Fen Management Handbook - Scottish Natural Heritage

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adjacent to the fen and not within the fen. Where adjacent fields are not grazed
as part of the unit, supplementary feeding must only be undertaken at the edge
of the fen on dry ground.
– Spring grazing hits hardest those species which start growing early. These
are often the most competitive species such as common reed (Phragmites
australis) and reed canary-grass (Phalaris arundinacea). If left ungrazed, these
tall fen species will swamp the lower-growing species which are less common
and more highly valued. Where birch scrub and/ or purple moor-grass (Molinia
caerulea) are a problem, graze intensively during March, April and May (0.5 to
1 head cattle/ha or 6 ewes/ha). Spring grazing can be beneficial for wetlands
but, if high stocking rates are used, it can result in livestock trampling the nests
of ground nesting bird species. Hence the importance of evaluating all the
important features on a site prior to undertaking any management
See Section 5: Fen Management and Restoration.
– Summer grazing can prevent flowering and seeding of key plant species and
may also cause trampling of birds nests.
Cattle grazing is effective for rush management and/or managing sward structure
for breeding waders. Although cattle tend not to graze rushes, they can destroy
dense tussocks by trampling. In addition, if rushes are mown and removed in
August, after the last wader chicks have fledged, cattle can then be introduced to
graze the aftermath and will eat some of the young rush growth.
There is clear evidence that grazing can be an extremely valuable tool for
maintaining and restoring conservation interest but grazing with the wrong type
or number of livestock, at the wrong time, or for too long, can have disastrous
consequences. Careful monitoring and adjustment of grazing regimes is therefore
essential to avoid any negative impacts on fen flora and fauna or the health of
grazing livestock.
6.2.6 Stocking rates and duration of grazing
Many variables influence and impact upon the ‘ideal’ grazing density. It is therefore
difficult to offer meaningful generic guidance on precise stocking levels. The aim is
to achieve the right balance between having sufficient animals to manage a range
of vegetation types across the site. The best way to establish the optimum grazing
regime is by trial and careful observation of ground conditions, the condition of the
grazing livestock and effect of grazing on habitat structure and species composition.
Extreme weather conditions, especially high rainfall must also be given due
consideration at all times throughout the year.
Cattle grazing an area of
fen and wet grassland
extending to over 50 ha
at Lough Beg, Northern
Ireland. The wetter areas in
the foreground are grazed
later when the ground
dries or when cattle have
exhausted higher wet
grassland and are forced
into the lower, wetter
areas in search of food (B.
Hamill).