8.2 Case Study Showing Evidence of Change: Newborough
Warren
Rhind et al. (2001) showed that over a 50-year period (1950–1990s), the vegetation at Newborough Warren changed almost beyond recognition. Nearly 75 % of
the total dune area in the 1950s consisted of mobile dunes and embryonic dune
slacks with open vegetation (Fig. 8.3), but by 1991 only about 6 % of the site
could be classed as mobile and open, and embryonic dune slacks were more or less
non-existent. Ranwell (1955) estimated the average rate of landward dune
migration at that time to be in the order of 0.3–0.6 m per year. Today, there is little
evidence of any major landward migration of dunes.
At that time the main sand binding grass, Ammophila arenaria, was mainly
confined to dune crests, the base of lee slopes and sheltered hollows. In other, more
level, areas with high sand mobility, a community described as an open Salix
repens association occurred (Fig. 8.4), often with no other associated species.
Nowadays, there are no remains of this Salix community at Newborough Warren,
and there is no recognized equivalent within the UK’s National Vegetation
Newborough Warren ca. 1950
Mobile Dunes
76%
Dune Slack
13%
Fixed dune Grassland
9%
Foredune
1%
Dune Heath
1%
Fig. 8.3 Estimated relative
proportions of the major sand
dune vegetation categories at
Newborough Warren around
1950, based on data from
Ranwell (1960a)
130
P. Rhind et al.
Warren
Rhind et al. (2001) showed that over a 50-year period (1950–1990s), the vegetation at Newborough Warren changed almost beyond recognition. Nearly 75 % of
the total dune area in the 1950s consisted of mobile dunes and embryonic dune
slacks with open vegetation (Fig. 8.3), but by 1991 only about 6 % of the site
could be classed as mobile and open, and embryonic dune slacks were more or less
non-existent. Ranwell (1955) estimated the average rate of landward dune
migration at that time to be in the order of 0.3–0.6 m per year. Today, there is little
evidence of any major landward migration of dunes.
At that time the main sand binding grass, Ammophila arenaria, was mainly
confined to dune crests, the base of lee slopes and sheltered hollows. In other, more
level, areas with high sand mobility, a community described as an open Salix
repens association occurred (Fig. 8.4), often with no other associated species.
Nowadays, there are no remains of this Salix community at Newborough Warren,
and there is no recognized equivalent within the UK’s National Vegetation
Newborough Warren ca. 1950
Mobile Dunes
76%
Dune Slack
13%
Fixed dune Grassland
9%
Foredune
1%
Dune Heath
1%
Fig. 8.3 Estimated relative
proportions of the major sand
dune vegetation categories at
Newborough Warren around
1950, based on data from
Ranwell (1960a)
130
P. Rhind et al.