Soil microarthropod effects on plant growth and development.

Background: Soil microarthropods influence many soil processes that support plant growth and development. Scope: In this paper we review the current understanding of direct microarthropod-plant interactions, how microarthropod-microbe interactions indirectly impact plant growth, and key areas for future study. Conclusion: Microarthropod impacts on plants are primarily routed through their interactions with microbial communities, mediating organic matter decomposition, nutrient cycling and allocation, and plant-pathogen dynamics in soils. The research investigating how microarthropod-saprotrophic microbe interactions affect plants through decomposition and nutrient cycling indicates a generally positive relationship, though this relationship is influenced by the overall diversity or species richness observed in the microarthropod communities. The effects of microarthropod-plant symbionts interactions on plants are varied and there is no clear benefit or detriment to plants via this mechanism. The effects of microarthropod-plant pathogen interactions on plants suggest that, in most cases, microarthropods will reduce disease incidence and severity. The limited diversity of the study taxa in this area of research is a major limitation to our understanding of how microarthropods impact plant health. Our review revealed that while much is known about microarthropod impacts on the intermediate processes that influence plants, only a subset of studies have quantified plant responses to microarthropod activity. Overall, existing evidence indicates that the overall effects of microarthropods on plants is positive. Future research should aim to incorporate more plant metrics and consider both microarthropod and microbial community dynamics in designed and observational studies. [ABSTRACT FROM AUTHOR]