Bulk density and soil resistance to penetration as affected by commercial thinning in northeastern Washington.

Influence of slope on physical soil disturbance due to farm tractor forwarding in a Hyrcanian forest of northern Iran

“…Tractor traffic with its associated wheel or track slip can directly affect the soil structure and alter physical soil properties down to deeper depths. In this study, increased soil compaction occurred throughout the soil profile with associated increases in BD and PR and reduction of TP, which has also been observed previously (Greacen & Sands 1980, Sidle & Drlica 1981, Gayoso & Iroume 1991, Landsberg et al 2003, Nugent et al 2003, Ares et al 2005, Eliasson & Wasterlund 2007. However, relative to values from different soil depths in the control plots, changes in BD, PR and TP following machine traffic were often (but not always) highest in the upper 5 cm layer and lowest in the 20 cm layer of the soil profile.…”

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iForest -Biogeosciences and Forestry

IntroductionThe entry of forestry machineries into forest has resulted in some cases in levels of soil disturbance that may have adverse effects on forest ecosystems and subsequently on long-term tree growth (Miller & Anderson 2002, Landsberg et al 2003, Ilstedta et al 2004, Murphy et al 2004. Numerous studies have documented changes in physical soil properties following harvesting machine traffic, such as increased soil compaction, soil displacement, rutting and soil profile disturbances (Adams & Froehlich 1984, Wronski & Murphy 1994, Rab 1996, Rohand et al 2004, Eliasson 2005, Susnjar et al 2006, Eliasson & Wasterlund 2007, Horn et al 2007, Wang et al 2007, Zenner et al 2007, Ampoorter et al 2010, 2012, Picchio et al 2012.

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Tree species composition rather than biodiversity impacts forest soil organic carbon of Three Gorges, southwestern China

“…These samples were transported to the lab shortly after sampling (Díaz-Pinés et al 2011) and air dried in shade. Soil bulk density and volume proportion of gravel at each soil sampling horizon were determined according to Landsberg et al (2003). The Kjeldahl method was carried out to obtain N concentrations of soil (Gong et al 2012).…”

Mechanical mastication thins Lake Tahoe forest with few adverse impacts

“…Following Landsberg et al (2003), we omitted all penetration values greater than five times the standard deviation of the mean resistance or greater than 3,400 kPa (500 psi) at a given depth for each respective transect, under the assumption that excessive pressure was used to penetrate rocks, root systems or thick organic matter decomposing below the surface.…”