Saltmarshes

Question 1

Saltmarshes form…

Answer 1

…in the intertidal zone of a low energy coastline

Question 2

High tide

Answer 2

Climax species grow here

Question 3

Low tide

Answer 3

• Harsh conditions for life (high salinity)
• Thin layer of nutrients in the ground (humus)
• Pioneer species grow here (e.g. glasswort, sea purslane, sedge)
• The pioneer species adds nutrients to the ground when they decompose, binding sediment

Question 4

Stages of saltmarsh creation

Answer 4

1) Salt Marshes form in Low Energy Environments where there is shelter from the wind and waves.
2) A large input of sediment is required, from the sea (marine) and rivers (fluvial).
3) The land needs to be flat (a tidal flat/mud flat). This means that any sediment carried will be deposited as the river loses energy and drops its load. When the high tides flood the flat they too will deposit sediment.
4) Over time, the sediment builds up, and the tidal flat is elevated. This is called coastal accretion. This new land, means tidal flooding is reduced, and so pioneer species can start to grow.
5) These pioneer species are “halophytes” which means they can withstand the salty conditions and withstand being submerged for much of the day.
6) These pioneer species trap sediment with their bodies, building up more land. Their roots also stabilise deposited sediment – increasing coastal accretion.
7) These pioneer species rapidly spread and by building up the land, create the conditions for the next plant species in the succession. As they die and decompose they improve the humus (nutrient) layer and allow larger plants to grow.
8) This process of coastal accretion and plant succession continues until the upper marshes, where the climax species will dominate.