Image: © Forestry Commission
Having once covered almost 90% of the UK’s land area woodlands were significantly reduced by the 11th Century, to pockets of small woods covering around 15% of the country.
During the last millennium these remnants of our original ancient forest have been subject to continual land use pressure; many being completely cleared and others converted from semi-natural woodlands into productive plantations. Woodland cover reached an all time low of 5% just after the First World War but a number of government-backed schemes and policy changes run through the Forestry Commission have led to a gradual recovery.
The Broadleaves Policy (1985) is one of the most notable, which was set up specifically to help halt and reverse the decline. The policy is against clearance of broadleaved woodland for conversion to other land use, and supports conservation of ancient semi-natural woodlands. As a consequence of such initiatives the Office of National Statistics reported an increase in woodland cover from 9% in 1980 to 12% in 2002. Outside of these official figures there are also considerable numbers of micro-woodlands, copses and hedgerow trees, often known as Trees Outside Woodlands (TOWs). In certain areas of the country their combined area is substantial.
The UK government recognises the role that trees and woods play in delivering important international commitments including the UN Framework Convention on Climate Change and its Kyoto Protocol, and the EU Habitats and Species Directives, the Water Framework Directive and the Convention on Biological Diversity. Indeed, with woodland habitats now covering only 12% of our land (Office of National Statistics, June 2010) they make up one third of the priority terrestrial habitats in the UK Biodiversity Action Plan. So while the UK is one of the least wooded European countries it is one of the few where woodland cover is still increasing.
Priorities for conservation
1. Protect what we have
According to the latest Joint Nature Conservation Committee figures (March 2010), of the 12% woodland cover in the UK only 1.2% is classified as ancient semi natural woodland and only 1.4% of this has some kind of protected status. The recent Space for Nature government report (Lawson. J: September 2010) states that the protection of all remaining ancient woodland as a priority habitat is an absolute priority. This was included in the second of 24 key recommendations made by the report to preserve Britain’s nature for the future.
It is easier to protect our woodlands if we know exactly what we have to start with. Ongoing monitoring programmes are essential in providing information about the extent of change.
The National Inventory of Woodlands and Trees is administered by Natural England and provides up-to-date information on the extent, size and composition of our woodlands. In particular, the objective is to provide an accurate assessment of woodland area and to estimate other characteristics such as forest type, species, age class, stocking, timber potential and woodland structure. The inventory now includes all woodlands in the UK from two hectares and above.
2. Restore and expand
A number of policies are driving the restoration and expansion of woodland. Many types of woodland in Britain are regarded as PAWS (Plantations on Ancient Woodland Sites) and during the past two decades there has been considerable interest in converting coniferous plantation back to native broadleaf species. The aim of this restoration effort is to increase the biodiversity and cultural value of the site where there is still potential for remnant ancient woodland populations to regenerate and ancient woodland features to be preserved.
The UK Biodiversity Action Plan (BAP) has been responsible for driving forward the restoration of sites in order to increase the area of specific woodland types for which with Habitat Action Plans (HAPs) have been set.
In terms of woodland expansion, the UK government released a white paper UK Low Carbon Transition Plan (2009) which estimated that planting 10,000 hectares of new woodland every year over the next 15 years could remove 50 million tonnes of carbon dioxide from the atmosphere between now and 2050. If these planting figures can be achieved then it would help to increase our woodland cover by about 1%. In spring 2010 the government recruited a Woodland Carbon Task Force to try to create the right conditions to deliver these targets. Although success in these targets relies upon the support of partnerships and private funding, overall government policy on climate change will ensure that net woodland cover continues to grow.
3. Buffer and link
Due to the reduction of woodland habitat over large timescales and for different demands, remaining woodland is often isolated by an expanse of agricultural or urban land and hence ‘broken apart’ or fragmented. When woodland is reduced in size or cut off from a larger area of habitat then woodland structure is changed. An increase in light around the edge of the woodland can alter tree and plant species significantly; specialist woodland plants are replaced by more general weedy species; a phenomenon known as ‘edge effect’. Furthermore, the isolation of the wood can threaten biodiversity by hindering the movement of species between remaining fragments; increasing the risk of local extinctions.
There are a number of solutions to fragmentation; best used in combination:
- Buffer and expand smaller woodlands with additional tree planting of several metres around the edge to retain the darker, moister conditions associated with more specialist woodland plants.
- To ease the problem of isolation, wooded corridors, networks or stepping stones can be retained or planted which link the isolated woodlands with larger areas of forest habitat.
- The area of land surrounding a small wood and its corridors can be ‘softened’ by allowing areas of long grass or scrub to grow making it safer and easier for mobile species to move around.
These actions can go a long way towards improving the resilience of small woodlands while creating a more robust ecological landscape by ensuring species can move and disperse in their natural way. Predictions of rising temperatures with climate change may force many species to adapt by moving to cooler habitat. Allowing this movement is vital if we are to protect as much of our biodiversity as possible.
4 . Manage woodland sustainably
Sustainable woodland management means managing our woodlands in a balanced way by ensuring their vitality and health now and in the future. Managing woodland sustainably involves planning for a number of objectives: supporting biodiversity; providing safe places for the public to enjoy; securing a renewable supply of wood; and delivering environmental services such as absorbing carbon and alleviating floods.
A sustainable approach to management will be vital in protecting our woodland resource for the future because it will ensure that no single objective is pursued to the detriment of overall woodland health.
5. The right tree in the right place
Climate change is fast becoming one of the biggest threats to our trees and woodlands. Water shortages from hotter, drier summers and threats from new diseases and pests are just a taste of the possible conservation issues that could threaten our woodland resource. Some tree species may become less suited to the areas in which they currently live.
Managers need to consider planting schemes on existing or new sites and select species and seeds that will have the best chance of succeeding in the changing environment. The Forestry Commission has developed a computer-based support system known as Ecological Site Classification which evaluates the location and conditions of a woodland and advises managers on which species to plant.
6. The woodland business
In order to make woodland truly sustainable as an ongoing land use we will also have to make woodlands competitive as businesses. This means promoting the development of new or improved markets for sustainable woodland products and encouraging the public to switch to greener wood-based choices. It also involves identifying and providing public support for the critical services that woodlands provide nationally and locally: such as ecosystem services; protecting soil and water resources; and the reduction of carbon emissions.
A further task of the government’s Woodland Carbon Task Force is to encourage and grow viable markets for UK timber to help support sustainable management of our woodland.