Plants experience reduced a negative plant-soil feedback due to mycorrhizal fungi change with neighbors in a harsh environment
摘要
The fierce competition for limited nutrients, the dilution and activation of immunity to pathogens with the presence of other individuals could contribute to the lessening of negative plant-soil feedback (PSF). However, the relative contribution of these pathways to changes in negative PSF remains unknown in habitats with severe nutrient limitation. We conducted a PSF experiment on two common plant species in northwestern China’s desertified soil. Kalidium foliatum and Reaumuria songarica were grown with or without intra- or interspecific neighbors. The PSF was separated into biological (B-PSF) and abiotic (A-PSF) components by adding a parallel treatment without any plant conditioning in the traditional soil sterilization processes to understand the effect of resource competition and microbial communities on the PSF changes. We found that the negative PSF of R. songarica were lifted with either intra or interspecific individuals; the negative PSF K. foliatum was only improved by the presence of interspecific neighbors. The decrease in negative PSF was mainly attributed to the decrease in negative B-PSF. The decrease in negative B-PSF was affected by mycorrhizal fungi and almost not by pathogens. Thus, at a low-density, plant individuals from harsh environments tend to facilitate each other, especially with the presence of interspecific species. This facilitation primarily occurs through enhanced cooperation with mycorrhizal fungi, thereby mitigating the negative PSF and improving coexistence of species.