Plant–soil feedbacks: role of plant functional group and plant traits

Abstract

Summary1. Plant-soil feedback (PSF), plant trait and functional group concepts advanced our understanding of plant community dynamics, but how they are interlinked is poorly known. 2. To test how plant functional groups (FGs: graminoids, small herbs, tall herbs, legumes) and plant traits relate to PSF, we grew 48 grassland species in sterilized soil, sterilized soil with own species soil inoculum and sterilized soil with soil inoculum from all species, and quantified relative growth rate (RGR), specific leaf area (SLA), specific root length (SRL) and per cent arbuscular mycorrhizal fungi colonization (%AMF). 3. Plant growth response to the plant species' own soil biota relative to sterilized soil (PSFsterilized) reflects net effects of all (generalist + specialized) soil biota. Growth response to the plant species' own soil biota relative to soil biota of all plant species (PSFaway) reveals effects of more specialized soil organisms. 4. PSFsterilized showed that graminoids and small herbs have a negative and tall herbs a positive response to their own soil biota, whereas legumes responded neutrally. However, PSFaway showed that on average, all plant FGs benefitted from growing with other species' soil biota, suggesting that pathogens are more specialized than plant growth-promoting soil biota. Feedback to plant growth from all soil biota (PSFsterilized) was stronger than from more specialized soil biota (PSFaway) and could be predicted by SRL and especially by %AMF colonization. Species with high SRL and low %AMF colonization when grown in away soil experienced most negative soil feedback. 5. Synthesis. Plant species from all plant FGs grow better in soil from other species because of less net negative effects of soil biota (in graminoids), or because of more net positive soil biota effects (in tall herbs). Explorative plant species (high SRL, low %AMF colonization) suffer most from negative feedback of all soil biota, whereas more resource conservative species (low SRL, high %AMF colonization) benefit from soil feedback of all soil biota. These findings help to understand replacement of explorative species during succession. Moreover, we suggest a potentially larger role for species with positive feedback than for species with negative feedback to contribute to maintain plant community productivity of diverse communities over time.

Linking ecology and plant pathology to unravel the importance of soil-borne fungal pathogens in species-rich grasslands

“…These patterns of host specificity are consistent with results of plant-soil feedback studies that have shown reduced plant growth on soil with a history of plants of the same species or functional group compared to the average community soil (e.g. Cortois et al 2016;Hendriks et al 2013;Mangan et al 2010;Petermann et al 2008). It is, however, crucial to reveal the (fungal) actors and their functional role in grassland plant communities, if we want to increase our understanding of the myriad of plantfungal interactions belowground.…”

“…by comparing plant growth on soils with and without soil biota (e.g. Cortois et al 2016;Hendriks et al 2015b;Kos et al 2013;McCarthy-Neumann and Ibáñez 2013;Wubs and Bezemer 2018). For example, Schnitzer et al (2011) grew plant communities in field and sterilized field soil.…”

Remote sensing of plant trait responses to field-based plant–soil feedback using UAV-based optical sensors

“…Garnier et al, 2007;de Bello et al, 2010). However, recently trait based approaches are being used to predict plant legacy effects in soil and subsequent plant responses (Orwin et al, 2010;Ke et al, 2015;Cortois et al, 2016). To date most PSF experiments have focused on plant biomass as sole measure of plant responses to soil legacies.…”

Range-expanding plant species and their belowground neighbours : digging into novel interactions

“…Recent research has shown that some structural root traits show a global organization, as plants adapted to dry and seasonal conditions generally have thinner roots than plants adapted to humid, non-seasonal conditions . In turn, this variation in structural root traits will also affect mycorrhizal dependency and colonization of the plant species, as thin roots can replace the functions otherwise performed by mycorrhizal fungi (Cortois et al 2016;Ma et al 2018). Potentially, adaptations to specific environments and soil communities may also, at least in part, explain differences in plant-soil interactions observed in Chapter 6.…”

“…Soil biota play important roles in plant community dynamics by causing positive or negative plantsoil feedback effects (Kardol, Bezemer & van der Putten 2006;Van Der Heijden, Bardgett & Van Straalen 2008), which differ among plant species (Cortois et al 2016). Plant-soil feedbacks on conspecifics vary with phylogenetic distance (Anacker et al 2014) and are affected by plant origin (Klironomos 2002) when phylogenetically diverse plant species were examined.…”