Multiscale assemblage of an ectomycorrhizal fungal community: the influence of host functional traits and soil properties in a 10-ha miombo forest

Abstract

Ectomycorrhizal fungi (EMF) are highly diversified and dominant in a number of forest ecosystems. Nevertheless, their scales of spatial distribution and the underlying ecological processes remain poorly understood. Although most EMF are considered to be generalists regarding host identity, a preference toward functional strategies of host trees has never been tested. Here, the EMF community was characterised by DNA sequencing in a 10-ha tropical dry season forest-referred to as miombo-an understudied ecosystem from a mycorrhizal perspective. We used 36 soil parameters and 21 host functional traits (FTs) as candidate explanatory variables in spatial constrained ordinations for explaining the EMF community assemblage. Results highlighted that the community variability was explained by host FTs related to the 'leaf economics spectrum' (adjusted R(2) = 11%; SLA, leaf area, foliar Mg content), and by soil parameters (adjusted R(2) = 17%), notably total forms of micronutrients or correlated available elements (Al, N, K, P). Both FTs and soil generated patterns in the community at scales ranging from 75 to 375 m. Our results indicate that soil is more important than previously thought for EMF in miombo woodlands, and show that FTs of host species can be better predictors of symbiont distribution than taxonomical identity.

Soil abiotic variables are more important than Salicaceae phylogeny or habitat specialization in determining soil microbial community structure

“…Responses of symbiotic fungi to host species and habitat specialization are corroborated in several other studies on host identity: Bauman et al. () found that plant traits explained up to 11% of ectomycorrhizal community variation. Öpik et al.…”

“…For example, plants may exert influence outside the rhizosphere via microbe-microbe interactions (e.g., through mycorrhizal fungi) or plant-litter feedback that modifies the local environment (Mart ınez-Garc ıa, Richardson, Tylianakis, Peltzer, & Dickie, 2015; Urbanova, Snajdr, & Baldrian, 2015). Similarly, studies that have measured plant traits and soil microbial communities in parallel find that plant functional diversity, traits and habitat specialization can explain soil microbial community diversity, richness and composition (Bauman et al, 2016;Chagnon, Bradley, & Klironomos, 2015;Lang, Seven, & Polle, 2011;Nguyen, Williams, et al, 2016;€ Opik, Metsis, Daniell, Zobel, & Moora, 2009;Sikes, Cottenie, & Klironomos, 2009).…”

Edaphic specialization in relation to termite mounds in Katanga (DR Congo): A reciprocal transplant experiment with congeneric tree species

“…Bauman et al. () have shown spatial correlations between mycorrhizal community and soil properties in our study site. The three genera in this study ( Combretum, Strychnos, Ziziphus ) are known to host endomycorrhizae (Bâ, Duponnois, Diabaté, & Dreyfus, ; Högberg, ; Högberg & Piearce, ).…”

“…Other mutually non-exclusive mechanisms that may explain the poor survival of matrix species on termite mounds include pathogenic microorganisms and mycorrhizal symbionts. Bauman et al (2016) have shown spatial correlations between mycorrhizal community and soil properties in our study site. The three genera in this study (Combretum, Strychnos, Ziziphus) are known to host endomycorrhizae (Bâ, Duponnois, Diabaté, & Dreyfus, 2011;Högberg, 1982;Högberg & Piearce, 1986).…”

Disentangling good from bad practices in the selection of spatial or phylogenetic eigenvectors

“…1) can then be used 1) as predictors to study the multiscale spatial patterns of the response data (e.g. species abundances; Declerck et al 2011, Bauman et al 2016, Vleminckx et al 2017), or 2) as covariables (spatial filters) to remove spatial autocorrelation from residuals (spatial eigenvector mapping, SEVM; Griffith 2003, Diniz-Filho and Bini 2005, Dormann et al 2007, Bini et al 2009, Corkeron et al 2011. However, all eigenvector-based methods, including MEM, face a common issue.…”