No Change Detected in Culturable Fungal Assemblages on Cave Walls in Eastern Canada with the Introduction of Pseudogymnoascus destructans

Abstract

Studies of fungi in caves have become increasingly important with the advent of white-nose syndrome (WNS), a disease caused by the invasive fungus Pseudogymnoascus destructans (Pd) that has killed an estimated 6.5 million North American bats. We swabbed cave walls in New Brunswick, Canada, in 2012 and 2015 to determine whether the culturable fungal assemblage on cave walls changed after the introduction of Pd and subsequent decrease in hibernating bat populations. We also compared fungal assemblages on cave walls to previous studies on the fungal assemblages of arthropods and hibernating bats in the same sites. The fungal diversity of bats and cave walls was more similar than on arthropods. The diversity and composition of fungal assemblages on cave walls was significantly different among media types and sites but did not differ over time. Therefore, no change in the culturable fungal assemblage present on cave walls was detected with the introduction of Pd and subsequent disappearance of the hibernating bat population over a 3-year period. This suggests that fungi documented in caves in the region prior to the outbreak of Pd do not require regular transmission of spores by bats to maintain fungal diversity at these sites.

Diverse subterranean fungi of an underground iron ore mine

“…Those in the Ascomycota include Scytalidium sp. (38), Mariannaea camptospora (22), Hypocrea pachybasidioides (20), Oidiodendron griseum (15), Pochonia bulbillosa (13), Penicillium spinulosum (12) and Cosmospora viridescens (10). The most encountered in the Basidiomycota were Postia sp.…”

“…24, Amyloathelia sp. (11) and the most common Mucoromycota were Mortierella parvispora (27), M. gamsii (14) and M. hyalina (12).…”

“…While many Pseudogymnoascus species are often associated with terrestrial soils and they would be expected to be isolated from subterranean environments, the extent of their growth within the mine was extraordinarily high. While fungi associated with rock surfaces of subterranean and above ground environments [12,55,56] have had some study, it is not clear what nutrient sources are being utilized by these species. We hypothesize that because many of the areas where growth is occurring on the walls and ceiling are wet, moisture may be leaching additional nutrients to wall and ceiling surfaces.…”

“…Recently, a review on the diversity of fungi in caves and mines with information from numerous studies revealed a diverse assemblage of fungi, slime molds and yeasts (1029 species), and that the majority of the taxa belonged to the Ascomycota (69.1%) followed by the Basidiomycota (20%) and the Zygomycota (6.6%) [8]. With the North American introduction of the fungal bat pathogen Pseudogymnoascus destructans (Pd) causing white-nose syndrome (WNS) that has decimated bat populations, many more studies have focused on microbial diversity of subterranean environments (caves/mines) in search of WNS antagonists for possible control measures and to elucidate Pd ecology [9][10][11][12].…”

Environment-driven control of fungi in subterranean ecosystems: the case of La Garma Cave (northern Spain)

“…Related with arthropods is also the genus Acrodontium . Species of Acrodontium have been found on cave arthropods (Vanderwolf et al 2019 ), particularly A. salmoneum on mites (Kubátová et al 2001 ), whereas A. luzulae was isolated from dead leaves (Videira et al 2016 ).…”