Posts tagged ‘climate change’
I wrote a year ago about Environmental Consciousness, when I created this image to encourage reflection of our collective responsibility towards the future of mother Earth.
The landmark United Nations climate conference at Durban that ended December 9th 2011, reached consensus to start negotiations on a new accord that would place all countries under the same legal regime enforcing commitments to control greenhouse gases by 2020. In other words, the people on Earth are beginning to act responsibly although progress compared to targets discussed in conferences a decade ago are still to be achieved. It is early days, hence my use of the words ‘awakens’. Governments have heralded the conference as a major breakthrough but campaigners believe that our ‘climate debt’ continues to deepen with the world’s poorest countries faring worst.
June 18, 2011
Britain is the second-least wooded country in Europe, a fact that I’ve written about previously. The prominent clarion call by Professor Sir David Read and colleagues in the Read Report of 2009 (see below) identified “a clear need for more woodlands”. The proposed woodland expansion programme is for an additional 4% of forest cover to be established in Britain, which would see a welcome increase to a total of 16%, although Britain would remain one of the least-wooded European countries.
Unfortunately some seem to have seen used this as a call for more ‘native woodlands’. Try a Google search for “read report increase woodland cover” and you will see what I mean. As far as I recall, Read never called specifically for more ‘native woodlands’. The native obsession is ironic and narrow-minded in that plantations of any appropriate species, if they are well-designed and managed, will remove the pressure from our existing and precious native semi-natural woodlands that many of these same organisations are striving to protect.
There’s nothing wrong with new ‘native woodlands’ per se but when their design and composition has ambition limited to greening the countryside, which is admirable in its own narrow way, they fall very far short of deliverying the sort of outputs that Read anticipated.
Read saw the increase in Britain’s woodland cover making a “significant contribution to meeting the UK’s challenging emissions reduction targets” with the aim of creating an emissions abatement equivalent to 10% of total green house gas emissions. To achieve these targets we need to either lock up carbon in wood, and the most efficient means of doing this is by growing trees as a crop that will produce timber, or create renewable energy by producing wood fuel. These can be provided together with social (e.g. recreation) and environmental (e.g. habitat provision) benefits. This is the essence of modern plantation forestry: the activity in which the UK Forestry Commission excels.
If we continue to plant green fuzz across our food-producing fields, with little concern either for the impending need to be more self-sufficient in food production (read more), or for the need to reduce our enormous reliance on timber imports (Britain’s sixth largest import), Britain’s environmental credibility will be increasingly undermined.
Forest plantations in the 21st Century are a long way in their design from the monocultural and regimental coniferous plantings that scarred so much of Britain’s upland landscapes in the early and mid 20th Century. Advances in tree breeding are bringing the production of quality hardwoods nearer to becoming economically viable, while the new market for wood fuel is helping by producing income from thinnings; a natural by-product of a well-managed woodland. Woodlands with ambitions to produce timber and fuel can deliver equally well in greening the landscape, or in providing wildlife habitat and places for people to exercise than any ‘native woodland’. Conversely, planting more of the same ‘native woodlands’ that now litter the English countryside with little more ambition in their creation and management than a membership publicity drive or community engagement excercise, will be regretted long after the PR-masters behind them have past. In their own way, these are as regrettable as the dark satanic rows of conifers that were planted sixty years ago.
The WWF is promoting a New generation of plantations that (note the fourth objective):
- maintain ecosystem integrity;
- protect the high conservation values;
- are developed through effective stakeholder participation processes;
- contribute to economic growth and employment.
The WWF suggest we should rethink our attitude to plantations, suggesting that they can be part of the solution more than the problem. They recognise that plantation forestry is controversial:
Some companies have put profit before the planet and destroyed valuable forest habitats in order to expand their plantations. Some have also trampled the rights of forest communities and workers. Yet tree plantations can be developed without these impacts and thus help maintain the most valuable ecosystems while contributing for economic development and employment.
So, in the global context, Britain could help in its own way by aiming to satisfy more of its own timber and wood fuel needs by planting and managing more forest plantations. We must wake up to our real environmental responsibilities, which extend way beyond our tiny shores.
As a first step, and so as to avoid the native debate for now (remember beech, sweet chestnut, walnut and all productive conifers are not native to most of Britain), let’s have a drive to plant ‘native plantations’. To do so will mean that some environmental bodies will have to bite the bullet and start talking to their members about felling trees as well as planting them. Now, that would demonstrate real environmental vision.
Read, D.J., Freer-Smith, P.H., Morison, J.I.L., Hanley, N., West, C.C. and Snowdon, P. (eds). 2009. Combating climate change – a role for UK forests. An assessment of the potential of the UK’s trees and woodlands to mitigate and adapt to climate change. The synthesis report. The Stationery Office, Edinburgh.
May 5, 2011
Britain is currently being impacted by a large number of forest fires; from Swinley Forest in Berkshire, to forests further north in England at Merseyside and Yorkshire, and also in the Scottish Highlands (see BBC news article). With changes in our projected climate, these may become a more common in the future.
Forest fires in Britain
Compared to many other European countries, particularly those further south, Britain has a relatively low occurrence of forest fires. The most damaging forest fires tend to occur during a dry Spring, such as the one we are currently experiencing, when material from the previous growing season still litters the forest floor.
According to Forest Research statistics, fire incidences peak in years with extended summer droughts, the most recent being 1976.
Forest fires and British wildlife
Wildfires are a natural part of some forest ecosystems but unlike some other areas of the world the ecosystems and forest wildlife of Britain are not adapted to, nor require, fire to regenerate.
For many decades the United States Forest Service tried to suppress all fires. This policy was epitomised by the mascot Smokey Bear. The policy was questioned in the 1960s, when it was realised that Giant Sequoia trees (Sequoia sempervirens) were not regenerating in the forests of California because fire is an essential part of their life cycle. Some tree species are adapted to fire by retaining non-dormant seeds, releasing them only after exposure to fire (this is called serotiny). Some tree species even encourage fire, for example eucalypts contain flammable oils in their leaves as a way to eliminate competition from less fire-tolerant species.
In Britain however, native tree species, and other forest wildlife, will be poorly adapted and changes to forest ecology difficult to predict to any increase in forest fires. It is likely that fast colonisers and invasive species may benefit, altering existing ecological communities.
Climate change and fire – planning for the future
According to the Intergovernmental Panel on Climate Change the effects of temperature increases have already been documented on forest management in the Northern Hemisphere, including increased incidences of fires. There are a number of practical steps that could be taken in Britain to deal with any increased fire risk:
- develop ‘fire-smart’ landscapes
- need to plan at the landscape scale, while …
- at a local scale, incorporate firebreaks, resilient species (including non-natives?)
- plant species that retard fire spread (e.g. Aspen is used to retard fire progress in boreal forests)
- plant species that are fire resilient (e.g. alder Alnus glutinosa)
- focus effort appropriately (e.g. allow wildfires to run their course if little socio-economic threat)
- improve management (e.g. thinning, forest floor maintenance)
- British foresters should look to France, Portugal and Spain to understand drought and fire modelling elsewhere in Europe.
- Coultherd, P., (1978). The effect of the 1976 drought on established and recently-planted trees is discussed with particular reference to their greater susceptibility to disease and to the fire danger. Quarterly Journal of Forestry, 72(2): 67-80.
- Groisman, P., Sherstyukov, B., Razuvaev, V., Knight, R., Enloe, J., Stroumentova, N., Whitfield, P., Førland, E., Hannsen-Bauer, I., Tuomenvirta, H., Aleksandersson, H., Mescherskaya, A. and Karl, T., (2007). Potential forest fire danger over Northern Eurasia: changes during the 20th century. Global and Planetary Change, 56: 371-386.
- Hemery, G.E. (2007). Forest management and silvicultural responses to predicted climate change impacts on valuable broadleaved species. Short-Term Scientific Mission report for Working Group 1, COST Action E42. Download
April 8, 2011
Trees in the UK are facing significant threats on two major fronts. The warming climate is making new territories habitable for unwanted pests and pathogens; while our insatiable appetite for the newest or cheapest plants and woody materials, imported via global trade, is making the situation ever worse.
The massive growth in the global trade of plant material has led to a steady increase in the number new economically or environmentally-damaging plant pests and diseases, and incidentally invasive ‘alien’ species too. These can be brought in on small container-grown or bare-root nursery material, or increasingly on large (e.g. 10m tall) trees planted in landscaping schemes.
The pathogen responsible for Sudden Oak Death (Phytophthora ramorum) is a recent example of a serious alien pest and disease that has been introduced (read more). Others include the oak processionary moth and horse chestnut leaf miner.
The wood trade is another potential vector for pests and diseases. Currently there is an aim to halt import of Birch timber (Betula spp.) because of the threat from the Bronze Birch Borer (Agrilus anxius); a pest native to North America.
Climate change and tree pests/pathogens
The establishment of new pests and pathogens has been helped by milder and wetter winters in recent decades, and the situation is predicted to get worse.
The map (left) shows risk modelling by scientists at Forest Research for Phytophthora kernoviae and P. ramorum (sudden oak death) in the UK. This was based on an average annual climate for the UK using parameters adopted in predicting the disease development in California by Meentemeyer et al. 2004 (see ref below). By considering climate factors such as rainfall, maximum and minimum temperature and relative humidity, it seems that the western fringes of the UK are most at risk. However, it is important to note that such modelling does not consider current host distribution and abundance, nor microclimates.
A recent scientific article by Netherer and Schopf (see section below) studied the potential effect of climate change on insect pests, using the oak processionary moth as a case study. It seems that in southern European conditions will become generally less suitable for tree pests (and the trees!) due to increased drought and wild fires, while current northern limits will shift northwards in latitude. New pests and pathogens are therefore likely in boreal forests of continental Europe and in other new areas such as the UK. So a combination of favourable climate with the help of man in the global trade of materials is a lethal combination for our trees.
Risk management in the UK
The UK Government established the Forestry Commission Biosecurity Programme Board in 2010. Its aims are to:
“Preserve the health and vitality of our forests, trees and woodlands through strategies which exclude, detect, and respond to, existing and new pests and pathogens of trees, whether of native or exotic origin.”
March 11, 2011
Changes projected in the climate will affect tree growth in most parts of the world. Warmer and wetter conditions in many temperate regions, at certain times of the year, will favour many trees. But if the trees grow faster will this be good for sequestering carbon and for producing more home-grown timber?
For conifers that produce softwood timber, their accelerated growth will lead to a fall in timber density and therefore strength. As a large part of the market for softwood is the construction industry then the consequences may be quite serious.
Broadleaved trees producing hardwood timber on the other hand are likely to be affected positively by a warming climate, as a longer growing season will lead to increased yields without loss of strength. Why?
Broadleaved trees can be split into two types in terms of their hardwood timber character.
1. Diffuse-porous wood type: timber quality is independent of growth rate. Species include beech, birch, wild cherry, maple and sycamore.
2. Ring-porous wood type: these act the opposite of softwoods, becoming denser, harder and stronger with increased growth rate. Species include ash, oak, sweet chestnut and walnut.
So what does this mean for carbon management in our woodlands? Simply, the better the quality of timber produced the greater the carbon sequestration; as the carbon is locked into solid wood products for longer. The long rotation time (time between planting, felling and restocking) and the high long-term yields are also factors in favour of hardwood forestry for carbon sequestration.
November 2, 2010
What are the top ten most important priorities facing trees in the 21st Century?
Policy is traditionally led by civil servants with the agenda of delivering Government policies. However, these may not always reflect the views and the vision of the experts and practitioners amongst an industry. They may also be out of step with practical requirements, particularly in forestry where life cycles are so many times greater than any Government policy; a point I made in Slow-growing trees, fast-changing policies.
I have been involved in a project over the last two years that set out to ask the forestry community what it believed were the most important priorities for trees and forestry, and how the scientific community should respond. The initiative was called the T10Q project.
An online survey was used to collate responses from 481 researchers, policy makers and woodland owners, who contributed 1594 research questions. These were debated and prioritised by 51 participants from the UK and Republic of Ireland who attended a workshop at the University of Oxford. The results:
The Top Ten Questions for forestry
1. What are the most technically and financially effective ways of identifying, monitoring and controlling invasive species, pests and disease?
2. How can we achieve better understanding between foresters and other parts of society?
3. What are the most effective landscape planting schemes to ensure connectivity between woodland fragments while maintaining connectivity between other land use types?
4. How will climate change affect both natural forest ecosystems and forestry and how should management be adapted to minimize adverse impacts and optimize benefits?
5. What is the value of forestry to human health and well-being?
6. Who are the private woodland owners and how can they be engaged and influenced? What are their concerns?
7. Which parts of forest ecosystems form the largest and most stable carbon pools and how are these impacted by forest management and climate change?
8. How can we address the economic, environmental, social and institutional constraints of expanding woodfuel in the UK?
9. What species or provenances should we be considering in relation to a range of forestry systems including urban and agroforestry, in the light of climate change?
10. What are the barriers to knowledge transfer in forestry from research to practice and how can they be removed?
The story behind this work and the full details were recently published in a scientific journal. Read the full article.