TMAP Monitoring Handbook

1 Introduction

Salt marshes form the upper parts of the intertidal zone, the interface between land and sea, and are strongly controlled by geomorphological, physical and biological processes, such as sedimentation in interaction with the vegetation, tidal regime and wind-wave pattern. They constitute a habitat for a wide range of organisms. On a European scale, among 1068 plant species that are bound to coastal habitats, nearly 200 are restricted to salt marshes. The highest species diversity in salt marshes is found among the invertebrate fauna; about 1500 arthropod species inhabit salt marshes of which a considerable number are restricted to this habitat (QSR 2004).

Salt marshes provide resting, breeding and feeding grounds for a number of birds. Coastal waders which feed on the intertidal flats use the salt marshes as roost during high tide. A number of migratory birds such as brent goose and barnacle goose use the salt marshes to replenish their body reserves to reach their northern breeding grounds (QSR 2004).

About one third of the salt marsh area shows the natural patterns of accretion, erosion and vegetative diversification. Entirely natural salt marshes prevail on the barrier islands and, in the Northern Wadden Sea, also behind sandy barriers of the mainland. Along most of the mainland, salt marshes are man-made, and in some cases managed for coastal protection. Both types together represent an area of 400 km² in the Wadden Sea Area with a quite diversity of distinctive salt marsh types consisting of a species-rich dynamic mosaic of vegetation patches.

There are various human activities which have or may have an impact on salt marshes, including costal defense measures, land use and management (grazing, cutting), pollution and eutrophication, hunting and tourism (QSR 2004). Nowadays, all salt marshes in the Wadden Sea are under nature protection.

2 Objectives

Trilateral policy and management aims “to achieve, as far as possible, a natural and sustainable ecosystem in which natural processes proceed in an undisturbed way” (Guiding Principle).

The salt marshes include all mainland and island salt marshes, including the pioneer zone and the brackish marshes in the estuaries. The following targets apply to salt marshes (Wadden Sea Plan):

• an increased area of natural salt marshes;
• an increased natural morphology and dynamics, including natural drainage patterns of artificial salt marshes, under the condition that the present surface area is not reduced;
• an improved natural vegetation structure of artificial salt marshes, including the pioneer zone;
• favorable condition for migrating and breeding birds.

The monitoring of salt marshes (all island and mainland salt marshes including brackish marshes in the estuaries) is carried out to support trilateral policy and management. It should:

• assess changes in location and the area of salt marshes (natural and artificial),
• assess changes in the vegetation types,
• contribute to causal analyses of changes, especially with regard to the impacts of climate changes, coastal protection measures, and agricultural utilization (e.g. grazing).

3 Monitoring requirements

Wadden Sea Plan (WSP)

Targets on “Tidal Area”

Targets:

• an increased area of natural salt marshes;
• an increased natural morphology and dynamics, including natural drainage patterns of artificial salt marshes, under the condition that the present surface area is not reduced;
• an improved natural vegetation structure of artificial salt marshes, including the pioneer zone.
• favorable condition for migrating and breeding birds.

Habitats directive/Birds directive (HD/BD)

Article 11 Monitoring of habitat types

Favorable conservation status of salt marsh habitat types (1310 Salicornia, 1320 Spartina, 1330 Atlantic salt meadows)

Article 11 Surveillance of conservation status of habitats and species
Article 17: Assessment, monitoring and reporting

Water framework directive (WFD)

Annex 5, chapter 1.2.4 and Article 4

Article 8, Annex V, Quality element: Angiosperms

Oslo Paris convention (OSPAR)

Biological Diversity and Ecosystems Strategy, Annex V and Appendix 3

No specific requirements for salt marsh monitoring.

4 Definitions

Salt marsh types
Salt marshes develop in close interaction of hydrodynamic processes with vegetation development and can be distinguished in relation to their geomorphologic features (Dijkema, 1987). On the islands, four types could be distinguished. Barrier-connected salt marshes develop on the lee side of the sand dune system of the barrier islands. Green beaches are salt marshes which developed on the North Sea side of the islands. In addition to the categories in the 1999 QSR, salt marshes in summer polders and in de-embanked summer polders have been included.

On the mainland, foreland marsh (including the estuarine salt marshes), salt marshes in summer polders and de-embanked (summer) polders are the main salt marsh types. Most foreland marshes have been developed from sedimentation fields protected by brushwood groynes. As a special case, the salt marshes in St. Peter-Ording (Schleswig-Holstein) and Skallingen (Denmark) have been added as barrier-connected type, because they have developed in the shelter of a beach-barrier system comparable to the barrier islands.

Hallig salt marshes have been accreted on surviving parts of marshes flooded in the past and are highly exposed to wave energy. They represent a separate type as they resemble more the mainland foreland type.

1. Barrier islands	2. Mainland	3. Halligen
A. barrier-connected (incl. Foreland)	A. barrier-connected
B. green beaches	B. foreland marsh
C1. summer polder	C1. summer polder
C2. de-embanked (summer) polder	C2. de-embanked summer polder

Salt marsh zones (zonation)
Three main salt marsh zones with different vegetation can be distinguished: The pioneer zone where plant growth starts at about 40 cm below mean high tide (MHT); the low marsh, inundated during mean spring tides (100-400 floods/year), and the middle/high marsh with less than 100 floods per year. In addition, the sandy green beach and the brackish marsh can be differentiated by a special type of vegetation. Adjacent to the salt marshes fresh (anthropogenic) grassland occurs. The different zones have been defined by vegetation types (see Annex 1[to be included]).

Vegetation types
Different classification systems are applied for salt marsh vegetation in the three countries. They consist a number of vegetation sub-types with different definition e.g. concerning species composition, dominant or characteristic species, or in the case of biotope types, also information about land use. These detailed classification systems are necessary for regional management. For trilateral purpose these sub-types have been aggregated to a higher level, the salt marsh vegetation types (TMAP typology) (see Annex 1).
The TMAP typology also includes the connection with the habitat types of the EU Habitats Directive (habitat type 1310, 1320 and 1330).

Border of pioneer zone
The border between the pioneer zone and bare soil is chosen at 5% coverage (10% in SH). This is based on practical reasons when mapping with aerial photos.

Land use
Land use can be subdivided into agricultural exploitation and nature conservation. The respective areas are not (yet) quantified. Within agricultural exploitation and nature conservation management practices such as grazing, cutting, abandoning are recognized and quantified. In general, the intensive agricultural exploitation of salt marshes observed has decreased during the past two decades. Today, large areas of the salt marsh are grazed moderately, often for nature conservation purposes, for example for geese management on the Halligen in Schleswig-Holstein.

5 TMAP Monitoring Strategy

Monitoring of salt marshes is carried out in all countries on a regular basis. Different national vegetation keys are in use (e.g. the Dutch SALT97) which are translated into a common TMAP vegetation typology (QSR 2004). It allows a trilateral comparable assessment of salt marsh vegetation on the basis of the existing monitoring schemes. The vegetation reflects the important salt marsh zones (pioneer zone, low marsh, high marsh, green beaches, brackish marsh) and human interference including drainage, groynes and land use (Bakker et al. 2005). It can be applied

• to assess long-term and short term changes in the vegetation also with respect to animal life, especially with regard to birds,
• to assess the development of single vegetation types or typical species,
• to analyze the distribution pattern of the vegetation in relation to land use.

The TMAP vegetation key can also be used as a basis for an assessment within the WFD (Dijkema et al., 2005, Adolph et al., 2007) and the HD (QSR 2004).

Further parameters may be selected on national level depending on local pressures and risk assessment procedures under the Habitats and Water Framework Directive.

(Table 5.1) Parameters with monitoring locations and frequencies and the relation to the other monitoring requirements.

Parameters	Description	Location	Frequency	Method	WFD	BD/HD	OSPAR	OTHER	Remark
Mandatory TMAP parameters
Area (saltmarshes)	Size and location (ha)	Entire area	6 years		X	X	-	-	-
Drainage (saltmarshes)	3 types (none, within last 10 years, more than 10 y ago)	Entire area	6 years		X	X	-	-	-
Land use (saltmarshes)	Cutting, grazing (intensive, moderate, none)	Entire area	6 years		-	X	-	-	-
Vegetation (saltmarshes)	HD types (ha)	Entire area	6 years		X	X	-	-	HD type Spartina not in DK
Optional TMAP parameters
Selected typical species (saltmarshes)	Abundance and composition of typical species	Selected areas	Annually		X	X	-	-	-
Vegetation types (saltmarshes)		Entire area	6 years (sel. Site 1/y) (selected sites: annually)		X	X	-	-	TMAP key in NL + D

Remarks:

* DK: Salt marshes not part of WFD monitoring. NL: Mainland salt marshes not part of WFD monitoring
**Under discussion in national HD and WFD monitoring

5.1 Parameters

Area

Location and spatial extent (GIS polygon) of salt marshes (total area and vegetation types) should be calculated for sub-areas by GIS procedures.

Vegetation

Habitat Directive (HD) types: Location and spatial extent (GIS polygon) of HD types 1310, 1320 and 1330.

TMAP vegetation types: Location and spatial extent (GIS polygon) of TMAP vegetation types aggregated from the national salt marsh monitoring data (Note: Data on vegetation types for the entire area are available from The Netherlands and Germany. For Denmark, data are available from selected monitoring sites).

Species (not mandatory)

Abundance and composition of typical salt marsh species (for selected monitoring sites only).

Land use

The effects of the management or agricultural utilization of salt marshes by grazing are reflected in the vegetation structure. The terms ‘no grazing’, ‘moderate grazing’, ‘intensive grazing’ and ‘cutting’ are defined by the canopy of the vegetation and its heterogeneity, and thus describe the real grazing situation of a certain area irrespective of the stocking density.

Three types can be distinguished concerning grazing intensity:

• no grazing (areas without any management or utilization by grazing; year of grazing ceased)
• extensive grazing (areas with grazing; diverse canopy heights, but not a uniform vegetation and short canopy as under c, but a mosaic of short and tall canopy).
• intensive grazing (whole area with uniform vegetation and short canopy height)

Additional information like stocking rates and types of animals are also important to assess grazing intensity.

Drainage measures

Three different types of drainage pattern of salt marshes should be distinguished:

• no artificial drainage in the past (number of years to be specified; sometimes only estimation possible);
• no artificial drainage on a regular basis (maintenance works only episodic);
• ongoing drainage measures on a regular basis (e.g. every 2-5 years).

It has to be tested if the information can be derived from the vegetation maps or if also information from other sources are necessary which would require additional effort.

Additional parameters (not mandatory)

In addition, further parameters are be monitored on project basis, depending on scientific objectives and/or management goals for specific areas. These parameters should also be made available for a trilateral assessment

• Hydrology: mean high tide, mean low tide, inundation time and frequency,
• Morphology: height, salt marsh edge, topography,
• Sediment characteristics,
• Coastal protection measurement,
• Biological parameters: vegetation (dominance/diversity, canopy height and pattern therein, biomass).

It is recommended to compile information about coastal protection measures with a direct impact on the salt marshes, e.g. construction or maintenance of brushwood groynes, sod removal and clay extraction.

Breeding and migratory birds

Monitoring of breeding and migratory birds on salt marshes are carried out in the Joint Monitoring Programs of Breeding and Migratory Birds.

5.2 Monitoring locations

The entire area of salt marshes in the Wadden Sea (including brackish marshes in the estuaries) shall be monitored for the parameters:

• area,
• vegetation (HD types and TMAP vegetation types),
• land use,
• drainage measures.

Selected monitoring sites can be specified by the countries to monitor species composition or additional parameters relevant for specific national assessment.

6 Methods

6.1 Remote sensing

The following remote sensing techniques can be applied for salt marsh monitoring

• Aerial photographs (CIR) with a scale 1:5,000 - 1:10,000,
• Digital aerial mapping (such as line scannHRSC-AX)

			Digital mapping	Aerial photographs
Mapping techniques	Data acquisition	source	Line scanner HRSC-AX	Digital aerial photography
		n bands	9 bands	4 bands
		ground resolution	32 cm	…..
	Image classification	information	Optical reflection values of 4 bands	stereo information of overlapping photographs: colour, texture, structure
			no height information	height information
		polygons	raster and vector based filtering	on screen digitizing by hand

Ground truth surveys are necessary for the interpretation of aerial photographs. The digitized photographs should be transferred to a Geographical Information System. Standard software should be used.

Intercalibration exercises should be carried out to assess the comparability of different interpretation procedures.

6.2. Field surveys

Field surveys should be carried out

• as ground truth in conjunction with remote sensing techniques,
• to get more detailed information (quantitative and qualitative) to be able to characterize the ecological status of salt marshes (species composition, abiotic characteristics)

Salt marsh field surveys should be carried out at several sites on annual basis (permanent plots) in combination with large scale monitoring by remote sensing. They are necessary to meet the objectives of the TMAP and the Targets, to support management decisions with regard to grazing or to assess the development of sedimentation rates in different types of salt marshes with regard to sea level rise.

The existing field surveys are carried out using different monitoring strategies. They should be harmonized with the aim to make the results of the different surveys comparable for a trilateral assessment.

7 Parameter

8 Frequency and time

Monitoring shall be carried out at least every 6 years during summer (June – August) for the following parameters:

• area
• vegetation (HD types and TMAP vegetation types)
• land use
• drainage measures

Yearly monitoring shall be carried out for selected sites (permanent plots) for the parameter “species” (during summer, June – August).

For details see [Table 5.1].

9 Assessment

The entire area of salt marshes in the Wadden Sea (including brackish marshes in the estuaries) shall be monitored for the parameters:

• area,
• vegetation (HD types and TMAP vegetation types),
• land use,
• drainage measures.

Selected monitoring sites can be specified by the countries to monitor species composition or additional parameters relevant for specific national assessment.

10 Reporting

All data obtained from remote sensing and field surveys should be transferred to a geographical information system (GIS) for the analysis and assessment of the data (spatial and temporal development) and in combination with other GIS based information.

The data should be reported as they were measured:

• area and location of main salt marsh types (km²)
• area salt marsh vegetation (HD types, vegetation types) according to the TMAP vegetation typology (km²)
• land use types (3 categories) (km²)
• drainage types (3 categories) (km²)

A description of the applied methods should also be reported. If available the accuracy of the data should be included in reporting.

[NOTE: To be included: a more detailed description of data which have to be delivered to the TMAP Data Units. See also: TMAP Data Handling Manual].

11 Quality assurance

A successful monitoring program is directly related to the collection and interpretation of relevant and reliable data. In addition to appropriate sampling and interpretation procedures, it is vital to establish a system of data quality assurance. This concerns accuracy and precision of sampling and analytical procedures, regular check of the applied methods and intercalibration exercises.

Specific QA activities for salt marsh monitoring should be carried out for the following items:

• intercalibration exercises concerning interpretation of aerial photographs,
• field surveys: comparability of different monitoring strategies, intercalibration exercises.

Appropriate monitoring protocols should be developed on national level. Intercalibration exercises should be carried out nationally and in the framework of the TMAP.

12 Monitoring authorities

Denmark

Danmarks Miljøundersøgelser (DMU, NERI)

Germany

Landesbetrieb für Küstenschutz, Nationalpark und Meeresschutz (LKN)

Nationalparkverwaltung Niedersächsisches Wattenmeer (NLPV)

Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz (NLWKN)

Netherlands

Rijkswaterstaat DID Delft

Denmark

Miljøministeriet, Miljøcenter Ribe

Germany

Landesamt für Natur und Umwelt (LANU)

13 Literature

Adolph, W., Petri, G. , Jaklin, S., Petersen, P., 2007: Aufbau einer Bewertungsmatrix für die Gewässertypen nach EG-WRRL im Küstengebiet der Nordsee, Schwerpunkt Flussgebietseinheiten Weser und Elbe. Abschlussbericht Teil B, Makrophyten (Röhrichte, Brack- und Salzmarschen), Makrozoobenthos, Schadstoffe.

Dijkema, K. S., D. J. de Jong, M. J. Vreeken-Buijs, W. E. van Duin, 2005: Salt marshes in the Water Framework Directive. Development of Potential Reference Conditions and of Potential Good Ecological Statuses. Report RIKZ/2005.020

Stock, M., Gettner, S., Hagge, H., Heinzel, K., Kohlus, J., Stumpe, H., 2005: Salzwiesen an der Westküste Schleswig-Holstein 1988 – 2001. Schriftenreihe des Nationalparks Schleswig-Holsteinisches Wattenmeer, Heft 15.