Umbra sand dunes

• What percentage of the Irish coastline is composed of beaches backed by sand dunes?

  20%
• Where do dune systems typically develop?

  On the landward side of beaches
• What is the primary source of sand for the Umbra dunes?

  Magilligan Point
• How does sand move up the beach?

  By saltation due to onshore winds
• What is the length of the Magilligan sand dune ecosystem?

  11 km
• Why is the Umbra area designated as an Area of Special Conservation (SAC)?

  Due to its unique flora and fauna
• What was the historical population of rabbits in the Magilligan dune system?

  40,000 rabbits
• What is the primary direction of the wind that supplies sand to the Umbra dunes?

  Westerly direction
• How do spring tides contribute to the dune formation process?

  They deposit seaweed that traps sand
• What happens to the fragile dune environments during winter?

  They are eroded by storm waves
• What is the process of change across sand dunes called?

  Autogenic
• What are the two interconnected components vital for explaining succession on a psammosere?

  Biotic and abiotic factors
• What are the key stages in sand dune vegetation and soil development?

  1. Embryo Dunes
  2. Fore-dunes (Yellow Dunes)
  3. Fixed Dunes
  4. Mature Grey Dunes
  5. Climatic Climax Vegetation
• What are embryo dunes characterized by?

  Youngest, lowest, and most scattered dunes
• Why are embryo dunes prone to erosion?

  They are low-lying and near the sea
• What pH levels are found in the embryo dunes?

  8-9
• Why is the soil in embryo dunes so dry?

  Large pore spaces allow free drainage
• What is the height range of fore-dunes?

  2-3 meters
• What plant species begins to colonize the fore-dunes?

  Marram grass
• How does marram grass contribute to dune stability?

  It slows wind speed and reduces sand movement
• What is the height of fixed dunes?

  10-30 meters
• What type of plants dominate the fixed dunes?

  Marram grass
• How does the soil change as one moves inland from the fixed dunes?

  It becomes richer in humus and nutrients
• What is the pH level of mature grey dunes?

  5-6
• Why does species diversity increase in mature grey dunes?

  Improved soil quality and moisture retention
• What are dune slacks?

  Depressions between dunes
• What conditions do dune slacks experience in winter?

  They are often covered by rising water levels
• What type of vegetation thrives in dune slacks?

  Meadowsweet and rush
• What is the height of climatic climax vegetation?

  400 meters inland
• How does the canopy of deciduous trees affect ground-level vegetation?

  It limits light levels for ground vegetation
• What is a significant element of the soil in climatic climax vegetation?

  Substantial DOM layer
• What impact does the removal of coniferous forest have on the dunes?

  It restores natural vegetation and biodiversity
• What are the management practices observed at Umbra sand dunes?

  • Cattle grazing to maintain biodiversity
  • Removal of coniferous forest to restore natural vegetation
  • Monitoring the impact of management practices
• Why is the area significant as an ASSI?

  It conserves indigenous species of flora and fauna
• How does the presence of plagioclimax vegetation affect the dunes?

  It prevents climatic climax vegetation from developing