The effects of seasonal change of water level in an estuary on Ludwigia octovalvis (Jacq.) P. H. Raven (Onograceae) growth

Acta Botanica Brasilica

Jose Pedro Nepomuceno Ribeiro¹  Reginaldo Sadao Matsumoto¹  Maria Inês Salgueiro Lima¹ 

[1] ,Federal University of São CarlosSão Carlos São Paulo ,Brasil

关键词: etiolation;    estuary ecology;    stress;    submergence;    tidal;    ecologia de estuário;    estiolamento;    maré;    estresse;    submersão;   

DOI  :  10.1590/S0102-33062012000400017

来源: SciELO

【 摘 要 】

The Massaguaçu River estuary is an irregular estuary with sandbar breaching cycles that are irregular and happen several times each year. The species Ludwigia octovalvis is a perennial weed in several places around the world, but it is seasonal in the Massaguaçu River. In this survey we determined the relationship between the rain, estuary water level variation, and the spatial and temporal distribution of this species. In a laboratory we simulated the water level variation in water tanks in order to understand how this species responds to flooding. In the field, we determined the distribution of L. octovalvis in the higher pluviose season and in the lower pluviose season. This species is relatively common in the higher pluviose season and completely absent in the lower one. There is strong evidence that this happens due to the longer and deeper sandbar breaching cycles during the dry season, which induce this species to etiolation, and, therefore, mechanical fragility. The seasonality of species in aquatic environments that do not have a dry biological season is unusual and little studied.

【 授权许可】

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