Titre du document / Document title

Mechanical resistance by an ectorganic soil layer on root development of seedling Pinus sylvestris

Auteur(s) / Author(s)

DEN OUDEN J. ⁽¹⁾ ; VOGELS D. ⁽²⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Environmental Sciences, Group of Silviculture and Forest Ecology, Wageningen Agricultural University, P.O. Box 342, 6700 AH Wageningen, PAYS-BAS
⁽²⁾ Department of Ecology, University of Nijmegen, Tournooiveld 1, 6525 ED Nijmegen, PAYS-BAS

Résumé / Abstract

We investigated early root development of Pinus sylvestris seedlings in relation to bulk density and natural particle layering in an ectorganic soil layer from a bracken (Pteridium aquilinum) stand. Responses in root development to two levels of bulk density (0.07 and 0.15 g/cm³) in mixed bracken substrate were compared with effects in peat of similar bulk densities, and in sand of three different bulk densities (0.37, 0.52, and 0.67 g/cm³). The effect on root growth of the natural horizontal layering of the organic particles was examined by comparing intact with mixed ectorganic bracken soil profiles of similar bulk densities (resp. 0.09 and 0.07 g/cm³). Root length growth was significantly reduced in the organic and sandy substrates of high bulk density. Root diameter was not affected by bulk density in the organic substrate, but increased with higher bulk density in sand. Preservation of horizontal layering in the intact ectorganic profile significantly reduced root length compared with mixed substrate of similar bulk density. Roots growing in high bulk density, and intact, organic substrate showed increased twisting, which resulted in a smaller depth reached by the root relative to total root length produced. In sand, root twisting did not change with increased bulk density. It is suggested that roots growing through organic substrate follow a path of least resistance. This implies that organic particle size and orientation are more important in determining root development than bulk density. This study points out that the natural layering of organic particles presents another constraint on the establishment of plant species in sites with a well-developed ectorganic soil layer. Disturbance of this layer may therefore enhance establishment of seedlings by reducing the mechanical resistance of the ectorganic soil profile to developing seedling roots.

Revue / Journal Title

Plant and soil   ISSN 0032-079X   CODEN PLSOA2 

Source / Source

1997, vol. 197, n^o2, pp. 209-217 (36 ref.)

Langue / Language

Anglais

Editeur / Publisher

Springer, Dordrecht, PAYS-BAS  (1949) (Revue)

Mots-clés anglais / English Keywords

Growth ; Bulk density ; Development ; Edaphic factor ; Fermentation ; Mixing ; Perturbation ; Strength ; Stratification ; Early phase ; Plant juvenile growth stage ; Root ; Seedlings ; Plantlet ; Pinus sylvestris ; Pteridium aquilinum ; Organic matter ; Sand ; Substrate ; Peat ; Netherlands ; Litter ; Soil profile ; Forest soil ; Greenhouse study ; ectorganic soil layer ; Pot experiments ; Coniferales ; Gymnospermae ; Spermatophyta ; Filicineae ; Pteridophyta ; Europe ; Interspecific competition ; Forestry ; Soil mechanics ; Forest regeneration ; Soil plant relation ; Softwood forest tree ; Herbaceous plant ;

Mots-clés français / French Keywords

Croissance ; Densité apparente ; Développement ; Facteur édaphique ; Fermentation ; Mélangeage ; Perturbation ; Résistance mécanique ; Stratification ; Phase initiale ; Stade juvénile plante ; Racine ; Plant semis ; Plantule ; Pinus sylvestris ; Pteridium aquilinum ; Matière organique ; Sable ; Substrat ; Tourbe ; Pays Bas ; Litière ; Profil pédologique ; Sol forestier ; Etude en serre ; Couche pédologique ectorganique ; Expérimentation en pot ; Coniferales ; Gymnospermae ; Spermatophyta ; Filicineae ; Pteridophyta ; Europe ; Compétition interspécifique ; Foresterie ; Mécanique sol ; Régénération forestière ; Relation sol plante ; Arbre forestier résineux ; Plante herbacée ;

Mots-clés espagnols / Spanish Keywords

Crecimiento ; Densidad aparente ; Desarrollo ; Factor edáfico ; Fermentación ; Mezclado ; Perturbación ; Resistencia mecánica ; Estratificación ; Fase inicial ; Estado juvenil planta ; Raíz ; Plantón semillero ; Plántula ; Pinus sylvestris ; Pteridium aquilinum ; Materia orgánica ; Arena ; Substrato ; Turba ; Holanda ; Hojarasca ; Perfil pedológico ; Suelo forestal ; Estudio en invernadero ; Experimentos en contenedor ; Coniferales ; Gymnospermae ; Spermatophyta ; Filicineae ; Pteridophyta ; Europa ; Competencia interespecífica ; Ciencias forestales ; Mecánica suelo ; Regeneración forestal ; Relación suelo planta ; Arbol forestal resinoso ; Planta herbácea ;

Localisation / Location

INIST-CNRS, Cote INIST : 4772, 35400007850077.0050