Ecological parameter: LANDOLT vascular plants - reaction Switzerland (Alpine region)

Parameter group: habitat related parameters

Explanation:
The reaction value characterises the content of free H-ions in the soil. Low reaction values indicate acid soils poor in bases, high values correspond to soils rich in bases.

Landolt, E., Bäumler, B., Erhardt, A., Hegg, O., Klötzli, F., Lämmler, W., Nobis, M., Rudmann-Maurer, K., Schweingruber, F.H., Theurillat, J.-P., Urmi, E., Vust, M. & Wohlgemuth, T. (2010): Flora indicativa - Ökologische Zeigerwerte und biologische Kennzeichen zur Flora der Schweiz und der Alpen, 2. Aufl., Haupt Verlag, Bern, Stuttgart, Wien, 378pp.

Type of assignment: single category assignment system (including variation)
A description of the coding system can be found here  Abbreviations/Coding Systems

Abbreviations:

Category name:	Abbreviations:	Explanation:
1	1	extremely acid, pH 2.5 - 5.5
2	2	acid, pH 3.5 - 6.5
3	3	weakly acid to weakly neutral, pH 4.5 - 7.5
4	4	neutral or alkaline basic, pH 5.5 - 8.5
5	5	alkaline, high pH, pH over 6.5 - 8.5
x	x	wide range of variation
variation		range of variation regarding the reaction value: I - small variation, II - large variation

Assigned taxa for each higher systematic unit:

Taxagroup	Number of assigned taxa / total number of taxa - percentage
Liliopsida	221 / 361 - 61.2%
Lycopsida	4 / 12 - 33.3%
Magnoliopsida	7 / 20 - 35%
Polypodiopsida	11 / 19 - 57.8%
Rosopsida	286 / 399 - 71.6%
Sphenopsida	8 / 9 - 88.8%