In: Sydowia 76, (2024): 279-295; ISSN 0082-0598, DOI 10.12905/0380.sydowia76-2024-0279, Published online on May 17, 2024

Naturalness is key: high species richness of woodinhabiting fungi does not automatically mean high species quality

Jan Holec, Pavel Hubený & Tomáš Kucera

1 Mycological Department, National Museum, Cirkusová 1740, Praha 9, CZ-193 00, Czech Republic
2 Šumava National Park Administration, 1. máje 260, Vimperk, CZ-385 01, Czech Republic
3 Department of Ecosystems Biology, Faculty of Science, University of South Bohemia, Branišovská 1760, Ceské Budejovice,
CZ-370 05, Czech Republic

e-mails: jan.holec@nm.cz; pavel.hubeny@npsumava.cz; kucert00@prf.jcu.cz

Holec J., Hubený P. & Kucera T. (2024): Naturalness is key: high species richness of wood-inhabiting fungi does not automatically
mean high species quality. – Sydowia 76: 279–295.

Diversity of wood-inhabiting macrofungi on large decaying trunks of Norway spruce and Silver fir was monitored in Zámecký
les near-natural forest in Czechia. The aim was to statistically evaluate the fungal species richness and composition in relation to
environmental/trunk parameters and to compare it with data on forest naturalness taken from historical documents. The results
were compared with data obtained by the same methods in Boubínský prales virgin forest and literature data from Mittelsteighütte
natural forest. Surprisingly, trunks in the near-natural forest were species-richer than in the virgin one, showing that
the available ecological niche, here a fallen trunk, can be occupied by a rich set of fungi regardless of human impact. However,
species composition differed considerably among the sites, especially by the presence of rare, red-listed and old-growth forests
fungi, designated as species of special interest (SSI). They were least represented in the near-natural forest, more in the natural
forest, and most in the virgin forest. This correlation shows that the independent concepts of both SSI species and classification
of forest naturalness go well together. Even seemingly small interventions in the past like selective cutting have a big impact on
fungal communities. The most sensitive fungi like Amylocystis lapponica, Fomitopsis rosea or Phellinus ferrugineofuscus require
unbroken forest continuity. They are absent from affected sites although their refugia as potential sources of propagules exist
nearby. Our data document that only spruces and firs 500–600 years old indicate true forest continuity. Linking fungal occurrence
data, environmental variables and historical documents on human interventions is crucial both for understanding ecosystem
processes and conservation management.

Key words: Central Europe, Bohemian Forest, mixed montane forests, ecology, spread limitations.