Publication

Trees and forests play important roles in reducing landslide risk through various mechanisms. Tree roots reinforce soil layers, anchor the soil to bedrock and form buttresses against soil movement. Trees also reduce landslide risk by lowering soil moisture levels – interception, evaporation and transpiration are the primary mechanisms. These mechanisms, and others, also make trees valuable in land reclamation following landslides.  Furthermore, trees help to reduce soil erosion and can form an effective barrier against rock, debris and soil slips, as well as limiting landslide run-out distances.

Trees and forests can also increase landslide risk by imposing load on unstable slopes and via wind-related effects; they are unlikely to prevent or minimise deep landslides or slides on very steep slopes. However, they can make a positive contribution in various situations as this policy brief explains.