Continuing our series of blog posts highlighting stories of small woodland ownership, this 2 part blog tells the story of Craggach Woods near Kirkhill, owned by David Shepherd and Annie Griffiths. In this second part they now explore the silvicultural aspects of their management in more detail.
We own 40ha of woodland on a fairly rich site suited to broadleaves. This has been undergoing transformation to productive native broadleaves for over 20 years.
Our aim is to develop a biologically and structurally diverse wood with an annual yield of good quality timber. The owner will undertake all management, harvesting and processing. We predict the wood will eventually support one full time job equivalent.
The following is a brief outline of our approach to silviculture.
As described in our previous post, we clearfelled 6ha of conifers from the 8ha wood we had purchased first, with the intention of converting it to native woodland.
Restocking was carried out at 1100 trees per hectare and one of us attempted to control deer sufficiently to get the trees away. Despite a cull of 17 roe deer in year three it ultimately proved necessary to tube all oak, ash, elm, and gean – then these and all other species established well (including aspen).
After 5 years our focus then turned to management for productive broadleaves, with overall stocking now around 4,000 stems per hectare, our original planting having been supplemented by natural regeneration of (mainly) birch and rowan.
The second site
Following the purchase of our second, larger site, we proceeded along similar lines. An initial 14ha clearfell of spruce was followed by restocking with broadleaves which we did ourselves. To facilitate deer control, this area was separately fenced.
Planting density was 1600 stems per hectare (40% oak, 40% ash, 10% hazel). We took a gamble that there would once again be good regeneration of birch. Things did not however go smoothly.
We had a severe hit from weevils in the second autumn after felling which required treatment (and one of us becoming trained/certified for spraying). Regeneration of birch was not visible at the end of year two so we decided to inter-plant oaks with birch – only to find profuse birch regeneration in year 3. Chalara hit the news a year later so we planted additional oak (Q. robur) in those ash sites that seemed suitable.
Outside the clearfell area we have been thinning 6 ha of p1995 Douglas fir (DF) and starting its transformation to CCF. Another 1.5 ha of DF, close to an area rich in ancient woodland indicator species, has been felled to recycle – giving a useful stand of regenerated birch that had survived the DF planting. A further 3 ha of dense birch regeneration that replaced a 2002 failed DF planting has been re-spaced and first thinned – the form is good and should yield 45cm good quality logs in a fairly short rotation.
Future business model
The 40ha comprising the 2 sites currently contains Yield Class (YC) 8 oak and YC 10 birch so it seems reasonable to expect an annual yield of at least YC 6 throughout the site. We assume a well-developed CCF site should contain 50% of its standing trees as sawlogs and 50% as small roundwood. Therefore, rounding down, there should be an annual production of about 100 cubic metres of sawlogs and 100 cubic metres of fuel wood.
Association of Scottish Hardwood Sawmillers (ASHS) members currently sell sawn and dried hardwoods (including birch) at around £1000 per cubic metre. Assuming 100 cubic metres of sawlogs yields 50 cubic metres of sawn timber this equates to income of about £50,000. 100 cubic metres of processed firewood costs about £100 delivered in our area – an additional income stream of £10,000.
We find it difficult to estimate the costs of this sort of enterprise. Equipment envisaged would include a 70/80 hp. tractor with trailer/crane, winch, firewood processor and road trailer for deliveries. Milling would be with a static bandsaw mill and drying by a kiln.
Is it likely that the running costs would exceed £30,000? If not there should be a net income of £30,000.
Development over time
We are now starting to fell 2 ha of p1958 larch/pine in our first wood in small groups. This is providing a modest yield of sawlog material to keep milling going. It is also letting larch and holly in the understory get away and produce better structural diversity. Birch thinning is keeping up the firewood output. This allows the system to tick along and cover running costs.
The 1995 DF will start to produce sawlogs in about 10 years taking output forward. A further 20 years will see about 4 ha of birch reach 45cm dbh and thus add to the momentum. French yield tables suggest the YC 8 oaks planted 20 years ago and already growing free should achieve 70 cm dbh in 80 more years.
We consider it realistic to expect that there will be a gradual increase of output (and therefore income) over time that would support a move from part-time to full-time working for the owner. Whilst one cannot predict the future world – and therefore whether this progression is possible – we believe it important to develop the vision and work positively towards it.
Our efforts are not focused solely on timber production. A range of conservation management operations have been carried out in parallel to the harvesting and restocking described above.
Burnsides have been cleared in an area of DF retention, and standing deadwood created throughout the site. We have also experimented with translocating ancient woodland plant species within the site. Survey work has mapped higher plants, freshwater snails and bryophytes, whilst we have also mapped and preserved woodland archaeological features.
A resource for the public
As well as giving us much pleasure, our woods provide opportunities for the wider public – for example, one kilometre of the Highland Council Core Path Network comes through the woodland and is well used by walkers and horse-riders.
Our management approach has also attracted a more specialist audience, regularly hosting visits from staff of various organisations and agencies (eg Woodland Trust, Trees for Life, FCS). We have part-hosted a PAWS restoration seminar, and recently been a demonstration site for a FCS productive broadleaf timber course run by Jens Haufe.
We are starting to close the current dichotomy between commercial and native woodlands.
In recognition of their work at Kirkhill, David & Annie received a highly commended Scottish Finest Woods Award for new native woodland in 2015, for their original (smaller) site.