Beach and Dune - Gower - page 160

WHITEFORD TRANSITION ZONE
Along the eastern fringe of Whiteford Burrows, along a line of seepage from the dunes onto the upper
salt marsh, light grazing by ponies has maintained an outstanding transitional habitat, which is highly re-
garded for both its plant and animal communities. Poaching of the soft peaty sediments keeps the lush
vegetation open and creates pockets of damp mud which are ideal egg-laying sites for wetland flies with
semi-aquatic larvae. The soldier flies, named on account of their bright coloration, which was thought to
look like old-fashioned military uniforms, are a characteristic group of flies found at such seepages. Spe-
cies at Whiteford include Vanoyia tenuicornis, Oplodontha viridula, Oxycera trilineata and Nemotelus
notatus . The latter is common on the coasts of southern Britain and Ireland, the larvae being found in
brackish pools.
Another speciality of this area is the very rare narrow-mouthed whorl snail Vertigo angustior , which
also occurs in a similar brackish marsh habitat on Oxwich dunes and a few other British sites. The snail
was first described by Jeffreys in 1833 following its discovery in flood debris at Marino, near Swansea.
A hundred and fifty years later, in 1983, populations were found in the transition zone between the salt
marsh and sand dune at both Whiteford and Oxwich Burrows and in Cwm Ivy Marsh. Like many non-
marine molluscs the whorl snail has exacting habitat requirements which contribute to its localised dis-
tribution and vulnerability, the species preferring open habitats without shading in dune slacks and moist
dunes.Thecontinuation ofgrazingonthedunegrasslandandadjoiningmarshisvitaltosustainthestruc-
ture of the habitat and the variety of species, and efforts are made to ensure that grazing levels do not
change substantially. Once an abundant species in lowland Britain, it was suppressed by the growth of
forests in the postglacial period and is now considered to be in serious decline. The populations in the
seven remaining sites in East Anglia, Glamorgan and Cumbria are particularly vulnerable to habitat dis-
turbance and a change in the hydrological conditions.
DUNE MANAGEMENT
For several centuries the stabilisation of dunes has been seen as a priority, but in recent decades there has
been a greater recognition of and respect for the natural dynamics of these systems. While sand dunes are
threatened habitats, it is incorrect to regard them as 'fragile'; indeed they have the ability to regenerate
and repair themselves and naturally move towards a stable state. In areas where for a variety of reasons
it is impossible for real soils to develop, dunes can also rework themselves, thus maintaining the early
stages of succession. As described in Chapter 3, external influences, particularly the stormy conditions of
thefourteenthtothenineteenthcenturies,resultedinalongperiodofdunedestabilisation,sanddriftanda
generalreworkingofthedunelandscape.Duringthisperiodtechniquesweredevelopedforreducingsand
drift by the planting of marram grass, the use of thatch and sand-trapping windbreaks, and the planting
of introduced species of conifers such as those at Whiteford. There is documentary evidence that in 1661
tenants of the manor were required to assist in fixing and stabilising Whiteford Burrows.
Aerial photographs of the Gower dunes show considerable dune mobility in the 1950s and 1960s res-
ulting from disturbance caused by military training in the 1940s. Most of the damage was caused by the
American army, who used some of the dunes as a training ground for the Normandy landings. Oxwich
dunes were also used by the RAF . They set up a series of lights, mimicking those of a nearby ordnance
factory, in order to persuade enemy aircraft to waste their bombs on the dunes. At the end of the war a
local botanist described Oxwich dunes as 'a sandy waste devoid of vegetation'. Many of the blowouts
wereactively erodingandoneendedinatongueofmobile sandthat spreadoutontotheroadeach winter.
Residents of Oxwich village often had to dig themselves out of sand drifts. Similarly the dunes at Port-