roots securing the soil of steep path

roots secure soil prevent erosion nutrients track steps stairs forest botany enviroment handrail ascend villuercas geopark gorge ruecas river destination geotourism mountainous rocks attraction idyllic spot natural space pine trees vertical canamero caceres extremadura spain appalachian trail nature europe chiquita cave stabilized slope bank materials absorb water transpires stormwater runoff evapotranspiration landslidecausing