Ant’s Nest as a Microenvironment: distinct Mucoromycota (Fungi)
community of the red wood ants’ (Formica polyctena) mounds
Abstract
Many social insect species build nests, which strongly differ from the
surrounding environment and are often occupied by specific organismal
communities. In temperate forests, red wood ants (e.g. Formica
polyctena) are known to create such distinct, highly developed nests,
which consist of large, above-ground mounds. Those structures are built
primarily out of plant matter collected from the forest litter. Common
fungal dwellers of forest litter are representatives of Mucoromycota,
engaged in the decomposition process of this substrate. However, data on
co-occurrence or interactions between these ants and fungi remains
unknown. In order to elucidate these interactions we characterized
Mucoromycota communities of Formica polyctena nests and the surrounding
forest litter. We sampled four sites, twice in a season and used: a
culturomics approach, complemented with DNA barcoding to describe fungal
communities; PERMANOVA test and non-metric multidimensional scaling
ordinations to compare those communities; and multilevel pattern
analysis to indicate taxa associated with the mounds. Our results show
that the Mucoromycota community of Formica polyctena’s mound is specific
and more stable than the community of the surrounding forest litter.
While representatives of Entomortierella lignicola and Absidia
cylindrospora clade were found to be associated with the mound
environment, representatives of Umbelopsis curvata and Podila
verticillata-humilis clade were associated with forest litter, and were
rarely present in the mounds. Our findings strongly suggest that the red
wood ants’ nest is a specific microenvironment in the temperate forest
floor, which is a preferred microhabitat for the mound-associated
Mucoromycota, possibly adapted to live in close proximity to ants.