Evidence has shown that plant-soil feedback (PSF) may play a crucial role in maintaining species diversity and predicting the patterns of plant relative abundance in natural communities. However, there is rarely information about how PSF can be influenced by altered environments and whether the change of plant relative abundance is associated with the change of PSF. We hypothesized that global change factors (i.e. warming, N enrichment) may alter the strength and direction of PSF by changing soil nutrients, soil community, and plant-competitive and facilitative interactions, further driving the change of plant relative abundance. To test this hypothesis, we conducted a greenhouse experiment to test the net effects of soil biota on 11 plant species under N enrichment and warming. Then, we investigated the relative abundance of these species in a field experiment under N enrichment and warming treatments in a Tibetan alpine meadow.
Results/Conclusions
We found that, under ambient condition, PSF was generally negative, and was negatively correlated with plant relative abundance, indicating that dominant species suffered more negative PSF than rare species. Under warming, N enrichment and their interaction, however, no significant relationships were found. Furthermore, the change in PSF was positively correlated with the change in species abundance caused by N enrichment and warming in field. Our findings indicate that soil biota may play a critical role in facilitating species coexistence by constraining dominant species due to the negative PSF in abundant species and negative relationship between PSF and plant relative abundance. This study first provides evidence showing the importance of PSF in predicting the change of plant relative abundance caused by elevated temperature and added N availability. The present study suggests that PSF could be an important mechanism in explaining plant dominance in nature and highlights the need to integrate PSF into plant community assembly in a changing world.