# Diversity and Seasonal Dynamics of Airborne Fungi in Nerja Cave, Spain
## 4 Discussion
The basionym is _Penicillium brunneum_. The references to this fungus in the literature are scarce, only to the original isolation from miller rice from Thailand [68], the production of anthraquinones [69] and the cellulolytic activity of a strain isolated from a cave [70]. In Nerja Cave, the spores of the genus _Cladosporium_ were detected in the two seasonal samplings, both outside and inside the cave. In summer, _C. cladosporoides_ accounted for 43.1% of all spores outdoor, but only 5.3% in the Ghosts Hall; C. _lebrasiae_ was only found in the Entrance Hall, with 6.5% abundance, denoting clearly the existence of a low ventilation period. However, in winter, the situation changed drastically, since the concentration of _C. cladosporoides_ spores outside was 30.2%, but its abundance increased in the different halls, such as the Entrance Hall (33.3%) and in Nativity Hall (42.2%), as correspondent with a higher ventilation period. In addition, _C. sphaersoperum_ was represented in Nativity (4.6%), Ghosts (5.3%), Cataclysm (12.1%), Immensity (3.7%), and Mountain (1.9%) halls. [PERSON] et al. [17] (2014) proved that in Altamira Cave _Cladosporium_ spores had a clear external origin, as the data obtained for Nerja Cave also suggest that the presence of these fungi in the cave was due to transport from outside through air currents. It also stands out for its abundance in the air of Nerja Cave when the ventilation in the cave is greater (winter) compared to its practical absence in summer, with less or little ventilation. Likewise abundant were the species of the genus _Cladosporium_ in the seasonal samplings (autumn and winter) in Ardales Cave [30]. The genus _Cladosporium_ and, specifically, the species _C. cladosporoides_, was previously identified in the air of different European and Chinese caves [5,9,17,37,50,62,64,66,71], while _C. sphaersoperum_ was retrieved from Slovakian and Chinese caves [49,50,66]. _Cladosporium lebrasiae_ was first described from contaminated foods and forms a sister clade with _Cladosporium domitinum_[72,73], but no reports on caves or air were found. Other remarkable fungal species were _Aurewoshiulum pulllums_, _Botrytis cinerea_, _Arthriumium arunditis_, _Alternaria tenuissima_, _Bipolaris cynodontis_, all plant pathogens, but also isolated from caves [5,53,50,61,62,74,75]. The origin inside the cave may be due to the vegetation around the cavity. In addition, other noticeable fungi were _Amphichorda felina_, _Cutaneotri-chospor mucoides_, and _Scopuliaropsis brevicaulis_. _Amphichorda_ is one of the most ubiquitous entomopathogenice fungal genera. The species _A. felina_ (syn. _Beauveria felina_, _Isaria felina_) appeared only in the Kitchen Hall with 8.7% abundance, but it deserves to be noticed for their ecology, since is a fungus colonizing animal feces in Spanish caves [76] and isolated from other caves [77,78]. _Scopularopsis brevicaulis_ is often recorded in indoor environments [79] and isolated from bat skin [80] as well as _Cutaneotrichospor mucoides_ (syn. _Trichospor mucoides_), the later common in caves populated by bats [81,82]. _Scopularopsis brevicaulis_ was previously isolated from the air and sediments of Nerja Cave [32]. The abundance of _Cladosporium cladosporoides_ spores in the air outside the cave is notable. Species of the genus _Cladosporium_ are very common outdoor, at any time of the year, and also inside buildings, along with _Alternaria_, _Aspergillus_, and _Penicillium_. Outdoor, according to [PERSON] et al. [83], (2006), _Cladosporium_ and _Penicillium_ are very common in the four seasons of the year, but _Penicillium_ was more abundant in winter and _Aspergillus_ in summer. In Nerja Cave, both _Penicillium_ and _Aspergillus_ showed outdoor higher abundances in winter than in summer, as well as a high diversity in the cave air. However, _A. versicolor_ stood out for their abundance in the cave in summer.