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You searched for +publisher:"Université Catholique de Louvain" +contributor:("Weis, Dominique"). One record found.

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Université Catholique de Louvain

1. Cornélis, Jean-Thomas. Impact of tree species on silicon cycling in temperate soil-tree systems.

Degree: 2010, Université Catholique de Louvain

The distribution and origin of silicon (Si) in the soil-tree system has not been thoroughly researched, despite the crucial role of the terrestrial Si cycle in major biogeochemical processes due to its close linkage with other cycles (i.e. N, P and C). The PhD thesis focuses on Si cycling in temperate forest ecosystems to investigate the effect of tree species on Si distribution in soil-tree systems and the relative role of biogenic and litho/pedogenic Si pools in the release of dissolved Si (DSi) in the aqueous phase. Our field location is a forest site in Central France (Morvan) with granitic bedrock combining various tree species in identical climate and soil conditions. Tree species clearly influence Si uptake rates and can affect Si transfer to hydrosphere since the DSi leaching from the soil profile is negatively correlated to the Si uptake by forest vegetation. In the top organic horizons, tree species impact (i) the amorphous Si (ASi) pool through contrasting Si uptake and restitution of biogenic ASi (phytoliths) to the topsoil and (ii) the litho/pedogenic Si distribution through different incorporation rates of silicate minerals by bioturbation. In underlying mineral soil horizons, pedogenic processes such as opaline sphere formation and ASi sorption onto Fe oxides can hide the impact of tree species on ASi distribution. In order to study the origin of DSi in shallow soil solutions, we measured Si isotope compositions and Ge/Si ratios in the different compartments of the soil-tree system. Relative to the granitic bedrock, clay-sized minerals are enriched in 28Si and have high Ge/Si ratio while biogenic Si from phytoliths is enriched in 28Si and has low Ge/Si ratio. The forest floor solutions are clearly enriched in 28Si and Ge relative to granite. This finding suggests that the release of DSi in shallow soil solutions is greatly influenced by the partial dissolution of secondary clay-sized minerals incorporated by bioturbation in organic-rich horizons. In the temperate soil-tree system studied, tree species thus influence the DSi content in forest floor solutions through various bioturbation rates and, to a lesser extent, through different ways of Si biocycling. Furthermore, this study opens up new horizons to assess the relative impact of biological and pedogenic processes on the carbon dynamic in forest soils.

(AGRO 3)  – UCL, 2010

Advisors/Committee Members: UCL - AGRO - Sciences agronomiques et ingénierie biologique, Delvaux, Bruno, Ranger, Jacques, Mahillon, Jacques, André, Luc, Lucas, Yves, Vanclooster, Marnik, Weis, Dominique.

Subjects/Keywords: Biogeochemical cycle; Silicon; Temperate forest ecosystem; Pedogenesis; Phytolith; Geochemical tracers

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APA (6th Edition):

Cornélis, J. (2010). Impact of tree species on silicon cycling in temperate soil-tree systems. (Thesis). Université Catholique de Louvain. Retrieved from http://hdl.handle.net/2078.1/32292

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Cornélis, Jean-Thomas. “Impact of tree species on silicon cycling in temperate soil-tree systems.” 2010. Thesis, Université Catholique de Louvain. Accessed August 19, 2019. http://hdl.handle.net/2078.1/32292.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Cornélis, Jean-Thomas. “Impact of tree species on silicon cycling in temperate soil-tree systems.” 2010. Web. 19 Aug 2019.

Vancouver:

Cornélis J. Impact of tree species on silicon cycling in temperate soil-tree systems. [Internet] [Thesis]. Université Catholique de Louvain; 2010. [cited 2019 Aug 19]. Available from: http://hdl.handle.net/2078.1/32292.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Cornélis J. Impact of tree species on silicon cycling in temperate soil-tree systems. [Thesis]. Université Catholique de Louvain; 2010. Available from: http://hdl.handle.net/2078.1/32292

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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