Monitoring the benefits of greening

 

Once brownfield sites are remediated it is important that their success is chronicled methodically in order to demonstrate that:

• Sites meet the aims and objectives set for them and there reclamation has brought true socio-economic and environmental benefits
• Remediation and reclamation  best practice has delivered a sustainable solutions
• Any remediation which was carried out meets minimum standards for pollution control and receptor exposure.

It is also important to assess how future projects of a similar nature can learn from past experiences, e.g. in improvements to specifications, operational practice or refinements to aims and objectives.

For all these reasons, it is important to instigate a programme of site monitoring, especially after remediation has been completed.

Measurements and observations

The following table identifies impacts that have the potential to be used as criteria for monitoring sites post-remediation.  Many of the impacts relate to the regeneration, establishment and management processes of re-greening (for example references [2], [9] and [11]) and therefore provide vital information on the effects of greening and help us learn lessons in order to improve best practice.  Other impacts have been identified or have benefitted from academic research and references are given for these in the table below. 

Not all will be appropriate. Their use will obviously depend on the particular attributes of the site in question and it’s context within the surrounding environment.

Impact	Details	Evidence
Tree/woodland performance (by management unit)	Tree density (live stems per hectare)	Site management, establishment and best practice monitoring criteria
	Tree vigour/health (by species)
	Foliage condition/discolouration	[1]
	Nature of damaging agents (where appropriate).	Site management, establishment and best practice monitoring criterion
Stand management (by management unit)	Weed control efficacy	Site management, establishment and best practice monitoring criteria
	Tree shelter efficacy
	Fencing efficacy
	Wildflower performance (species composition and cover)
	Evidence of animal damage (type, frequency).
Site infrastructure condition	General appearance of site – landscape value	[2]
	Degree of vandalism	[3] and site management monitoring
	Amount of litter	Site management monitoring
Air Quality	Improved local air quality including particulate abatement	[4], [5], [6], [7]
	Urban cooling	[8], [9], [10]
Aesthetics and noise abatement	Visual screening of urbanised structures e.g. roads	(Intuitive impact)
	Noise abatement	[11], [12], [13], [14]
Water quality and management	Chemistry and turbidity of water at selected discharge points from site (sampling frequency and sampling and analytical methodologies to be set out)	[1], [15]
	Chemistry and invertebrate biology in permanent surface water features
	Reduced risk of flooding	[15], [16]
Public use of site	Degree of informal use (number of visits by category)	[2]
	Number of formal uses for site (per annum)	[17]
	Use by community and ethnic groups	The full affects on these impacts of re-greening are still being researched
	Use as an educational resource
Conservation value	Assessment of ground vegetation composition	[17]
	Invertebrate and bird surveys (as appropriate)	[18]
	Mammal, reptile and amphibian surveys (as appropriate).	[18]
Social value	Increase in public well-being	[19]
	Sense of ownership	[17]
	Risk perception	[3]
	Psychological effects	[3], [20]
Pollution issues	Integrity of pollution control measures, e.g. acceptable interaction with plant roots	Site management, establishment and best practice monitoring criteria
	Erosion extent and impact
	Compartmentation of contaminants in soil and vegetation	[15], [16]
	Potential of food chain transfer
	Contaminant exposure to human visitors	[21]
Economic benefits	Increased prosperity within the local area	[19], [22], [23], [24], [25]
Engineering aspects	Evidence of compaction and/or waterlogging	Site management, establishment and best practice monitoring criteria
	Tip stability
	Engineering structures functionality (e.g. berms, drains, culverts)
	Road and path condition (fitness for purpose)
	Evidence of uncontrolled flooding on/from site
	Evidence of landslip
	Evidence of leachate breakout

References

1. Freer-Smith, P.H. and D.B. Read, The relationship between crown condition and soil solution chemistry in oak and Sitka spruce in England and Wales. Forest Ecology and Management, 1995. 79(3): p. 185.
2. Nijkamp, P., C.A. Rodenburg, and A.J. Wagtendonk, Sucess factors for sustainable urban brownfield development: A comparative case study approach to polluted sites. Special Section: Economics of Urban Sustainability. Ecological Economics, 2002. 40: p. S235-S252.
3. Kuo, F.E. and W.C. Sullivan, Environment and Crime in the Inner City: Does Vegetation Reduce Crime? Environment and Behavior, 1999. 33(3): p. 343-367.
4. Taha, H., Modeling impacts of increased urban vegetation on ozone air quality in the South Coast Air Basin. Atmospheric Environment, 1996. 30(20): p. 3423-3430.
5. McPherson, E.G., K.I. Scott, and J.R. Simpson, Estimating cost effectiveness of residential yard trees for improving air quality in Sacramento, California, using existing models. Atmospheric Environment, 1998. 72(1): p. 75-84.
6. Beckett, K.P., P.H. Freer-Smith, and G. Taylor, Urban woodlands: their role in reducing the effects of particulate pollution. Environmental Pollution, 1998. 99(3): p. 347.
7. Yang, J., et al., The urban forest in Beijing and its role in air pollution reduction. Urban Forestry & Urban Greening, 2005. 3(2): p. 65-78.
8. Brack, C.L., Pollution mitigation and carbon sequestration by an urban forest. Environmental Pollution, 2002. 116(Supplement 1): p. S195-S200.
9. Akbari, H., Shade trees reduce building energy use and CO2 emissions from power plants. Environmental Pollution, 2002. 116(Supplement 1): p. S119-S126.
10. Shashua-Bar, L. and M.E.M.E. Hoffman, Quantitative evaluation of passive cooling of the UCL microclimate in hot regions in summer, case study: urban streets and courtyards with trees. Building and Environment, 2004. 39(9): p. 1087.
11. Fang, C.-F. and D.-L. Ling, Guidance for noise reduction provided by tree belts. Landscape and Urban Planning, 2005. 71(1): p. 29-34.
12. Fang, C.-F. and D.-L. Ling, Investigation of the noise reduction provided by tree belts. Landscape and Urban Planning, 2003. 63(4): p. 187.
13. Martens, M.J.M., Noise abatement in plant monocultures and plant communities. Applied Acoustics, 1981. 14(3): p. 167-189.
14. Brown, A.L. and A. Muhar, An approach to the acoustic design of outdoor space. Journal of Environmental Planning and Management, 2004. 47(6): p. 827-842.
15. Willis, K.G., Benefits and costs of forests to water supply and water quality. Social and Environmental Benefits of Forestry Phase 2, in Report to the Forestry Commission. 2002: Edinburgh.
16. Hartanto, H., et al., Factors affecting runoff and soil erosion: plot-level soil loss monitoring for assessing sustainability of forest management. Forest Ecology and Management, 2003. 180(1-3): p. 361.
17. Dunnett, N., C. Swanwick, and H. Woolley, Improving Urban Parks, Play Areas and Open Spaces, ed. L.G.a.t.R.D. The Department for Transport. 2002, London: Stationary Office. 217.
18. Angold, P., et al. Biodiversity in Urban Habitat Patches: URGENT Annual Meeting 2000 Proceedings: Ecology Science Project Presentations. 2005 [cited 2005 20th July]; Available from: urgent.nerc.ac.uk/Meetings/2000/2000Proc/ecology/angold.htm.
19. De Sousa, C.A., Turning brownfields into green space in the City of Toronto. Landscape and Urban Planning, 2003. 62(4): p. 181.
20. Taylor, F.A., F.E. Kuo, and W.C. Sullivan, Coping With ADD: The Surprising Connection to Green Play Settings. Environment and Behavior, 2001. 33(1): p. 54-77.
21. Nowak, D.J., et al. Understanding and quantifying urban forest structure, functions, and value. in Proceedings of the 5th Canadian urban forest conference. 2002. Markham, Ontario, Canada: Urban Forest Council.
22. Gatrell, J.D. and R.R. Jensen, Growth through greening: developing and assessing alternative economic development programmes. Applied Geography, 2002. 22(4): p. 331.
23. Hanley, N., et al., Valuing the benefits of biodiversity in forests. Social and Environmental Benefits of Forestry Phase 2, in Report to the Forestry Commission. 2002: Edinburgh.
24. Willis, K.G., et al., Non-Market Benefits of Forestry: Phase 1, in Report to the Forestry Commission. 2000: London.
25. Thériault, M.K.Y. and F. Des Rosiers. The impact of mature trees on house values and on residential location choices in Quebec City. in Integrated Assessment and Decision Support. Proceedings of the 1st biennial meeting of the International Environmental Modelling and Software Society. 2002. University of Lugano, Switzerland.