not developed while that narrowly focused fight was being funded and won? That is in a sense what the 21st century land use struggle is addressing right now. This is what those involved in the widely supported ‘social forestry’ movement or Rural Development Forestry (RDF) as it would be generally called in an international context, are addressing at this time.
Helping to restore balance to the needs of industry and the needs for biodiversity - Tree’s for Life’s Dundreggan etc (Right – Photo Trees For Life)
The last part of the 20th century and the first years of the 21st had to focus on halting further destruction of remaining native woods and reversing this to re-establish and bring into active regeneration some significant areas of native forest-dominated land. This on-going work is being achieved by individual environmental charities, community groups and a small number of individual private landowners. Excitingly it is also being achieved by wide-ranging partnerships of all three types working alongside government agencies including the state forestry service in Scotland (now Scottish Forestry).
A new chapter is beginning to unfold as widespread regeneration of native woodlands begins to take place. Landscapes are changing quite rapidly, perhaps especially in the Highlands and, assisted by Land Reform and Community buy outs, including of State owned forest, a new world of silvicultural options presents itself. There are extraordinary opportunities awaiting us in the future for the development of native species based forest management and the integration of timber production with agriculture, horticulture and biodiversity management. Timber itself will hopefully be redefined in Scotland in the coming century to include broadleaves, so much neglected by the softwood focus. Our native birch is perhaps the most stunning example of a wasted opportunity. The tree that would naturally dominate over vast areas of our uplands has been largely overlooked and could with a similar amount of investment as was given to Sitka spruce, yet find its natural place as a commercial species.
Birch logs can be seen today stacked on the dock side in Inverness being shipped from the Baltic states to augment Scottish conifer supplies for our local OSB factory in the Highlands! What a deep irony this represents and what an incredibly persuasive argument for a radical re-appraisal of what can and should constitute ‘modern forestry’ in Scotland.
In north and west Scotland, red deer ravage our deforested hills, reducing them to a ‘wet desert’. In the central and east Highlands, the deforested hills are kept shorn and burnt for red grouse. Yet, despite these highly destructive factors, forest is returning to the country as a whole due to the combined efforts of industrial conifer foresters and ‘rural development foresters’. There is common ground between the two and perhaps the twain shall meet, if not exactly intertwine, in the coming years. Maybe the most exciting developments in forestry have yet to come. A phase of native species based agroforestry could deliver the ‘forested landscape mosaic’ now touted in both Scottish Government strategies and academic institutions as much as by activists of land-use and land reform. Now that could truly lead to a new landscape with a great many more shades of green than can be seen in either our dark conifer plantations or our long-deforested hills.
Bernard Planterose trained as an ecologist, was a founder of Reforesting Scotland and been designing and building timber projects across Scotland’s north west for over two decades. He has initiated reforesting projects, and written extensively on the potential of Scottish ecological forestry, including his new book, the Highlands and Islands Woodland Handbook.
