Threesomes destabilise certain relationships: multispecies interactions between wood decay fungi in natural resources

Abstract

Understanding interspecific interactions is key to explaining and modelling community development and associated ecosystem function. Most interactions research has focused on pairwise combinations, overlooking the complexity of multispecies communities. This study investigated three-way interactions between saprotrophic fungi in wood and across soil, and indicated that pairwise combinations are often inaccurate predictors of the outcomes of multispecies competition in wood block interactions. This inconsistency was especially true of intransitive combinations, resulting in increased species coexistence within the resource. Furthermore, the addition of a third competitor frequently destabilised the otherwise consistent outcomes of pairwise combinations in wood blocks, which occasionally resulted in altered resource decomposition rates, depending on the relative decay abilities of the species involved. Conversely, interaction outcomes in soil microcosms were unaffected by the presence of a third combatant. Multispecies interactions promoted species diversity within natural resources, and made community dynamics less consistent than could be predicted from pairwise interaction studies.

Fungus wars: basidiomycete battles in wood decay

“…Indeed, the combative hierarchy is not rigid, and interaction outcomes are often intransitive (non-hierarchical, species A beats B, and B beats C, but C beats A), presumably resulting from different combinations of attack and defence traits, with different opponents varying in susceptibility to different mechanisms ( Laird and Schamp, 2006 , Hiscox and Boddy, 2017 ). Intransitivity is likely to promote species coexistence within resources, due to the resulting cyclic competition structure ( Laird and Schamp, 2006 , Hiscox et al., 2017 ).…”

“…Most interactions' research has focused on pairwise combinations due to the challenges of working with multispecies systems. However, pairwise combinations are not always accurate predictors of outcomes of multispecies interactions, and outcomes are often less consistent in systems with multiple competitors ( Hiscox et al. 2017 ).…”

Metabolomics Investigation of an Association of Induced Features and Corresponding Fungus during the Co-culture of Trametes versicolor and Ganoderma applanatum

“…In the case of basidiomycetes, the induction of novel secondary metabolites or enhancement of secreting extracellular enzymes can be achieved by activating cryptic biosynthetic pathways through establishment of a fungi interaction in the co-culture (Peiris et al, 2008 ; Hiscox et al, 2010 ). This co-culture strategy mimics natural ecosystem, in which interspecies interaction of basidiomycetes is very common (Hiscox et al, 2015 , 2017 ). Recently, Zheng et al demonstrated that co-culture of basidiomycetes Inonotus obliquus and Phellinus punctatus resulted in the accumulation of lanostane-type triterpenoids, polyphenols, and melanins, compounds capable of scavenging free radicals and inhibiting tumor cell proliferation (Zheng et al, 2011 ).…”

Interdependence of Primary Metabolism and Xenobiotic Mitigation Characterizes the Proteome of Bjerkandera adusta during Wood Decomposition

“… B. adusta was cultured on 2-cm 3 beech ( Fagus sylvatica ) wood blocks for approximately 8 weeks to ensure complete colonization of the wood blocks so that hyphae were largely in log to stationary phase and exploiting the substrate, as described previously ( 2 ). Wood block cultures were then placed at either 20°C or 24°C and incubated for a further 7 days.…”

“… Bjerkandera adusta is a white rot fungus of the order Polyporales and an important member of the decomposer fungal community in attached branches and fallen wood of angiosperm trees, such as beech ( Fagus sylvatica ). In the successional community typically seen on decaying wood, B. adusta is a secondary colonizer capable of outcompeting pioneer species which begin the breakdown process ( 2 ), but it can also initiate the breakdown process independently of the primary decay community.…”