Donkioporia expansa (Fungi, Basidiomycota), an indoor wood destroyer, is also a prominent species of thermophilic old-growth forests with oak

The study deals with a rare polypore Donkioporia expansa and environmental parameters of its habitats, primarily using data from newly discovered sites in Slovakia and Czechia. This species prefers either thermophilic forests of lower altitudes, with dominant Sessile oak (Quercus petraea) or Turkey oak (Quercus cerris), or steep, sun-exposed slopes situated at higher elevations (350–676 m). All records in nature are from old-growth forests and oak wood in advanced initial to moderate decay stages. The occurrences in buildings are secondary; the fungus was likely introduced there either in construction timber or via spores. The growth conditions of D. expansa mycelium and basidiomata are summarized. Despite the increase of the number of recent localities and records, the species is rare and deserves both inclusion in Red Lists and protection. Its survival in most localities is ensured because most of them are in nature reserves. DOI: https://doi.org/10.2478/foecol-2026-0021