Root biomechanical traits in a montane mediterranean forest watershed: Variations with species diversity and soil depth

Plant roots play a key role in stabilizing slopes, particularly in the Mediterranean region,characterized by rough and unstable terrain. However, forest species differ in their stabilizingcapacities. The purpose of this study is to fill the gap of knowledge on root biomechanical propertiesof relevant Mediterranean trees and shrubs in relation to slope stability. Root specimens of typicalmontane Mediterranean tree and shrub species were sampled in Southern Italy. Root characteristics,such as tensile strength (Tr) and root area ratio (RAR), were assessed from live roots sampled intrenches, while root cohesion was calculated. Power law functions yielded the best fit for therelationship of Tr versus root diameter; however, no significant relationship was found between rootstrength and root moisture content. RAR varied amongst different tree and shrub species. Roots ofQuercus cerris L. were the most resistant to breaking under tension, while roots of Ilex aquifolium L.had the highest tensile strength among all shrub species. Results provide quantitative informationon the role of root systems of montane Mediterranean forest species in stabilizing soils and willimprove modeling of landslide susceptibility to the prevention and mitigation of natural hazards inmountain environments