The potential for utilising disturbed and contaminated sites for the production of willow short rotation coppice forestry

Rees, Stephen (2010) The potential for utilising disturbed and contaminated sites for the production of willow short rotation coppice forestry. MSc(R) thesis, University of Glasgow.

Abstract

The utilisation of disturbed and contaminated sites for the production of willow (Salix) short rotation coppice forestry is an area of opportunity that has not been fully addressed. The significant areas of contaminated and disturbed sites in the UK that require remediation represent an opportunity for exploring alternative low cost remediation strategies. Conventional approaches to site remediation have involved costly engineered solutions, solutions which clearly cannot be afforded on all contaminated and disturbed sites. As an alternative to hard engineered solutions this thesis considers the potential to utilise these areas for the production of willow short rotation coppice forestry. The planting of these sites with willow provides a potential income stream through the sale of the biomass produced. In addition willow short rotation coppice forestry provides many additional benefits to these sites such as their ability to absorb heavy metals, provide fast site enhancement and stabilisation, act as a carbon sink and as a potential route for the recycling of organic matter.

Current knowledge and experience of willow short rotation coppice forestry has been gained from its production on agricultural land. As part of this research a field trial was established on a capped former steelworks site to quantify the ability of contaminated and disturbed sites to successfully establish and promote the growth of willow. The silvicultural practices employed to grow willow Short Rotation Coppice were considered to assess their impact upon the survival and biomass produced at the end of each growing season, and specifically to consider whether adopting different management techniques were beneficial in growth conditions associated with disturbed and contaminated sites. The silvicultural practices considered in this field trial were the addition of fertiliser, the use of herbicide, rotation length before coppicing (1, 2 or 3 Years) and planting density (0.5 m and 1.0 m). In addition a further 18 clones were screened to consider their ability to establish and survive in such harsh growing mediums.

Results have indicated considerable variability within the field trial, which may be indicative of the heterogeneity of the growing medium. The main silvicultural practice in the field trial that influenced survival and growth was weed control. All other silvicultural practices used were considered to have less influence on the survival and growth of the willow. Yields obtained from willow short rotation coppice forestry grown on disturbed and contaminated sites fail to compare with those grown on the higher grades of agricultural land. On contaminated and disturbed sites however, survival rather than biomass yield is viewed as the key issue to ensure that ground cover is established.

Work undertaken by the Water Research Council to assess the potential of a rapid screening technique for willow establishment and survival on metal contaminated sites is replicated and expanded to other clones of willow and heavy metals. The results obtained from this quick and simple leaf disc screening trial would in the first instance seem to indicate that the leaf damage suffered by leaf discs obtained from differing clones of willow to be consistently more pronounced amongst individual cultivars. Limitations are imposed upon this quick screening test by the lack of available information to allow comparison of these screening trials with information for willows established in growing mediums of a similar metal contamination.

To fully appreciate the value of growing willow on disturbed and contaminated sites it is considered that the economic equation should be readdressed and that the value of additional opportunities/ benefits are included if the true value of utilising these sites for its production is to be demonstrated. Studies to identify the non-marketable benefits for woodlands and energy crops grown in Sweden are used to give an indication of the true economic value of growing willow SRC on disturbed and contaminated sites, and are used to provide an insight into the economic value that can be attributed to the social and environmental benefits of willow production.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Contaminated land, short rotation coppice willow
• Subjects: S Agriculture > SD Forestry; Q Science > Q Science (General)
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: Duncan, Dr. H. and Pulford, Dr. Ian.
• Date of Award: 2010
• Depositing User: Mr Stephen Rees
• Unique ID: glathesis:2010-1888
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 04 Jun 2010
• Last Modified: 10 Dec 2012 13:48
• URI: https://theses.gla.ac.uk/id/eprint/1888