Keyhaven Salt Marsh Flashcards
Give an example of a plant in these stages: Low marsh High marsh Marsh border Transitional communities
Eg: Low marsh-cordgrass High marsh-sea lavenders Marsh border-shrubs Transitional communities-oak trees
Why have Keyhaven salt marshes developed?
Keyhaven salt marshes have developed due to the shelter behind Hurst Spit providing a place for sediment to be deposited. Over time sediment accumulates allowing vegetation to develop.
Why is cordgrass suited to being a pioneer species?
Cordgrass is suited to being a pioneer species because it is a halophyte meaning it is salt tolerant. Also it grows fast on flat land and its long roots bind sediment together thus absorbing nutrients from afar.
What is a halophyte?
A halophyte is a plant that is salt tolerant.
How are Keyhaven salt marshes under threat?
The salt marshes are under threat from the construction of groynes to the west potentially starving the marshes of sediment. Global warming has lead to thermal expansion which may leave the marshes submerged by sea level rise. Finally animals that graze on the marsh trample vegetation along with tourists.
What is being done to protect the marshes?
In 1996 500m of Rock armour was placed to protect the spit and the marsh along with 300,000m^3 of shingle being placed on the spit. This project cost £5m. The marsh has also become a national nature reserve and an SSSI (Site of Special Scientific Interest) allowing visitors restricted access to reduce trampling.
Describe vegetation succession.
The gradual increase in size and diversity of vegetation the further from the salt marsh. The area close to the marsh is inhabited by halophytes that bind the sediment to form soil. Over time more complex vegetation develops.
