Sand dunes #2

?
How are the third dunes (Grey dunes) formed?
As the plant life on a foredune dies, it forms a layer of humus (not the same thing as hummus). This is an organic layer of soil that is somewhat acidic and helps lower the pH of the soil. It is now more stable.
1 of 6
Describe grey dunes.
The lowered pH allows some new species of plants to develop. Vegetation such as marram grass will still prevail though as grey dunes are still dry and exposed to the wind. The really interesting vegetation grows in dune slacks.
2 of 6
How are dune slacks formed?
If a foredune grows large enough it can form a dune ridge and the slack is formed behind. Another way is a blowout.
3 of 6
Describe dune slacks.
Fresh water is exposed at the surface, new types of vegetation can grow in the dune slack, e.g. reeds and rushes. A dune slack that forms behind a grey dune often contains a variety of vegetation-the humus on the grey dune blown into slack-hospitable
4 of 6
What is the last stage of the dune succession?
The plagioclimax.
5 of 6
Describe the plagioclimax and how it occurs.
Here, soil pH is much more acidic (~4.5–5) thanks to a thick layer of humus developing. This allows vegetation like shrubs and trees to grow. Often forests develop at the climax of a sand dune succession. It is formed due to human activiy
6 of 6

Other cards in this set

Card 2

Front

Describe grey dunes.

Back

The lowered pH allows some new species of plants to develop. Vegetation such as marram grass will still prevail though as grey dunes are still dry and exposed to the wind. The really interesting vegetation grows in dune slacks.

Card 3

Front

How are dune slacks formed?

Back

Preview of the front of card 3

Card 4

Front

Describe dune slacks.

Back

Preview of the front of card 4

Card 5

Front

What is the last stage of the dune succession?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Coastal environments resources »