A guide for planners and managers - IUCN

236 MARINE AND COASTAL
PROTECTED AREAS
Photo by Erkki Siirila.
Photo by Rod Salm.
features of the landscape. If any of the dunes are removed or diminished, the reserve
sand in storage may be reduced to a level no longer capable of replacing sand losses
from severe storms. The beach system then becomes unstable and slumps.
The main protection needed for dunes is to prohibit any removal of sand—no
taking of sand should ever be permitted (Figure II-45). In addition the vegetation that
binds the dune together needs protection. Vegetation that grows on shifting dunes is
adapted to withstanding the rigors of wind, sand and salt, but not human feet,
vehicles, or herds of grazing animals. Once a frontal dune is worn down by vehicles
or foot traffic or by consequent loss of vegetation, it may be eroded by wind or wave
action and no longer serve its unique protective role.
FIGURE II-45.
Sand mining continues in spite of being legally prohibited on the
Vigie beach in St. Lucia.
FIGURE II-46.
Inexpensive techniques, such as flexible fencing, are a good
approach to dune maintenance.
Two inexpensive and effective
methods to protect beachfronts are
simple fences (Figure II-46) and
revegetation programmes. Fences
have two initial advantages over
vegetative planting that often
warrant their use before or with
planting: (a) sand fences can be
installed during any season and (b)
the fence is immediately effective as
a sand trap once it is installed.
There is no waiting for trapping
capacity to develop in comparison
with the vegetative method. But, It
is not necessarily “either one or the
other” because it is best to use both
plantings and fences (Box II-4).
In revegetation, it should be
noted that only a few plants thrive
on the dunes and these are adapted
to conditions that include abrasive
and accumulating sand, exposure
to full sunlight, high surface temperatures,
occasional inundation
by saltwater, and drought. They
are long-lived, rhizomatous or
stoloniferous perennials with
extensive root systems, stems
capable of rapid upward growth
through accumulating sand, and
tolerance of salt spray.