Beach and Dune - Gower - page 147

Other notable plants found on the Gower dunes include ferns such as moonwort Botrychium lunaria ,
so called because its frond is fringed with half-moons, which is found in fixed dune grassland at Llan-
gennith and Oxwich. The very small and rare annual hutchinsia Hornungia petraea is locally common at
Pennard, Llangennith and Whiteford. Similarly lesser meadow-rue Thalictrum minus is locally common
in grassland at Whiteford and is usually associated with large numbers of pyramidal orchids Anacamptis
pyramidalis . The early sand grass Mibora minima is found at Whiteford (Fig. 78). The endemic British
species Isle of Man cabbage Coincya monensis is still abundant on Pennard Burrows, which is its south-
ernmost locality in Britain. This is some distance from its other stronghold on Formby Dunes in Lan-
cashire.
On fixed dunes the increased stability of the surface and the increased nutrient and moisture regimes
beneath the vegetation would normally allow scrub or woodland to develop. On dune systems such as
Whiteford this process is held in check by the grazing of ponies and rabbits, but where the grazing pres-
sureisreduced,bedstraw,marramandfalseoat-grass Arrhenatherum elatius grasslandswardsgrowrank,
with grasses such as red fescue, Yorkshire-fog and cock's-foot taking on a more tussocky appearance
and herbs such as hogweed, common knapweed Centaurea nigra and wild carrot growing profusely.
Continued absence of grazing may allow the invasion of bramble into the grassland, producing patches
of bramble and Yorkshire-fog with a rank growth of red fescue, smooth meadow-grass Poa pratensis ,
cock's-foot,falseoat-grassandumbellifersaroundthebramble.Alternativelybrackenmayspreadtoform
densestands.Treessuchasbirchmayalsocoloniseareasofthedunesifthegrazingisdrasticallyreduced.
FIG 78. Early sand grass at Whiteford Burrows. (David Painter)
INSECTS
The Gower sand dunes are well known for their rich variety of insects, and in common with the other
sand dunes in South Wales there is a tradition of recording that extends back to the nineteenth century,