The restoration of bogs has received
considerable attention in recent years.
Given that no truly natural bogs
remain in the lowlands of Britain (Lindsay &
Immirzi 1996), those who take on the
management of an ombrotrophic bog system,
particularly in the lowlands, are generally
faced with a site requiring significant, if not
substantial, ‘restoration’ management.
A considerable body of experience about
restoration methods for conservation purposes
has accumulated over the years and its
compilation in Brooks & Stoneman (1997)
for the UK and, for example, Dupieux (1998)
and Manneville, Vergne & Villepoux (1999)
for France, complements the detailed review
of restoration on commercially cut-over bogs
undertaken by Wheeler & Shaw (1995).
Concept of ‘restoration’
Ideally, the objective, and indeed the measure
of success for such activities, might be based
on complete restoration of all original
features. Some components of a peat bog
can, however, never be recreated (the peat
archive, for example). The practical objective
for peatland restoration must therefore be
focused on the reinstatement of an ecological
process rather than any particular end point.
For the purposes of the EU Habitats Directive
(EC Directive 92/43/EEC) the Commission
definition of “damaged raised bog capable of
natural regeneration” specifies that “there is a
reasonable expectation of re-establishing
vegetation with peat-forming capability within 30
years” (Romão 1996). Such wording makes it
clear that, in the European Commission view,
successful restoration is achieved when the
potential for peat formation once again exists.
In other words the resulting vegetation should
be one that is widely accepted as being
capable of forming peat. The timescale of 30
years can be regarded as a useful milestone
that encourages judgments of success to be
made within a specified period rather than
leaving the question completely open-ended.
The EC does not require the complete
reconstruction of a peat bog, with all its
structural features, within 30 years.
If the EC definition is taken as the
yardstick of restoration success (and it is
difficult to find specific or better alternative
forms of yardstick within the literature), the
key is clearly the establishment of appropriate
peat-forming vegetation. Given this
objective, it is very important to understand
the mechanisms by which such vegetation
types arise spontaneously when devising,
evaluating or choosing restoration techniques
for a particular bog.
Peat formation and restoration
This paper will consider the natural processes
of peat bog formation and structure, as they
relate to bog restoration via the establishment
of peat-forming vegetation. It sets out a
conceptual framework for these various
approaches, and compares the benefits of
differing restoration strategies.