The genus Tilia (Malvaceae) comprises long-lived broadleaf trees of considerable ecological, cultural, and historical importance in temperate Europe and Asia. Among these, Tilia × europaea L. (common European linden) is a key native species in Central and Northern Europe, with individuals documented to live for several centuries. While the phyllosphere and soil-associated microbiomes of linden have been studied, the internal fungal communities inhabiting ancient trees remain poorly understood. In this study, the complete mycobiome of linden tree wood was analyzed. Wood-inhabiting fungi (the wood mycobiome) include endophytes, saprotrophs, and potential pathogens that can strongly influence host vitality and ecosystem processes. Advances in high-throughput amplicon sequencing (HTAS) now provide unprecedented opportunities to characterize these hidden communities. In this study, we investigated the trunk wood mycobiome of an ancient T. × europaea L. individual using a culture-independent HTAS approach. The results reveal a diverse fungal assemblage, including taxa like Arthinium or Phialemonium not previously reported from living linden wood, and highlight potential implications for tree health and longevity. This work provides a first baseline characterization of the internal mycobiome of the ancient Tilia tree and contributes to broader efforts to conserve its biological and cultural value.

This study investigated the composition and temporal dynamics of wood-inhabiting fungal communities in four aging tree species in Lednice Castle Park (Czech Republic), located within the Lednice–Valtice Cultural Landscape, a UNESCO World Heritage Site. Forty wood cores were collected from 20 trees at two time points (2023 and 2024). The hosts included horse chestnut (Aesculus hippocastanum L.), copper beech (Fagus sylvatica ‘Atropunicea’ L.), oak (Quercus robur L.), and poplar (Populus alba L.), each exhibiting visual signs of decline. Fungal assemblages were profiled using ITS2 high-throughput amplicon sequencing. Ascomycota dominated across all hosts (72–89% of reads), while Basidiomycota contributed 8–24%, largely represented by Agaricomycetes in F. sylvatica. Alpha diversity varied significantly among hosts (Shannon: F_3,36 = 10.61, p = 0.001 in 2023; F_3,36 = 10.00, p = 0.001 in 2024). Temporal shifts were host-dependent: F. sylvatica exhibited the strongest year-to-year decline in richness (Chao1: −83%, p = 0.007) and increased beta dispersion, while A. hippocastanum and P. alba showed significant increases in diversity (+65% and +42%, respectively). Community composition was shaped by host species (PERMANOVA Bray–Curtis: p = 0.001) and shifted over time (Jaccard: p = 0.001), with F. sylvatica showing the highest temporal turnover. Functional guild analysis revealed consistent dominance of saprotrophs (29–41%) and mixed pathotroph–saprotroph guilds (23–36%) across hosts, indicating active degradation processes inside functional xylem. These results indicate that, within the studied system, the wood mycobiome of aging trees is host-dependent and temporally dynamic rather than static or functionally neutral. Short-term temporal turnover observed between sampling years may contribute to shifts in fungal community composition and succession within wood, with potential implications for tree decline processes in managed historical park landscapes.

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, the scientific journal of the Mendel University in Brno, Czech Republic

The genus Tilia (Malvaceae) comprises long-lived broadleaf trees of considerable ecological, cultural, and historical importance in temperate Europe and Asia. Among these, Tilia × europaea L. is a key native species in Central and Northern Europe, with individuals documented to live for several centuries. While the external and soil-associated microbiomes of linden have been studied, the internal fungal communities inhabiting ancient trees remain poorly understood. Wood-inhabiting fungi (the wood mycobiome) include endophytes, saprotrophs, and potential pathogens that can strongly influence host vitality and ecosystem processes. Advances in high-throughput amplicon sequencing (HTAS) now provide unprecedented opportunities to characterize these hidden communities. In this study, we investigated the trunk wood mycobiome of an ancient Tilia × europaea L. individual using a culture-independent HTAS approach. The results reveal a diverse fungal assemblage, including taxa like Arthinium or Phialemonium not previously reported from living linden wood, and highlight potential implications for tree health and longevity. This work provides a first baseline characterization of the internal mycobiome of ancient Tilia trees and contributes to broader efforts to conserve their biological and cultural value.

This study investigated the composition and temporal dynamics of wood-inhabiting fungal communities in four aging tree species in Lednice Castle Park (Czech Republic), located within the Lednice–Valtice Cultural Landscape, a UNESCO World Heritage Site. Forty wood cores were collected from 20 trees at two time points (2023 and 2024). The hosts included horse chestnut (Aesculus hippocastanum L.), Copper beech (Fagus sylvatica ʻAtropuniceaʼ L.), oak (Quercus robur L.), and poplar (Populus alba L.), each exhibiting visual signs of decline. Fungal assemblages were profiled using ITS2 high-throughput amplicon sequencing. Ascomycota dominated across all hosts (72 – 89 % of reads), while Basidiomycota contributed 8 – 24 %, largely represented by Agaricomycetes in F. sylvatica. Alpha diversity varied significantly among hosts (Shannon: F₃,₃₆ = 10.61, p = 0.001 in 2023; F₃,₃₆ = 10.00, p = 0.001 in 2024). Temporal shifts were host dependent: F. sylvatica exhibited the strongest year-to-year decline in richness (Chao1: - 83 %, p = 0.007) and increased beta dispersion, while A. hippocastanum and P. alba showed significant increases in diversity (+ 65 % and + 42 %, respectively). Community composition was shaped by host species (PERMANOVA Bray–Curtis: p = 0.001) and shifted over time (Jaccard: p = 0.001), with F. sylvatica showing the highest temporal turnover. FUNGuild analysis revealed consistent dominance of saprotrophs (29 – 41 %) and mixed pathotroph–saprotroph guilds (23 – 36 %) across hosts, indicating active degradation processes inside functional xylem. These results demonstrate that the wood mycobiome of aging trees is neither static nor functionally neutral, but host-dependent and temporally dynamic. Short-term environmental variation may accelerate fungal succession inside wood, potentially influencing tree decline trajectories in managed historical park landscapes.