Woodland management at Steward Wood

Steward Wood is plantation woodland, and has been heavily managed in the recent past. Both native and non-native trees and plants are well established. The highest storey of the wood consists of conifers in blocks of the same species and age. Most conifers have reached their maximum height and a diverse understorey of broadleaves is succeeding. These are mainly hazel and sycamore but oak, beech, ash, hawthorn and small groups of blackthorn, willow, wild cherry, and birch are also present. The hazel has been coppiced in the past; while the coppice has been neglected and is overgrown, the lack of disturbance has encouraged the establishment of wildlife habitat.

The community is in the process of gradual conversion of the wood, from one dominated by conifers to a broadleaf wood. We manage the wood using continuous cover techniques.

Apologies for the following heavy referencing – our methods of woodland management have been queried during our 2008-2009 planning battle and it seems sensible to show that we’re not managing our woodland on a whim!

What is continuous cover management?

Continuous (syn. constant) cover is a traditional forest management system in many heavily forested parts of Europe, and is now becoming more important in modern British forestry [1]. While the concept is contested, the theory of minimum intervention management for wildlife and amenity value is long-standing [for example: 2 p. 46]. The discussion of the need for stability and sustainable management of forest worldwide at the 1992 UNCED summit at Rio de Janeiro brought continuous cover to the fore, as an alternative to conventional management [3 p. 29].

The literature concurs that continuous cover aims to promote equilibrium of mixed age trees, the ideal being a steady decline in the number of trees in each year cohort as it ages; resulting in a stable, self-managing wood of many seedlings, fewer saplings and a few veteran trees [3 p. 28, 4 p. 6]. Intervention is informed by designed monitoring [4 pp. 1-7].

Clear felling of compartments over a certain size is not practiced in continuous cover management [3 pp. 30-31, 5]. The ideal maximum size of compartments is debated and varies from between 0.25 and 3 hectares. It is recognised that the larger the felling compartments, the more the continuity of the forest is disturbed. Instead, selective felling, selective restocking, and allowing natural regeneration are practices that maintain the continuity of the tree cover throughout the forest [3 p. 30, 6 p. 85].

This management system has the following advantages over block felling and restocking:

Woodland management decisions are made concerning trees in small groups, or even individually where appropriate, rather than large sectors;

A mixture of tree species, undershrubs and dead wood are recognised as having value to the biodiversity and stability of the forest;

If it occurs, organised felling (and replanting) is gradual, rather than by large compartments;

This avoids local problems associated with clearfelling caused by discontinuity of woodland conditions, such as bramble overgrowth, disturbance of the water table and soil erosion;

Woodland of mixed species and ages are less sensitive to the spread of disease and insect epidemics and recover more quickly from severe storm damage;

It does not displace the animal and plant species that require continuity of habitat to survive;

Thus: it is ecologically sensitive, minimising disturbance to wildlife and habitats and increasing the long term resilience of woodland [3 pp. 31-34].

Our rationale for using this system at Steward Wood

Clearfelling in large blocks that are pre-determined on a map is inappropriate for a biodiverse wooded area [6 p. 85, 8]. Continuous cover management is becoming a standard alternative for conversion of single age plantations to mixed age woods [3 p. 35, 4 p. 1, 6 p. 85]. Over a mid-to-long term period, Steward Wood will develop to a mixed, mainly native broadleaf wood. This will increase the woodland’s stability and biodiversity, and its resilience to pests and climate change.

The gradual nature of continuous cover management suits us humans too. We are guided by an overall plan, as all woodland managers are, but we have a detailed knowledge of the wood through the seasons because we live here. The selective, incremental work of continuous cover matches the human scale of our lives [6 p. 122].

Our methods

The wood is divided into compartments that roughly correspond with species of the coniferous top storey. We have slightly different overall restocking plans for each. These are influenced by direct observation, so are subject to some change. All tree felling is carried out with strong consideration for native tree species in situ so that there is minimal or preferably no damage to any trees to be retained. During the selective marking of trees over the next 5 years preference has been given to those which will aid the growth of native species in proximity to the selected trees.

We selectively fell a small number of conifer trees every year. We ensure they are replaced, either by natural regeneration or where appropriate, planted saplings. Natural regeneration allows the soil and microclimates of the wood to choose the most suitable species for us, and trees that have grown from seed in one spot will not have suffered the setback of transplanting. Our wood does contain a great deal of sycamore - a good approach for us, is to allow natural regeneration, keep an eye on it and be prepared to intervene to suppress sycamore growth if necessary for native broadleaf to become established. The Forestry Commission recommend a spacing of 2.1m x 2.1m between saplings [6 p. 70]. As happens in a natural wood, some of these will die as the trees grow [3, pp 29-30].

Deer are present and do damage growing trees, and particularly coppice. Frustratingly their least favourite food appears to be sycamore! We don’t cull deer or practice any kind of population control. Instead we use reusable tree guards to protect young wanted trees from deer damage, and find that a regular human presence is an effective deer deterrent.

We use the following designed method for continuous cover monitoring ongoing continuous cover management: random sampling of 8 metre wide plots within the wood. All plant and animal species within the plots are noted and tree diameters noted. The monitoring continues every five years and, provided enough plots are sampled, the data provides a useful indicator of (for example) which species and diameters of trees are over represented, informing felling decisions [4, pp 1-7]. In addition, living here full time and knowing the wood through the seasons enables us to make informed decisions of the impact of any intervention [6 p. 29].

Coppicing

Coppicing is a system that has the potential to sustain more forestry workers than any other management system in our temperate climate [6 p. 7]. Carried out sensitively and in the minimum possible blocks, it does not contradict continuous cover principles [3 p. 30]. So far it has not been carried out by the community on a wide scale. We plan to coppice small blocks this autumn.

Coppicing is defined as the successional cutting of broadleaf trees at the base during the dormant season. The following spring the trees will set new shoots. The time between cuttings depends on the tree species and intended use of the coppiced wood. As well as economic value of the product, coppice also contributes to the biodiversity of woodland – it offers a cyclical habitat, and leaves the soil totally undisturbed, so retaining its ground flora, structure and microorganisms [6 pp 7-9]. Green hazel is a traditional wood for crafting added value products, and coppices well, so our hazel understorey is perfect for coppice with economic value. We also have coppiced sycamore in the short-term, for fast growing firewood [7, pp 83 and 86].

Coppicing should be done in blocks between around 0.3 and 3 acres [6 p. 77]. We plan to coppice blocks on the smaller end of this range. We have found that coppice stools, when mixed with mature uncoppiced trees, tend to be too shaded and relatively difficult to monitor for deer damage or other problems. Recently coppiced trees here have been on the edge of the woodland.

Managing tree species

Where appropriate, we plan to replant with mixtures of native oak, ash, birch, hazel, native shrubs and sweet chestnut to provide future biodiversity, amenity, the potential for a broad range of woodland produce, and some resistance to the possible direct and indirect effects of climate change on some species. We also intend to plant a small number of larch and fir trees to provide future timber and give continuity of habitat. Existing broadleaf trees, except sycamore, are almost always coppiced rather than killed. 

Edible woodlands

Provided that non-native species are selected carefully and monitored to ensure they do not become invasive, and that native species are chosen where possible to meet a food requirement [8 p. 370], the planting of food producing plant and tree species increases the economic and social value of woodland produce. Food production can in this way be integrated into the transformation of plantation woodland to continuous cover woodland [6 p. 127]. Note that the introduction of non-native species into ancient and semi-natural woodland is not good practice and should be avoided [9].

We intend to incorporate food producing trees and woodland edge plants into incremental transformation to mixed woodland. Trees may not come into full bearing for five or ten years, but will bear food for decades with minimal input, relative to annual crops. This is our alternative to complying with the destructive nature of conventional agriculture and the enormous worldwide social, economic and environmental costs of importing food into Britain. When one factors in the long-term instability of the global food system (hence the temporary nature of the food it provides us), planting food-producing trees becomes a rational strategy [8 pp 5-9, 37-38, 169, 226-228].

Machinery use in the wood

The community fells trees by hand only (excepting dangerous trees). This policy was initially a compromise between those of us who don’t want chainsaws here, and those who wanted to use them. However it seems to be sufficiently functional for everyone. While it has its disadvantages, hand felling is respectful to the large and beautiful trees we are felling and keeps an essential woodland skill functional.

Petrol chainsaws are noisy, expensive to run, polluting and have been used to indiscriminately destroy irreplaceable habitat the world over. For these reasons, the community elected to work without chainsaws when it was founded in 2000. Chainsaw use was agreed here in 2006 – the only fossil fuel members use here.

This is a complicated (and emotive) issue for the community. Before chainsaws were used here, there was pressure from the outside world for concrete markers of “progress” within the community, without considering the time and huge effort required just to process firewood by hand. There was also an expectation to see a certain rate of “woodland management” (as measured by felled conifers) without considering the external cost of using fossil-fuel powered machinery. Undoubtedly, chainsaws have enabled us to become much more time-efficient in our woodland work, and this has had a significant knock-on benefit to both the working side of the project, and our personal lives.

We use Aspen fuel, a relatively clean-burning fossil-fuel byproduct, and vegetable based chain oil in the saws. In the very long term, such machinery is not a solution. Functional, simple and climate-responsible solutions to the labour-intensive hand-processing of timber are certainly needed.

We move all timber by hand – large pieces of conifer can be moved using a winch, a time-consuming but satisfying process. Although our mature conifer crop is suitable for planking, this would need plant machinery to extract the uncut lengths. Heavy machinery is very destructive to woodland soil, causing long-lasting ground compaction and habitat damage [6 p 85], but there are a few areas of conifer trees adjacent to the track that are suitable for timber extraction using a tractor, so we haven’t ruled this out.

Forestry tools in the wood

We use hand tools for much of our woodland work. Using hand tools to work with wood is a very personal experience, and relative to powered tools, they have many advantages. They are cheaper and easier to mend, they don’t need power or fuel and don’t emit fumes or loud noise, and they are lighter and smaller to carry. As long as they are kept sharp, hand tools are very effective and satisfying to use.

Tools used include:

Axes: different size axes are used for different tasks. They range from large axes designed to fell trees, to small axes for snedding branches. Felling axes are used to cut the gob cut when felling a tree.

Two-person crosscutting saw: a six-foot-long saw with a handle at each end. The saw is used to make a back cut in the tree to be felled.

Wedges and a sledgehammer: when felling using a crosscut saw, wedges are driven into the back cut using the hammer to ensure the tree falls in the right direction. They can also be used while cutting to widen the back cut, to make sure the saw doesn’t get stuck halfway through the cut!

Log-moving equipment: log-lifting tongs and pulp hooks for ease of lifting very large logs.

Felling bar: a long bar with a flat plate at one end. We don’t usually use this for actual felling because we don’t fell with chainsaws, but it is useful as a lever to start a large log rolling. We have used felling bars when felling dangerous trees with chainsaws.

Bowsaw: a relatively inexpensive, general use saw for one person with a bow-shaped handle, they come in different lengths for ease of use. Some have a pointed end for access during coppicing. We find these are best for processing firewood.

The curved pruning saw (pullsaw): an expensive but better alternative to bowsaws for work on trees, as they allow better access between tree stems and do not bend in use.

Sycamore

Sycamore is a rampantly self-seeding, quick growing tree species [7 pp 192-193] with a low biodiversity value, as measured by the number of British native insect species it is capable of supporting [10].

It is certainly the fastest growing broadleaf here. Where necessary, we will cut back or kill sycamore to allow neighbouring trees to thrive. However the issue is not totally straightforward, as the species does contribute to the biodiversity of a wood: it is a bee plant, is capable of supporting a very high biomass of aphids [7, p.194], and hosts epiphytes that was supported by the now almost extinct English elm [6 p. 370]. In our experience sycamore trees do not take over from previously established tree species, as they don’t tolerate shade well - they become one species among many. Note that they do dominate freshly afforesting ground if not checked.

As a fast-growing tree that coppices well, it is valuable as firewood [7 p. 86], and indeed this is its only satisfactory use for us here. While it has a reputation for being a good construction wood [7 p. 194] and we do use poles to build with, we find that it has low strength and durability.

Wildlife at Steward Wood

For many reasons, continuous cover management is the most wildlife-sensitive woodland intervention plan (see above), and when making selective felling decisions we are guided by the potential impact on the surrounding flora and fauna.

Some of our major wildlife friendly policies are: not carrying out tree works during the bird nesting season; leaving piles of deadwood and not cutting standing dead trees; opening up rides – increasing potential for different habitat, ground flora and flight paths for hunting bats; putting up mammal boxes and drilling dormouse holes in stumps; keeping most human activity within the Settlement zone in the woods. A low-intervention compartment within the wood is set aside as a buffer zone between the remainder of Steward Wood and the neighbouring site of ancient woodland. This is managed as little as possible, only to keep sycamore levels down, to keep wildlife disturbance at a minimum.

For more details of the species found here at Steward Wood, please see our Wildlife section.

References

[1] Forestry Commission (1999) “The Quiet Revolution in Britain’s Forests” in News Release no. 2354, online at http://www.forestry.gov.uk/newsrele.nsf/AllByUNID/AE406717129F5C1F802567D90049F095

[2] Brooks, A. (1980) “Woodlands: A practical handbook”, British Trust for Conservation Volunteers

[3] Pommerening, A. and Murphy, S.T. (2004) “A review of the history, definitions and methods of continuous cover forestry with special attention to afforestation and restocking” in Forestry: An International Journal of Forest Research, 77 (1)

[4] Kerr, G., Mason, B. Boswell, R., Pommereng, A. (2002) “Monitoring the Transformation of Even-aged Stands to Continuous Cover Management”, Forestry Commission information note, online at http://www.forestry.gov.uk/website/publications.nsf/WebpubsbyISBN/0855385669.

[5] Continuous Cover Forestry Group (2009) “Principles” available online at http://www.ccfg.org.uk/wordpress/?page_id=3

[6] Law, B. (2001) “The Woodland Way: A permaculture approach to sustainable woodland management”, Permanent Publications, Hampshire

[7] For example Evans, J. (1984) “Silviculture of Broadleaved Woodland”, Forestry Commission Bulletin 62, HMSO

[8] Whitefield, P. (2004) “The Earth Care Manual”, Permanent Publications, Hampshire

[9] DEFRA and the Forestry Commission (2005) “Keepers of Time: A statement of policy for England’s ancient and native woodlands”

[10] Southwood, T.R.E. (1961) The numbers of species of insect associated with various trees. J. Animal Ecology 30: 1-8, cited by Offwell Woodland and wildlife Trust, online at http://www.countrysideinfo.co.uk/woodland_manage/tree_value.htm

Last updated: 2009-04-25

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