Information

Ecological parameter:  pH van Dam

Parameter group: habitat related parameters

Explanation:
Classification as pH indicator (measure of the acidity or basicity of an aqueous solution) following van Dam et al. (1994). Two different classifactions are provided: values modified by Coste (Lecointe et al., 1993) and values by van Dam et al. (1994).
Van Dam, H., Mertens, A. & Sinkeldam, J. (1994): A coded checklist and ecological indicator values of freshwater diatoms from the Netherlands. Netherlands J. Aquatic Ecol. 28 (1): 117-133.
Lecointe, C., Coste, M. & Prygiel, J. (1993): OMNIDIA software for taxonomy, calculation of diatom indices and inventories management. Hydrobiologia 269/270: 509-513.

Abbreviations:

Category name	Abbreviation	Explanation
1	1	acidobiontic: optimal occurunce at pH < 5.5
2	2	acidophilous: mainly occurring at pH < 7
3	3	circumneutral: mainly occurring at pH-values about 7
4	4	alkaliphilous: mainly occurring at pH > 7
5	5	alkalibiontic: exclusively occurring at pH > 7
6	6	indifferent: no apparent optimum

Assigned taxa for each higher systematic unit

Taxagroup	Number of assigned taxa / total number of taxa - percentage
Surirellacees	855 / 6949 - 12.3%