References and links
1. The Forestry Commission is actively involved with the climate change issue and details of its various initiatives can be found at: www.forestry.gov.uk/climatechange
See also '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', Read DJ, Freer-Smith PH, Morison JIL, Hanley N, West CC, and Snowdon P (eds), The Stationery Office, Edinburgh, 2009. Both the synthesis and main science report are available from: www.forestry.gov.uk/readreport
2. A recent study of Kielder Forest's 150 million trees indicated they sequester 82,000 tonnes of carbon each year - so it is calculated that each tree is locking up 0.546kg of carbon annually, equivalent to 2kg of CO2. A study by Lancaster University of trees in the West Midlands estimated that the total amount of carbon stored in trees within that conurbation represented the equivalent of three week's CO2 emissions. Finally, in 'Forestry Matters', published by Forestry Commission Scotland are a number if interesting comparative examples of trees' capacity to store carbon in relation to typical energy usages, e.g. 5 cubic cm of Sitka spruce contains the same amount of carbon as would be emitted by a boiling kettle, while 6 cubic m of timber (i.e. a timber-framed house) is equivalent to driving an average petrol car for a year (11,000 miles).
3. See 'Preventing greenhouse gas emissions through wood substitution', Journal of Forestry, Chapter 3, 2008
4. Data sourced from 'The UK Low-carbon Transmission Plan'. Although burning wood releases CO2, this is offset by the additional CO2 being absorbed by the new trees planted in place of those harvested as woodfuel. See also Forest Research's 'Wood Fuel Information Pack' available at: www.forestresearch.gov.uk/woodfuel
5. Every 5% increase in tree cover reduced water run-off by 2%, cited in 'The role of woodland in flood control: a landscape perspective'. Nisbet TR, Thomas H, Forest Research; 'Identified Benefits of Community Trees and Forests', Coder KD, University of Georgia Cooperative Extension Service - Forest Resources Publication FOR96-39, 1996; 'How trees fight climate change', American Forests, 1999; 'Opportunity Mapping for Woodland to reduce flooding in the Yorkshire and the Humber region', Broadmeadow S. & Nisbet T., Final report to Forestry Commission England 2009; 'Loss of trees increases storm water runoff in Atlanta', Soltis D, in Water Engineering and Management 144, 1997.
6. 'The potential of vegetation in reducing summer cooling loads in residential buildings', Huang YJ, Akbari H, Taha H & Rosenfield AH, Journal of Climate and Applied Meteorology 26, 1978; ' Improving urban parks, plays areas and green spaces', Dunnett N, Swanwick C, Woolley, H., Urban Research Paper, DTLR, May 2002; 'Quantifying urban forest structure, function and value: the Chicago Urban Forest Climate Project', McPherson E.G., Nowak D., Heisler G, Grimmond S, Souch C, Grant R, Rowntree R, Urban Ecosystems 1, 49–61, 1997; 'Benefits of urban trees', Michigan State University Extension, #07269501; 'Adapting cities for climate change: the role of green infrastructure', Gill SE, Handley JF, Ennos AR & Pauleit S, Built Environment 33, 2007; ‘The essential role of trees – adapting cities to climate change by managing high temperatures and reducing pressure on drainage systems’, Gill S in proceedings 'Trees & Urban Climate Adaptation: a sociable agenda for living cities', 19th November 2009.
7. It is acknowledged that trees provide shelter and reduce wind speed, thereby cutting heat loss from buildings during winter. While their added shade in the summer can cut household temperatures and reduce the demand for energy-hungry air-conditioning.
8. 'Bird life of woodland and forest', Fuller RJ, Cambridge University Press, 1995, who stressed the importance of woodland structure alongside tree species composition; 'Small urban woodlands as biodiversity conservation hot-spot: a multi-taxon approach', Croci S, Butet A, Georges A, Aguejdad R & Clergeau P, Landscape Ecology, 23(10), pp1171-86, 2008.
9. 'Biodiversity by Design: A guide for sustainable communities' Town and Country Planning Association (TCPA), London, 2004; 'Coping with ADD - The Surprising Connection to Green Play settings' Taylor AF, Kuo FE, Sullivan WC, Environment and Behaviour 33 (1), pp54-77, 2001.
10. It has been calculated that a football pitch-sized area of woodland removes a sack of potatoes weight of particulates in a year.
11. 'Ecological Functions within a Sustainable Urban Drainage System', Jackson JI & Boutle R, 11th International Conference on Urban Drainage, Edinburgh, Scotland 2008; 'Identified benefits of community trees and forests', Dr. Kim D. Coder, University of Georgia, Oct 1996; 'Trees and Water – A Forestry Perspective', Nisbet TR, Thomas H & Broadmeadow SB, Journal of Practical Ecology and Conservation 7(1): pp100-103, 2008.
12. 'Using woodland for soil protection and sediment control', Nisbet TR, Orr H, and Broadmeadow SB, In Proceedings of the SAC and SEPA Biennial Conference on Land Management in a Changing Environment, Edinburgh, 26-27 March 2008, pp 84-90, 2008.
13. 'Stress recovery during exposure to natural and urban environments', Ulrich RS, Simmons RF, Losito BD, Fiority E, Miles MA and Zeison M, Journal of Environmental Psychology 11, 1991; 'Restorative qualities of favourite places' Korpela K & Hartig T, Journal of Environmental Psychology 16: pp221-233, 1996; 'Assessing public perception of landscape: the LANDMAP experience', Scott A, Landscape Research 27, pp271-295, 2002.
14. 'Making the links: greenspace and quality of life', Land Use Consultants, 2005, demonstrated the converse when they reported that poor quality greenspace can negatively affect local activities and businesses, undermining an area's image and the confidence of both local inhabitants and potential investors.
15. Research by CABE Space in 'Does money grow on trees?', CABE, 2005, reported that, in the 8 UK parks they studied, proximity to them added a premium to house prices of between 5 to 7%; While a US study of parks claimed house values were between 10-20% higher; The value of US properties in tree lined areas was estimated as being 6% higher by 'Urban Forest Values: Economic Benefits of Trees in Cities', Wolf K, University of Washington College of Forest Resources, Factsheet 29, 1998; 'Benefits of community trees', Nowak DJ, USDA Forest Service General Technical Report; 'The contribution of trees to residential property value', Morales DJ, Journal of Arboriculture 6, 1980.
16. 'Urban Nature Benefits: Psycho-Social Dimensions of People and Plants', Wolf K, University of Washington College of Forest Resources, Factsheet 1, 1998
17. 'The role of Nature in the workplace', Kaplan R, Landscape and Urban Planning, 26, pp193-201, 1993. This study noted that office workers were less frustrated, more patient and displayed higher overall job satisfaction wherever they could see trees; consistent with these findings was 'Urban Forestry: planning and managing urban greenspaces', Miller RW, second edition Prentice-Hall, New York, 1997 which reported that employees who could see trees out of their office window were happier at work.
18. Several studies conducted in the US have revealed many benefits for business districts with trees, including customers' preparedness to pay more for parking and goods (between 9-12% more for some products) in landscaped malls. These studies include 'Trees in Business Districts - Positive Effects on Consumer Behaviour', Wolf K, University of Washington College of Forest Resources, Factsheet 30; 'Grow for the Gold', Wolf K [in] Tree Link 14, Washington State Department of Natural Resources, 1999; 'Public Response to the Urban Forest in Inner-City Business Districts,' Wolf K, Journal of Arboriculture 29(3), 2003. The quality of landscaping along approach routes to business districts positively influenced consumer perceptions, viz. 'Community Image - Roadside Settings and Public Perceptions, Wolf K, University of Washington College of Forest Resources, Factsheet 32, 2000.
19. 'Revealing the True Value of the Natural Environment in England', Defra, 2004. By way of an example, estimates for the East of England suggest its woodland "contributes to about 20% of the region's 'out of town' attractions" - cited in 'Regional Woodland Strategy for the East of England, Draft Consultation', June 2003
20. 'Managing Urban Spaces in Town Centres - Good Practice Guide', DoE and The Association of Town Centre Management, 1997
21. Although grass management practices vary considerably and it is difficult to arrive at national averages, an estimate based on Standard Costs for London, which assumes mown grass receives around 6 cuts a year, indicates an annual maintenance cost approaching £4,000 per ha per annum. Whereas tree/woodland maintenance, excluding fencing and mammal control, although also varying considerably, was never more than £2,000 per ha per annum. This is a significant cost advantage that, when considered alongside the additional possibility of greenspace with trees benefiting from woodland grants (EWGS), makes the installation of trees into greenspace doubly attractive.
22. 'Greenspace, urbanity and health: relationships in England', Mitchell R & Popham F, Journal of Epidemiology and Community Health. 61: pp681-683, 2007
23. 'Children living in areas with more street trees have lower prevalence of asthma', Lovasi GS, Quinn JW, Neckerman KM, Perzanowski MS, Rundle A, Journal of Epidemiology and Community Health 62(7): pp647-9, 2007; 'Trees and our air', Galveston-Houston Association for Smog Prevention, January 1999; 'The effects of urban trees on air quality', Nowak D.J., USDA Forest Service, Syracuse NY.
24. 'Aggression and Violence in the Inner City - Effects of Environment via Mental Fatigue', Kuo FE and Sullivan WC, Environment and Behaviour 33 (4), pp543-571, 2001; 'Open Space - a Literature Review', Morris, N., Edinburgh, 2003; 'Landscape planning and stress', Grahn P & Stigsdotter UA, Urban Forestry and Urban Greening 2 (1): pp1-18, 2003
25. 'View through a window may influence recovery from surgery', Ulrich RS, Science Journal 224, pp420-421, 1984; 'Stress recovery during exposure to natural and urban environments', Ulrich RS, Simmons RF, et al, Journal of Environmental Psychology 11, pp201-230, 1991; 'Urban Nature Benefits: Psycho-Social Dimensions of People and Plants', Wolf K, op.cit.
26. 'Physical activity as a possible mechanisms behind the relationship between greenspace and health: A multilevel analysis', Maas J, Verheij RA, Spreeuwenberg P, Groenewegen PP, BMC Public Health 8, 2008
27. There is a solid theoretical link between UVB/shading and improved skin protection.
28. 'Adapting cities for climatic change: the role of GI', Gill SE, Handley JF, Enoss AR & Pauleit S, Built Environment 33 (1), pp115-133, 2007; 'The potential of vegetation in reducing summer cooling loads in residential buildings', Huang YJ, Atawi H, Taha H, Rosenfield AH, Journal of Climate and Applied Meteorology 26 (9), pp1103 - 1106, 1997.
29. Tree lined routes not only provide a buffer between vehicles and pedestrians, but apparently such routes give the impression to drivers of narrowing the street, which duly encourages slower driving.
30. 'Assessing the Benefits and Costs of the Urban Forest, Dwyer JF, McPherson EG, Schroeder HW & Rowntree R, Journal of Arboriculture 18 (5), pp227-234, 1992; 'Identified Benefits of Community Trees and Forests', Coder KD, University of Georgia Cooperative Extension Service - Forest Resources Publication FOR96-39, 1996.
31. 'Environment and Crime in the Inner City. Does Vegetation Reduce Crime?' Kuo FE & Sullivan WC, Environment and Behaviour 33 (3), pp 343 - 367, 2001; 'Aggression and Violence in the inner city: Effects of Environment via Mental Fatigue', Prof. Kuo FE & Sullivan WC, Environment and Behaviour 33 (4) July, pp 543-571, 2001
32. 'People, parks and the urban green: a study of popular meanings and values for open spaces in the city', Burgess M, Harrison CM, Limb M, Urban Studies. 25, 455-473, 1988; 'The power of trees', Tina Prow, University of Illinois, Human Environmental Research Library
33. Research from Norway suggests that spending part of school time in small woodlands has a positive influence on 5-7 year olds' motor development skills - cited in 'Regional Woodland Strategy for the East of England, Draft Consultation', June 2003
34. Amanda Rend of the Royal College of Agriculture, UK found that plants in lecture halls had positive effects on students and noted that inattentive behaviour signs were much lower.
35. The Mayor’s London Plan is a spatial development strategy that sets out an integrated economic, environmental, transport and social framework for the Capital's development over the next 20-25 years - web link: www.london.gov.uk/thelondonplan
36. An investigation by Manchester University, as part of a wider programme of research into Adaptation Strategies for Climate Change in the Urban Environment (ASCCUE), focussed on the urban environment, assessed climate change impacts and developed and tested appropriate adaptation responses through spatial planning and urban design. Continuing investigation indicates that increasing tree cover by ten percent can reduce the surface temperature of a city by between three and four degrees Celsius, thereby reducing the 'urban heat-island' effect.
37. The selection of more appropriate tree species can also present a productive landscape opportunity.
38. The GreenArc partnership's commitment is to: conserve the Green Belt and enhance its public use, landscape and wildlife; increase and expand the open space and green corridors available for public enjoyment across the area; protect and improve biodiversity and wildlife.
39. ‘The Coalition: Our programme for government’, Cabinet Office, May 2010
40. Cabinet Office, 11th May 2010
41. Cabinet Office, 18th May 2010
43. Budget 2010, Return to an order of the House of Commons, 22nd June 2010
45. Islington Tree Strategy link: www.islington.gov.uk/DownloadableDocuments/Environment/Pdf/greenspace/a_policy_for_trees_in_islington.pdf
46. 1APP link: www.planningportal.gov.uk/PpApplications/genpub/en/Ecabinet
47. TPO link: www.communities.gov.uk/publications/planningandbuilding/tposguide
48. Conservation Areas web link: www.direct.gov.uk/en/HomeAndCommunity/Planning/PlanningPermission/DG_10026179
49. Tree felling web link: http://www.forestry.gov.uk/forestry/infd-6dfk86
50. BS5837 web link: http://shop.bsigroup.com/en/ProductDetail/?pid=000000000030139494
51. Cited in 'No trees, no future' published by Trees & Design Action Group (TDAG), published February 2010. Chapter 6 of this report deals with a range of problems associated with trees in development.
55. ibid., it is observed that the concept of valuing ecosystem services provided by trees is becoming more widely appreciated and 'An introductory guide to valuing ecosystem services' published by Defra, 2007, is cited as a reference in this publication.
56. For a fuller assessment of the four valuation methods see 'Application and methodologies: a review', Vadims Sarajevs, Forest Research, 2010. Also note the 'Summary of Tree Valuation Based on CTLA Approach' - Council of Tree and Landscape Appraisers (CTLA), 2003.
57. In Appendix 2 of CABE Space's 'Making the invisible visible: the real value of park assets', published in 2009 are examples of tree valuations conducted in two UK parks. At Highbury Fields in Islington, using the CAVAT system, its 578 trees were valued in 2008 at £44,960,886. While in the same year 6,756 mature trees were valued, using the Helliwell system, at Sefton Park in Liverpool at £86,645,700.
58. Forest Research is a world leader in the research and development of sustainable forestry and Britain's principal organisation for forestry and tree related research: www.forestresearch.gov.uk
60. View this programme at: www.forestry.gov.uk/GI-east
61. For a demonstration of this mechanism see: 'Transforming landscapes - transforming lives', Forestry Commission, 2010
Additional links
Forest Research - http://www.forestry.gov.uk/landregeneration;
Sustainable Cities - www.sustainablecities.org.uk/public-space/;
The London Plan, 'Trees and Development Sites Supplementary Planning' - www.london.gov.uk/thelondonplan/spg-bpg.jsp;
TCPA - www.tcpa.org.uk;
Glossary
Ancient Woodland: Ancient Semi-Natural Woodlands are woods that have been part of the landscape since the Middle Ages, i.e. continuously wooded since at least 1600 AD. It is generally considered that a wood present in the 1600s was likely to have developed naturally on undisturbed soils.
Carbon sink: A forest acts as a carbon sink as long as it continues to effect a net transfer of carbon (in the form of CO2) from the atmosphere to the forest.
Greenhouse gases: Any gas in the atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the 'greenhouse effect'. Common examples include water vapour, carbon dioxide, methane, nitrous oxide and ozone.
Green Infrastructure: While there are many different meanings of this term in circulation, the Forestry Commission subscribes to the following definition: Green Infrastructure is a network of multi-functional greenspace, both new and existing, both urban and rural, which supports natural and ecological processes and is integral to the health and quality of life of sustainable communities.
Landscape-scale: A holistic development approach over large areas potentially involving a number of projects. Such programmes are not confined to single issues but can embrace a wide range, including biodiversity, local economies and agriculture.
Low-carbon options: A wide range of products, services and practices that offer reduced carbon consumption opportunities.
Peri-urban: The urban fringe around the edges of towns and cities is a patchwork of multiple land uses, including housing, underutilised, derelict and agricultural land that can be converted into publicly accessible and valuable greenspace.
Productive landscapes: A term indicating an intention to derive some form of economic benefit from environmental/social landscapes.
Sequestration/sequestering carbon: The act of removing CO2 from the atmosphere and (in the case of trees) storing it in biological material.
Sustainable Urban Drainage Systems (SUDS): A sequence of water management practices and facilities designed to drain surface water in a way that provides a more sustainable approach than the conventional practice of routing run-off through a pipe to a watercourse.
'Urban heat-island': A built-up area that is significantly warmer than less densely developed or rural areas surrounding it.
Woodfuel: The calorific value of wood for heat generation compared to many fossil fuels is impressive, while the comparative energy costs are relatively low. Thus the use of woodfuel in heating as a replacement for burning fossil fuels can reduce carbon dioxide emissions considerably. Schemes are underway across the UK to bring under-managed and non-managed woodland into use as sources of bio-energy supply that at the same time improve the environment and generate woodfuel income for their owners.
Further Reading
'A Strategy for England's Trees, Woods and Forests', Defra, 2007;
'Delivery Plan 2008 - 2012 - England's trees, woods and forests', Forestry Commission, 2008
'Combating climate change - a role for UK forests' TSO, 2009
'Application and methodologies: a review', Vadims Sarajevs, Forest Research, 2010
'Green Infrastructure Guidance', Natural England, 2009
