Factor 1 - Status of
food-plant:
The percent index for the abundance of Succisa
prutensis on 53 transects representative of marsh fritillary
habitat on the western block not required not less than
30
Upper limit: Not required
Lower limit: not less than 30
Factor 2 - Average
sward height:
The average sward height on 53 transects
representative of marsh fritillary habitat on the western block
will be as follows:
Upper limit: 25cm
Lower limit: 8cm
Status of Feature:
Favourably maintained
Between 2000 and
2005, the fritillary population crashed and, again, David Wheeler
had to re-examine management practices (Fig. CS 4.6).
Remaining confident
that management was appropriate on the western block, the manager
was now anxious to pursue the reversion of agriculturally improved
fields in the NNR that had the potential to revert to a rhos
pasture type vegetation. These fields had been used to manage the
grazing programme up to 2000), taking stock coming off the
"unimproved rhos pasture' when required. Ongoing research into
appropriate reversion techniques was indicating that at least some
improved land had the potential to revert to rhos pasture and marsh
fritillary habitat. A programme of management was based on biomass
removal to reduce nutrient levels. The long-term aim was to revert
all improved pasture and thereby significantly extend the amount of
marsh fritillary habitat on the NNR. The winter grazing of the
improved pasture by ponies in the 1990s had created a certain
amount of poaching, leading to the spread of soft rush Juncus
effusus in some fields. This proved difficult to control and
required intensive cutting programmes followed by grazing of the
aftermath.
