Ecotechnological Solutions for Unstable Slopes: Ground Bio- and Eco-engineering Techniques and Strategies

For centuries vegetation has been used to prevent and control the effects of erosion and mass wasting processes. Techniques have developed continuously until now, when the increased environmental awareness of society has resulted in them being used as key tools in landscape conservation. The need for environmentally friendly techniques to mitigate the problems generated by soil instability (mass movements, rockfall, landslides, etc.) and the incidence of erosion have provoked the appearance in recent years of two different ecotechnological concepts:ground bio-engineering and eco-engineering. Both concepts are complementary, sometimes controversial, and have in common the use of biological materials (live and inert plant materials) as main and essential tools. In this Chapter, an updated and complete review of the different ground bio- and eco-engineering techniques in use is presented. The possible advantages and drawbacks of their application with regard to different degradation factors and processes are pre sented and future perspectives discussed.From the simplest methods such as seeding, mulching or planting, to the most complex ones that integrate different engineering techniques using very different materials (live cribwalls, vegetated gabions, etc.), we describe the uses of vegetation for increasing slope stability and restoring and preserving degraded land. The use of eco-engineering techniques against rockfall and windthrow, relevant problems in many European mountainous areas have also been considered. Finally, the possibilities of combining both eco- and bio-engineering techniques are described.