Sustainable restoration of brownfield sites

Summary

Summary

Brownfield sites are often host to hostile conditions which have to be overcome to successfully and sustainably establish greenspace. Soils are often characterised by compaction and poor structure, low organic matter and poor fertility associated with their previous use or method of reinstatement. They may exhibit poor winter drainage or, at the other extreme, severe summer droughtiness. Some sites may completely lack soil resources and require the use of soil-forming materials to simulate soil conditions. Other sites may pose restrictions to tree growth through the presence of landfill caps, contaminants or other pollution control measures. The key to creating effective and sustainable greenspace is to plan for and create the correct site conditions, prior to first planting, which will enable trees and other vegetation to reach maturity.

Planning for brownfield land regeneration to woodland

Overview

Planning for brownfield land regeneration to woodland Practice Note contains six stages, each containing multiple tasks. Information presented on these pages should be used in conjunction with the Practice Note.

Each of the stages and tasks are presented, accompanied by detailed information concerning their characteristics (type, status, inputs, outputs), the implications of the stage and tasks to regeneration delivery and the skills required to deliver them.

The process presented is the ‘ideal’ approach to regeneration focusing on woodland end use; however the process is equally applicable to other forms of greenspace.

The process presented herein is supported by PRiSM, a Microsoft Project Model template to help you plan your regeneration project, and a Checklist of Questions.

Contact

Kieron Doick

Reducing soil compaction of brownfield sites

What are the best options for planting trees on brownfield sites with compacted soil?

Brownfield sites typically suffer from soil compaction. The processes involved in the remediation and reclamation of brownfield sites can also lead to soil compaction where best practice is not followed. Soil compaction inhibits plant growth as their roots struggle to take up water and nutrients. Poor root development also increases the risk of strong winds uprooting trees. Forest Research tested a range of cultivation methods to maximise the soil depth available for planting. Measurements of tree health and soil properties over five years showed that complete cultivation is the most effective method to alleviate compactions.

Status

2001-2006

Findings and Recommendations

• A model to predict the critical penetration resistance value at which plant rooting will be significantly affected
• Comparison of two methods for measuring penetration resistance: the penetrometer and the ‘lifting driving tool’
• The ‘lifting driving tool’ is the most cost effective and user-friendly method to assess soil compaction
• No benefit from post-planting soil loosening – use of industrial ‘rippers’ after cultivation makes no significant improvement to soil penetration resistance or tree health
• Complete cultivation recommended – soil compaction best alleviated with complete cultivation to a depth of 1.1 m

Publications

• Sinnett, D., Poole, J. and Hutchings, T.R. (2006). The efficacy of three techniques to alleviate soil compaction at a restored sand and gravel quarry. Soil Use and Management 22: 362-371.
• Sinnett, D. (2008). Complete Cultivation. Best Practice Guidance Note for Land Regeneration No. 13: Forest Research, Farnham.
• Sinnett, D., Poole, J. and Hutchings, T.R. (2008). Comparison of cultivation techniques for successful tree establishment. Forestry 81(5): 663-679.
• Sinnett, D., Morgan, G., Williams, M. and Hutchings, T.R. (2008). Soil penetration resistance and tree root development. Soil Use and Management 24: 273-280

Contact

Kieron Doick