Sand dune succession Flashcards
What initiates the formation of embryo dunes?
Wind-blown dried sand is trapped by debris and deposition begins
This process marks the beginning of dune formation.
Which pioneer species colonize embryo dunes?
Lyme Grass and Sea Couch Grass
These species are crucial for stabilizing the dunes.
What are the soil characteristics of embryo dunes?
Little soil content and high pH levels (alkaline)
This makes embryo dunes very fragile.
What is the maximum height of embryo dunes?
1 metre
This height reflects their fragile nature.
What role do embryo dunes play in the dune ecosystem?
They bring some protection against the prevailing wind
This protection allows for further plant growth.
Which plant species begins to grow in fore dunes?
Marram Grass
Marram Grass is important for stabilizing the dune with its root system.
How does Marram Grass contribute to the dune ecosystem?
It stabilizes the dune and adds organic matter to the soil
This makes the dunes more hospitable for other plant species.
What forms in the dune slack due to the changes in the ecosystem?
A microclimate
This microclimate supports diverse plant and animal life.
What is the maximum height of fore dunes?
5 metres
This height is a result of stabilization by vegetation.
What happens to the color of yellow dunes as organic material accumulates?
They darken as humus is added to the soil
This change reflects increased organic content.
What percentage of the dune is exposed in yellow dunes?
20%
This is a significant decrease from the initial 80% exposure.
What is the maximum height of yellow dunes?
8 metres
This height reflects the stability gained from organic material.
What characterizes grey dunes?
More stable with less than 10% exposed sand
They support a good range of biodiversity.
What happens to soil characteristics as humus is added to grey dunes?
Soil acidity and water content increase
This supports a wider range of plant life.
What type of vegetation begins to appear in grey dunes?
Shrubs and bushes
These plants further enhance the biodiversity of the area.
What is the height range of grey dunes?
Between 8 - 10 metres
This indicates their stability compared to earlier dune stages.
What defines mature dunes?
They are the oldest and most stable dunes, found several hundred metres from the shoreline
They represent the final stage in dune succession.
What type of vegetation can mature dunes support?
A variety of flora and fauna such as oak trees and alders
This is indicative of the climax community stage.
What is the climax community stage?
The final stage in succession represented by mature dunes
It features a stable ecosystem with diverse species.
