Reintroduction of fen plant communities on a degraded minerotrophic peatland

We have developed an approach to restore bogs after peat extraction, but, when sedge-peat layers are exposed, the minerotrophic remnant peat conditions require restoration towards a fen ecosystem. Three restoration techniques, all including rewetting actions, were tested to assist fen vegetation recovery. None of the restoration techniques were effective at establishing fen bryophytes. However, for vascular plants, two techniques gave promising results in terms of species composition, although the vascular plant cover remained lower than in the reference fens. Depending on the site conditions, we suggest applying two restoration techniques to restore peatlands in areas of exposed sedge peat. In areas where sparse cover of fen species may have spontaneously established, rewetting should be carried out to raise water levels and create favourable conditions for their expansion. In areas covered with undesirable species or with inadequate topography for rewetting, surface peat should be remodeled and vegetation introduced. Since mechanized diaspore transfer did not result in a satisfactory cover of fen plants, other means of introduction could be considered, alone or in combination. A complementary fertilization experiment showed that fertilization with phosphorus could be an effective solution to enhance the establishment of mechanically introduced plant diaspores.

Patterns of distribution of microfungi in decomposing bog and fen plants

The microfungal assemblages from the litter of the dominant vegetation of a forested bog and a riverine, sedge-dominated fen in southern boreal Alberta, Canada, were investigated over a 2-year period. Canonical correspondence analyses showed distinctly different fungal communities associated with litter of the dominant plant species of this bog (Sphagnum fuscum (Schimp.) Klinggr.) and fen (Carex aquatilis Wahlenb. leaves and rhizomes and Salix planifolia Pursh leaves and roots). Plant tissue quality variables, including total phosphorus and total nitrogen tissue concentrations, correlated most strongly with the fungal communities. In contrast, site-specific environmental (surface water chemical variables) and physical (peat and water temperatures, water level) variables were not correlated with the fungal communities of these five decomposing fen and bog plant litters. Of 93 identified fungal taxa, 25% occurred exclusively in the bog and 56% occurred exclusively in the fen. Eighteen species (19%) were common to the materials examined from both peatlands. Several species of (i) Aspergillus, Mortierella, and Oidiodendron were restricted to the Sphagnum litter in the bog, and species of (ii) Phialophora, Phialocephala, Fusarium, Dimorphospora foliicola, Monocillium constrictum, and several basidiomycetes were restricted to the Carex and Salix plant litters in the fen. These taxa constitute components of the bog and fen fungal communities, respectively.Key words: fungal communities, decomposition, bog, fen, canonical correspondence analysis (CCA).

Studies in the Post-glacial history of British vegetation XIV. Late-glacial deposits at Moss Lake, Liverpool

Investigations of deposits at a built-over site near the centre of Liverpool disclose a basal stratigraphic sequence characteristic of the west-European Late-glacial period. Detailed pollen analyses confirm that the deposits extended from the Late-glacial (Zone I) to the Post-glacial thermal maximum (Zone VII a ). The lake was overgrown in Zone VI by floating sphagna , and in Zone VII a typical raised bog developed. Macroscopic remains of lake and fen plants were recovered in great abundance and together with frequent non-tree pollen these permitted a detailed reconstruction of the vegetational history of both the lake and the surrounding upland. Several species of notably disjunct or restricted present-day range have been recorded here, Cotoneaster cf. integerrima Medic., Elatine hexandra (Lapierre) D.C., Lycopodium annotinum L., Pilularia globulifera L., and Linum anglicum Mill., whilst tentative identification of species such as Agropyron junceiforme, A. & D. Löve, Gentiana campestris (L.), Lotus uliginosus Schkuhr, and Vicia sepium L. cast new light on the natural status of other British plants. Numerous further records confirm and extend our knowledge of the history of the British flora, especially in the Late-glacial and early Post-glacial periods.