Proposal for a transformation scale between bioindicatively determined water supply levels of grassland sites and mean moisture indicator values according to Ellenberg

Abstract

Data on the moisture level of grassland sites have traditionally been based on the water supply levels according to Petersen (1952) in east German relevant technical literature. The question was to what extent these data are comparable to Ellenberg's widely-known moisture indicator values. The transformation scale for water supply levels and moisture values suggested in this paper was based on more than 500 grassland relevés collected in the German federal states of Brandenburg and Mecklenburg-Western Pomerania. The water supply levels were appraised according to the bioindicative method by Hundt (1964). There was a high rank correlation coefficient between average moisture values and water supply levels (rSpearman = 0.939). The water supply levels were related to the following amplitudes of the average moisture values: W5−/4−: < 3.5; W3−: 3.5 – 4.4; W2−: 4.5 – 5.3; W2 +: 5.4 – 6.1; W3 +: 6.2 – 7.1; W4 +: 7.2 – 8.4; W5 +: > 8.4.