Decay stages of wood and associated fungal communities characterise diversity–decomposition relationships

Abstract

The biodiversity–ecosystem function relationship is a central topic in ecology. Fungi are the dominant decomposers of organic plant material in terrestrial ecosystems and display tremendous species diversity. However, little is known about the fungal diversity–decomposition relationship. We evaluated fungal community assemblies and substrate quality in different stages of wood decay to assess the relationships between fungal species richness and weight loss of wood substrate under laboratory conditions. Wood-inhabiting fungal communities in the early and late stages of pine log decomposition were used as a model. Colonisation with certain species prior to inoculation with other species resulted in four-fold differences in fungal species richness and up to tenfold differences in the rate of wood substrate decomposition in both early- and late-decaying fungal communities. Differences in wood substrate quality had a significant impact on species richness and weight loss of wood and the relationships between the two, which were negative or neutral. Late communities showed significantly negative species richness–decay relationships in wood at all decay stages, whereas negative relationships in early communities were significant only in the intermediate decay stage. Our results suggest that changes in fungal communities and wood quality during wood decomposition affect the fungal diversity–decomposition relationship.

Assessing the role of fungal diversity in decomposition: A meta-analysis

“…These differences between manipulated experiments and natural ecosystems show a possible discrepancy in the representativeness of manipulated experiments for field situations as stated in hypothesis 5. This can be explained in four ways as already discussed by Fukasawa and Matsukura (2021).…”

“…Second, the amount of detected species in field experiments is larger than the amount of used species in laboratory conditions (Grossart et al ., 2019; Fukasawa and Matsukura, 2021). Only one experiment in this meta-analysis used dilution-to-extinction (Wagg et al ., 2014) as a method to reduce diversity in laboratory conditions.…”

“…These differences between manipulated experiments and natural ecosystems show a possible discrepancy in the representativeness of manipulated experiments for field situations as stated in hypothesis 5. This can be explained in four ways as already discussed by Fukasawa and Matsukura (2021). First, the fungal diversity levels used to determine the effect of increasing diversity levels on decomposition in experimental settings are the initial levels constructed by the researcher.…”

“…Furthermore, in manipulated experiments, a random assembly of fungal species is used as inoculation while in field experiments succession and colonization are not random and can be selected by forces based on functioning, stimulating co-occurrence (Palmer, Stanton and Young, 2003;Dickie et al, 2012;van der Wal et al, 2013). Second, the amount of detected species in field experiments is larger than the amount of used species in laboratory conditions (Grossart et al, 2019;Fukasawa and Matsukura, 2021). Only one experiment in this meta-analysis used dilution-to-extinction (Wagg et al, 2014) as a method to reduce diversity in laboratory conditions.…”

Surface Area of Wood Influences the Effects of Fungal Interspecific Interaction on Wood Decomposition—A Case Study Based on Pinus densiflora and Selected White Rot Fungi

“…Despite the widespread assumption that the dead wood of conifer trees is dominated by brown rot fungi that decay wood holocellulose preferentially with little modification of lignin, white rot of coniferous dead wood is quite common [ 22 , 23 , 24 , 25 , 26 ]. Bringing this system into laboratory incubation experiments, Fukasawa and Matsukura observed a negative fungal species diversity–decomposition relationship in experiments using wood and fungi in the late stages of wood decomposition, but not in experiments using those in the early stages [ 27 ]. Hence, some relationships may exist between such a change in preference for lignocellulose decomposition and the negative species diversity–decomposition relationship during the wood decay process.…”