Soil compaction and water content as factors affecting the growth of lodgepole pine seedlings on sandy clay loam soil

Abstract

. 2005. Soil compaction and water content as factors affecting the growth of lodgepole pine seedlings on sandy clay loam soil. Can. J. Soil Sci. 85: 667-679. The response of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelman.) seedlings to three levels of soil compaction and water content was evaluated in raised beds filled with a sandy clay loam soil. In compacted soils, seedling survival, height, root collar diameter and root growth were reduced. Soil water regime was adjusted with irrigation to levels associated with plant moisture stress (near wilting point) and limiting soil aeration (near 0.10 m 3 m -3 air-filled porosity). Soil water regime affected seedling performance, with higher survival, root collar diameter and root growth observed on treatments with higher water content. Compaction had detrimental effects on growth at all levels of soil water availability. Compaction and water content had strong effects on soil mechanical resistance. Limitations to seedling growth and survival were at least partly explained through their relationships with soil water content and soil mechanical resistance, and combinations of these factors as described by the least limiting water range concept. Le taux de survie, la hauteur de la plante, le diamètre du collet et la croissance des racines diminuent avec le compactage. On a ajusté le régime hydrique par irrigation afin d'obtenir la teneur en eau qui correspondait au stress hydrique pour l'espèce (près du stade de flétrissement) et on a réduit l'aération du sol (porosité de près de 0,10 m 3 d'air par mètre cube de sol). Le régime hydrique affecte le rendement des plantules avec une hausse du taux de survie, du diamètre du collet et de la croissance des racines quand l'apport d'eau est plus élevé. Le compactage entrave la croissance peu importe la teneur en eau. Le compactage et la teneur en eau du sol influent considérablement sur la résistance mécanique du sol. La croissance et le taux de survie plus faibles des plantules s'expliquent en partie par le lien entre ces facteurs et la teneur en eau ainsi que la résistance mécanique du sol. Suit une description de la combinaison de ces facteurs selon le principe de la fourchette des teneurs en eau la moins limitante. Mots clés:Compactage, propriétés physiques du sol, disponibilité d'eau, réaction de la croissance des plantes, fourchette des teneurs en eau la moins limitante

Soil Compaction Caused by Cut-to-Length Forest Operations and Possible Short-Term Natural Rehabilitation of Soil Density

“…As mentioned before, we considered RBD exceeding 80% MBD (RBD > 0.80) as a soil density at which tree growth is probably reduced because of lowered air-fi lled porosity, reduced infi ltration, and higher mechanical resistance as proven by da Silva et al (1994) and Bulmer and Simpson (2005). Since Proctor density increases with increased water content up to MBD and decreases with a further increase of water content beyond MBD, the moisture-density relationship displays the shape of an inverse parabola resulting in a range of water content between both lower and upper water content limits associated with the 80% MBD thresholds on the dry and wet side of the parabola.…”

The long-term effects of silvicultural thinning and partial cutting on soil compaction in red pine (Pinus resinosa Ait.) and northern hardwood stands in the northern Great Lakes Region of the United States

“…In a review of soil compaction studies, Graecen and Sands (1980) concluded that both thinning and clear-cut harvesting are forest management practices most likely to cause soil compaction, although quantitative data on the impact of thinning on soil compaction were not given. Compaction decreases soil porosity and reduces the movement of air, water and nutrients through the soil, which can reduce tree rooting space and tree growth, and negatively impact microbial populations, nutrient availability and organic matter decomposition (Brussaard and van Faassen 1994;Thibodeau et al 2000;Bulmer and Simpson 2005;von Wilpert and Scha¨ffer 2006).…”

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

“…Cheatle (1991) found that tree survival and basal areas of Terminalia brasii were much lower on compacted soils. Detrimental effects on growth of Pinus contorta on a sandy clay loam soil were observed by Bulmer & Simpson (2005). Rhoades, Brosi, Dattilo & Vincelli (2003) showed that the mortality of Castanea dentata seedlings due to the incidence of Phytophthora root rot was largest in wet, compacted soils.…”