Changes in the amount and distribution of neutral monosaccharides of savanna soils after plantation of Pinus and Eucalyptus in the Congo

European Journal of Soil Science - Tập 47 Số 1 - Trang 51-59 - 1996
Claire Trouvé1, J‐R. DISNAR1, André Mariotti2, B. Guillet1
1Université d'Orléans‐CNRS URA 724, Laboratoire de Géochimie Organique, BP 6759, 45067 Orléans Cedex 02, France
2Université Pierre et Marie Curie-CNRS/INRA UMR 162, Laboratoire de Biogéochimie Isotopique, Case 120, 4 Place Jussieu, 75252 Paris Cedex 05, France

Tóm tắt

Summary

In the Congo, near Pointe‐Noire, Pinus and Eucalyptus were planted on the savanna for 30 years. We have characterized the effects of this change on land‐use on the composition of carbohydrates in whole soil and particle‐size fractions of the soil. Carbohydrates represent variable proportions of the total soil organic carbon (TOC) of various particle size fractions. The largest proportions of sugar‐C were found in the savanna soil with as much as 250 mg g−1 TOC in the coarsest plant remains and approximately 190 mg g−1 TOC in the finest organo‐mineral fractions, whereas there was always less sugar in plantation soils. The monosaccharide xylose and mannose have different distributions: xylose appears to be the marker of the vegetal inheritance, whereas the dominance of mannose in the clay fraction bears the signature of current microbial sugar synthesis.

The quantitative and qualitative evolution of the whole soil carbohydrates was studied as a function of plantation age. Carbohydrate‐C represents 131 mg g−1 of the soil organic carbon in the savanna soil, but decreases to an average value of 75 mg g−1 in plantations more than 6 years old. This appears to be due mainly to the stimulation of the mineralization of the glucose, which represented 60% of the total sugars in savanna soil and only 45–48% in tree plantations. The ratio [arabinose + galactose + fucose]/[rhamnose + xylose], which is the largest in the oldest plantations, is significant for evaluating the replacement of carbohydrates of the original grass savanna by those of the trees.

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Tài liệu tham khảo

Andreux F.&Munier‐Lamy C.1994.Genese et propriétés des molécules humiques. In:Pé dologie. 2‐Constituants et Proprié té s du Sol. (edsM.BonneauandB.Souchier) pp.109–142. Masson Paris.

10.1016/0038-0717(87)90120-9

10.1016/S0031-9422(00)84324-1

10.1038/329708a0

10.1016/0016-7037(90)90267-O

10.1016/0038-0717(92)90230-U

Cerri C.C., 1985, Application du traćage isotopique naturel en 13C, àľon;étude de la dynamique de la matière organique dans les sols, Comptes Rendus de ľon;Académie des Sciences, Paris, 300, 423

Cheshire M.V., 1979, Nature and Origin of Carbohydrates in Soils

10.1111/j.1365-2389.1981.tb01733.x

10.1007/BF00013103

10.1111/j.1365-2389.1990.tb00042.x

10.1111/j.1365-2389.1973.tb00741.x

10.2136/sssaj1988.03615995005200050029x

10.1016/B978-0-444-41780-0.50015-8

10.1021/ac60111a017

10.1007/BF00378547

Feller C., 1991, Nature des matières organiques associées aux fractions argileuses ?on;un sol ferrallitique, Complex Rendus de ľon;Académic des Sciences, Paris, 312, 1491

Feller C., 1991, Comparaison de différentes méthodes ?on;hydrolyse acide en vue du dosage des glucoses totaux dans les sols, Science du Sol, 29, 13

Girardin C., 1991, Analyseisotopiquedu 13C en abondance naturelle dans le carbone organique: un système automatique avec robot préparateur, Cahiers ORSTOM, Série Pédologie, 26, 371

Goodwin T.W., 1983, Introduction to Plant Biochemistry

Guckert A., 1974, Biodegradation et Humification, 116

Guggenberger G., 1994, Land‐use effectsonthecompositionof organic matterinparticle‐size separates of soil: I. Lignin and carbohydrates signature, European Journal of Soil Science, 45, 449, 10.1111/j.1365-2389.1994.tb00530.x

Jamet R.&Rieffel J.M.1976.Notice ?on;explication no 65. Carte pédologique du Congo. Feuille Pointe‐Noire feuille Loubomo à 1/200000. ORSTOM‐Paris.

Mariotti A., 1991, Le carbone 13 en abondance naturelle, traceur de la dynamique de la matière organique des sols et de lcar;SeAvolution des paléoenvironnements continentaux, Cahiers ORSTOM, Série Pédologie, 26, 299

10.1016/0009-2541(90)90218-V

Martin A., 1990, Estimate of organic matter turnover rate in a savanna soil by 13C naturalabundance measurements, Soil Biologyand Biochemistry, 22, 517, 10.1016/0038-0717(90)90188-6

10.1080/00380768.1984.10434702

10.1007/BF02205590

10.2136/sssaj1983.03615995004700030023x

Trouvé C.1992.Apport de la géochimie isotopique (δ13C) àľon;étude du renouvellement des matières organiques et des sucres neuters dans les sols tropicaux soumis à des changements ?on;écosystèmes. Thèse Université?on;Orldèans.

Trouvé C., 1991, Etude par le traçagenaturel en 13C de la dynamique du renouvellement des matières organiques des sols de savane après plantation de pins et dcar;Eucalyptus au Congo, Cahiers ORSTOM, Série Pédologie, 26, 357

10.1016/0038-0717(94)90169-4

10.1016/0016-7061(79)90005-3