Bryophytes of springs and flushes - 2009 course notes - Plantlife

encourage natural regeneration by excluding grazing animals can be bad news for flushes as
the bryophytes can be overwhelmed by the growth of coarse vegetation or dense
regeneration of trees. There is a good (or should that be bad) example of this on the
Morrone NNR, where dense birch regeneration in exclosures is changing the nature of the
extensive flushes associated with the limestone there.
Trampling by livestock
Springs and flushes are attractive to livestock as they often offer localised patches of more
lush vegetation and a source of water during dry spells. Certain flushes seem to become
popular and attract large numbers of animals and can be badly poached. The damage by
poaching can look dramatic but as long as it does not persist for long periods, the bryophytes
can recover and some may even benefit. The obvious problem lies in those sites with a
small population of a particularly vulnerable species.
Management recommendations
Climate change and atmospheric pollution
The problems that face flushes on the higher hills are global in nature and regrettably are not
within the scope of the scale of management to which we might aspire!
Survey and assessment
Perhaps the most important management tool for the well-being of these diverse habitats is
to recognise both their presence and their local, and sometimes national, importance. This is
not always easy to achieve for features which are usually small in comparison to the area
being ‘managed’. Where large-scale changes to an area are being considered, be it for
woodland regeneration or windfarms, it is important that any prior assessment of the site is
competent to identify the conservation value of the bryophyte-rich springs and flushes that
may occur.
Drainage
To be effective, drainage has to target those areas where water movement can be enhanced
and by definition this means that the lines of flushes will be preferentially affected either by
drains running through them or water channelled into them. This means that if an area has
to be drained then any flushes will almost certainly be lost or at least radically altered.
Where the drainage is designed to protect installations or access tracks, it should be possible
to design this so as to have minimum impact on important spring and flush sites. At a
smaller scale it should be possible to avoid having ditches and culverts emptying into existing
flushes.
Forestry
Again, the best possibility of protecting flushes is at the design stage. It has to be accepted
that if the prime objective is to establish a woodland, then not all open flushes can be
preserved. However, if there are flushes of conservation interest on the site some effort
should be made to limit disturbance to these sites. Not only does this mean not planting
through the flush but also retaining an open buffer zone around the flush so that shading and
litter fall are also limited. It is probable that, over time, the nature of the run-off will alter and
even those flushes that are undisturbed will change in nature but may still have interesting
bryophytes.
Poaching by livestock and deer
Where poaching is limited in both extent and duration, its effects on the flush vegetation are
likely to be moderate given that these are dynamic habitats. Poaching may even be
beneficial in restricting the growth of rapidly growing, carpet-forming, vascular plants like
Montia fontana and Chrysosplenium oppositifolium. Where stocking levels are consistently
high it is likely that most flushes will have been altered by eutrophication as well as poaching,
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