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26- The species with both Si content and density available were Aspidosperma album,* Scleronema micranthum, Protium insigne*, Protium sp*, Tretragastris sp., Svartzia reticulate*, Eperua bijuga,* Macrolobium sp.,* Swartzia panacoco, Caryocar palidum,* Cecropia sp.,* Pourouma cectropiifolia,* Couepia canomensis,* Lycania heteromorpha,* Lycania ind.,* Parinari excels,* Buchenavia sp.,* Andira unifoliata,* Dipteryx odorata, Laetia procera,* Licaria aritu, L Icaria aurea,* Nectandra rubra,* Eschweileraodora, Eschweilera sp.,* Mouriria sp.,* Guarea sp.,* lnga sp.,* Brosimum sp.,* Ficus sp.,* Hellicostylis sp.,* Virola calophylla, Minquartia guianensis,* Ecclinusa bacuri,* Pouteria sp.,* Prieurella sp.,* Erisma sp.,* Qualea paraensis, and Qualea sp.,* Data from species marked with an asterisk are Qualea sp.,* Data from species marked with an asterisk are from Taux de silice dans Differenta Bois Amazoniens (Laboratoire de Chime du Bois du Centre Technique Forestier Tropical, Nogent-sur- Marne, France,1990), and those marked by a dagger are from Estudo de 55 Especies Lenhosas, para Geracao de Energia em Caldeiras (Lab. Quimica da Madeira, Instituto Nacional de Pesquisa da Amazonia, Manaus, Brazil,1986).
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34- We thank J.Proctor, B.Forsberg, C.Forti, and A. Herbillon for improving the text and for improving the text and for their constructive.