An excellent briefing paper ‘Urban Green Infrastructure and Ecosystem Services’ has just been released – this is a responsive policy briefings developed by the Parliamentary Office of Science and Technology based on mini literature reviews and peer review.
Ecosystem services are the benefits provided to humans by natural systems that range from food and water to recreation and climate regulation and elements of the natural environment that provide benefits to humans are referred to as ‘natural capital’ . The best outcome for ecosystem service provision is optimal human health and subjective well-being.
The EU defines green infrastructure strategy as: ‘a strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services – incorporating green spaces and blue if aquatic ecosystems are concerned plus other physical features in terrestrial and marine areas’. However, existing urban green infrastructure in the UK has not been strategically planned to deliver ecosystem services.
Research points to the benefits of exposure and frequency of exposure to green infrastructure for well-being – although the specific elements of the natural environment need further research to demonstrate clear correlation. In addition, there is growing evidence that green infrastructure can provide other ecosystem services in urban areas such as reducing the risk of flooding and cooling high urban temperatures. The demand for this will increase in relation to climate change.
The report goes on to define what constitutes an urban area plus the effects of increased urbanisation on the environment such as excessive air pollution form increased traffic in cities such as London and Birmingham and the statistically significant relationships between soil metal content and respiratory illness reported in Glasgow.
Natural capital – elements of the natural environment that provide benefits for humans -is discussed. The report states that the value of green infrastructure may be enhanced through appropriate management of its natural capital and that the Natural Capital Committee’s 4th Report recommends that local authorities and major infrastructure providers ensure that natural capital is protected and improved.
The Department for Business, Energy and Industrial Strategy has funded an Ordinance Survey open data initiative to map green spaces throughout Great Britain. The data collected, along with property information, will be used to value natural capital in urban environments. [Ordnance Survey releases open dataset and free map of Britain’s Greenspaces + OS MasterMap Greenspace Layer ] This will allow you to identify the variety of different greenspaces in any location plus provide information on their extent, function and accessibility, and the provision of ecosystem services.
The report identifies the following key services provided by ecosystem services with accompanying up-to-date references for links to research, reports and policy documents:
- Urban temperature regulation
- Provision of community food
- Improving air quality
- Reducing surface water flooding
- Noise Reduction
- Carbon Storage
- Environmental Settings and Biodiversity
The report discusses how levels of service provision can be assessed and rcognises that further research in relation to how biodiversity generates ecosystem services benefits in different urban habitats and at different scales may be required to be able to effectively assess ecosystem condition. The EU Biodiversity Strategy to 2020 requires member states to map and assess ecosystems with guidance for mapping and assessing urban ecosystems provided by the European Commission. [Mapping and Assessment of Ecosystems and their Services, Urban ecosystem, 4th Report, Technical Report 102]
The report also recognises that not all contributions from ecosystem services are positive – these may be actual or perceived – such as the negative effects on human health from pests and diseases. Cultural perceptions in relation to green infrastructure is mentioned and these may vary between individuals depending on factors such as age, gender and socioeconomic status. The importance of public consultation is recognised when green infrastructure strategies are being developed to overcome such cultural perceptions.
Planning Green Infrastructure
Strategically designed and planned, green infrastructure can deliver multiple benefits for human well-being with Birmingham, Manchester and London already developing green infrastructure plans to address this. [ Green Infrastructure Task Force Report, 2015, Natural Capital: Investing in a Green Infrastructure for a Future London] England’s National Planning Policy Framework requires that Local Plans should take account of climate change over the longer term, including factors such as flood risk, coastal change, water supply and changes to biodiversity and landscape. Two variables are the combination of low density urban areas of built land interspersed with green spaces and compact urban areas alongside separate, large, contiguous green space, such as city greenbelts with the proviso that some interspersion of accessible green infrastructure may be necessary to ensure that people continue to gain benefits. The report notes that despite the development of new ‘garden’ cities and towns in the UK and proposals for legislation for New Towns Development Corporations there are no planning rules based on available evidence for ecosystem service provision from garden cities and new town developments.
The development of urban green space strategies
The House of Commons Communities and Local Government Select Committee has recommended that local authorities work collaboratively with Health and Wellbeing Boards, and relevant bodies, to develop and publish joint park and green space strategies. The UK’s National Planning Policy Framework requires planning to be based on robust and up-to-date assessments of the needs for open space, sports and recreation facilities and opportunities for new provision. The assessments should identify specific needs and deficits or surpluses of open space, sports and recreational facilities in the local area. However, in the UK, local authorities directly manage only a small proportion of the green space in urban areas, creating challenges for strategic management of urban green space.
How best then to optimise urban green infrastructure? At present the emphasis on green space provision is its amenity outcomes rather than the benefits derived from ecosystem service. Lack of evidence in relation to the economic benefits is commonly sited as the most significant gap in the case for investing in green infrastructure.