Editing Salt marsh (section)

==Formation==
The formation begins as tidal flats gain elevation relative to sea level by sediment [[accretion (coastal management)|accretion]], and subsequently the rate and duration of [[tidal flooding]] decreases so that vegetation can colonize on the exposed surface.<ref name="pethick">Pethick, J. (1984). ''An introduction to coastal geomorphology''. Edward Arnold, London.</ref> The arrival of [[propagules]] of [[pioneer species]] such as [[seed]]s or [[rhizome]] portions are combined with the development of suitable conditions for their germination and establishment in the process of colonisation.<ref name="boorman"/> When rivers and streams arrive at the low gradient of the tidal flats, the [[Discharge (hydrology)|discharge]] rate reduces and [[suspended sediment]] settles onto the tidal flat surface, helped by the backwater effect of the rising tide.<ref name="chapman"/> Mats of filamentous [[Cyanobacteria|blue-green algae]] can fix silt and clay sized sediment particles to their sticky sheaths on contact<ref name="ginsburg">{{Cite journal |last=Ginsburg |first=Robert N. |last2=Lowenstam |first2=Heinz A. |date=1958-05-01 |title=The Influence of Marine bottom Communities on the Depositional Environment of Sediments |url=https://www.journals.uchicago.edu/doi/10.1086/626507 |journal=The Journal of Geology |language=en |volume=66 |issue=3 |pages=310–318 |doi=10.1086/626507 |issn=0022-1376|url-access=subscription }}</ref> which can also increase the erosion resistance of the sediments.<ref name="aspden">{{Citation |last=Aspden |first=Rebecca J. |title=Salt Marsh Microbial Ecology: Microbes, Benthic Mats and Sediment Movement |date=2004-01-01 |work=The Ecogeomorphology of Tidal Marshes |pages=115–136 |editor-last=Fagherazzi |editor-first=Sergio |url=http://doi.wiley.com/10.1029/CE059p0115 |access-date= |place=Washington, D. C. |publisher=American Geophysical Union |doi=10.1029/ce059p0115 |isbn=978-1-118-66511-4 |last2=Vardy |first2=Suzanne |last3=Paterson |first3=David M. |editor2-last=Marani |editor2-first=Marco |editor3-last=Blum |editor3-first=Linda K.|url-access=subscription }}</ref> This assists the process of sediment accretion to allow colonising species (e.g.,&nbsp;[[Salicornia]] spp.) to grow. These species retain sediment washed in from the rising tide around their stems and leaves and form low muddy mounds which eventually coalesce to form depositional terraces, whose upward growth is aided by a sub-surface root network which binds the sediment.<ref name="bird">Bird, E. (2008). ''Coastal geomorphology: an introduction''. John Wiley & Sons Ltd, West Sussex, England.</ref> Once vegetation is established on depositional terraces further sediment trapping and accretion can allow rapid upward growth of the marsh surface such that there is an associated rapid decrease in the depth and duration of tidal flooding. As a result, competitive species that prefer higher elevations relative to sea level can inhabit the area and often a succession of [[plant communities]] develops.<ref name="pethick"/>