Potential Roles of Soil Microorganisms in Regulating the Effect of Soil Nutrient Heterogeneity on Plant Performance

Abstract

The spatially heterogeneous distribution of soil nutrients is ubiquitous in terrestrial ecosystems and has been shown to promote the performance of plant communities, influence species coexistence, and alter ecosystem nutrient dynamics. Plants interact with diverse soil microbial communities that lead to an interdependent relationship (e.g., symbioses), driving plant community productivity, belowground biodiversity, and soil functioning. However, the potential role of the soil microbial communities in regulating the effect of soil nutrient heterogeneity on plant growth has been little studied. Here, we highlight the ecological importance of soil nutrient heterogeneity and microorganisms and discuss plant nutrient acquisition mechanisms in heterogeneous soil. We also examine the evolutionary advantages of nutrient acquisition via the soil microorganisms in a heterogeneous environment. Lastly, we highlight a three-way interaction among the plants, soil nutrient heterogeneity, and soil microorganisms and propose areas for future research priorities. By clarifying the role of soil microorganisms in shaping the effect of soil nutrient heterogeneity on plant performance, the present study enhances the current understanding of ecosystem nutrient dynamics in the context of patchily distributed soil nutrients.

Keywords: arbuscular mycorrhizal fungi (AMF); clonal plants; foraging mechanism; nutrient acquisition strategy; plant–soil microbe interactions; selective placement.

Figure 1

The role of soil microorganisms in regulating the effects of soil nutrient heterogeneity.

Figure 2

(a) Total, (b) aboveground, and (c) belowground mass of Leymus chinensis in the homogeneous or heterogeneous treatment in the presence of live or sterilized soil biota and each of the three soil substrates (field soil, potting soil, and ceramsite–quartz mixture substrates). Mean ± SE (n = 6) are given. See Table 2 for ANOVA results. Adapted with permission from Adomako et al. [13]. Copyright 2021, Springer Nature Switzerland AG 2021.

Figure 3

Schematic representation of the interactions between the plant, soil microorganisms, and soil nutrient heterogeneity. Both plants and soil microorganisms can acquire their nutrients from patchy microsites and alter soil properties by organic litter decomposition and metabolic activities, respectively. Soil microorganisms have diverse, direct effects on plants, e.g., mineralization of organic matter and homogenization of patchy nutrients. Plants interact with soil microorganisms through metabolites exuded by the roots, particularly in the rhizospheric zone.