coastal dune mobility can be a long-term project, requiring periodic human
intervention. In this sense, Arens and Geelen (2006) found that even extensively
destabilized areas (tens of hectares) are likely to re-stabilize within a few decades
and that new measures to reduce stabilization may be required every 10 or
20 years (see Arens et al, Chap. 7, this volume). Lastly, it is very important to bear
in mind that any attempt to create dunes where they do not exist, or to increase the
dynamism of stabilized dunes, must have a strong public information component
to demonstrate their feasibility and increase their acceptability. When people are
informed, they may even be willing to pay for the remobilization of dunes, as well
as the containment and elimination of exotic species (Lehrer et al., Chap. 17, this
volume).
20.2.4 Stabilizing Active Dunes
Having shown the negative effects of overstabilization, it is necessary to also
consider that stabilization and re-vegetation can sometimes be a required action.
This is the case when coastal dunes are created de novo, artificially, and they need
to be planted with preferably native plants in order to enhance further sand
accumulation and dune growth (Vestergaard, Chap. 4, this volume; GallegoFernández et al. 2011). Sometimes, cities may develop on coastal dunes or are
surrounded by them, as occurs with the Port of Veracruz, on the Gulf of Mexico,
Mexico. For centuries, the Port of Veracruz has suffered the consequences of its
unfortunate location, with sand blowing into the city from neighboring mobile
transgressive dunes when the strong winds blow and the weather is relatively dry
during the winter months. In this case, the stabilization of mobile dunes was seen
as a societal need (Moreno-Casasola et al. 2008). The relevant fact is, in these
cases, how restoration–revegetation was performed.
In Denmark, an artificial dune was built with earth-moving machinery and was
then planted with native species and natural regeneration was allowed to occur
(Vestergaard, Chap. 4, this volume). In contrast, the dunes surrounding the city of
Veracruz were stabilized with the exotic tree Casuarina equisetifolia. Usually, this
is a very aggressive invasive species that does not promote natural regeneration
(Mailly and Margolis 1992; Moreno-Casasola et al., Chap. 14, this volume).
Nevertheless, Moreno-Casasola et al. (Chap. 14, this volume) found that, under
high moisture conditions and if tropical rainforest remnants occur in the vicinity,
the original tropical forest can, in fact, regenerate beneath the shade of the exotic
trees. This is a very peculiar situation and should not be interpreted as a sign that
Casuarina is a good option for dune re-vegetation outside its native distribution
range (Australia). Native species should always be the preferred plants in any
restoration project. Interestingly, in spite of the overwhelming evidence of the
negative impacts of artificial stabilization, coastal dune forestation programs are
still commonplace in many countries.
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M. L. Martínez et al.
intervention. In this sense, Arens and Geelen (2006) found that even extensively
destabilized areas (tens of hectares) are likely to re-stabilize within a few decades
and that new measures to reduce stabilization may be required every 10 or
20 years (see Arens et al, Chap. 7, this volume). Lastly, it is very important to bear
in mind that any attempt to create dunes where they do not exist, or to increase the
dynamism of stabilized dunes, must have a strong public information component
to demonstrate their feasibility and increase their acceptability. When people are
informed, they may even be willing to pay for the remobilization of dunes, as well
as the containment and elimination of exotic species (Lehrer et al., Chap. 17, this
volume).
20.2.4 Stabilizing Active Dunes
Having shown the negative effects of overstabilization, it is necessary to also
consider that stabilization and re-vegetation can sometimes be a required action.
This is the case when coastal dunes are created de novo, artificially, and they need
to be planted with preferably native plants in order to enhance further sand
accumulation and dune growth (Vestergaard, Chap. 4, this volume; GallegoFernández et al. 2011). Sometimes, cities may develop on coastal dunes or are
surrounded by them, as occurs with the Port of Veracruz, on the Gulf of Mexico,
Mexico. For centuries, the Port of Veracruz has suffered the consequences of its
unfortunate location, with sand blowing into the city from neighboring mobile
transgressive dunes when the strong winds blow and the weather is relatively dry
during the winter months. In this case, the stabilization of mobile dunes was seen
as a societal need (Moreno-Casasola et al. 2008). The relevant fact is, in these
cases, how restoration–revegetation was performed.
In Denmark, an artificial dune was built with earth-moving machinery and was
then planted with native species and natural regeneration was allowed to occur
(Vestergaard, Chap. 4, this volume). In contrast, the dunes surrounding the city of
Veracruz were stabilized with the exotic tree Casuarina equisetifolia. Usually, this
is a very aggressive invasive species that does not promote natural regeneration
(Mailly and Margolis 1992; Moreno-Casasola et al., Chap. 14, this volume).
Nevertheless, Moreno-Casasola et al. (Chap. 14, this volume) found that, under
high moisture conditions and if tropical rainforest remnants occur in the vicinity,
the original tropical forest can, in fact, regenerate beneath the shade of the exotic
trees. This is a very peculiar situation and should not be interpreted as a sign that
Casuarina is a good option for dune re-vegetation outside its native distribution
range (Australia). Native species should always be the preferred plants in any
restoration project. Interestingly, in spite of the overwhelming evidence of the
negative impacts of artificial stabilization, coastal dune forestation programs are
still commonplace in many countries.
332
M. L. Martínez et al.