Diapositiva 1

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Introduction

• Soft engineering projects are needed to restore,
  rehabilitate, or recreate degraded salt marshes,
  with cordgrasses (genus Spartina) being one of
  the most popular biotools. Thus, Spartina
  alterniflora Liosel, S. foliosa Trin., and S.
  anglica Hubb. have been used in salt marsh
  manipulation and restoration projects in North
  America (Konisky et al. 2006), Asia (An et al.
  2007), and Europe (Bakker et al. 2002).
• However, little is known about restoration of
  European salt marshes using Small cordgrass
  (Spartina maritima (Curtis) Fernald), the only
  native cordgrass in many European estuaries.
  Improving our knowledge is a key step for the
  restoration of these estuaries given that using
  exotic cordgrasses for salt marsh restoration may
  have significant negative environmental impacts
  (Huang Zhang 2007).

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Restoring With Spartina maritima

• Our salt marsh restoration project was carried
  out from November 2006 to January 2007 in Odiel
  Marshes (S.W. Iberian Peninsula lat
  3708937209N, long 64597029W). The restored
  area, known locally as Punta del Sebo,borders
  the main channel of the estuary. Before the
  installation of an industrial site in the 1960s,
  these marshes were used by Huelva citizens as a
  recreational area, originally occupied by
  multiple Spartina maritima tussocks.

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Restoring With Spartina maritima

• Previous to restoration of the marshes, the
  sediments were polluted with heavy metals
  (VanGeen et al. 1997), and several oil deposits
  were found 1.5 m below the sediment surface due
  to historic oil spills from neighboring
  industries. Furthermore, the South American
  neophyte Spartina densiflora Brongn., which
  colonizes a wide range of habitats and
  competitively displaces native species (Nieva et
  al. 2001).

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Restoring With Spartina maritima

• The presence of native vegetation in the low
  marshes was restricted to one stand of S.
  maritima of 6,026 m2 and isolated clumps of
  Sarcocornia perennis (Mill.) Scott ssp. perennis,
  Sarcocornia perennis X fruticosa (Figueroa et al.
  2003), Atriplex portulacoides L.,and the annual
  Salicornia ramosissima J. Woods. A degraded
  landscape dominated by unvegetated mudflats was
  the most obvious consequence of these
  conservation problems.

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Restoring With Spartina maritima

• Our ecological restoration project had four
  specific goals
• (1) to recover native vegetation, restoring the
  degraded landscape
• (2) to phytostabilize oil-polluted sediments
• (3) to prevent erosion and stabilize banks
• (4) to promote the conservation of S. maritima,
  an endangered species included on some European
  red lists

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Restoring With Spartina maritima

• Plantation zones
• were delimited with small wood stakes between
  1.50 and 2.30 m Spanish hydrographic zero(SHZ)
  (8.37 ha) based on the lower general distribution
  limit of S. maritima in the tidal range (1.41 m
  SHZ) (Castillo et al. 2000).
• Spartina maritima clumps had to be obtained from
  natural populations because it does not produce
  seeds and it is not produced at nurseries.

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Restoring With Spartina maritima

• To minimize extraction impacts and to increase
  biodiversity at the restored marshes, the
  extraction of S. maritima plants was spatially
  dispersed and only done where it was being
  outcompeted by Sarcocornia perennis. Then,
  fragments of Sarcocornia perennis were
  transplanted together with S. maritima.
• Natural tussocks of S. maritima were fragmented
  in situ to small clumps (about 20 tillers) and
  transported to the intervention area by boats. A
  mean of 80 clumps were obtained from every 1 m2
  of the natural population.
• Additionally, A. portulacoides clumps cultivated
  at a nursery were planted at the edges of
  interior marshes to accelerate its colonization.
  The invasive cordgrass S. densiflora was
  eliminated manually from 2.00 ha around the site.

Spartina maritima
Sarcocornia perennis
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One year after transplantation

• Survivorship of transplanted S. maritima clumps
  has been very high (99 at channel banks and 75
  at interior marshes) and they have colonized
  surrounding bare sediments at expansion rates of
  1.1 0.0 cm/month (n 76).
• At the same time, Sarcocornia perennis has been
  growing at interior marshes accompanying 20 of
  the cordgrass clumps with an expansion rate of
  1.8 0.2 cm/month (n 21).
• Atriplex portulacoides clumpsshowed a
  survivorship of 90 and newly germinated emergent
  seedlings of S. densiflora appeared at three
  interior marshes and require manual weeding for
  removal.
• Establishment of new species is expected during
  the development of ecological succession at
  interior marshes because adequate propagule
  sources are present in the neighboring marshes
  and dispersal is not limited.

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Currently

• Project environmental monitoring
• Birds, invertebrates, vegetation, fish ...

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