Legacies of invertebrate exclusion and tree secondary metabolites control fungal communities in dead wood

Abstract

During decomposition of organic matter, microbial communities may follow different successional trajectories depending on the initial environment and colonizers. The timing and order of the species arrival (assembly history) can lead to divergent communities through priority effects. We explored how assembly history and resource quality affected fungal communities and decay rate of decomposing wood, 1.5 and 4.5 years after tree felling. Additionally, we investigated the effect of invertebrate exclusion during the first two summers. We measured initial resource quality of bark and wood of aspen (Populus tremula) logs and surveyed the fungal communities by DNA metabarcoding at different times during succession. We found that gradients in fungal community composition were related to resource quality and we discuss how this may reflect different fungal life history strategies. As with previous studies, the initial amount of bark tannins was negatively correlated with wood decomposition rate over 4.5 years. The initial fungal community explained variation in community composition after 1.5, but not 4.5, years of succession. Although the assembly history of initial colonizers may cause alternative trajectories in successional communities, our results indicate that the communities may converge with the arrival of secondary colonizers. We also identified a strong legacy of invertebrate exclusion on fungal communities, even after 4.5 years of succession, thereby adding crucial knowledge on the importance of invertebrates in affecting fungal community development. By measuring and manipulating aspects of assembly history and resource quality that have rarely been studied, we expand our understanding of the complexity of fungal community dynamics.

Convergence effect during spatiotemporal succession of lacustrine plastisphere: loss of priority effects and turnover of microbial species

“…Invasive species may benefit from priority effects more than plastisphere priority colonizers, amplifying the spatiotemporal distribution and ecological impact of species establishing later in the plastisphere [ 45 ]. Particularly, random fluctuations and genetic variation (drift and diversification) are inherent properties of time-dependent ecological studies, leading to divergent or convergent communities [ 46 ]. Composition of such microbial pioneer species varies among different microplastics under the same environmental background due to the selective enrichment of microbial communities on different microplastic types [ 40 , 47 , 48 ].…”

Let sleeping logs lie: Beta diversity increases in deadwood beetle communities over time

“…Many deadwood colonizers, including beetles, carry saproxylic fungi and thus inoculate wood upon entry and these fungi modify the quality and quantity of resources for deadwood invertebrates (Skelton et al, 2019). Moreover, the arrival pattern of fungi can change subsequent fungal succession (Fukami et al, 2010; Lunde et al, 2022). Seibold et al demonstrate that deterministic processes (e.g.…”

“…Seibold et al demonstrate that deterministic processes (e.g. abiotic environmental filters like traits associated with tree species) are important in early succession, but if early colonizers vector microbes more stochastically, this could lead to increasingly heterogeneous resources as decomposition progresses depending on microbial succession (Lunde et al, 2022; Skelton et al, 2019). Lastly, stochastic processes of population abundance changes, dispersal and colonization can lead to divergent community composition.…”

“…Moreover, the arrival pattern of fungi can change subsequent fungal succession (Fukami et al, 2010;Lunde et al, 2022). Seibold et al demonstrate that deterministic processes (e.g.…”

Drivers of community assembly change during succession in wood‐decomposing beetle communities

“…Furthermore, saproxylic communities depend not only on wood characteristics associated with tree species but also on the composition of preceding (Fukami et al, 2010; Jacobsen et al, 2015; Lunde et al, 2022; Weslien et al, 2011) and co‐occurring communities (Jonsell et al, 2005; Ovaskainen et al, 2010). Positive and negative associations with co‐occurring species and priority effects of early‐ on late‐successional species, for example linked to niche modification (Fukami, 2015), can maintain beta‐diversity over time despite increasing similarity in wood characteristics.…”