Figure 4
From: A sonic root detector for revealing tree coarse root distribution
Root biomass density (kg m−3) distribution at different distances from the bark surface (0–40 cm, 0–80 cm; 0–120 cm) and to 30 cm soil depth within 36 10-degree sectors for the two studied Olea europaea trees. 0° coincides with the down-slope direction. Each bar indicates the root biomass density of the first three orders of lateral roots within the 10-degree sector. If present, the black arrow from the centre indicates the significant direction of root clustering (centre of mass).
