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H1320 - Spartina swards

General

Description habitat

This habitat type includes Perennial pioneer grasslands of coastal salt muds, formed by Spartina or similar grasses. It belongs to the class (Spartinion). Characteristic species are Small Cordgrass (Spartinetum maritimae) and Common Cordgrass (Spartinetum townsendii).

General occurrence

Spartina Swards can be found on saltmarshes in the lower areas, mainly on the transition of saltmarshes and mudflats. In The Netherlands, it is found in the Oosterscheldebekken. Well-developed versions of this habitat type occur in all sheltered coastal zones of the Wadden Sea area and the Deltas of Zeeland and South-Holland. A large Saginion covered area can be found in Grevelingen on dry sandflats #1.

Environmental conditions

Spartina Swards prefer soft and salty soil. In the Netherlands, it needs salt to growth. The soil is silt rich #6.

Spartina Swards is adapted to anoxic circumstances. The species has aerial roots to transport air to the roots #6. It can thus endure deeper and longer inundation during the growing season. The average inundation depth at high water can be up to 1 metre, the average inundation length up to 6 hour. According to measurement data of the Haringvliet #3 this type can be found between the mean low water line (MLW) and the mean high water line (MHW), especially between half tide and MHW. Between MLW and half tide, mostly silt can be found and occasionally H1310 and H1320.

Erosion by, for instance, wave impact and current, restricts the colonisation by Spartina Swards. However, once it is settled, it can better withstand erosion. Spartina Swards is very sensitive to wave impact, so it only occurs on sheltered locations. If dynamics are high, vegetation cannot survive resulting in a bare beach. Habitat type H1320 is more vulnerable to high dynamics (maximum moderate dynamics) than (H1310).
The chloride concentrations as referred to in literature, vary between 0.3gCl/L and 70gCl/L #3, #4, #5.

Control and growth opportunities

In grazed areas, open spots in Spartina Swards fields are sometimes colonised by seaside alkaligrass (Puccinellia maritima) and the latter can slowly cover the entire area. In case of further silt up, this vegetation transfers into Plantagini-Limonietum (class of sea lavender and Sea Plantain). Puccinellinetum maritimae can survive for a long time in grazed areas #3. In ungrazed areas, it often is replaced by sea clubrush (Bolboschoenus maritimus).

Dose-effect relations

Flowchart

Doses-effect relations

	HAI
< MLW	0
MLW - half tide	0.4
half-tide - MHW	1
> MHW	0

MLW = mean low water level
MHW = mean high water level

	HAI
0	0
0.3	0
4	0.5
5	1
10	1

	HAI
low	1
moderate	1
height	0

Dynamics has not been qualified, for instances in terms of velocity or wave height. This should be studied further in a project.

Uncertainty and validation

These dose-effect relations have not been validated.

Applicability

These dose-effect relations apply to banks of salt and brackish waters.

Example project

At present, there is no example of a project available.

References

1 http://www.minlnv.nl/natura2000
2 Haasnoot, M. en K.E. van de Wolfshaar (ed). (2006). Habitat analyse in het kader van de Planstudie/MER voor Krammer, Volkerak en Zoommeer. WL report Q4015
3 Hansson Ecodata. Calibratie van het model EMOE voor de vegetatie van de voordelta van het Haringvliet. Freiburg, 2005.
4 Schaminée, J.H.J., Weeda, E.J. en Westhoff, V. (1998). De vegetatie van Nederland. Deel 4. Plantengemeenschappen van de kust en van binnenlandse pioniermilieus. Opulus Press, Uppsala-Leiden.
5 Van der Meulen, Y.A.M.. Meren Ecotopen Stelsel. RIZA nota 97.076. 1997
6 Weeda, E.J., J.H.J. Schaminee, L. van Duuren (2003). Atlas van Plantengemeenschappen in Nederland. Deel3 Kust en binnenlandse pioniermilieus. KNNV Uitgeverij.