Hydropus atramentosus is a rare lignicolous fungus included in the Red Book and Red List of the Czech Republic and in red lists of 5 other European countries. To date, it has been recorded at 15 localities in the Czech Republic. Most of them are almost pure Fagus forests with rare presence of Picea and/or Abies at lower altitudes or mixed submontane or montane forests composed predominantly of Fagus, Abies and Picea. There is also one record from a man-made Picea forest. H. atramentosus was mostly found at slopes of mountains or hills but also in deep stream valleys in the hilly country. The fungus shows a clear preference for old-growth forests (mostly nature reserves). However, it is rarely found in man-influenced or even man-made stands. Consequently, H. atramentosus cannot be considered a relict species confined exclusively to true virgin forests almost untouched by man but can be used as a bioindicator of conservationally valuable stands (natural vegetation, presence of dead wood of Abies or Picea, stable meso– and microclimate). This conclusion was verified also in the Slovakia and Ukrainian Eastern Carpathians.
Holec J. (2008): Ecology of the rare fungus Hydropus atramentosus (Basidiomycota, Agaricales) in the Czech Republic and its potential value as a bioindicator of old-growth forests. – Czech Mycology 60(1): 125–136.
