Research progress on the effects of root niche differences on ecosystems

Root systems play an important role in plants, communities, and ecosystems, and plants are also influenced by the external environment. For communities with high plant diversity, root niche differences have different impacts on the biomass, root distribution, soil structure, and nutrient resource allocation of the entire community, which in turn determine species coexistence and community ecological stability. In this study, after summarizing domestic and foreign literature relating to root systems, we drew the following three conclusions. 1) Communities characterized by higher species diversity have higher productivity, and with an increase in species richness, an increase in community biomass is closely related to an increase in the root biomass of deep-rooted plants. 2) In communities characterized by different species richness, there will be vertical distribution of the root niche. Consequently, root exudates and root traits will affect the structural characteristics of soil aggregates and nutrient utilization, thereby improving soil nutrition. Furthermore, the co-occurrence of shallow- and deep-rooted species is conducive to species coexistence and a more effective use of soil resources. 3) Both root complementation and selection effects will have an effect on the ecosystem, and with an increase in species diversity, the complementation effect will increase and the selection effect will decrease. This complementary effect is considered to be a key factor with respect to increasing resource utilization. In this study, we examined the impact of the interactions between specific species and competition in the community, and briefly summarized the effects of root systems on terrestrial ecosystems. On the basis of our findings, we propose further research on root systems, with a particular focus on the following two areas of root ecology research. 1) The influence of the community on variations in the vertical distribution of underground root characters needs to be further verified and clarified. 2) Given the difficulties associated with sampling roots, future research should be combined with modern molecular and imaging technologies to gain a better understanding of the characteristic of belowground roots.