[en] Abstract : The terrestrial biogenic Si (BSi) pool in the soil plant system is ubiquitous and substantial, likely impacting the land-ocean transfer of dissolved Si (DSi). Here, we consider the mechanisms controlling DSi in forest soil in a temperate granitic ecosystem that would differ from previous works mostly focused on tropical environments. This study aims at tracing the source of DSi in forest floor leachates and in soil solutions under various tree species at homogeneous soil and climate conditions, using stable Si isotopes and Ge/Si ratios. Relative to granitic bedrock, clays minerals were enriched in Si-28 and had high Ge/Si ratios, while BSi from phytoliths was also enriched in Si-28, but had a low Ge/Si ratio. Such a contrast is useful to infer the relative contribution of silicate weathering and BSi dissolution in the shallow soil on the release of DSi in forest floor leachate solutions. The delta Si-30 values in forest floor leachates (-1.38 parts per thousand to -2.05 parts per thousand) are the lightest ever found in natural waters, and Ge/Si ratios are higher in forest floor leachates relative to soil solution. These results suggest dissolution of Si-28 and Ge-enriched secondary clay minerals incorporated by bioturbation in organic-rich horizons in combination with an isotopic fractionation releasing preferentially light Si isotopes during this dissolution process. Ge/Si ratios in soil solutions are governed by incongruent weathering of primary minerals and neoformation of secondary clays minerals. Tree species influence Si-isotopic compositions and Ge/Si ratios in forest floor leachates through differing incorporation of minerals in organic horizons by bioturbation and, to a lesser extent, through differing Si recycling. (C) 2010 Elsevier Ltd. All rights reserved.
Abraham K., Opfergelt S., Fripiat F., Cavagna A.-J., de Jong J.T.M., Foley S., André L., Cardinal D. δ30Si and δ29Si determinations on BHVO-1 and BHVO-2 reference materials via new configuration on Nu Plasma Multi Collector (MC)-ICP-MS. Geostand. Geoanal. Res. 2008, 32:193-202.
Alexandre A., Meunier J.-D., Colin F., Koud J.M. Plant impact on the biogeochemical cycle of silicon and related weathering processes. Geochim. Cosmochim. Acta 1997, 61:677-682.
Alleman L.Y., Cardinal D., Cocquyt C., Plisnier P.D., Descy J.P., Kimirei I., Sinyinza D., André L. Silicon isotopic fractionation in lake Tanganyika and its main tributaries. J. Great Lakes Res. 2005, 31:509-519.
André L., Cardinal D., Alleman L.Y., Moorbath S. Silicon isotopes in 3.8Ga West Greenland rocks as clues to the Eoarchean supracrustal Si cycle. Earth Planet. Sci. Lett. 2006, 245:162-173.
Aurousseau P. (1976) Morphologie et genèse des sols sur granite du Morvan. Ph. D. thesis, Université de Rennes, 210 p.
Azam F., Volcani B.E. Germanium-silicon interactions in biological systems. Silicon and Siliceous Structures in Biological Systems 1981, 43-67. Springer-Verlag, New York. T.L. Simpson, B.E. Volcani (Eds.).
Barman A.K., Varadachari C., Ghosh K. Weathering of silicate minerals by organic acids. I. Nature of cation solubilisation. Geoderma 1992, 53:45-63.
Bartoli F. The biogeochemical cycle of silicon in two temperate forest ecosystems. Environ. Biogeochem. Ecol. Bull. 1983, 35:469-476.
Basile-Doelsch I. Si stable isotopes in the Earth's surface: a review. J. Geochem. Explor. 2006, 88(1-3):252-256.
Berner R.A. The rise of plants and their effect on weathering and atmospheric CO2. Science 1997, 276:544.
Blecker S.W., King S.L., Derry L.A., Chadwick O.A., Ippolito J.A., Kelly E.F. The ratio of germanium to silicon in plant phytoliths: Quantification of biological discrimination under controlled experimental conditions. Biogeochemistry 2007, 86:189-199.
Bonneau M., Brêthes A., Lacaze J. F., Lelong F., Levy G., Nys C. and Souchier B. (1977) Modification de la fertilité des sols sous boisement artificiel de résineux purs. C.R. Fin d'Etude D.G.R.S.T., Nancy-Champenoux, p. 88.
Brahy V., Titeux H., Delvaux B. Incipient podzolization and weathering caused by complexation in a forest Cambisol on loess as revealed by a soil solution study. Eur. J. Soil. Sci. 2000, 51:475-484.
Calvaruso C., Mareschal L., Turpault M.-P., Leclerc E. Rapid clay weathering in the rhizosphere of Norway spruce and oak in an acid forest ecosystem. Soil Sci. Soc. Am. J. 2009, 73:331-338.
Cardinal D., Alleman L.Y., De Jong J., Ziegler K., André L. Isotopic composition of silicon measured by multicollector plasma source mass spectrometry in dry plasma mode. J. Anal. Atom. Spectrom. 2003, 18:213-218.
Carignan J., Hild P., Mevelle G., Morel J., Yeghicheyan D. Routine analyzes of trace element in geological samples using flow injection and low pressure on-line liquid chromatography coupled to ICP-MS: a study of geochemical reference materials BR, DR-N, UB-N, AN-G and GH. Geostand. Newsl. 2001, 25:187-198.
Conley D.J. Terrestrial ecosystems and the global biogeochemical silica cycle. Global Biogeochem. Cycles 2002, 16(4):1121.
Cornelis J.-T., Ranger J., Iserentant A., Delvaux B. Tree species impact the terrestrial cycle of silicon through various uptakes. Biogeochemistry 2010, 97:231-245.
Cornelis J.-T. (2010) Impact of tree species on silicon cycling in temperate soil-tree systems. Ph.D. thesis, Université catholique de Louvain, Louvain-la-Neuve, p. 223.
De La Rocha C.L., Brzezinski M.A., De Niro M.J. Purification, recovery, and laser-driven fluorination of silicon dissolved and particulate silica for the measurement of natural stable isotope abundances. Anal. Chem. 1996, 68:3746-3750.
De La Rocha C.L., Brzezinski M.A., De Niro M.J. A first look at the distribution of the stable isotopes of silicon in natural waters. Geochim. Cosmochim. Acta 2000, 64:2467-2477.
Delstanche S., Opfergelt S., Cardinal D., Elsass F., André L., Delvaux B. Silicon isotopic fractionation during adsorption of aqueous monosilicic acid onto iron oxide. Geochim. Cosmochim. Acta 2009, 73:923-934.
Delvigne C., Opfergelt S., Cardinal D., Delvaux B. and André L. (2009) Distinct silicon and germanium pathways in the soil-plant system: evidence from banana and horsetail. J. Geophys. Res. Biogeosciences 114, G02013, doi:. doi:10.1029/2008JG000899.
Demarest M.S., Brzezinski M.A., Beucher C.P. Fractionation of silicon isotopes during biogenic silica dissolution. Geochim. Cosmochim. Acta 2009, 73:5572-5583.
Derry L.A., Kurtz A.C., Ziegler K., Chadwick O.A. Biological control of terrestrial silica cycling and export fluxes to watersheds. Nature 2005, 433:728-731.
Ding T., Wan D., Wang C., Zhang F. Silicon isotope compositions of dissolved silicon and suspended matter in the Yangtze River, China. Geochim. Cosmochim. Acta 2004, 68:205-216.
Ding T.P., Ma G.R., Shui M.X., Wan D.F., Li R.H. Silicon isotope study on rice plants from the Zhejiang province, China. Chem. Geol. 2005, 218:41-50.
Ding T.P., Zhou J.X., Wan D.F., Chen Z.Y., Wang C.Y., Zhang F. Silicon isotope fractionation in bamboo and its significance to the biogeochemical cycle of silicon. Geochim. Cosmochim. Acta 2008, 72:1381-1395.
Douthitt C.B. The geochemistry of the stable isotopes of silicon. Geochim. Cosmochim. Acta 1982, 46:1449-1458.
Engström E., Rodushkin I., Öhlander B., Ingri J., Baxter D.C. Silicon isotopic composition of boreal forest vegetation in Northern Sweden. Chem. Geol. 2008, 247:247-256.
Fraysse F., Pokrovsky O.S., Schott J., Meunier J.D. Surface chemistry and reactivity of plant phytoliths in aqueous solutions. Chem. Geol. 2009, 258:197-206.
Gaillardet J., Dupre B., Allegre C.J. A global geochemical mass budget applied to the Congo Basin rivers: Erosion rates and continental crust composition. Geochim. Cosmochim. Acta 1995, 59:3469-3485.
Gaillardet J., Dupre B., Allegre C.J. Geochemistry of large river suspended sediments: Silicate weathering or recycling tracer?. Geochim. Cosmochim. Acta 1999, 63(23-24):4307-4351.
Georg R.B., Reynolds B.C., Frank M., Halliday A.N. Mechanisms controlling the silicon isotopic compositions of river waters. Earth Planet. Sci. Lett. 2006, 249:290-306.
Georg R.B., Reynolds B.C., West A.J., Burton K.W., Halliday A.N. Silicon isotope variations accompanying basalt weathering in Iceland. Earth Planet. Sci. Lett. 2007, 261:476-490.
Georg R.B., Zhu C., Reynolds B.C., Halliday A.N. Stable silicon isotopes of groundwater, feldspars, and clay coatings in the Navajo Sandstone aquifer, Black Mesa, Arizona, USA. Geochim. Cosmochim. Acta 2009, 73:2229-2241.
Giesler R., Ilvesniemi H., Nyberg L., van Hees P., Starr M., Bishop K., Kareinen T., Lundström U.S. Distribution and mobilization of Al, Fe and Si in three podzolic soil profiles in relation to the humus layer. Geoderma 2000, 94:149-263.
Henriet C., De Jaeger N., Dorel M., Opfergelt S., Delvaux B. The reserve of weatherable primary silicates impacts the accumulation of biogenic silicon in volcanic ash soils. Biogeochemistry 2008, 90:209-223.
Hodson M.J., White P.J., Mead A., Broadley M.R. Phylogenetic variation in the silicon composition of plants. Ann. Bot. 2005, 96:1027-1046.
IUSS Working Group WRB (2006) World reference base for soil resources 2006, 2nd ed. World Soil Resources Reports No. 103. FAO, Rome.
Jones L.H.P., Handreck K.A. Studies of silica in the oat plant. III. Uptake of silica from soils by plant. Plant Soil 1965, 23(1):79-96.
Kelly E.F., Chadwick O.A., Hilinski T.E. The effect of plants on mineral weathering. Biogeochemistry 1998, 42:21-53.
Kurtz A.C., Derry L.A. Tracing silicate weathering and terrestrial silica cycling with Ge/Si ratios. Proceedings of 11th International Symposium on Water Rock Interaction 2004, 833-836. A.A. Balkema, Leiden, Netherlands. R.B. Wanty, R.R. Seal (Eds.).
Kurtz A., Derry L.A., Chadwick O.A. Germanium-silicon fractionation in the weathering environment. Geochim. Cosmochim. Acta 2002, 66:1525-1537.
Lucas Y. The role of plants in controlling rates and products of weathering: importance of biological pumping. Annu. Rev. Earth Planet. Sci. 2001, 29:135-163.
Lucas Y., Luizao F.J., Chauvel A., Rouiller J., Nahon D. The relation between biological activity of the rain forest and mineral composition of soils. Science 1993, 260:521-523.
Lugolobi F., Kurtz A.C., Derry L.A. Germanium-silicon fractionation in a tropical, granitic weathering environment. Geochim. Cosmochim. Acta 2010, 74:1294-1308.
Mareschal L. (2008) Effet des substitutions d'essences forestières sur l'évolution des sols et de leur mineralogie. Ph. D. thesis, Université Henri Poincarré, Nancy-I, p. 324.
Mortlock R.A., Froelich P.N. Determination of germanium by isotope dilution-hydride generation inductively coupled plasma mass spectrometry. Anal. Chimica Acta 1996, 322:5638-5645.
Murnane R.J., Stallard R.F. Germanium and silicon in rivers of the Orinoco drainage basin. Nature 1990, 344:749-752.
Oliva P., Viers J., Dupré B., Fortuné J.P., Martin F., Braun J.J., Nahon D., Robain H. The effect of organic matter on chemical weathering: study of a small tropical watershed: Nsimi-Zoétélé site, Cameroon. Geochim. Cosmochim. Acta 1999, 63(23/24):4013-4035.
Opfergelt S., Cardinal C., Henriet C., Draye X., André L., Delvaux B. Silicon isotope fractionation by banana (Musa spp.) grown in a continuous nutrient flow device. Plant Soil 2006, 285:333-345.
Opfergelt S., Cardinal D., Henriet C., André L., Delvaux B. Silicon isotope fractionation between plant parts in banana: In situ vs. In vitro. J. Geochem. Explor. 2006, 88:224-227.
Opfergelt S., Delvaux B., André L., Cardinal D. Plant silicon isotopic signature might reflect soil weathering degree. Biogeochemistry 2008, 91:163-175.
Opfergelt S., de Bournonville G., Cardinal D., André L., Delstanche S., Delvaux B. Impact of soil weathering degree on silicon isotopic fractionation during adsorption onto iron oxides in basaltic ash soils, Cameroon. Geochim. Cosmochim. Acta 2009, 73:7226-7240.
Opfergelt S., Cardinal D., André L., Delvigne C., Bremond L., Delvaux B. Variations of δ30Si and Ge/Si with weathering and biogenic input in tropical basaltic ash soils under monoculture. Geochim. Cosmochim. Acta 2010, 74:225-240.
Parkhurst D. L. and Appelo C. A. J. (1999) User's guide to PHREEQC (Version 2)-A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations: U.S. Geological Survey Water-Resources Investigations Report 99-4259, p. 310.
Peel M.C., Finlayson B.L., McMahon T.A. Updated world map of the Köppen-Geiger climate classification. Hydrol. Earth Syst. Sci. 2007, 11:1633-1644.
Pokrovski G.S., Martin F., Hazemann J.-L., Schott J. An X-ray absorption fine structure spectroscopy study of germanium-organic ligand complexes in aqueous solution. Chem. Geol. 2000, 163:151-165.
Ranger J. (Ed), Andreux F. (Ed), Bienaime S., Berthelin J., Bonnaud P., Boudot J.P., Brechet C., Buee M., Calmet J.P., Chaussod R., Gelhaye D., Gelhaye L., Gerard F., Jaffrain J., Lejon D., Le Tacon F., Leveque J., Maurice J. P., Merlet D., Moukoumi J., Munier-Lamy C., Nourrisson G., Pollier B., Ranjard L., Simonsson M., Turpault M. P., Vairelles D., Zeller B. (2004) Effet des substitutions d'essence sur le fonctionnement organo-minéral de l'écosystème forestier, sur les communautés microbiennes et sur la diversité des communautés fongiques mycorhiziennes et saprophytes (cas du dispositif experimental de Breuil - Morvan). Rapport final du contrat INRA-GIP Ecofor 2001-24, n°INRA 1502A Nancy: INRA-Champenoux, Biogéochimie des écosystèmes forestiers, p. 202.
Reynolds B.C., Aggarwal J., André L., Baxter D., Beucher C., Brzezinski M.A., Engström E., Georg B., Land M., Leng M.J., Opfergelt S., Rodushkin I., Sloane H.J., Van den Boorn S.H.J.M., Vroon P.Z., Cardinal D. An inter-laboratory comparison of Si isotope reference materials. J. Anal. Atom. Spectrom. 2007, 22:561-568.
Robert M., Tessier D. Méthode de préparation des argiles des sols pour des études minéralogiques. Ann. Agron. 1974, 25:859-882.
Rouiller J., Burtin G., Souchier B. La dispersion des sols dans l'analyse granulométrique. Méthode utilisant les résines échangeuses d'ions. ENSAIA Nancy 1972, 14:194-205.
Scribner A.M., Kurtz A.C., Chadwick O.A. Germanium sequestration by soil: Targeting the roles of secondary clays and Fe-oxyhydroxides. Earth Planet. Sci. Lett. 2006, 243:760-770.
Smetacek V. Diatoms and the ocean carbon cycle. Protist 1999, 150:25-32.
Sommer M., Kaczorek D., Kuzyakov Y., Breuer J. Silicon pools and fluxes in soils and landscapes-a review. J. Plant Nutr. Soil Sci. 2006, 169:310-329.
Tréguer P., Nelson D.M., Van Bennekom A.J., De Master D.J., Leynaert A., Quéguiner B. The silica balance in the world ocean: a reestimate. Science 1995, 268:375-379.
Volk T. Feedbacks between weathering and atmospheric CO2 over the last 100 million years. Am. J. Sci. 1987, 287:763-779.
Wedepohl K.H. The composition of the continental crust. Geochim. Cosmochim. Acta 1995, 59:1217-1232.
Yeghicheyan D., Carignan J., Valladon M., Bouhnik Le Coz M., Le Cornec F., Castrec-Rouelle M., Robert M., Aquilina L., Aubry E., Churlaud C., Dia A., Deberdt S., Dupré B., Freydier R., Gruau G., Hénin O., de Kersabiec A.-M., Macé J., Marin L., Morin N., Petitjean P., Serrat E. A compilation of silicon and thirty one trace elements measured in the natural river water reference material SLRS-4 (NRC-CNRC). Geostand. Newsl. 2001, 25:465-474.
Ziegler K., Chadwick O.A., Brzezinski M.A., Kelly E.F. Natural variations of δ30Si ratios during progressive basalt weathering, Hawaiian Islands. Geochim. Cosmochim. Acta 2005, 69:4597-4610.
Ziegler K., Chadwick O.A., White A.F., Brzezinski M.A. δ30Si systematics in a granitic saprolite, Puerto Rico. Geology 2005, 33:817-820.