There are many challenges to both the creation of greenspace and its protection during wider urban development. For example, sites that are to be developed to a green end-use often suffer from physical problems (e.g. soil compaction) and chemical problems (e.g. contamination), which must be treated prior to vegetation establishment. The quality of the wider environment (e.g. air pollution), and the position of a site in relation to existing green infrastructure, which may change as a result of other development, will all influence sustainability. Social factors (e.g. perceptions, vandalism, and fear of crime) will also greatly influence the success of any scheme.

These challenges can be overcome by defining achievable objectives for a site, and considering the development within a wider planning framework. Threats to existing green infrastructure, for example through trenching for service utilities or claims of subsidence risk, require special consideration.

Some commonly encountered or perceived challenges and threats to greenspace are given below.

Development

• Development pressure
• Trees around buildings
• Tree roots and trenching

Site level

• Invasive species
• Soil compaction
• Soil contamination
• Soil function

Social

• Crime and vandalism
• Social and environmental justice
• Social perception

Wider environmental

• Air pollution
• Biosecurity
• Climate change
• Habitat fragmentation