Abstract
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• From the summit downslope a granitic inselberg in French Guiana, soils and vegetation evolve from bare granite covered by cyanobacteria, to a savannah-type vegetation on thin patchy sandy accumulations, then to a low forest on shallow young soils and to a high forest on deep highly weathered ultisols.
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• We have used element budgets and Sr isotopic variations in soils and plants to investigate the mineral nutrient supply sources of the different plant communities.
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• Granite and atmospheric deposition have 87Sr/86Sr ratios of 1.3 and 0.71, respectively. The 87Sr/86Sr ratio of cyanobacteria (0.72) suggests granite weathering by cyanobacteria crusts. The 87Sr/86Sr ratio of the savannah-type vegetation is 0.73 and varies between 0.75 and 0.76 in the low and high forest leaf litter regardless of soil depth, age and degree of impoverishment.
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• These almost constant ratio suggest that forest Sr comes from rainwater and from the summit of this inselberg, where it is released and redistributed along the slope, by surface flow, lateral redistribution of litter, and mineral particles. However, because of its very low content in the rock and soils, Ca is supplied to plants by atmospheric deposition.
Résumé
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• Du sommet vers la base d’un inselberg granitique (Nouragues, Guyane Française), les sols et la végétation évoluent depuis des savanes sur des ilots sableux entre les affleurements rocheux couverts de cyanobactéries, vers une forêt basse sur sols peu épais, riches en minéraux altérables puis une forêt haute sur sols très profonds et altérés.
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• Les variations isotopiques du strontium des sols et des plantes ont été mesurées pour rechercher les sources de nutriments des différentes communautés végétales.
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• Les rapports 87Sr/86Sr du granite et des dépôts atmosphériques sont respectivement de 1,3 et 0,71. Le rapport 87Sr/86Sr des cyanobacteries (0,72) suggère une libération de Sr par altération du granite. Le rapport 87Sr/86Sr de la savanne est de 0,73 et varie entre 0,75 et 0,76 dans les litières de forêt basse et haute, quelle que soit la profondeur, et la richesse en minéraux altérables des sols.
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• La faiblesse et l’homogénéité surprenante de ces rapports suggèrent une alimentation en Sr des forêts essentiellement à partir de dépôts atmosphériques et des sols de la partie haute de l’inselberg, via des écoulements de surface, des redistributions latérales de litière et de particules minerales lors de crises érosives. Cependant, en raison de l’extrême pauvreté de la roche et des sols en calcium, le Ca des communautés végétales provient de la pluie.
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References
Åberg G., 1995. The use of natural strontium isotopes as tracers in environmental studies. Water Air Soil Pollut. 79: 309–322.
Aubert D., Stille P., and Probst A., 2001. REE fractionation during granite weathering and removal by waters and suspending loads: Sr and Nd isotopic evidence. Geochim. Cosmochim. Acta 65: 387–406.
Bailey S.W., Hornbeck J.W., Driscoll C.T., and Gaudette H.E., 1996. Calcium inputs and transport in a base poor forest ecosystem as interpreted by Sr isotopes. Water Resour. Res. 32: 707–719.
Bain D.C. and Bacon J.R., 1994. Strontium isotopes as indicators of mineral weathering in catchments. Catena 22: 201–214.
Bern C.R., Townsend A.R., and Farmer G.L., 2005. Unexpected dominance of parent-material strontium in a tropical forest on highly weathered soils. Ecology 86: 626–632.
Bongers F., Charles-Dominique P., Forget P.M., and Théry M., 2001. Nouragues. Dynamics and plant-animal interactions in a neotropical rainforest, Kluwer, Dordrecht, The Netherlands. 421 p.
Boyé M., Cabaussel G., and Perrot Y., 1979. Climatologie. Atlas de la Guyane, Collection des Atlas des Départments d’Outre Mer, II. La Guyane, CNRS et ORSTOM, Paris.
Braun J.J., Herbillon A., and Rosin C., 1993. Mobilization and redistribution of REEs and thorium in a syenitic lateritic profile: a mass balance study. Geochim. Cosmochim. Acta 57: 4419–4434.
Büdel B., Weber B., Kühl M., Pfanz H., Sültemeyer D., and Wessels D., 2004. Reshaping of sandstone surfaces by cryptoendolithic cyanobacteria: bioalkalization causes chemical weathering in arid landscapes. Geobiology 2: 261–268.
Burke A., 2001. Determinants of inselberg floras in arid Nama Karoo landscapes. J. Biogeogr. 28: 1211–1220.
Capo R.C., Stewart B.W., and Chadwick O.A., 1998. Strontium isotopes as tracers of ecosystem processes: theory and methods. Geoderma 82: 197–225.
Chadwick O.A., Derry L.A., Vitousek P.M., Huebert B.J., and Hedin L.O., 1999. Changing sources of nutrients during four million years of ecosystem development. Nature 397: 491–497.
Charles-Dominique P., Blanc P., Larpin D., Ledru M.P., Riéra B., Sarthou C., Servant M., and Tardy C., 1998. Forest perturbations and biodiversity during the last ten thousand years in French Guiana. Acta Oecol. 19: 295–302.
Chave J., Riera B., and Dubois M.A., 2001. Estimation of biomass in a neotropical forest of French Guyana: spatial and temporal variability. J. Trop. Ecol. 17: 79–96.
Choubert B. 1974., Les Précambriens des Guyanes. BRGM, Orléans, France. 213 p.
Clark D.A., Brown S., Kicklighter D.W., Chambers J.Q., Thomlinson J.R., Ni J., and Holland E.A., 2001. Net primary production in tropical forests: an evaluation and synthesis of existing field data. Ecol. Appl. 11: 371–384.
Clow D.W., Mast M.A., Bullen T.D., and Turk J.T., 1997. Stronium 87/strontium 86 as a tracer of mineral weathering reactions and calcium sources in an alpine/subalpine watershed, Loch Vale, Colorado. Water Resour. Res. 33: 1335–1351.
Dambrine E., Loubet M., Vega J.A., and Lissarague A., 1997. Localisation of mineral uptake by roots using Sr isotopes. Plant Soil 192: 129–132.
Depagne J. and Lelong F., 1965. Feuille de Haute Comté et notice explicative; carte géologique à l’échelle du 1/100 000. Carte géologique détaillée de la France, département de la Guyane. BRGM, Orléans, France.
Derry L.A. and France Lanord C., 1996. Neogene Himalayan weathering history and river 87Sr/86Sr: impact on the marine Sr record. Earth planet. Sci. Lett. 142: 59–74.
Dojani S., Lakatos M., Rascher U., Wanek W., Lüttge U., and Büdel B., 2007. Nitrogen input by cyanobacterial biofilms of an inselberg into a tropical rainforest in French Guiana. Flora 202: 521–529.
Faure G., 1986. Principles of Isotope Geology, Second edition, Wiley, New-York, NY, 589 p.
Granville J.J., 1982. Rain forest and xeric flora refuges in French Guiana. In: Prance G.T. (Ed.), Biological diversification in the tropics. Colombia Univ. press, New York, NY, p. 159–181.
Graustein W.C. and Armstrong R.L., 1983. The use of strontium 87Sr/86Sr ratios to measure atmospheric transport into forested watersheds. Science 219: 289–292.
Graustein W.C., 1989. 87Sr/86Srratios measure the source and flow of Sr in terrestrial ecosystems. In: Rundel P., Ehleringer J., and Nagy K. (Eds.), Stable isotopes in ecological research, Springer, New York, pp. 491–512
Grimaldi M. and Riéra B., 2001. Geography and climate. In: Bongers F., Charles-Dominique P., Forget P.M., and Théry M. (Eds.), Nouragues: Dynamics and plant-animal interactions in a neotropical rainforest, Kluwer, Dordrecht, pp. 9–18.
Grousset F.E., Rognon P., Coude Gaussen G., and Pedemay P., 1992. Origins of peri-Saharian dust deposits traced by their Nd and Sr isotopic composition. Palaeogeogr. Palaeoclimatol. Palaeoecol. 93: 203–212.
Gruau G., Martin H., Leveque B., and Capdevila R., 1985. Rb-Sr and Sm-Nd geochronology of lower proterozoic granite-greenstone terrains in French Guyana, South America. Precambrian Res. 30: 63–80.
Hodson M.E., 2002. Experimental evidence for mobility of Zr and other trace element in soils. Geochim. Cosmochim. Acta 66: 819–828.
Jordan C.F., 1982. The nutrient balance of an Amazonian rain forest. Ecology 63: 647–654.
Kennedy M.J., Chadwick O.A., Vitousek F.M., Derry L.A., and Hendricks D.M., 1998. Changing sources of base cations during ecosystem development, Hawaiian Islands. Geology 26: 1015–1018.
Larpin D., Sarthou C., and Tardy C., 2000. Dynamique de la végétation sur l’inselberg des Nouragues (Guyane française) à différentes échelles de temps (pluriannuelle à plurimillénaire). In: Servant M., Servant-Vildary S. (Eds.), Dynamique à Long Terme des Ecosystèmes Forestiers Intertropicaux, UNESCO, Paris, France, pp. 189–197.
Marschner 1995. Mineral nutrition of higher plants, 2nd ed., Academic Press, London, 889 p.
Meybeck M., 1986. Composition chimique naturelle des ruisseaux non pollués en France. Sci. Géol. Bull. Strasbourg 39: 3–77.
Miller E.K., Blum J.D., and Friedland A.J., 1993. Determination of soil exchangeable-cation loss and weathering rates using Sr isotopes. Nature 362: 438–441.
Nakai S., Halliday A.N., and Rea D.K., 1993. Provenance of dust in the Pacific Ocean. Earth Planet. Sci. Lett. 119: 143–157
Négrel P., Lachassagne P., and Laporte P., 1997. Caractérisation chimique et isotopique des pluies de Cayenne (Guyane française). C. R. Acad. Sci. Paris, Ser. 2, 324: 379–386.
Négrel P. and Lachassagne P., 2000. Geochemistry of the Maroni River (French Guyana) during low water stage: implications for water rock interaction and groundwater characteristics. J. Hydrol. 237: 212–233.
Poncy O., Sabatier D., Prévost M.F., and Hardy I., 2001. The lowland high rainforest: structure and tree species diversity. In: Bongers F., Charles-Dominique P., Forget P.M., and Théry M. (Eds.), Nouragues: Dynamics and Plant-Animal Interactions in a Neotropical Rainforest, Kluwer, Dordrecht, The Netherlands, pp. 31–46.
Porder S., Clark D.A., and Vitousek P.M., 2006. Persistence of rock-derived nutrients in the wet tropical forests of the Selva, Costa Rica. Ecology 87: 594–602.
Porder S., Paytan A., and Vitousek P.M., 2005. Erosion and landscape development affect plant nutrient status in the Hawaiian Islands. Oecologia 142: 440–449.
Porembski S. and Barthlott W., 2000. Inselbergs: Biotic Diversity of Isolated Rock Outcrops in Tropical and Temperate Regions, Springer, Berlin, Germany, 528 p.
Poszwa A., Dambrine E., Pollier B., and Atteia O., 2000. A comparison of Ca and Sr cycling in forest ecosystems. Plant Soil 225: 299–310.
Poszwa A., Dambrine E., Ferry B., Pollier B., and Loubet M., 2002. Do deep tree roots provide nutrients to the tropical rainforest? Biogeochemistry 60: 97–118.
Probst A., El’GhMari A., Aubert D., Fritz B., and McNutt R., 2001. Strontium as a tracer of weathering processes in a silicate catchment polluted by acid atmosperic inputs, Strengbach, France. Chem. Geol. 170: 203–219.
Puig H. and Delobelle J.P., 1988. Production de litière aérienne, nécromasse, apports minéraux au sol par la litière en forêt guyanaise. Rev. Ecol. 43: 3–22.
Rascher U., Lakatos M., Büdel B., and Lüttge U., 2003. Photosynthetic field capacity of cyanobacteria in small scale zones across the furrows of an inselberg of the Guyana Highlands. Eur. J. Phycol. 38: 247–256.
Rosique T., Pous S., and Charles-Domminique P., 2000. Evolution morphogénique holocène d’un bassin versant de la forêt guyanaise: La Nourague occidentale (Guyane Française). C. R. Acad. Sci. Paris, Ser. 2, 330: 333–340.
Sarthou C., 1992. Dynamique de la végétation pionnière sur un inselberg en Guyane française. M.S. thesis, Université Pierre et Marie Curie, Paris, France.
Sarthou C. and Grimaldi C., 1992. Mécanismes de colonisation par la végétation d’un inselberg granitique en Guyane Française. Revue Ecol. 47: 329–349.
Sarthou C., Therezien Y., and Coute A., 1995. Cyanophycées de l’inselberg des Nouragues (Guyane Française). Nova Hedwigia 61: 85–109.
Sarthou C. and Villiers J.F., 1998. Epilithic plant communities on French Guiana Inselberg. J. Veg. Sci. 9: 847–859.
Swap R., Garstang M., and Greco S., 1992. Saharian dust in the Amazon basin. Tellus. 44B: 133–149.
Tardy Y., 1993. Pétrologie des latérites et des sols tropicaux, Masson, Paris, France. 459 p.
Vaçulik A., Kounda-kiki C., Sarthou C., and Ponge J.F., 2004. Soil invertebrate activity in biological crusts on tropical inselbergs. Eur. J. Soil Sci. 55: 539–549.
White A.F. and Brantley S.L., 1995. Chemical weathering rates of silicate minerals. Rev. Mineral. 31: 1–583 p.
Wickman T. and Jacks G., 1993. Base cation nutrition for pine stands on lithic soils near Stockholm, Sweden. Appl. Geochem. Suppl. 2: 199–202.
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Poszwa, A., Ferry, B., Pollie, B. et al. Variations of plant and soil 87Sr/86Sr along the slope of a tropical inselberg. Ann. For. Sci. 66, 512 (2009). https://doi.org/10.1051/forest/2009036
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DOI: https://doi.org/10.1051/forest/2009036