New woodlands

Most new woodlands are created by planting, rather than by natural regeneration. There is a strong commitment through the grant system of the Forestry Commission, the UKBAP and through other agencies and initiatives to new woodland planting of native, local provenance species in mixtures which imitate natural vegetation communities, to create multi-purpose woodlands.

Although new woodlands cannot replace the ancient woodlands, with the right management they can quickly become important features for wildlife, amenity, landscape and other values. Many of the woodlands planted from the 1960s onwards around new towns, reservoirs, in reclaimed industrial areas and elsewhere have become mature, attractive landscape features and valuable habitats. Mobile species, such as mammals and birds, and including some rare species have taken advantage of the new woodland habitats.

When planning new planting schemes of over a hectare, it should be borne in mind that grants for planting new native woodlands give higher priority to those woodlands which:

• Are in priority areas such as Rural Priority Areas or Community Forests.
• Contribute to a national or local BAP, HAP or SAP target.
• Extend an Ancient Semi-Natural Woodland.
• Include proposals for public access.
• Include proposals for community involvement in design or management.

See here for further details on grants.

Choosing species

The species chosen should be native to the local area. The species and mixture chosen should mimic local semi-natural woods on similar soils, and with aspect and other conditions to the site you want to plant. Advice may be needed on which local woodlands are thought to match the local type most closely, and whether the planting site has any limitations of soil, drainage or other factors which may make it unsuitable.

The National Vegetation Classification (NVC) describes 19 different woodland types, which are listed in Table 5b. Further details on the species, distribution and soils of 15 of these woodland types are included here For full details see Creating New Native Woodlands (Rodwell, John and Patterson, Gordon, 1994).

The National Vegetation Classification table (Table 5b) can be used to:

• Predict the type of woodland vegetation which would naturally develop on a site.
• Provide lists of ecologically appropriate trees and shrubs to plant, with an indication of the proportions and patterns that could be used.
• Identify optimal plant precursors that may already occupy the site, to give a head start in the development of appropriate ground cover.
• Indicate other desirable plants characteristic of the woodland type, which could be planted or otherwise encouraged.
• Suggest forms of woodland management which could aid development of the full community of woodland and herbaceous plants.

For small amenity woods, planting schemes in urban areas, shelterbelts and other ‘non-woodland’ planting, species and communities of the local woodland type may not be the most appropriate. Native trees, notably beech and Scots pine, have been widely planted over many centuries out of their natural range, where they are valued. Shelterbelts may need to include non-native species which are able to survive in exposed conditions, and act as a nurse for native and locally native species. Planting on reclaimed sites, which normally have soils which are compacted, prone to waterlogging or otherwise disturbed, may need to include pioneer species which are not of the local type. These may include alder, rowan, birch and goat willow. For further details see Reclaiming Disturbed Land for Forestry (Forestry Commission, 1994).

Table 5b: Woodland types : classification and nomenclature

Local provenance

The use of planting stock which has been propagated from trees native to the locality is important for the maintenance of local genetic variety. Its importance is recognised in the Forestry Commission’s UK Forestry Standard, BAPs, the UK Woodland Assurance Scheme, grant schemes, and through the advice of forestry and nature conservation agencies.

One approach is to grow your own planting stock from seed collected locally. Comprehensive details on collection and propagation are given in Tree Planting and Aftercare – Propagation.

Many nurseries supply native provenance trees and shrubs, and supplies of local provenance trees and shrubs are increasing. The voluntary scheme of local seed zones is described in Using Local Stock for Planting Native Trees and Shrubs (Forestry Commission, 1999). Under this scheme 24 different seed zones are identified in England, Scotland and Wales, to help growers source and supply, and buyers identify, stock of local provenance. Some nurseries are able to collect seed and propagate trees ‘to order’, to replicate local genetic stock for particular planting schemes.

Species mix

The woodland types recommended for creating new native woodlands (table 5b above) include details of the recommended major and minor tree species, and major and minor shrub species for each woodland type.

From the lists of recommended tree and shrub species, a mixture should be chosen which suits the particular soil type and other physical aspect of the site, and which suits the purpose of the planting. For upland types, the choice is limited to only a few tree and shrub species. For lowland mixed broadleaved woodland on neutral and alkaline soils, there is a much larger range of trees and shrubs which can be used.

The species mixture must ensure that vigorous species do not suppress the slower growing species, and that the mixture has the potential to create the desired woodland structure. Recommended percentages of each species should be chosen after consideration of all factors affecting the individual site.

There are some rare species which it is recommended should not be planted, because their remaining distribution pattern is of intrinsic importance, and could be altered by planting. They are listed below. Any planting of these species should be recorded with the nature conservation agency, and only local provenance stock should be used.

Silvicultural system

This describes the system which is going to be used to manage the woodland, and may vary between different areas or compartments of the woodland. Systems include coppice, coppice with standards and high forest. Management of high forest will require thinning and selection. Systems of shelterwood, group felling or continuous cover may be used for maintaining and regenerating the woodland.

Open space

Glades, rides and other open grassy spaces within woodlands are valuable for wildlife and amenity. The recreational use of most woodlands is concentrated in these open spaces, and given the choice, many people prefer to walk along the woodland edge, or in the grassy spaces between wooded clumps, rather than actually under the canopy of trees.

When planning the open spaces in a woodland, their future management must be considered. In most locations, unplanted areas will rapidly grow over with rough grasses, brambles and scrub. This may create a useful wildlife habitat, but supporting different species to an open grassy space. Eventually, scrub will succeed to woodland. Grassy spaces have to be regularly maintained by mowing or grazing, and grazing whilst preventing damage to young trees is difficult to manage. Small glades are awkward to mow, and will ‘shrink’ as the trees mature, so open spaces should be designed in simple, generous shapes. Clumps of trees in grassland, parkland and wood-pasture type landscapes are normally much more expensive to maintain than closely-spaced and fairly uniform tree planting. The Woodland Grant Scheme allows 20% of the area to be unplanted.

Table 5c: RARE TREE SPECIES NOT RECOMMENDED FOR PLANTING

Planting patterns and spacing

The standard plant spacing for large scale planting, as required under Forestry Commission grant schemes for broadleaved and conifer planting, is 2,250 trees per hectare (910 per acre), which is equivalent to 2.1m x 2.1m (6’10” x 6’10”) spacing. This is the quickest way to establish woodland cover, as the canopy closes rapidly, reducing the competition from weeds. Strong upright growth for maximum timber value is encouraged. A mixture of canopy and underwood species can be used, and thinning will be needed.

The plant spacing for new native woodlands, amenity woodlands and small broadleaved woodlands less than 3 hectares (7.4 acres), under current grant schemes, is 1,100 per hectare (445 trees per acre), which is equivalent to 3m x 3m (9’10” x 9’10”).

Wider spacing results in slower canopy closure and a bushier form of tree or shrub. There must be equal attention to effective weed control whatever the spacing, but with the wider spacing there will be more need to manage the ‘inter-row’ vegetation. In the years before the canopy closes, the gaps between 3m spaced trees will normally need be mown, in order to prevent brambles and scrub overtaking the planted species. If cut once a year in late summer, the inter-row vegetation may provide a useful short term habitat for ground nesting birds, small mammals and invertebrates, before it closes over to a shaded habitat. The wider spacing means there will be less requirement for thinning.

The subject of planting patterns is complex. Different species of trees do not grow at the same rate, and slower growing species will be at a disadvantage. Groups of at least 9 of the same species are recommended for 2m x 2m spacing, from which one or more trees will be selected during thinning. At 3m x 3m, groups of 5 or 7 may be appropriate. Repetitive formula-driven patterns of groups of species at regular spacing are easy to plan and plant, but may not introduce sufficient variety for a natural effect. Clumps of unevenly spaced trees of varying species mixes, with varying gaps between clumps can be used to introduce a more natural pattern. However, this is more difficult to plan and plant, and complicates the management of ‘inter-row’ vegetation in the early years. Even gaps of about 10m, which appear so large at planting, will eventually disappear as the canopy closes, and management in the interval may be a problem. It may be easier and cheaper to plant fairly uniformly, and then use thinning to introduce variation. Natural variation will develop as trees grow at different rates due to site conditions and other factors. For further information on planting patterns see the Forestry Commission publications Creating New Native Woodlands (Rodwell, John and Patterson, Gordon, 1994) and Creating and Managing Woodlands around Towns (Hodge, Simon J, 1995).

Where grants are not being used, the plant spacing and pattern is open to choice. Wider spacing is cheaper to supply and plant, but maintenance in the establishment years may be a problem. Close spacing is more expensive to supply and plant, but is the quickest and cheapest way to establish woodland cover. The establishment of a woodland flora is likely to be more successful and can be started earlier under a closely-planted canopy. Open grassy spaces, to remain open as the trees mature, need to be at least 25m diameter.