Editing Salt marsh (section)

===Land reclamation===
Reclamation of land for agriculture by converting marshland to upland was historically a common practice.<ref name="bromberg"/> [[Levee|Dikes]] were often built to allow for this shift in land change and to provide flood protection further inland. In recent times intertidal flats have also been reclaimed.<ref name="long">Long, S. P. and Mason, C. F. (1983). ''Saltmarsh ecology''. Blackie & Son Ltd, Glasgow.</ref> For centuries, [[livestock]] such as sheep and cattle grazed on the highly fertile salt marsh land.<ref name="adam"/><ref name="andresen">{{Cite journal |last1=Andresen |first1=H. |last2=Bakker |first2=J. P. |last3=Brongers |first3=M. |last4=Heydemann |first4=B. |last5=Irmler |first5=U. |date=1990 |title=Long-Term Changes of Salt Marsh Communities by Cattle Grazing |url=https://www.jstor.org/stable/20038672 |journal=Vegetatio |volume=89 |issue=2 |pages=137–148 |doi=10.1007/BF00032166 |jstor=20038672 |s2cid=20754802 |issn=0042-3106|url-access=subscription }}</ref> Land reclamation for agriculture has resulted in many changes such as shifts in vegetation structure, sedimentation, salinity, water flow, [[biodiversity loss]] and high nutrient inputs. There have been many attempts made to eradicate these problems for example, in New Zealand, the cordgrass ''[[Spartina anglica]]'' was introduced from England into the [[Manawatū River]] mouth in 1913 to try and reclaim the estuary land for farming.<ref name="te ara"/> A shift in structure from bare tidal flat to pastureland resulted from increased sedimentation and the cordgrass extended out into other estuaries around New Zealand. Native plants and animals struggled to survive as non-natives out competed them. Efforts are now being made to remove these cordgrass species, as the damages are slowly being recognized.

In the [[River Blyth, Suffolk|Blyth estuary]] in [[Suffolk]] in eastern England, the mid-estuary reclamations (Angel and Bulcamp marshes) that were abandoned in the 1940s have been replaced by tidal flats with compacted soils from agricultural use overlain with a thin veneer of mud. Little vegetation colonisation has occurred in the last 60–75 years and has been attributed to a combination of surface elevations too low for pioneer species to develop, and poor drainage from the compacted agricultural soils acting as an [[aquiclude]].<ref name="french">French, J. R. and Burningham, H. (2003). "Tidal marsh sedimentation versus sea-level rise: a southeast England estuarine perspective", ''Proceedings Coastal Sediments'', 1–13.</ref> Terrestrial soils of this nature need to adjust from fresh to saline interstitial water by a change in the chemistry and the structure of the soil, accompanied with fresh deposition of estuarine sediment, before salt marsh vegetation can establish.<ref name="boorman">Boorman, L., Hazelden, J., and Boorman, M. (2002). "New salt marshes for old – salt marsh creation and management". ''The Changing Coast'', EUROCAST/EUCC, EUROCOAST Littoral 2002: Porto, Portugal; 35–45.</ref> The vegetation structure, species richness, and plant community composition of salt marshes naturally regenerated on reclaimed agricultural land can be compared to adjacent reference salt marshes to assess the success of marsh regeneration.<ref name="angus">Angus, G. and Wolters, M. (2008). "The natural regeneration of salt marsh on formerly reclaimed land". ''Applied Vegetation Science'', 11: 335–344.</ref>