of the vegetation. Grazing and other influences have held most coastal dunes
systems to a sub-climax or plagio-climax, with a generally limited extent of shrub
and tree cover. In all likelihood, in the absence of this interference, large parts of
many dune systems may have been developing into mature woodland by now.
However, in terms of conservation we are still facing the dilemma that if we do
not reverse this trend we will continue to witness the loss of suitable habitat for
rare and uncommon obligate or semi-obligate psammophytes such as Eryngium
maritimum, Euphorbia paralias, Matthiola sinuata, Mibora minima, Phleum
arenarium, and Vulpia fasciculata, and dune slack hygrophytes, such as Epipactis
leptochila var. dunensis, Liparis loeselli var. ovata, and Pyrola rotundifolia,
together with many dune fungus and invertebrate species (e.g., Howe et al. 2010).
In order to try to further clarify issues relating to stabilization, and to have
better information on how to deal with this problem, a detailed look at the changes
to the vegetation at Newborough Warren has been compiled, together with
accounts of how stabilization is affected by external factors such as sediment
supply, nutrient enrichment, climate change, and predicted sea-level rise, and
internal factors such as soil development, grazing, and scrub development.
Welsh Sand Dune Resource
Foredunes
2%
Mobile Dunes
11%
Semi-fixed Dunes
32%
Fixed dune Grassland
34%
Sand Sedge Dunes
1%
Grey Dunes
0%
Acidic dune Grassland
2%
Dune Slack
13%
Sea-Buckthorn Scrub
4%
Dune Heath
1%
Fig. 8.2 Proportions of the major sand dune vegetation categories in Wales based on data
collected in the 1980s and 1990s
8 The Impact of Dune Stabilization
129
systems to a sub-climax or plagio-climax, with a generally limited extent of shrub
and tree cover. In all likelihood, in the absence of this interference, large parts of
many dune systems may have been developing into mature woodland by now.
However, in terms of conservation we are still facing the dilemma that if we do
not reverse this trend we will continue to witness the loss of suitable habitat for
rare and uncommon obligate or semi-obligate psammophytes such as Eryngium
maritimum, Euphorbia paralias, Matthiola sinuata, Mibora minima, Phleum
arenarium, and Vulpia fasciculata, and dune slack hygrophytes, such as Epipactis
leptochila var. dunensis, Liparis loeselli var. ovata, and Pyrola rotundifolia,
together with many dune fungus and invertebrate species (e.g., Howe et al. 2010).
In order to try to further clarify issues relating to stabilization, and to have
better information on how to deal with this problem, a detailed look at the changes
to the vegetation at Newborough Warren has been compiled, together with
accounts of how stabilization is affected by external factors such as sediment
supply, nutrient enrichment, climate change, and predicted sea-level rise, and
internal factors such as soil development, grazing, and scrub development.
Welsh Sand Dune Resource
Foredunes
2%
Mobile Dunes
11%
Semi-fixed Dunes
32%
Fixed dune Grassland
34%
Sand Sedge Dunes
1%
Grey Dunes
0%
Acidic dune Grassland
2%
Dune Slack
13%
Sea-Buckthorn Scrub
4%
Dune Heath
1%
Fig. 8.2 Proportions of the major sand dune vegetation categories in Wales based on data
collected in the 1980s and 1990s
8 The Impact of Dune Stabilization
129