ECOLOGY OF AMPHIDIUM-MOUGEOTII STANDS (MU SCI) IN VOSGES (FRANCE)

Thirty-five stands of Amphidium mougeotii in the Vosges Mtns., France, were studied. The species occurs on vertical rocks of granite and san dstone with seeping water. It is accompanied in two thirds of the stan ds by basiphilous, in one third by acidophilous bryophyte species. pH measurements of seepage water varied accordingly between 4.8 and 8.2. In spite of this broad amplitude, the species lacks in many seemingly suitable habitats. Analyses of the seepage water from habitats with an d without Amphidium revealed that the occurrence of this species seems to depend on higher amounts of K+ and Mg2+ ions.