The colonisation by vegetation of colliery spoil heaps in the Forest of Dean, Gloucestershire, and implications for biodiversity management

  • V. G. Fletcher

    Student thesis: Master's Thesis


    In the Forest of Dean Coalfield industrial activities have created a landscape where colliery spoil heaps have ecological, cultural, historical and amenity interest. Sensitive management of the sites is therefore important. The study aims to provide information relevant to their conservation management. This is particularly valuable due to the cull of all 'free-roaming' Forest sheep following Foot and Mouth Disease (2002).

    A chronosequence was constructed by applying selection criteria to more than 30 spoil heaps of different ages. On the 36-year site, one grazed plot was selected and one enclosed plot. Floristic and environmental data (pH, pyrites content, slope factor and aspect, canopy cover and plant vigour) were collected from 8 plots ranging 0-100 years since disturbance. Correlation analysis was used to identify potential relationships between the vegetation and environmental data. Floristic data were analysed using complementary multivariate analysis techniques, TWINSPAN and DCA. Mean (S)/quadrat and Shannon 'E' diversity indices were calculated.

    Succession was measured using a series of 'expected trends'. Species-richness increased over time until 60 years since disturbance, but the species-evenness pattern did not appear to be affected by time or pH. The bryophyte layer colonised plots over 16 years since disturbance rather than starting the succession, and its abundance appeared to be affected by aspect more than age.

    On the 36-year site, the grazed plot had developed a higher species diversity that the non-grazed plot, but woody species were starting to colonise. Temporary exclusion of grazing was recommended on plots vulnerable to disturbance in order to reduce additional pressures from grazing. However, management techniques would still be required on sites valued as open grassland or heathland habitats to prevent potential colonisation by woody species.
    Date of Award2018
    Original languageEnglish


    • plan succession
    • primary succession
    • chronosequence
    • derelict land
    • colliery spoil
    • Forest of Dean
    • nature conservation
    • Biodiversity
    • species diversity
    • species-area effect

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