ABSTRACT
In low-nutrient
ecosystems such as forests developed on acidic soil, the main limiting factor
for plant growth is the availability of soil nutrients. The aim of this study
was to investigate in a
temperate forest: 1) the influence
of the rhizosphere processes on the availability of nutrients and trace elements
during one year period and 2) the seasonal evolution of this rhizosphere effect. Bulk soil and rhizosphere
were collected in organo-mineral and mineral horizons of an acidic soil during autumn, winter, and spring under Norway spruce (Picea abies Karst) and beech (Fagus sylvatica). Soil solutions were
extracted by soil centrifugation. Rhizosphere solutions were enriched in K, and in Ca, Mg, and Na
(principally in spring) compared to those of the bulk soil. Our
study reveals seasonal variations of the rhizosphere effect for Ca, Mg, and Na
under both species, i.e., higher
enrichment of the rhizosphere solution in spring as compared with that in
autumn and winter. An enrichment of
the rhizosphere solutions was also observed for trace elements regardless of
the season under both species in the mineral horizon, only. In contrast, seasonal variations of the rhizosphere
effect for the trace elements were observed in the solutions of the organomineral
horizon under beech, i.e., enrichment
in autumn and depletion in winter. This study demonstrates that rhizosphere
biological activities significantly increase nutrient bioavailability during
the growth period. These complex interactions between roots, microbial
communities and soils are a key-process that supports tree nutrition in
nutrient-poor forest soils. This research also reveals that rhizosphere
processes a) occur throughout the year, even in winter, and b) influence
differently the dynamics of nutrients and trace elements in the root vicinity
of the organo-mineral horizon.
Share and Cite:
Calvaruso, C. , Collignon, C. , Kies, A. and Turpault, M. (2014) Seasonal Evolution of the Rhizosphere Effect on Major and Trace Elements in Soil Solutions of Norway Spruce (
Picea abies Karst) and Beech (
Fagus sylvatica) in an Acidic Forest Soil.
Open Journal of Soil Science,
4, 323-336. doi:
10.4236/ojss.2014.49034.