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h1. H7140 - Transition mires and quaking bogs


h1. General
{section:border=false}{column}
|| General characteristics || ||
| Common name | Transition mires and quaking bogs |
| Region | Europe |
| Water systems | Rivers, streams |
| Nature parameter | Habitat type |
| HR nr | H7140 |
| Fact sheet by | K.E. van de Wolfshaar |{column}{column}{align:right}
{column}{section}

h1. Description habitat
This habitat type consists of peat-forming communities developed at the oligotrophic to mesotrophic water surfaces, with characteristics intermediate between soligenous and ombrogenous types. They present a large and diverse range of plant communities influenced by base-rich groundwater or surface water, which mixes with acidic, oliogotrophic precipitation. Two vegetation types are included in this habitat type in The Netherlands: 1) Quaking bog (association _Scorpodio-Caricetum diandrae_) and 2) Peat bog (association _Pallavicinio-Sphagnetum_). These communities are a developing stage of the *verlanding*hydrosere of ditches and *petgaten* in low laying peat areas. They are preceded by [H3150 - Natural eutrophic lakes with Magnopotamion or Hydrocharition -type vegetation ] and succeeded by bush or forest, and possibly swamp heath [#2].

h3. General occurrence

This habitat type mainly can be found in Dutch low-lying peat lands. Quaking bog can mostly be found in low-lying peat lands near Pleistocene sandy grounds, as can be found in North West Overijssel, The Utrecht-Holland lake area and, in some cases, in Brabant near the Kempens plateau. Peat bog can be found more regularly. It develops in low lying peat areas after acidification of quaking bog and can also be found in peat areas with brackish water in North Holland  [#2]


h3. Environmental conditions

Peat bog comprises of a bottom layer consisting of large marsh plant rootstocks that are still in contact with eutrophic and base-rich water. Within the vegetation layer, eutrophication and base richness of the water decreases from the bottom upwards. The upper layer consists of various reed species. The bottom layer is related to the class of peat moor channels [#1].
Quaking bog consists of a floating plant layer with various kinds of sedge and moss. These plant communities are restrained to contact zones where base rich mesotrophic surface water or groundwater mixes with acidic, oliogotrophic, precipitation water in a quiet surrounding (no waves). The water level should be more or less at a constant level. The communities can be found near pleistocene sandy grounds in low-lying peat areas in The Netherland. Yearly mowing is necessary for a prolonged preservation of this community [#1].

h3. Control and growth opportunities

Both plant communities are endangered in The Netherlands because of acidification, drying out and forestration. Forestration occurs spontaneously if the mowing management of peat bogs and quaking bods is no longer prolonguated. For Peat bog, former management measurements such as light grazing and adding of a thin sludge layer can enhance its species richness. In addition, restoration of the former maximum level in a  'boezem' can enhance the species-richness. For Quaking bog, yearly mowing proves to be helpful. Without mowing, the community converts into woods and brush wood. Eutrophication reduces the species richness of Quaking bog and less rare vegetation types will occur [#1]. For this habitat type, digging of new *petgaten* is essential for the survival of these plant communities as it is a part of the verlandingsproceshydrosere process.

h1. Dose-effect relations

These dose-effect relations have been based on information of plant communities belonging to this habitat type. 
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h4. Flow chart
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h4. Dose-effect relations


{section}{column:width=33%}
{chart:type=bar|title=surge |xlabel=surge|yLabel=Habitat Availability Index |dataDisplay=true|dataOrientation=vertical|legend=false}
||surge|| HSI ||
| present |0 |
| absent | 1 |
{chart}
Reference: [#1]{column}{column:width=33%}
{chart:type=bar|title=mowing policy|xlabel= mowing policy |yLabel=Habitat Availability Index |dataDisplay=true|dataOrientation=vertical|legend=false}
|| mowing policy || HSI ||
| never | 0 |
| yearly | 1 |
{chart}
Reference: [#1] {column}{column:width=33%}
{chart:type=bar|title=Soil type|xlabel=Soil type|yLabel=Habitat Availability Index |dataDisplay=true|dataOrientation=vertical|legend=false}
|| Soil type || HSI ||
| sand | 1 |
| loamy sand | 1 |
| loam | 1 |
| peat | 1 |
|other|0|
{chart}
Reference: [#2] {column}{section}{section}{column:width=33%}
{chart:type=bar|title=Water level|xlabel=water level|yLabel=Habitat Availability Index |dataDisplay=true|dataOrientation=vertical|legend=false}
||water level || HSI ||
| shallow en temporal drying| 1 |
| wet| 1 |
| other | 0 |
{chart}
Reference: [#2] {column}{column:width=33%}
{chart:type=bar|title=salinity|xlabel=zoutgehalte|yLabel=Habitat Availability Index |dataDisplay=true|dataOrientation=vertical|legend=false}
|| salinity|| HSI ||
| very fresh| 1 |
| other | 0 |
{chart}
Reference: [#1] \\ {column}{column:width=33%}
{chart:type=bar|title=water level fluctuation|xlabel= water level fluctuation |yLabel=Habitat Availability Index |dataDisplay=true|dataOrientation=vertical|legend=false}
|| water level fluctuation || HSI ||
| hardly| 1 |
| other | 0 |
{chart}
Reference: [#1]{column}{section}

h1. Uncertainty and validation

(!) These dose-effect relations have not been validated.

h1. Applicability

These dose effect relations have been based on habitat factors of plant communities belonging to this habitat type. Relations are not complete, as it is very difficult to identify distinguished relations for plant communities that belong to a successive development from open water to forest. 

h1. Example project

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

h1. References

1 {anchor:1} Weeda, E.J., Schaminée, J.H.J., Van Duren, L.. Atlas van Plantengemeenschappen in Nederland. Deel 1. Wateren, moerassen en natte heiden. KNNV 2000.
2 {anchor:2} [http://www.minlnv.nl/natura2000]