Lignicolous fungal assemblages and relationships with environment in broadleaved and mixed forests from the north-east region of romania

Abstract

Background and aims – Lignicolous fungal assemblages perform numerous functions in forest ecosystems, one of the most important being their capacity to decay wood. As a consequence of their belonging to different ecological niches, the forest ecosystem influences the fungal assemblages in terms of species richness and composition. Methods – In this study we analyzed the main lignicolous macrofungal assemblages in some deciduous and mixed deciduous-coniferous forests in the North-East Region of Romania. We searched to find fungal indicator species for a certain forest type and which are the main drivers and their effects on the composition of the lignicolous macrofungal assemblages. Fungal assemblages were identified using a hierarchical agglomerative clustering procedure, while diagnostic species for each cluster were identified based on the indicator value index. Relationships between fungal composition of plots and environmental variables were performed using detrended and canonical correspondence analyses. Key results – A total of 377 fungal taxa in approximately 4600 records (in 59 plots) were identified. Six distinct clusters of lignicolous fungal assemblages were defined and separated three groups: 1) species-rich lignicolous fungal assemblages in beech forests (1 cluster), 2) well defined fungal assemblages in the mixed broadleaved-coniferous forests (2 clusters), and 3) fungal assemblages typical to oak forests (3 clusters). Ordination methods highlighted the forest type as the most important factor influencing the fungal composition of plots. Forestry Aridity Index, tree diversity and large trees basal area were also important factors for fungal assemblages but with a lower contribution. Conclusion – In the studied region, fungal assemblages changed from oak to beech and to mixed, broadleaved-coniferous forests mainly as a consequence of different tree composition. Climate also shaped fungal composition but to a lesser extent.