Abstract
AimsTest the effects of root drying on biomechanical properties of fibrous roots.MethodsTensile strength and Young’s modulus of Festuca arundinacea roots were tested after full hydration and during progressive drying. Root diameter, water loss, and water content were measured for all treatments.ResultsHydrated roots showed weak relations between biomechanical properties and diameter. After only 30 min air-drying, both tensile strength and Young’s modulus increased significantly in thin roots (< 1 mm) and after 60 min drying, both strength and Young’s modulus showed a negative power relation with root diameter. The maximum strength and Young’s modulus values recorded after 60 min drying were respectively three- and four-times greater than in hydrated roots. Strength and Young’s modulus increased rapidly when water content dropped below 0.70 g g−1. These biomechanical changes were the result of root diameter shrinkage of up to 50% after 60 min drying, driven by water loss of up to 0.7 g g−1.ConclusionsStrength and Young’s modulus largely increased with root drying. We suggest controlling root moisture and testing fully hydrated roots as standard protocol, given that slope instability is generally caused by heavy rainfall events and loss of matric suction.
Highlights
The use of vegetation in soil-bioengineering is recognized as an environmentally sustainable solution for slope stabilization (Ghestem et al 2014; Kim et al 2017)
We suggest controlling root moisture and testing fully hydrated roots as standard protocol, given that slope instability is generally caused by heavy rainfall events and loss of matric suction
Our results suggest over relatively short air-drying periods significant water loss can lead to increases in both tensile strength and stiffness of thin roots, exaggerating negative power relationships between biomechanical properties and diameter
Summary
The use of vegetation in soil-bioengineering is recognized as an environmentally sustainable solution for slope stabilization (Ghestem et al 2014; Kim et al 2017). Roots can provide mechanical reinforcement, anchoring the soil mass and creating a composite material, with enhanced mechanical properties (e.g., resistance in tension; Docker and Hubble, 2008). Plant ability to stabilize soil on slopes varies between species and functional types with fibrous roots of grasses being more effective in creating a root-soil composite material, similar to fiber-reinforced soil, and preventing erosion and shallow failures (Norris et al 2008). Prediction of root derived mechanical reinforcement relies on robust empirical data including root biomechanical properties (Bischetti et al 2009; Schwarz et al 2016). Root tensile strength and Young’s modulus are the most widely studied biomechanical traits in relation to soil bioengineering (Bischetti et al 2005; Mao et al 2012) and are common model inputs to predict root mechanical reinforcement and slope stability (Schwarz et al 2013; Wu et al 1979)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
