The plant ecology of re-vegetated peat cuttings in ombrotrophic mires, with special reference to Thorne Moors, S. Yorkshire.

1. The plant ecology of re-vegetated peat cuttings in ombrotrophic mires was investigated to elucidate factors having a major influence on the vegetation, with the aim of formulating management guidelines for the rehabilitation of such areas for nature conservation. 2. Most of the investigations were carried out at Thorne Moors, a cut-over derelict raised bog near Doncaster, S. Yorkshire. 3. The vegetation of the wide range of abandoned peat cuttings present at this site is described. Particular attention was paid to re-vegetated peat cuttings within an area comprising a series of cuttings, baulks and canals abandoned about 1920, now a proposed National Nature Reserve. Successional, hydrological and chemical factors and processes important in determining the distribution of vegetation were investigated. 4. Stratigraphical investigations show that some species which recolonized the abandoned peat cuttings (e. g. Sphagnum imbricatum and S. magetlanicum) have disappeared from the site since 1920. They have been replaced by species which were not major components of the undisturbed mire (e. g. Sphagnum recurvum and S. fimbriatum). 5. The distribution of the vegetation in peat cuttings principally reflects the height of the water table. Hydrological studies have also shown that the methods used to maintain the water table in the proposed National Nature Reserve (dams in ditches and drains and peat baulks), a virtually isolated peatland block, are effective. The peat of the baulks appears to have an extremely low hydraulic conductivity which may be a result of drainage.