In the Netherlands we assess the quality of the habitat (Structure & function) based on 4 components:
Other features of Structure and Function
The four parts of Quality of the habitat should be taken together when assessing the quality.
As part of the definition, based on the information of the interpretation manual, we made a list of vegetation types according to national classification (Schaminée et al. 1995-1999) that are part of the habitat type. In these vegetations a distinction is made between vegetation types that represent “good” or “moderate” quality of the habitat. This is only an indicator of the quality of the vegetation, not of fauna. The “good” vegetation types are typical, more bio divers or rare vegetations , the “moderate” vegetation sites are more modified vegetations (but still worthy of the habitat type) or vegetation types that form only a small part of the habitat and need to occur in combination with “good” habitat types.
The ratio between “good” and “moderate” habitat types is part of the assessment of the quality of the habitat.
The abiotic conditions give the conditions of the environment that are best for the vegetation types that are part of the habitat type. They are based on scientific research and are valid at the national level. Depending on local circumstances the values may vary in a particular site. The information on vegetation types gives an indication of the environmental needs of the habitat at a national level.
For every vegetation type of the habitat type the following habitat conditions are used:
level of eutrophy
tolerance of inundation
mean lowest ground water level
For aquatic habitat types also quantitative information on nutrient content is used to make the connection with the Water Framework Directive.
To assess the possibilities for restoration or the effect of external influences the total of the abiotic conditions is to be taken into account.
The Netherlands distinguishes two types of typical species:
exclusive and characteristic species: species that occur only (or mostly) in the habitat type (E and K);
constant species: species that always occur in the habitat, but may also occur elsewhere (C); Ca means that the species is an indicator for good abiotic circumstances, Cb species indicate a good biotic structure.
4.Other features of Structure and Function
Other biotic, abiotic and landscape features.
Coverage of species (functional) groups (mosses, grasses, shrubs, annual species);
Water quality, (clearness, phosphate), depth and dynamics;
Dynamic processes (sedimentation and erosion, change in water level, wind)
Location within the landscape;
minimum area (standard 100 m2, H6110 and H7220:10 m2 and forests 1.000 m2 (= 0,1 hectare).
This means we have large lists of vegetation types and typical species ánd a standard table for abiotic conditions for each habitat. By this structure these first three parts cannot be filled in in the table of structure and function started up by Finland. These parts are constant factors in the assesment of the quality, so they have to be looked at separately. Only tart 4, “other features” could be inserted in the table.
In Annex I an example of the paragraphs “definition” and “quality of the habitat” from a “profile” is given (in Dutch) to illustrate the way we present it. More profiles can be found at http://www.synbiosys.alterra.nl/natura2000/gebiedendatabase.aspx?subj=profielen
In Annex II a translation of “other features of structure and function” of several habitats is giving (it is going to take too much time to do them all right now).
Annex 1: example of description of quality of the habitat in “Profielendocument”
Niet tot het habitattype gerekend worden rompgemeenschappen op hoger niveau dan het verbond, bijvoorbeeld met dominantie van Moerasstruisgras (Agrostis canina), Pijpenstrootje (Molinia caerulea), veenmos (Sphagnum sp.) of Hennegras (Calamagrostis canescens).
On relatively high parts in the winter bed of the river: on sedimentation banks, old river dunes and on the gradient to higher sand landscape.
Soil sandy of clay, mostly calcareous
Minimum area > ten of hectares.
1 Ca = constante soort goede abiotische toestand; Cb = constante soort goede biotische structuur; Cab = constante soort goede abiotische toestand en goede biotische structuur; K = karakteristieke soort; E = exclusieve soort