The Novel Application of a Geosynthetic as Vegetation Substrate for Ecological Restoration on Steep Concrete and Rock Slopes

Abstract

Civil, transportation, and hydraulic projects often result in concrete or rocky slope surfaces that have difficultly sustaining vegetation due to the lack of suitable substrate. A geosynthetic-based vegetation substrate was proposed to replace traditional soil-based vegetation substrates for vegetation restoration on steep concrete or rock surfaces. The geosynthetic vegetation substrate (GVS) provides the following four key functions for vegetation restoration: 1. Germination environment for seeds. 2. Room for root development and vegetation fixation. 3. Allowing water and nutrients to be transported and stored within the substrate. 4. Sufficient strength to support vegetation on steep or vertical surfaces. An 8-month field study revealed the following: vegetation leaf length peaked at over 400 mm by the 100th day, with annual fresh biomass reaching 2.99 kg/m2 (94% from stems/leaves). The geosynthetics maintained 91.6% to 99.5% of initial tensile strength and 82.9% to 98.2% creep resistance. These findings establish GVS as a viable solution for ecological restoration on engineered slopes.