Soil disturbance and 10-year growth response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades

Abstract

Abstract:We (i) quantified effects of skidder yarding on soil properties and seedling growth in a portion of western Oregon, (ii) determined if tilling skid trails improved tree growth, and (iii) compared results with those from an earlier investigation in coastal Washington. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were hand planted at eight recent clearcuts in skid ruts in either nontilled or tilled trails, in adjacent soil berms, and in adjacent logged-only portions. Four and 5 years after skidding, rut depths averaged 15 cm below the original soil surface; mean fine-soil bulk density (0-30 cm depth) below ruts of nontilled trails exceeded that on logged-only portions by 14%. Height growth on nontilled trails averaged 24% less than on logged-only portions in year 4 after planting and decreased to 6% less in year 7. For years 8-10, mean height growth was similar for all treatments. Reduced height growth lasted for about 7 years compared with 2 years for coastal Washington. Ten years after planting, trees in skid-trail ruts averaged 10% shorter with 29% less volume than those on logged-only portions. Tillage improved height and volume growth to equal that on logged-only portions. Generalizations about negative effects of skid trails on tree growth have limited geographic scope. R~sum~ : Nous avons (i) mesur6 les effets du d6bardage par t616ph6rage sur les propri6t6s du sol et la croissance de jeunes arbres dans une partie de l'ouest de l'Oregon, (ii) d6termin6 si le fait de labourer 16g~rement le sol dans les ornitres am~liore la croissance des arbres et (iii) compar6 nos r6sultats avec une exp6rience prdc6dente r6alis6e dans la r6gion c6ti6re de l'6tat de Washington. Des semis de douglas de Menzies (Pseudotsuga menziesii (Mirb.) Franco) ont 6t6 plant6s manuellement sur le site de huit coupes ~ blanc r6centes, dans des ornibres labour6es ou non, dans les talus adjacents et dans des coupes adjacentes. Quatre et 5 ans apr~s le d6bardage, la profondeur des orni~res atteignait en moyenne 15 cm sous la surface initiale du sol; la densit6 moyenne du sol (0 ~t 30 cm de profondeur) sous les orni~res non labour6es 6tait 14% plus 61ev6e que celle des zones qui avaient seulement 6t6 coup6es. La croissance en hauteur des arbres dans les orni~res non labour6es 6tait, en moyenne, inf6rieure de 24% ~t celle observ6e dans les zones qui avaient seulement 6t6 coup6es 4 ans apr~s la plantation et la diff6rence n'6tait plus que de 6% inf6rieur apr~s 7 ans. Entre la huiti~me et la dixibme ann6e, la croissance moyenne en hauteur des arbres 6tait similaire pour tousles traitements. La rdduction de croissance a dur6 environ 7 ans comparativement ~t seulement 2 ans dans la r6gion c6tibre de l'6tat de Washington. Dix ans apr~s la plantation, les arbres qui avaient pouss6 dans les ornibres 6taient 10% plus petits et avaient un volume inf6rieur de 29% aux arbres dans les zones qui avaient seulement 6t6 coup6es. Le labourage a amdlior6 la croissance en hauteur et en volume des arbres au point d'6galer celle dans les zon...

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

“…In fact, rutting is caused by machine wheels both in FT and ST, but in ST the passing of the top end of the dragged logs (Wood et al 2003) may change the impacts on soil in two ways: (i) the top ends of the dragged logs reshape the ground after the skidder passes, hiding the rut left by the wheels; (ii) the top ends of the dragged logs displace a certain quantity of soil in the dragging direction during each extraction trip. The latter effect may be particularly intense close to slope changes, because the heads of the logs scratch and displace the soil (Williamson & Neilsen 2000, Heninger et al 2002, Horn et al 2007, Agherkakli et al 2010. Soil compaction and soil crumbling and displacement may result in increased water runoff and soil erosion (Williamson & Neilsen 2000, Cambi et al 2015, Venanzi et al 2016, with a consequent loss of fertile soil (Venanzi et al 2016).…”

The impacts of ground-based logging equipment on forest soil

“…Severely disturbed (subsoil exposed) soils accounted for only just over 1% with nearly all attributable to tree uprooting during logging operations. Heninger et al (2002) found that soils with a thin topsoil (A and A-B horizons), therefore, are more likely to be classified as severely disturbed than are soils with a thick topsoil. Gondard et al (2003) found 52% undisturbed and shallow disturbance, 3% deep disturbance, and 37% slash residues, when skidder and terraces were used, they also found 27% undisturbed and shallow disturbance, 0% deep disturbance, and 58% slash residues, when forwarder and terraces were used.…”

Soil Compaction - Impact of Harvesters' and Forwarders' Passages on Plant Growth

“…Revitalisation and amelioration of compacted soil is a long-term process and it is not known if it is fully achievable (Heninger et al, 2002). The regeneration period after the compaction may be less than 10 years near the soil surface (Thorud & Frissel, 1976;Lowery & Schuler, 1994), but others claim it could last several decades (Wert & Thomas, 1981;Jakobsen, 1983;Froehlich et al, 1985).…”