Effets des techniques d'exploitation foresti�re sur l'�tat de surface du sol

Abstract

Résumé -L'utilisation d'une méthode standardisée de description de l'état de surface du sol dans des coupes du sud-ouest de la France permet de montrer que l'exploitation forestière laisse en moyenne 30 % de la surface du sol non perturbée, couvre 32 % par des réma-nents, perturbe légèrement 29 % et affecte fortement 9 %. Les techniques traditionnelles d'exploitation laissent moins de rémanents, dont le volume apparent peut être estimé avec la méthode, l'utilisation de skidder provoque plus d'impact forts. L'étude montre d'une part la faisabilité d'une description standardisée des états de surface d'une coupe et d'autre part la variabilité qui existe entre les techniques d'exploitation. On peut supposer qu'elles auront donc des conséquences différentes sur la biodiversité. Des améliorations méthodo-logiques sont proposées afin de faciliter la comparaison des techniques d'exploitation forestière. exploitation forestière / état de surface du sol Abstract -Effects of logging techniques on the soil surface. A standardised method for the description of the ground surface in logged area in south-western France shows that 30% of the area remain without perturbation, 32% are covered by slash, 29% are slightly perturbed and 9% are heavily perturbed. Traditional logging techniques keep less slash (the volume could be estimated by the method), the use of skidder induces more heavy impacts. The study shows on one hand the feasibility of a standardised description of ground surface in logged areas, and on the other hand, the variability between logging techniques. They should have different effects on biodiversiy. Methodological improvements are proposed to compare logging techniques. logging / ground surface perturbation

Estimating machine impact on strip roads via close-range photogrammetry and soil parameters: a case study in central Italy

“…Gondard et al (2003) assessed the impacts of clear-cutting in Aleppo pine (Pinus halepensis) forests in southern France using both forwarders and skidders, observing deep disturbance (i.e., "topsoil removed, subsoil exposed'', according to methods and classification proposed by McMahon 1995) only when a skidder was used and no ruts. Similar results were reported by Deconchat (2001) in mixed oak coppices (Quercus robur, Q. petraea and Q. pubescens) in southern France under an Oceanic climate. In this study, the observed greater soil disturbance was due to skidders rather than forwarders, though skidders were responsible for less than 1% of ruts.…”

Effects of soil surface disturbances after logging on plant functional types

“…As many ground surface classes had low frequencies in our studies, we simplified the classes of the original reference list into three broad groups: N = not perturbed, P = perturbed (litter removed but topsoil intact, litter and topsoil mixed, rut etc. ), R = remnant depot (slash cover deep) [14]. Data collection on plant species composition was carried out on the same spots as the ground surface description in the MED area and on a 1 square meter in ATL.…”

Long-term evolution of understorey plant species composition after logging in chestnut coppice stands (Cevennes Mountains, southern France)

“…Logging also changes ground surface conditions [7,19,22,33]. All these changes influence spatial distribution of plant species in the understorey, and thus its biodiversity [9].…”