Effects of pressure on the root systems of Norway spruce plants (Picea abies[L.] Karst.)

Abstract

Roots are stressed quire often under natural conditions, e.g. when considering sloping terrain, layers of fluvial deposits, huge layers of melting snow, load of heavy forest machinery during logging and hauling operations, recreational activities of people, high density of deer or cattle, etc. We focused our experiments on Norway spruce (Picea abies [L.] Karst.) seedlings grown in containers with glass walls under the permanent load of 5.1 kPa during the whole growing season. The applied pressure affected roots both directly and indirectly due to the occurrence of hypoxia. Root growth ceased under such conditions. Growth dynamics and capability to occupy available soil also changed. For example, the total root area of experimental plants decreased to 52% but the root area index (RAI) was higher by 33% when compared to the control. It indicates that the pressure applied to the soil surface caused the development of only smaller root systems but more compacted into smaller volumes of soil. Mean longitudinal growth of stressed roots decreased by about 50% when compared to the control. Growth of experimental roots was also delayed, which is a typical general response to stress. However, a tendency to create dense and small root systems is in contradiction with the typical strategy of tree root systems.

Impact of mechanized harvesting on compaction of sandy and clayey forest soils: results of a meta-analysis

“…Previous studies have shown that the elongation and penetration of primary roots are reduced in a compacted soil, which may induce a lower uptake of nutrients and water (e.g., Kozlowski 1999). This may lead to higher seedling mortality and a reduced tree growth (e.g., Gebauer and Martinková 2005), among other factors dependent on soil type and tree species. Compaction can also induce a shift in the herb layer from interior forest species to more ruderal and pioneer species (e.g., Zenner and Berger 2008).…”

Effects of soil compaction on growth and survival of tree saplings: A meta-analysis

“…Higher penetration resistance reduces elongation and penetration of roots, and thus lowers the uptake of water and nutrients (Kozlowski, 1999). A higher seedling mortality and reduced tree growth was observed by Gebauer & Martinková (2005). The level of these effects depends on soil type and examined tree species (Gomez, Powers, Singer & Horwath, 2002;Heninger, Scott, Dobkowski, Miller, Anderson et al, 2002).…”

Early response ofQuercus roburseedlings to soil compaction following germination

“…In the last few decades, scientists have begun investigating the effects of soil compaction on root morphological development; nevertheless, few studies have aimed to determine the effect of soil compaction on seedling development by comparing above‐ and below‐ground data (Cambi, Hoshika, et al, ; Gebauer & Martinková, ). According to Bengough and Mullins (), studies on the effect of soil compaction have followed two research lines: empirical measures of soil strength such as penetrometer resistance (Bengough et al, ) or the application of a known resistance to plants growing in an artificial medium compressed by a known pressure (Passioura, ).…”

“…In Mediterranean Quercus species, which develop a deep taproot during early growth stages, it was observed that a well-developed root system is a key factor for overcoming summer drought (Cubera, Moreno, & Solla, 2009;Tsakaldimi, Zagas, Tsitsoni, & Ganatsas, 2005). Early, rapid establishment is also important for a forest understory to take advantage of transitory available resources (Jones, Allen, & Sharitz, 1997) In the last few decades, scientists have begun investigating the effects of soil compaction on root morphological development; nevertheless, few studies have aimed to determine the effect of soil compaction on seedling development by comparing aboveand below-ground data (Cambi, Hoshika, et al, 2017;Gebauer & Martinková, 2005). According to Bengough and Mullins (1991), studies on the effect of soil compaction have followed two research lines: empirical measures of soil strength such as penetrometer resistance (Bengough et al, 2011) or the application of a known resistance to plants growing in an artificial medium compressed by a known pressure (Passioura, 2002).…”

“…According to Bengough and Mullins (1991), studies on the effect of soil compaction have followed two research lines: empirical measures of soil strength such as penetrometer resistance (Bengough et al, 2011) or the application of a known resistance to plants growing in an artificial medium compressed by a known pressure (Passioura, 2002). Penetrometer measurements have indicated that the critical value for root growth is approximately 2 MPa (Gebauer & Martinková, 2005;Kozlowski, 1999). However, several authors have reported a negative influence on plant growth and mechanical impedance when penetration resistance values exceed 2.5 MPa (Blouin, Schmidt, Bulmer, & Krzic, 2008;Cambi, Hoshika, et al, 2017;Mancilla-Leytón, Leiva, & Martín, 2016;Smith & Du Toit, 2005).…”