A Common Resource - Gower - page 212

is dominant on the summit and upper slopes of the sandstone ridge, where it is interspersed with areas
of heathland dominated by bristle bent Agrostis curtisii . Much of the bracken-covered area also has an
understorey of bristle bent rather than deep bracken litter (and sometimes bluebells, which flower before
the bracken canopy develops) and could be returned to grass heath by management. This has been one
of the main themes of the Tir Cymen agri-environment scheme, which was taken up by the commoners
in the early 1990s. In areas where the bracken community is more open other species present include
Yorkshire-fog, harebell Campanula rotundifolia , common dog-violet, field wood-rush Luzula campestris
and foxglove Digitalis purpurea .

TABLE 11. Habitats on Cefn Bryn Common. (Adapted from Penford et al ., 1990)

AREA (HA ) HABITAT % COVER

Continuous bracken 395.7 47.8

Wet heath/acidic grassland 236.2 28.6

Dry heath/acidic grassland 101.8 12.3

Species-rich grassland 28.1 3.4

Acid flush 24.5 3.0

Scattered bracken 20.8 2.5

Acid grassland 15 1.8

Standing water 2.2 0.4

Streams 1.0 0.1

Scattered scrub 1.0 0.1

Total 826.3 100

Bracken is an extremely aggressive and vigorous plant in the open conditions of the commons. The
plant colonises an area initially by spores and thrives in conditions where there is a reasonable depth of
soil. Once established, bracken spreads principally by vegetative means through its horizontal rhizomes,
whichcangrowuptoonemetre inlength each year.Theshadeproducedbythefrondsreduces theability
of other plants to grow and when combined with a thick layer of litter can completely obliterate other
plants. This extreme condition is not often reached in Gower, and other plants can survive beneath the
fronds as well as grasses. Bracken cannot grow where the soil is compacted or where trampling occurs,
and this explains why many paths across the commons are free from the plant. The large areas of bracken
on many commons restrict the area available for grazing and may force sheep onto vulnerable vegetation
such as heathland.
Themanagement ofthebrackenandgorseonthecommonshasbeenamatterofdebateformanycen-
turies, as this extract from a survey of 'Oxwych Manor' undertaken around 1632 shows. In referring to
the new enclosed 'Porteinons moore' the surveyor notes that:

And the Lords tenants paying justments did alwaies use to cut furres and fearnes upon ye said
moore, and none to our knowledge did ever seek the Lords licence soe to doe, and we conceaiue
yt they may doe soe still. But the said tenants did use by consent to leave some standing bushes
of furres for shadowe and shelter unto theire sheepe and cattle depasturing upon the said justmt
land. And when such standing bushes in convenient places for being preserved and left, weare
suddenly cutt and destroyed, they did use to threattne punishmt upon the offenders in that kinde .