Forestry and climate change in England

 

Forestry policy in England is the responsibility of the Department for Environment, Food and Rural Affairs (Defra) and Forestry Commission England is responsible for policy implementation. Climate change: the UK Programme recognises the contribution that woodlands and trees can make to its priorities for action. The England Forestry Strategy A New Focus for England’s Woodland (1998) set out a broad agenda for forestry and highlighted the numerous public benefits that trees and woods could provide but this is now being reviewed in the light of new government policies. Sustainable development however will be at the heart of policies on trees, woods and forests, as it is in the current forestry strategy.

The consultation on the England Forestry Strategy sets out why understanding of the ways woodland management can be adapted to ensure that woodland can continue to deliver the full range of benefits in a sustainable way as the climate of England changes should be treated as a national priority. It also sets out how woodlands and trees can help deal with climate change through carbon sequestration, by providing woodfuel as a substitute for fossil fuels; timber to substitute for other products; and by protecting natural resources, particularly soil and water.

Adaptating to climate change

Scientists offer a range of scenarios for England’s future climate, with southern England likely to face the greatest changes. Winters are expected to be wetter and milder with summers hotter and drier. In common with other plants, trees will have to adapt to different patterns of temperature and rainfall but because trees have such a long growing cycle adaptation strategies need to be planned urgently.

Adaptation means making woodlands more resilient to the threats posed by climate change and supporting woodland functions within the wider ecosystem. Policies shall seek to deliver management that makes entire landscapes more resilient by buffering woods from edge effects (such as fertiliser and spray drift) and by reducing fragmentation of woodland habitats. It is particularly important that adaptation measures do not make woodland less resilient, in case climate changes fall outside the range of current projections.

Woodland managers and land owners will need help in predicting the effects of climate change and advice on how to alter their management, where to plant trees, which species to use, how to deal with new pests and diseases and how to maximise opportunities for wildlife.

Mitigating climate change

Substituting for fossil fuels

England’s trees and woodlands can contribute to meeting the UK targets for reducing greenhouse gas emissions in two ways, by:

• using wood in place of fossil fuels as a source of heat and energy;
• using timber as a substitute for materials that have high carbon dioxide emissions associated with their production, such as concrete and plastics.

Government is looking at the potential of biomass as a renewable energy source and, in its response to the Biomass Taskforce Report, has asked the Forestry Commission to prepare a woodfuel strategy to identify the measures needed to increase the amount of ‘woody’ biomass available to a sustainable woodfuel supply chain. The focus of the strategy is on English woodlands that are not currently managed since they represent a significant, currently under-utilised, potential woodfuel resource. Whilst bringing this woodland back into management will be a significant challenge, it offers potential carbon savings of around 0.4 million tonnes of carbon per year, through substituting for fossil fuels, based on bringing an additional 2 million green tonnes woodfuel per year to market from currently unmanaged woodlands. Managing neglected woodlands for bioenergy may also enhance carbon dioxide sequestration in biomass and soil organic matter, as well as providing other benefits associated with sustainable woodland management, such as improving habitat condition. There may be an opportunity to deliver these benefits via small scale, local heating schemes in rural areas which are dependent on oil or coal heating. The development of a supply chain must be sustainable and include new biomass sources, including both conventional woodland creation and the planting of dedicated energy crops. However, in the case of energy crops, the environmental implications of introducing fast-growing species and intensive cultivation techniques would require careful consideration.

Wood products help to reduce carbon emissions because they are generally ‘carbon-lean’, having low carbon emissions associated with their production when compared to some other materials for which they can be substituted, such as concrete or plastics. We want to encourage the forestry industries sector and its partners to stimulate and expand markets for English timber. This will mean exploring issues of timber quality and how English timber is perceived, availability of processing facilities and the skills needed in the workforce. The English Forest Industries Partnership is already playing an important role in mapping the market and bringing together interests from across the industry to discuss the future.

Carbon sequestration

Planting trees to absorb carbon is recognised as a way of enhancing the carbon sink to compensate for carbon dioxide emissions from fossil fuels. Under the United Nations Framework Convention on Climate Change and the Kyoto Protocol the UK Government is committed to reducing greenhouse gas emissions by 12.5% of the 1990 total by 2008/12. This is equivalent to 21 megatonnes of carbon per year. A more demanding UK target has also been set, to cut carbon dioxide emissions by 20% by 2020, equivalent to 30 megatonnes of carbon per year. More recently, Government has signalled its intention to introduce into statute a 60% reduction in carbon dioxide emissions by 2050.

Woodland which has been established since 1990 will remove an average of 0.265 megatonnes of carbon per year between 2006 and 2020, assuming that annual planting continues at current levels. However, the dynamics of tree growth mean that increasing the rate of woodland creation now would have limited impact on these targets, because maximum carbon sequestration would be achieved after 2020. As an illustration, tripling the area planted annually (from 4500 hectares to 12,223 hectates) between 2006 and 2020 would only realise relatively modest increases in annual sequestration of 0.023 megatonnes of carbon in 2010 rising to 0.288 megatonnes in 2020 and 0.290 megatonnes in 2035.

The contribution of woodland creation to carbon savings is worthwhile but limited. A more significant contribution would mean a large increase in planting rates. The area of land required for planting to make a major contribution to carbon sequestration targets far exceeds that which is likely to become available. All contributions to meeting the challenging emissions reduction targets are valuable, but we do not believe that carbon sequestration alone is a reason for supporting afforestation, although it is an important additional gain from managing and planting woodlands and forests for other public benefits. This strengthens the case for targeted, multipurpose woodland creation.

We also need to protect the existing carbon sequestration capacity of our woodlands, including the forest soils which represent a much larger carbon reservoir than the trees. It is important for owners to follow soil conservation guidelines on current best practice.

The overall trend in England is still one of afforestation, with deforestation of around 1000 hectares a year more than compensated for by new woodland creation at a rate of around 4500 hectares a year. The deforestation figure includes some 500–1000 hectares a year, that is restored to priority open habitat. The majority of these are mature conifer woodlands that would have been felled anyway in a conventional rotation. The current balance of woodland removal and creation is adequate to ensure that we do not diminish the existing carbon sink, although it is vital that managers follow guidance on best practice to avoid soil disturbance and so protect the soil carbon store. However, if the rate of deforestation for open habitat restoration increases, we should take steps to ensure the carbon sink is not reduced.

Natural resource protection and management

Within the pattern of land cover, trees and woodlands can protect resources and air and may also help us to cope with some of the extreme weather events predicted. Trees planted in riparian zones can reduce soil erosion, river siltation, transportation of diffuse pollutants, and there is good evidence that floodplain can reduce peak flood flows. It is expected, therefore, that woodlands could have a role to play in catchment management and in meeting the requirements of the Water Framework Directive. The resource protection benefits are not confined to soils – for example roadside trees can help to filter particulate air pollution.

However there is some uncertainty about these effects and further understanding is needed of the potential contribution of trees to resource protection and management to develop a more integrated approach to land use, taking into account the places trees may use more water than other vegetation. There is not sufficient evidence, at present, to make natural resource protection one of the principal drivers of woodland creation, nationally, but it will be an added benefit of planting in many locations, particularly where the effects are well understood.