Supporting Information
Figure S1 Root richness per cube (a) and relative root distributions (mean ± SE) (b) for the 613 0-30 cm soil cubes.
Figure S2 Proportions of each rooting type (i.e. Fig. 1 in the main text) of the 53 most common species.
Figure S3  Multivariate variance partitioning for four individual species’ relative root distributions.
Figure S4 The effect of heterospecific root richness in the 0-30 cm soil zone on the six most common species’ relative root abundance (mean ± SE) in the 0-10 cm soil zone.
Figure S5 Species-specific root distributions for the seven most common species with occurrences ≥ 3 cubes throughout the 0-100 cm soil zone.
Table S1 Summary of the 32 soil variables measured.
Table S2 The details of measurements of soil variables.
Table S3 The comparison of relative root abundance among soil zones for the 53 most common species.
Table S4 Testing vertical root segregation based on species relative root abundance in the 0-10 (P1), 10-20 (P2) and 20-30 cm (P3) soil zone using three different parameters.
Table S5 The relationship between relative root abundance of the six most common species in the 0-10 cm soil zone and heterospecific root abundance in the 0-30 cm soil zone.
Table S6 The relationships between relative root abundance of the six most common species in the 0-10 cm soil zone and heterospecific root richness in the 0-30 cm soil zone.
Table S7 The relationship between relative root abundance of the six most common species in the 0-10 cm soil zone and heterospecific root abundance in the 0-10 cm soil zone.