Figure 3. Root morphological traits for roots of different branching levels (basal root: B, secondary root: S, tertiary root: T, quaternary root: Q) from seven temperate perennial herb and grass understory species.

Error bars represent one standard error of the mean. Lowercase letters within a species indicate significant (P < 0.05) differences among individual root branching levels. Abbreviations of species names are shown in Table 1.