Impact of common European tree species and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) on the physicochemical properties of the rhizosphere

Abstract

Trees play a crucial role in nutrient cycling and ecosystem fertility, notably through rhizosphere processes. The aim of this study was to compare soil physicochemical properties between bulk soil and rhizosphere of several tree species, and to compare rhizosphere properties between fertilized and nonfertilized conditions. The soil sampling was performed in Breuil-Chenue forest (North-East of France) in seven stands: native forest (old beech (Fagus sylvatica L.) and oak (Quercus sessiliflora Smith) coppice with standards; CwS), beech, oak (Quercus petraea [Matt.] Liebl.), Douglas-fir and fertilised Douglas-fir, Norway spruce (Picea abies Karst.) and fertilised Norway spruce. Systematic soil sampling was performed at 0-3, 3-10, and 10-23 cm in 20 calibrated pits. The rhizosphere of the different species was generally enriched in C, N, Ca, Mg, and K. Interestingly, the same positive effect was observed in the fertilised plots. The rhizosphere effect varied between tree species for C, "base" cations, pH water and cation exchange capacity. This study reveals that interactions between roots, microorganisms and soil can enrich the pool of nutrients in the rhizosphere compared to bulk soil whatever the soil fertility conditions, and that the magnitude of the rhizosphere effect depends on tree species.

Temporal dynamics of exchangeable K, Ca and Mg in acidic bulk soil and rhizosphere under Norway spruce (Picea abies Karst.) and beech (Fagus sylvatica L.) stands

“…Base saturation (BS) was calculated as the sum of Mg 2+ + Ca 2+ + K + . The good linear relation observed by Calvaruso et al (2011) between the CEC values extracted by cobaltihexamin and by the method described by Espiau and Peyronel (1976) suggests that our extraction procedure (e.g., 1 M KCl and 1 M NH 4 Cl) is adapted to exchangeable cation measurements in forest soils.…”

“…The Na + measurements were not considered in the CEC calculation because of pollution of some samples in this element during analyses. However, the Na + concentrations were very low in these soils (<1% of the CEC; Calvaruso et al 2011). Base saturation (BS) was calculated as the sum of Mg 2+ + Ca 2+ + K + .…”

“…After removing the forest floor, soil sampling was carried out systematically at three depths (layer 1: 0-3 cm, layer 2: 3-10 cm and layer 3: 10-23 cm). The choice of 0-3, 3-10 and 10-23 cm was motivated by the fact that these depths correspond approximately to the limits of three distinct and homogeneous soil horizons (from organo-mineral to mineral soil horizons) in both Norway spruce and beech stands (Calvaruso et al 2011). For each pit, soil material was cut and extracted from the profile by layer (0-3, 3-10, and 10-23 cm).…”

“…In the nutrient-poor and acidic soil of the BreuilChenue experimental forest site, a recent study (Calvaruso et al 2011) showed that the rhizosphere of different tree species (such as Norway spruce and beech) was enriched in exchangeable cations (such as K, Mg and Ca) during the summer. However, this observation raises a question: does the accumulation of exchangeable nutrients in the rhizosphere occur in all the seasons?…”

Effects of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia spec.) on soil chemical properties in a mixed deciduous forest

“…Root distribution, composition of root litter and rhizosphere properties are further factors which may cause species specific effects on soil properties (Hinsinger et al 2005;Calvaruso et al 2011). Meinen et al (2009aMeinen et al ( , 2009b determined total root biomass and root distribution of different tree species close to our cluster sites.…”