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Questions and Answers
Human activities that lead to the degradation of coastal dunes include recreation, industry, and ______.
agriculture
Abiotic threats to coastal dunes include construction, mining, and ______.
trampling
Biotic factors affecting coastal dunes involve community dynamics like trampling and ______.
seed dispersal
The concept of restoration is challenging to apply in coastal dunes due to their highly ______ systems.
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One of the aims of restoration is to increase the capacity of protection against ______.
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Restoring habitats and natural vegetation falls under the integrity aspect of ______.
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Sedimentary nourishment is a technique used in coastal dune restoration to aid natural ______.
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The main objective of sustainability in restoration is to enhance ______, particularly in recreational areas.
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The use of sand ______ helps in the morphological reconstruction of dunes.
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Proper placement of fences can reduce ______ speed and promote accumulation.
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Vegetation planting on dunes helps to stabilize surface ______ and provide habitat.
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Humid dune slacks represent the wetland component of dune systems, usually where the ______ table reaches the surface.
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One common pitfall is placing fences in areas where they cannot be ______ or vegetated.
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The primary intervention in Cadiz, Spain, was the installation of sand collectors and wooden ______.
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At Alvor dunes, a series of elevated ______ were created to control pedestrian access.
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Secondary dune slacks are becoming rare due to general stabilization of coastal dunes and ______ deposition.
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In Long Beach Island, NJ, the main intervention was the creation of a ______ and dune through nourishment.
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The mnemonic tool 'Please Help Improve Sand With New Strong Placement' aids in remembering the characteristics of sand ______.
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Study Notes
Coastal Dune Degradation and Loss
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Human activities leading to dune degradation include:
- Housing and recreation
- Industry and commercial development
- Waste disposal
- Agriculture
- Military activities
- Invasive species
Threats to Coastal Dunes
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Abiotic factors
- Landforms: Construction and mining activities can disrupt dune structures
- Sediment transport: Damming and construction of jetties can alter natural sand movement
- Water quality and quantity: Water extraction can lower groundwater levels, negatively impacting dune vegetation.
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Biotic factors
- Plant community structure: Grazing and invasive species can alter plant composition and distribution
- Community dynamics: Trampling and seed dispersal can affect plant communities and overall dune health
- Ecosystem dynamics: Eutrophication, caused by nutrient enrichment, can lead to algal blooms and negatively impact dune ecosystems.
Dune Restoration
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Definition: Restoration aims to bring a degraded dune ecosystem back to its natural state with respect to its health, integrity, and sustainability.
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Challenges: Coastal dunes are highly heterogeneous making restoration difficult.
- There is no single approach to restoration.
- Different restoration efforts can lead to distinct outcomes.
Dune Restoration Goals
| Heterogeneity | Aim of Restoration | Main Objective |
|---|---|---|
| Very dynamic landform | Health | Increased protection from erosion and overwash |
| Dynamic communities | Integrity | Restoration of habitats (e.g. nesting sites, vegetation) |
| Heterogeneous and diverse | Sustainability | Promote recreational opportunities and tourism |
Types of Dune Interventions
Restoring Foredunes
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Strategies: Interventions like sediment nourishment, dune reconstruction, and fencing are used to enhance foredune development.
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Fencing: Sand fences are used to trap sand and promote dune growth.
- Fence design and location are crucial for successful sand accumulation.
- Key aspects include: porosity, height, inclination, wind speed, and placement.
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Boardwalks and access delimitation:
- Well-designed boardwalks provide access to dune areas while minimizing foot traffic.
- Different types, like elevated wood or ground-level boards, cater to specific needs.
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Vegetation planting:
- Using native species that are easy to propagate and survive in dune environments.
- Planting techniques include covering with sand to avoid air trapping.
Restoring Dune Slacks
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Dune slacks are important wetland areas within dune systems.
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Threats:
- Water abstraction and drainage.
- General dune stabilization can reduce natural slack formation.
- Increased nitrogen deposition.
- Afforestation can lower groundwater levels.
- Under-grazing.
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Interventions:
- Mowing.
- Grazing.
- Rejuvenation (scraping).
- Rewetting and restoration of hydrological systems.
- Creation of new pools.
Dune Restoration Case Studies
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Cadiz, Spain: Nourishment and fencing efforts led to some success, but some areas remain susceptible to erosion.
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Long Beach Island, NJ: Nourishment was used to minimize flooding and coastal storm damage.
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Valdevaqueros dune, Cadiz: Fencing and dune flattening were used to address landward migration.
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Spanjaards dune, Netherlands: A new dune area was built to compensate for the impact of port expansion.
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Hondsbossche dunes, Netherlands: Nourishment was used to address dike erosion.
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Alvor dunes, Portugal: Elevated boardwalks were used to control pedestrian access to the beach.
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Description
Explore the various human activities and abiotic and biotic factors contributing to coastal dune degradation and loss. This quiz will test your knowledge on how these elements interplay and affect the delicate coastal ecosystems.
