Environmental Engineering Reference
In-Depth Information
WALLS
Like many areas of Britain, Gower has its own style of drystone walling. Here, given the large areas of
commonland,thewallsarebuiltwithanoverhangontheoutsidetohelpkeepanimalsoutofthefieldthey
enclose. Walls provide a variety of different habitats and microclimates in a comparatively small space
and there is always an exposed, wet side and a drier, warmer side. Even a well-maintained wall contains
numerous holes providing habitats for a variety of invertebrates including spiders, woodlice, millipedes,
beesandwasps.Woodmiceandbankvoles
Clethrionomys glareolus
,toadsandslow-wormsalsofindthe
cavities in walls attractive. A semi-derelict wall is more attractive than a well-maintained one since there
are more sheltered spaces and more is covered in soil. However, such a condition is relatively short-lived,
and once it is reduced to less than half its height the value of a wall for wildlife decreases considerably.
They therefore need to be sympathetically maintained if they are to continue to be of interest (Fig. 152).
Probably the earliest survey of the flora of Gower walls was undertaken by the Caradoc and Severn
Valley Field Club, who had their first 'Long Meeting' in Gower during July 1893 and recorded 'walls
richly covered with moss and ferns, among which were noticed the wall-rue
Asplenium ruta-muraria
,
maidenhair spleenwort, black stalked spleenwort, scaley fern, hart's tongue, &c., &c.' (Anon, 1896). In
crevices ivy-leaved speedwell
Veronica hederifolia
and white stonecrop
Sedum album
can be found. The
latterisprobablyintroduced,butsomeauthorsthinkitmaybeanativeplantofsouthwestBritain.Lichens
also grow well on the stones. A variety of snails can be found including common snail, which uses walls
as hibernation sites, rock snail
Pyramidula rupestris
, strawberry snail
Hygromia striolata
and hairy snail
H. hispida
.Greatblackslug
Arion ater
,largeredslug
A. rufus
andhedgehogslug
A. intermedium
arealso
present in many walls.
FIG
152.
Drystone wall above Devil's Truck, near Rhossili. (Harold Grenfell)
