this volume; Grootjans et al. 2001). It must be recognized that stabilization is a
perfectly natural evolutionary trend for coastal dunes in the absence of human
impact or interference. For example, foredunes can eventually evolve from
incipient foredunes dominated by a few pioneer species to stabilized relict
foredunes covered in tree and shrub species. Transgressive dunefields evolve from
highly mobile systems with minimal plants present, through various evolutionary
steps or phases. At some point the dunefields may have active interdunes, precipitation, and trailing ridges, deflation plains and slacks, nebkha, etc., with many
rare and endemic species present. At a later stage these may all disappear as largescale natural stabilization takes place (e.g., Martinho et al. 2010; Hesp 2011). We
must be careful not to view this as ecologically or geomorphologically ‘‘bad’’ just
because the natural diversity has decreased or changed. However, The negative
impact of the human-driven stabilization of dunescapes has been demonstrated in
many dune systems of the world, such as Israel (Kutiel, Chap. 11, this volume),
Wales (Rhind et al., Chap. 8, this volume), the Netherlands (Grootjans et al., Chap.
15, this volume; Arens et al., Chap. 7, this volume); New Zealand (Hesp and
Hilton, Chap. 5, this volume), the USA (Pickart, Chap. 10, this volume), Spain
(Muñoz-Vallés et al. 2011), South Africa, and many other countries.
Note that stabilization may also occur as a result of a reduction in human
activities, such as occurred in Israel. Here, when the State of Israel was established
in 1944, grazing was banned and exploitation of coastal vegetation was stopped.
Bedouin nomads, who intensively used the coastal dune vegetation for grazing and
fuel, moved elsewhere. The result was rapid dune stabilization (in a few decades)
and the loss of many endemic psammophytic species (Kutiel, Chap. 11, this
volume). Coastal dunes have also become artificially stabilized as a result of
atmospheric nitrogen deposition from atmospheric pollution, which enhances the
growth of a few species (Kooijman and de Haan 1995).
Different plant species have been used in stabilization actions, such as grasses
(Ammophila arenaria, or marram grass), shrubs (Acacia karroo, Acacia saligna,
Retama monosperma), and trees (Pinus spp., Eucalyptus spp., Casuarina spp.).
20.2.3 Reactivating Stabilized Dunes
Because of the perceived negative impact of artificial stabilization of dunes on
diversity and the formation/evolution of geomorphological units, the most frequent
restoration action currently taking place on parabolic and transgressive dunefields
is re-mobilization. In a way, restoration actions through the application of a
‘‘desertification process’’ aimed at reducing vegetation cover sound quite paradoxical. Nevertheless, it should be emphasized that in this case, a truly healthy
dune system according to some (but not all) requires all successional stages,
including mobile dunes. When all successional seres occur in a coastal dune
system, biodiversity increases and functionality is strengthened.
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perfectly natural evolutionary trend for coastal dunes in the absence of human
impact or interference. For example, foredunes can eventually evolve from
incipient foredunes dominated by a few pioneer species to stabilized relict
foredunes covered in tree and shrub species. Transgressive dunefields evolve from
highly mobile systems with minimal plants present, through various evolutionary
steps or phases. At some point the dunefields may have active interdunes, precipitation, and trailing ridges, deflation plains and slacks, nebkha, etc., with many
rare and endemic species present. At a later stage these may all disappear as largescale natural stabilization takes place (e.g., Martinho et al. 2010; Hesp 2011). We
must be careful not to view this as ecologically or geomorphologically ‘‘bad’’ just
because the natural diversity has decreased or changed. However, The negative
impact of the human-driven stabilization of dunescapes has been demonstrated in
many dune systems of the world, such as Israel (Kutiel, Chap. 11, this volume),
Wales (Rhind et al., Chap. 8, this volume), the Netherlands (Grootjans et al., Chap.
15, this volume; Arens et al., Chap. 7, this volume); New Zealand (Hesp and
Hilton, Chap. 5, this volume), the USA (Pickart, Chap. 10, this volume), Spain
(Muñoz-Vallés et al. 2011), South Africa, and many other countries.
Note that stabilization may also occur as a result of a reduction in human
activities, such as occurred in Israel. Here, when the State of Israel was established
in 1944, grazing was banned and exploitation of coastal vegetation was stopped.
Bedouin nomads, who intensively used the coastal dune vegetation for grazing and
fuel, moved elsewhere. The result was rapid dune stabilization (in a few decades)
and the loss of many endemic psammophytic species (Kutiel, Chap. 11, this
volume). Coastal dunes have also become artificially stabilized as a result of
atmospheric nitrogen deposition from atmospheric pollution, which enhances the
growth of a few species (Kooijman and de Haan 1995).
Different plant species have been used in stabilization actions, such as grasses
(Ammophila arenaria, or marram grass), shrubs (Acacia karroo, Acacia saligna,
Retama monosperma), and trees (Pinus spp., Eucalyptus spp., Casuarina spp.).
20.2.3 Reactivating Stabilized Dunes
Because of the perceived negative impact of artificial stabilization of dunes on
diversity and the formation/evolution of geomorphological units, the most frequent
restoration action currently taking place on parabolic and transgressive dunefields
is re-mobilization. In a way, restoration actions through the application of a
‘‘desertification process’’ aimed at reducing vegetation cover sound quite paradoxical. Nevertheless, it should be emphasized that in this case, a truly healthy
dune system according to some (but not all) requires all successional stages,
including mobile dunes. When all successional seres occur in a coastal dune
system, biodiversity increases and functionality is strengthened.
330
M. L. Martínez et al.