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Ellenberg reaction value

Formal name:  plant populations reaction indicator value according to Ellenberg
Abbreviation:  R
Local identifier:  TOP781
Synonym Term:  plant reaction preference
Definition:  a feature of the plant population (EFO:plant population) or plant species (Mayr:species) describing the occurrence of its individuals along gradient of soil acidity and lime content
Formal Unit:  unitless (ordinal)

Comment:  The values are indicators for the ecological behavior of a distinct plant species distributed in Central Europe, i.e. for its occurance under field conditions, including competition of many other plants. The different reaction values can be ordered as follows: 1=R1, 2=R2 3=R3, 4=R4, 5=R5, 6=R6, 7=R7, 8=R8, 9=R9
Reference:  Ellenberg, H., Weber, H. E., Duell, R., Wirth, V., Werner, W., Paulissen, D. (1992): Zeigerwerte der Pflanzen in Mitteleuropa, 2nd edition, Scripta Geobotanica, Vol. 18, Goltze KG, Goettingen