The importance of root strength and deterioration rates upon edaphic stability in steepland forests

Abstract

The additional strength provided by roots to the soil is generally considered to be in the form of a cohesive strength hC which may range in magnitude from 1 kPa to 20 kPa. Studies of the tensile strength of tree roots show that small roots sampled from living trees range in mean tensile strength from about 10 MPa to about 60 MPa. After tree felling small roots lose their strength at average rates between 300 and 500 kPa per month. Root biomass also decreases rapidly after clearfelling. The reduction in K after forest removal is a prime cause of landsliding on many steep slopes.