Soil Macroinvertebrate Presence Alters Microbial Community Composition and Activity in the Rhizosphere

Abstract

Despite decades of research, our understanding of the importance of invertebrates for soil biogeochemical processes remains incomplete. This is especially true when considering soil invertebrate effects mediated through their interactions with soil microbes. The aim of this study was to elucidate how soil macroinvertebrates affect soil microbial community composition and function within the root zone of a managed grass system. We conducted a 2-year field mesocosm study in which soil macroinvertebrate communities were manipulated through size-based exclusion and tracked changes in microbial community composition, diversity, biomass and activity to quantify macroinvertebrate-driven effects on microbial communities and their functions within the rhizosphere. The presence of soil macroinvertebrates created distinct microbial communities and altered both microbial biomass and function. Soil macroinvertebrates increased bacterial diversity and fungal biomass, as well as increased phenol oxidase and glucosidase activities, which are important in the degradation of organic matter. Macroinvertebrates also caused distinct shifts in the relative abundance of different bacterial phyla. Our findings indicate that within the rhizosphere, macroinvertebrates have a stimulatory effect on microbial communities and processes, possibly due to low-intensity microbial grazing or through the dispersal of microbial cells and spores by mobile invertebrates. Our results suggest that macroinvertebrate activity can be an important control on microbially-mediated processes in the rhizosphere such as nitrogen mineralization and soil organic matter formation.

Earthworms Building Up Soil Microbiota, a Review

“…These findings point out a positive interaction effect on nutrient mineralisation at the drilosphere and rhizosphere level, two hotspots of microbial activity in the soil. As recently highlighted by Bray et al (2019), there is a stimulatory effect of earthworms and other soil macrofauna on rhizosphere microbial communities and on the microbially-mediated processes, particularly on N mineralisation and SOM formation.…”

“…For example, the activity of the soil enzyme β-N-acetylglucosaminidase has been shown to be promoted in presence of P. corethrurus, which resulted in "NH + 4 -N hotspots" that might be accessed by arbuscular mycorrhizal fungi (Box 1), hence providing benefits for plant growth (He et al, 2018). Increases in phenol oxidase and glucosidase activity by earthworms and other macrovertebrates were also observed in the rhizosphere of Festuca arundinacea (Bray et al, 2019), and were attributed to the ingestion of fine roots and the stimulation of microbial activity during gut passage.…”

Spatial Organization of the Micromollusc Community under Recreational Load

“…The soil has protective properties, which facilitates the survival of pedobionts even under conditions of significant anthropogenic impact (Byrne et al, 2008;Byrne and Bruns, 2004;Joimel et al, 2017;Rochefort et al, 2006;Schrader and Böning, 2006). Nevertheless, the communities of invertebrates of urban soils are sensitive to the variability of physical and chemical properties of urban soils and land-use practices (Bray et al, 2019).…”

Effect of Redworm Extracts against Fusarium Root Rot during Wheat Seedling Emergence

“…Redworms (Annelida: Clittelata) have the ability to drive soil ecosystem processes through denitrification activities that take place in their gut, vermicast, and burrows (Bityutskii et al, 2012). As soil macroinvertebrates, redworms have been associated with increased bacterial diversity and fungal biomass, as well as increased phenol oxidase and glucosidase activities (Bray et al, 2019), crucial processes in the degradation of organic matter (Aira et al, 2007). During the degradation process, survival of phytopathogens may be compromised, including that of F. graminearum.…”