natural system dynamics and natural mobility, coastal dunes can be more functional, better preserved, and protect more efficiently.
Restoration of coastal dunes and recovery of characteristic dune species are
difficult tasks. Long-term monitoring of remobilization actions, for example, has
shown that a single restoration intervention is not sufficient to restore the largescale landscape forming process or to eliminate invasive species (Kutiel, Chap. 11,
this volume; Hesp and Hilton, Chap. 5, this volume). In this sense, Arens et al.
Chap. 7, this volume argue that for a number of years, a certain form of maintenance, such as the removal of re-growing roots, is necessary to get the dune
moving. In addition, recent evidence (Arens et al. 2004) shows that mobilization of
coastal dunes is more effective when dunes are connected to the coastline (Psuty
and Silveira, Chap. 3, this volume; Arens et al., Chap. 7, this volume). Thus, it
seems that foredune erosion, with sediment being transferred to inland coastal
dunes, might ‘‘restart the engine’’ of coastal dune mobility (Arens et al., Chap. 7,
this volume).
An important question here is whether there is equilibrium between the protection of human assets and the dynamic nature of coastal dunes. How much
should they be allowed to move? Is it possible to nourish our coasts, prevent
shoreline erosion, allow sand movement, and protect human infrastructure and
lives? Can we have it all? This is certainly an important challenge for the coming
years. While working on this, it is essential to bear in mind that there is no
equilibrium form or dimension in a functional dune system: each one is unique and
has its own dynamic equilibrium that changes in time and space.
Restoration is not always a real possibility. When coastal dunes and beaches are
very degraded, as occurs on urban and developed coasts, rehabilitation may be the
only viable option. In this case, the system is not self-sustainable and requires
periodic human intervention that repairs and maintains the integrity of the system.
When sediment is insufficient, as occurs on eroding coasts, rebuilding a dune is not
really restoration, but an artificial creation of a sand ridge that is unsustainable
over time (Psuty and Silveira, Chap. 3, this volume). Adaptive management, with
continued human input, is critical where space is restricted and long-term erosion
continues. Sustainability of natural features in developed areas requires humans to
act as intrinsic agents of landform change.
20.5 Conclusions
Coastal dune restoration efforts require the combination and integration of different criteria, including ecological, geomorphological, and social, so that we can
maximize the goods and services that coastal dunes can provide (Nordstrom and
Jackson, Chap. 2, this volume; Lithgow et al., Chap. 19, this volume; PérezMaqueo et al., Chap. 18, this volume). A theoretical and empirical catalog of the
actions needed to perform adequate coastal dune restoration should consider:
20 Coastal Dune Restoration: Trends and Perspectives
335
Restoration of coastal dunes and recovery of characteristic dune species are
difficult tasks. Long-term monitoring of remobilization actions, for example, has
shown that a single restoration intervention is not sufficient to restore the largescale landscape forming process or to eliminate invasive species (Kutiel, Chap. 11,
this volume; Hesp and Hilton, Chap. 5, this volume). In this sense, Arens et al.
Chap. 7, this volume argue that for a number of years, a certain form of maintenance, such as the removal of re-growing roots, is necessary to get the dune
moving. In addition, recent evidence (Arens et al. 2004) shows that mobilization of
coastal dunes is more effective when dunes are connected to the coastline (Psuty
and Silveira, Chap. 3, this volume; Arens et al., Chap. 7, this volume). Thus, it
seems that foredune erosion, with sediment being transferred to inland coastal
dunes, might ‘‘restart the engine’’ of coastal dune mobility (Arens et al., Chap. 7,
this volume).
An important question here is whether there is equilibrium between the protection of human assets and the dynamic nature of coastal dunes. How much
should they be allowed to move? Is it possible to nourish our coasts, prevent
shoreline erosion, allow sand movement, and protect human infrastructure and
lives? Can we have it all? This is certainly an important challenge for the coming
years. While working on this, it is essential to bear in mind that there is no
equilibrium form or dimension in a functional dune system: each one is unique and
has its own dynamic equilibrium that changes in time and space.
Restoration is not always a real possibility. When coastal dunes and beaches are
very degraded, as occurs on urban and developed coasts, rehabilitation may be the
only viable option. In this case, the system is not self-sustainable and requires
periodic human intervention that repairs and maintains the integrity of the system.
When sediment is insufficient, as occurs on eroding coasts, rebuilding a dune is not
really restoration, but an artificial creation of a sand ridge that is unsustainable
over time (Psuty and Silveira, Chap. 3, this volume). Adaptive management, with
continued human input, is critical where space is restricted and long-term erosion
continues. Sustainability of natural features in developed areas requires humans to
act as intrinsic agents of landform change.
20.5 Conclusions
Coastal dune restoration efforts require the combination and integration of different criteria, including ecological, geomorphological, and social, so that we can
maximize the goods and services that coastal dunes can provide (Nordstrom and
Jackson, Chap. 2, this volume; Lithgow et al., Chap. 19, this volume; PérezMaqueo et al., Chap. 18, this volume). A theoretical and empirical catalog of the
actions needed to perform adequate coastal dune restoration should consider:
20 Coastal Dune Restoration: Trends and Perspectives
335