3.3. ASV-ratios
The ASV-ratios were generally lower than one (Tab. S1), pointing out
that ASV richness values observed in the tourist areas were lower than
in the control area.
The results of the models (Tab. 2 and Fig. 3a) performed on the
ASV-ratios showed that the ASV-ratio of Fungi was negatively affected by
the distance from the tourist path and positively affected by its
interaction with the distance from the cave entrance (Fig. 3a). No
response was recorded for Bacteria and Archaea in relation to these two
parameters (Fig. 3a). In addition, both Fungi and Archaea were
negatively affected by the increasing dissimilarity of sediment
composition (Fig. 4a). In other words, the number of ASV in the
touristic part of Archaea and Fungi declined when sediment composition
differed from the control area.
3.4. Beta diversity
The total β-diversity was extremely high (Fungi = 0.96; Bacteria = 0.92;
Archaea = 0.93), with the β-richness component being dominant (Fungi =
0.55; Bacteria = 0.54; Archaea = 0.65) over the β-replacement component
(Fungi = 0.41; Bacteria = 0.38; Archaea = 0.28). The results of the
models (Tab. 2b-c and Fig. 3b-c) performed on the two components showed
an effect of the distance from the tourist path on the β-replacement of
the prokaryotic component, i.e. Bacteria (Fig. 3b) and Archaea (Fig.
3b). Both groups showed a significant decline of the β-replacement at
increasing distance from the cave entrance (Fig. 3b). In parallel, we
observed an increase in the β-richness component for Archaea (Fig. 3c)
and, to a lesser extent, for Bacteria (Fig. 3c). Our results also
highlighted a nearly significant effect of the cave depth on the
β-replacement (Fig. 3b), but not on β-richness (Fig. 3c), of Fungi with
decreasing species turnover at increasing distance from the cave
entrance (Tab. 2b). In addition, β-diversity of Fungi was significantly
affected by the sediment composition (Tab. 4), with increasing
β-replacement (Fig. 4b) and declining β-richness (Fig. 4c) at increasing
dissimilarity in sediment composition from the control areas.