# Airborne Fungi in Show Caves from Southern Spain
## 4 Discussion  
### Fungal Ecology  
The influence of air currents from the outdoors was observed in the three caves, which transport spores, giving rise to an increase in fungal concentrations in the areas of the cavity closest to the entrance. [PERSON] et al. [6] reported that in Cueva de Ardales, and as a consequence of the opening of the access door for the entrance of visitors, there was an increase in the concentrations of fungi. This was particularly high in Galeria del Calvario, the zone where the paintings and engravings are located, which increased by 100 times in terms of CFU/m\({}^{3}\) after a visit of 32 people. In our sampling, one year later and without the influence of previous visits, the CFU/m\({}^{3}\) in Galeria del Calvario was zero or negligible (Supplementary Tables S1-S4). These data note that the visits should be controlled or, if needed, cancelled in caves with rock art. In Gruta de las Maravillas, Sala de las Conchas, one of the areas closest to the entrance, the concentrations of fungi followed the same seasonal patterns observed in the outdoor air, highlighting the influence of the exterior atmosphere. The large volume of other rooms seemed to influence fungal concentrations, causing a dilution effect. Thus, the highest fungal concentrations were recorded in rooms and galleries of relatively small dimensions, which could contribute to the concentration of spores, as was the case in Cueva del Tesoro. Regarding the ecology of the most abundant fungal genera in the three caves, it was found that _Cladosporium_ was the predominant genus inside the three caves. Six species were identified, _C. cladosporoides_, _C. halotolerans_, _C. tenuissimun_, _C. limoniforme_, _C. raronetellum_, and _C. flocosum_, in addition to two species outdoor: _C. sphaerospermum_ and _C. subinflatum_. The abundance of _Cladosporium_ is a common pattern in Nerja and Altamira, among other caves [8; 12], in addition to indoor environments [19; 20]. The genus _Cladosporium_ is one of the most frequent in outdoor environments, so its presence indoors is generally attributed to transport through air currents [6; 8]. According to [PERSON] et al. [6] the higher concentrations of _Cladosporium_, in a sampling carried out after a visit of 40 people in Cueva de Ardales, showed the influence of the opening of the door in the creation of air currents between the interior and exterior of the cavity, with the consequent entry of spores. _Cladosporium cladosporoides_, one of the most abundant fungi in Cueva de Ardales and Cueva del Tesoro has been recorded in other caves, such as Lascaux [2], Altamira [8], and three Slovakian caves [21]. Pachonia dhamdosporia (=Metacordyces chlamdosporia), a recognized entomopathogen [22, 23], appeared distributed throughout the rooms of Cueva del Tesoro in summer and autumn, and in Gruta de las Maravillas in all season, except winter. Their presence in all seasons except in winter is remarkable. The occurrence is coincident with the bloom of insects in spring and death in autumn. This fungus was one of the most abundant species in Castanar de lbor Cave [7]. Other abundant entomopathogenic species in the caves were _Parengyodonium album_, _Leptobacillusum symbioticum_, _Leptobacillusum leptobactrum_ and _Beauveria bassiana_. _Parengyodonium album_ is related to spiders and mites. It is normally found in underground environments, such as catacombs [24] and caves [2]. This was the predominant species inside Cueva de Ardales in autumn. At the end of the entrance stair, the sampling provided 200 CFU/m\({}^{3}\) and _P. album_ presented an abundance of 91.9%. The high concentration of _P. album_ in this sampling point may be due to the fact that being closer to the exterior, it is more frequented by arthropods than other deeper cavity zones. The species of the genus _Leptobacillusum_ are saprotrophic, and includes entomopathogenic strains, such as _L. symbioticum_ and _L. leptobactrum_ (=_Verticillium leptobactrum_) [25, 26].