Dead wood represents an important pool of carbon and nitrogen in forest ecosystems. This source of soil organic matter has diverse ecosystem functions that include, among others, carbon and nitrogen cycling. However, information is limited on how deadwood properties such as chemical composition, decomposer abundance, community composition, and age correlate and affect decomposition rate. Here, we targeted coarse dead wood of beech, spruce, and fir, namely snags and tree trunks (logs) in an old-growth temperate forest in central Europe; measured their decomposition rate as CO₂ production in situ; and analyzed their relationships with other measured variables. Respiration rate of dead wood showed strong positive correlation with acid phosphatase activity and negative correlation with lignin content. Fungal biomass (ergosterol content) and moisture content were additional predictors. Our results indicate that dead wood traits, including tree species, age, and position (downed/standing), affected dead wood chemical properties, microbial biomass, moisture condition, and enzyme activity through changes in fungal communities and ultimately influenced the decomposition rate of dead wood.

Fungi are key players in vital ecosystem services, spanning carbon cycling, decomposition, symbiotic associations with cultural and wild plants and pathogenicity. The high importance of fungi in the ecosystem processes contrasts with the incompleteness of understanding of the patterns of fungal biogeography and the environmental factors that drive it. To close this gap of knowledge, we have here collected and validated data published on the composition of soil fungal communities in terrestrial environments including soil and plant-associated habitats and made them publicly accessible through a user interface at http://globalfungi.com . The GlobalFungi database contains over 650 million observations of fungal sequences across >20 000 samples with geographical locations and additional metadata contained in 207 original studies with millions of unique sequence variants of the fungal internal transcribed spacers (ITS) 1 and 2 representing fungal species and genera. As it is, the study represents the most comprehensive atlas of fungal distribution on the global scale open to further additions.