This case study is
based on the management of a marsh fritillary buttefly Eurodryas
aurinia population at Rhos Llawrcwrt National Nature Reserve from
1992 to 2006. From 1991 David Wheeler was the manager of this
site. This account is taken from his account of the way in
which the CMS plan was created and
adapted. In
particular he demonstrates the way in which an adaptable approach
to a specific management plan has taken place over three
decades. The plan has been adapted resulting from the
combined results of developments in the planning logic and its
practical application.
Significant changes have been in the
objective as a consequence of developments in management planning
and our understanding of what a smart objective should
be.
The objectives are also adapted to reflect
improvements in science, and particularly a better understanding of
the survival strategies and requirements of the
species.
Management of the
marsh fritillary population must take account of changes in the
butterfly population, changes in factors affecting the population
and new research informing understanding the ecology of the
butterfly. An adaptable approach to management is therefore
essential. Management objectives must also be adaptable in response
to better understanding of ecological systems.
The site manager
will need to balance short-term benefit against long-term gain. For
example, David Wheeler says:
" in retrospect, I would like to have avoided
the winter poaching of the improved fields that resulted in the
spread of Juncus. Science is an essential management tool. It
supports important judgements on management. However, the site
manager must interpret scientific data very carefully. Setting of
stocking levels was critical to the management of the habitat on
the NNR. The graph below shows stocking rates and vegetation height
and demonstrates that the relationship between the two is not
straightforward (Fig. CS 4.7). At low stocking levels, stock do not
graze an entire enclosure evenly but preferentially select certain
areas. The response of the vegetation to grazing is not the same
every year, mainly because growth rates are influenced by climate
conditions. A large element of informed judgement is often
required.
Index data from 2005 and 2006 suggests that the
butterfly population on the western block is building up to a peak,
possibly in 2007. There may once again be thousands of butterflies
emerging on the NNR. Given that the population is still one ot the
largest in the UK. it would be very easy to be complacent and be
content with the population being confined to the current areas of
unimproved rhos pasture on the western block. This would be nothing
short of foolhardy. Who knows what the future will bring and what
it will mean for this butterfly? The precautionary principle must
be applied and every effort made to increase the long-term
viability of the population at Rhos Llawrcwrt".
This example has
been taken from the Chapter 4 , Management Planning for Nature
Conservation, Springer, 2008
