Although periodically flooded ecosystems represent 25% of the total Amazon area, they contribute to 75% of timber production. Both periodically flooded and upland ecosystems are greatly diverse in species belonging to Leguminosae family. Some of these species are currently exploited, but the economic potential of the vast majority has been overlooked. The knowledge of the plant growth characteristics of these species under nursery conditions is the first step to understand their biology and establish artificial woodlands in deforested areas. This paper reports data on the initial growth and nodulation of 49 species native from both Amazonian ecosystems. All experiments were carried out at the Instituto Nacional de Pesquisas da Amazônia, State of Amazonas, Brazil, during 1985 and 1986. Pre-germinated seedlings were transplanted into plastic bags containing five different substrata under nursery conditions. All species developed well and no differences amongst substrata were observed, except for a few species which grew better in higher fertility substrata. Species originating from periodically flooded ecosystems grew better than those from upland ecosystems. Nodulation was observed in only thirty species. Some non-nodulating species grew as fast as the nodulating ones, indicating that biological nitrogen fixation is not the only efficient mechanism of nitrogen acquisition for tropical legume species. Species with maximum growth rate were: Enterolobium maximum, Swartzia polyphylla and Vatairea guianensis.
Biological nitrogen fixation; Leguminosae; rhizobia; forest species; substrate