Conditions of plant cultivation affect the differences in intraspecific plant-soil feedback between invasive and native dominants
Abstract
Intraspecific plant-soil feedback (PSF), a process in which a plant species affects the soil and the modified soil affects further growth of the same plant species, has been proposed to be one of the mechanisms controlling plant dominance in the field, as well as plant invasiveness. However, very few studies compared the PSF of invasive species with native species of a similar level of dominance.
In this study, we compared PSF of three pairs of invasive and native congeners with the same level of dominance in the field and with similar ecological requirements. Additionally, we assessed the role of conditions of plant cultivation for the PSF by growing the plants under four treatments (two moisture x two shading regimes).
Both invasive and native dominants showed neutral to positive PSF for seedling establishment and negative PSF for biomass. Native species had more negative PSF for belowground biomass than invasive species.
PSF for seedling establishment and aboveground biomass showed no overall difference between invasive and native dominants, although differences existed under some cultivating conditions. PSF for seedling establishment was affected by moisture with the response of individual genera reflecting their ecological requirements.
PSF for aboveground biomass was affected by the interaction of moisture and shading and was most negative under the dry light treatment. PSF for aboveground biomass was negatively correlated to root biomass, indicating that higher allocation into roots under dry conditions might lead to intensified interactions with soil biota and thus more negative plant-soil feedback.
Our study showed that cultivating conditions can significantly affect results of PSF experiments and pointed to the importance of including multiple measures of PSF in future experiments.