Fig. 3 Correlation of the absolute value of species-level plant-soil feedback (PSF) and relative competition intensity (RCI). The positive slope indicated that competitive species were associated with small PSF values and poor competitors were associated with large PSF values. A low RCI indicates greater biomass in two-species communities than would be expected from monocultures (i.e., a strong competitor). Solid lines and filled circles from 2017, dashed lines and filled triangles from 2018. Current data from 2016-2017, pre-existing data from 2003-2004. All correlations were significant (P < 0.05), R2 = 0.11 – 0.23. Red, black and blue values represent negative, neutral and positive PSFs, respectively.