Morphology, strength, and biomass of manuka roots and their influence on slope stability

Manuka (Leptospermum scoparium J.R. et G. Forst.) root systems growing in shallow, stony, hillslope and terrace soils consisted of shallow lateral structural roots up to 275 cm long, and rapidly tapering sinker roots which extended to 120 cm below the ground surface. Mean tensile strength of manuka root wood (34.2 MPa) was similar to that of Nothofagus root wood. Total root biomass averaged 25 tonnes/ha. Manuka roots provide good soil protection against shallow landslides, but this protection diminishes quickly after clearing of manuka scrub