Lampenflora consists of phototrophic organisms which grow
near artificial light. In caves with artificial lighting, a vegetation
of aerophytic cyanobacteria and algae, bryophytes and
ferns can be found around lamps; these communities represent
an alteration of the underground environment and may cause
damages both to speleothems and cave fauna. The development
of lampenflora is a typical problem for show cave management.
A floristic research of bryophytes and ferns (land plants) of
lampenflora was carried out in 2012 in Grotta Gigante, a very
well-known show cave of the Trieste Karst (NE Italy), in order
to compile a species inventory. 26 sites near artificial lights of
different kinds were sampled in the dark zone of the show cave.
16 moss species and 2 ferns were found; no liverworts were observed.
The most common species are the mosses Eucladium
verticillatum, Fissidens bryoides, Oxyrrhynchium schleicheri,
Rhynchostegiella tenella and the fern Asplenium trichomanes; 7
moss species were found only in one to two sites. Some moss
species belong to the flora of natural cave entrances of the Italian
Karst, while other are typical of disturbed, open habitats.
Various moss species and A. trichomanes are colonizing areas
around LEDs and fluorescent lamps installed in 2009 along
the cave’s pathways for safety lighting. Species richness of
bryophytes and ferns of lampenflora in Grotta Gigante is the
highest compared to other recently investigated show caves
in the neighbouring Slovenia. Lampenflora of Grotta Gigante
conforms to that found in other Slovenian show caves studied
starting from the ’40. The main ecological factors affecting
lampenflora identified in this work are: light intensity, water
availability, type of substrate, morphological features of surfaces,
presence of clay. Aspects of species ecology and distribution
in the cave are discussed.
