Relationships between fungal community composition in decomposing leaf litter and home‐field advantage effects

Abstract

Increasing evidence suggests that specific interactions between microbial decomposers and plant litter, named home‐field advantage (HFA), influence litter breakdown. However, we still have limited understanding of whether HFA relates to specific microbiota, and whether specialized microbes originate from the soil or from the leaf microbiome. Here, we disentangle the roles of soil origin, litter types and the microbial community already present on the leaf litter in determining fungal community composition on decomposing leaf litter and HFA. We collected litters and associated soil samples from a secondary succession gradient ranging from herbaceous vegetation on recently abandoned ex‐arable fields to forest representing the end stage of succession. In a greenhouse, sterilized and unsterilized leaf litters were decomposed for 12 months in soils from early‐ to late‐successional stages according to a full‐factorial design. At the end, we examined fungal community composition on the decomposing litter. Fungal communities on decomposed late‐successional litter in late‐successional soil differed from those in early‐ and mid‐successional stage litter and soil combinations. Soil source had the strongest impact on litter fungal composition when using sterilized litter, while the impact of litter type was strongest when using unsterilized litter. Overall, we observed HFA, as litter decomposition was accelerated in home soils. Increasing HFA did not relate to the dissimilarity in overall fungal composition, but there was increasing dissimilarity in the relative abundance of the most dominant fungal taxon between decomposing litter in home and away soils. We conclude that early‐, mid‐ and late‐succession litter types did not exert strong selection effects on colonization by micro‐organisms from the soil species pool. Instead, fungal community composition on decomposing litter differed substantially between litter types for unsterilized litter, suggesting that the leaf microbiome, either directly or indirectly, is an important determinant of fungal community composition on decomposing leaves. HFA related most strongly to the abundance of the most dominant fungal taxa on the decomposing litter, suggesting that HFA may be attributed to some specific dominant fungi rather than to responses of the whole fungal community. A plain language summary is available for this article.

The Role of Plant Litter in Driving Plant-Soil Feedbacks

“…The hypothesis is that home-field advantage effects are driven by species-specific associations between plants and decomposer communities (Freschet et al, 2012a;Austin et al, 2014). Recent experimental work showed that different litter types can indeed harbor specific litter microbiomes (Keiser et al, 2011;Lin et al, 2019) and that variation in abundant litter fungal groups can contribute to home-field advantage effects (Veen et al, 2019). This results in plant-specific patterns in nutrient release (Perez et al, 2013) and, hence, may contribute to littermediated PSFs.…”

“…(3) Elucidate the species-specificity of litter-mediated PSF effects. Evidence is accumulating that plant litters build up unique decomposer communities (Lin et al, 2019;Veen et al, 2019), which may drive litter-mediated PSF via the biotic plant pathway. This may however generate relatively unspecific feedback effects, because different plant species may all profit from nutrients liberated from litter by specialized decomposer communities, however this is not tested.…”

“…Therefore, managing PSFs can be of importance for improving sustainability in agroecosystems (Mariotte et al, 2018), for restoration of natural ecosystems Wardle, 2010 review TREE, Wubs et al, 2016) and for enhancing the resilience of ecosystems under global change and species invasions (van der Putten et al, 2016). For example, exploiting positive PSF effects may allow us to improve yield and reduce the use of artificial fertilizer and pesticides in agricultural fields (Mariotte et al, 2018;Veen et al, 2019). However, to be able to manage PSFs it is crucial to unravel how PSFs operate.…”

Cover Crop Diversity as a Tool to Mitigate Vine Decline and Reduce Pathogens in Vineyard Soils

“…Since soil fungi are saprophytic, diversity may have increased if cover crops were left to decompose [60]. This likely would have result in compositional differences in fungal communities, as decomposers are strongly affected by plant litter type [114].…”

“…In many "home vs away" studies, plants perform better when grown with soil from the same region as the plant [56][57][58]. Moreover, decomposition rate is increased when a plant litter is sympatric to the soil compared to allopatric soils [59,60]. Since plant-microbe interactions heavily depend on genotypic differences [61] and resource availability [40,62], microbial communities under native plants may differ compared to common cultivar cover crops, leading to differences in ecosystem services and possibly the suppression of pathogens.…”