Fen Management Handbook - Scottish Natural Heritage

8. Managing Fen Nutrient Enrichment
Section 4: Understanding Fen Nutrients explained nutrient
enrichment and the role of individual nutrients in relation to fens, and
how to assess evidence of enrichment. This section explores the
practicalities of different strategies which can be adopted to address
nutrient enrichment on fens. These fall into three main categories:
i. managing the source or root cause of nutrient enrichment
e.g. catchment management to prevent nutrients from
becoming available within the wider landscape through
appropriate land use;
ii. managing the nutrient pathway i.e. how nutrients get from
the source to the fen e.g. through reedbed filtration or creation
of buffer zones;
iii. on-site management/restoration of the fen habitat
to reduce the effects of enrichment by removing nutrients and/
or preventing the release of nutrients already accumulating
within the fen
On some fens it may be possible to treat the root cause of the
nutrient enrichment, whereas on others where no control can
be influenced over the underlying causes or sources, it may only
be possible to treat the symptoms. For example, if nutrients are
entering a site from a point source such as a stream, then creation
of a buffer zone or constructed wetland to help ‘mop up’ excess
nutrients and prevent them entering the fen may be appropriate.
However, if the nutrients are entering from a diffuse source such as
aerial pollution over which only limited control can be exerted locally,
then management of the fen itself to remove nutrients by vegetation
cutting and/or grazing may be required. Some practical options for
management of nutrient enrichment at each scale are presented
below.
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