1. Localisation The potential action of forest stands Management objectives Sylvicultural objectives Sylvicol actionsSuitable stand profilIdeal stand type Type of intervention Aforestable zoneForested zone Departure zone Slope > 30° (58%) Be aware of the particular case of rocks yet stopped by trees - Destabilization Roots : water infiltration, cliff alteration, increasing joins discontinuities, increasing the gelifraction The crown : increasing the join discontinuities during windy events The Tree :local overweighed To avoid the destabilization of the area To stabilize the area To limit the production of projectile To trap the projectile since the departure zone To work as near as possible of the departure zone If cutted trees are not sellable than use them toincrease the soil roughness (haring bones) To avoid the decreasing of the efficacy of the civil engineering protection works present on the site To obtain a permanent forest covering the maximal area as possible To have trees the nearest possible of the departure zone To limit factors increasing rock alteration To plant with a high density To mix the species To choose preferably species with high evapotranspiration capacity To choose preferably deciduous species which can naturaly make coppice stand None unstable and weighting tree (depending on the topographic conditions and size of the projectile, use the stand profil given for the two other zones) Coppice stand Uneven age stand Irregular stand by cluster Civil engineering and with afforestation in complemenation To have trees the nearest possible of the departure zone To obtain a stable, efficient and permanent forest To improve and maintain the stability of the actual forest To assure the sustainability of the canopy closure To look at the maximal spatial occupation by forest cover To limit factors increasing rock alteration If civil protection works are present then to let a buffer zone around them To cut unstable and weighting trees To stabilize the forest structure To maintain the highest forest cover as possible To aforest the gaps To obtain a sustainable regeneration Not to open gap regeneration more than 30 m in the slope To have buffer zone around civil protection works : to avoid consequences of windthrow by cutting unstable trees and to let stump less than 1,30 m high to avoid and trampoline effect. None unstable and weighting tree (depending on the topographic conditions and size of the projectile, use the stand profil given for the two other zones) Coppice stand Uneven age stand Irregular stand by cluster Forest management and bioengineering (eventually civil engineering in complemenation) + Stabilization : Roots : scree fixation, water regulation Trunk : able to fix potential projectiles Tree : buffering the climat, decreasing of the gelifraction Transit zone Slope > 30° (58%) - Re-mobilization of rocks after windthrow or after total trunk decaying Increasing of the destructive strength of the phenomena is stump or trunk are put in movement Trampoline ffect of stumps To dissipate the maximum of the energy To trap the maximum of projectiles To avoid the remobilization of proectiles previously trapped To canalise the propagation if it happens in a path with trees on each of its borders. To limit the Average Obstacle Free Distance If cutted trees are not sellable than use them to increase the soil roughness (haring bones) To avoid to decrease the efficacy of civl protection works present on the site To obtain a permanent forest covering the maximal area as possible To assure the sustainability of the canopy closure To plant with a high density To mix the species To choose preferably species with high evapotranspiration capacity To choose preferably deciduous species which can naturaly make coppice stand To protect the aforestation with bio or civil engineering technics None unstable tree to limit windthrow Multilayered stand None gap more than 30m along the slope Minimal basal area : 30 m 2 /ha Miminal density of tree with a DBH >25: 400 stem/ha Value of the summer canopy closure >= 70% If possible having a mix deciduous-coniferous forest The energy dissipation capacity of species is increasing from : Picea abies - Abies alba – Pinus nigra – Acer campestris – Fagus sylvatica – Quercus sp. Coppice stand Uneven age stand Irregular stand by cluster Civil engineering and with afforestation in complemenation To obtain a stable, efficient and permanent forest To improve and maintain the stability of the actual forest To assure the sustainability of the canopy closure To look at the maximal spatial occupation by forest cover To limit factors increasing rock alteration If civil protection works are present then to let a buffer zone around them To cut unstable and weighting trees To stabilize the forest structure To maintain the highest forest cover as possible To aforest the gaps To obtain a sustainable regeneration Not to open gap regeneration more than 30 m in the slope To have buffer zone around civil protection works : to avoid consequences of windthrow by cutting unstable trees and to let stump less than 1,30 m high to avoid and trampoline effect. None unstable tree to limit windthrow Multilayered stand None gap more than 30m along the slope Minimal basal area : 30 m 2 /ha Miminal density of tree with a DBH >25: 400 stem/ha Value of the summer canopy closure >= 70% If possible having a mix deciduous-coniferous forest The energy dissipation capacity of species is increasing from : Picea abies - Abies alba – Pinus nigra – Acer campestris – Fagus sylvatica – Quercus sp. Coppice stand Uneven age stand Irregular stand by cluster A mosaic of regular stand : the elementary cell of the pattern should not exceed 30x30 m Forest management (eventually civil engineering in complemenation) + For rocks having a mass < 5m 3 Potential high lateral deviation (maximal deviation angle = 30°) Border effect (canalisation) along existing paths Diminution of the rebond’s heigh Braking effect Trapping effect Deposit zone Slope < 30° (58%) Due to the value of the slope, rocks stop without the need of any obstacle. If this area is forested then rocks will stop ona shorter distance. Diminution of the rebond’s heigh Braking effect Trapping effect To increase the soil roughness To limit the Average Obstacle Free Distance To look at the maximal spatial occupation by forest cover If civil protection works are present it’s not necessary to let a buffer zone around them To have the maximal number of stem per ha as possible To plant with a high density To mix the species To choose for planting deciduous species which can naturaly make coppice stand Multilayered stand None gap more than 30m along the slope Value of the summer canopy closure > 30% Regeneration by line of no more than 30m of width As rocks stop by themselves there is no minimal value for stem density and DBH, but the manager should work to obtain the highest stem density possible. Coppice stand Regular stand Forest management (eventually civil engineering in complemenation) To work at the benefit of the deciduous species which can naturaly evoluate to coppice stand To maintain the highest forest cover as possible