The succession dynamics of a macroalgal community after a flood disturbance in a tropical stream from São Paulo State, southeastern Brazil

• Autor(a) principal: Branco,Ciro Cesar Z.
• Data de Publicação: 2005
• Outros Autores: Branco,Luis Henrique Z., Moura,Maurício Osvaldo, Bertusso,Fernando Rodrigo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Botany
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042005000200007
• topic: disturbance; macroalgae; rainfall; stream; succession; tropical

The succession dynamics of a macroalgal community in a tropical stream (20º58' S and 49º25' W) was investigated after disturbance by a sequence of intensive rains. High precipitation levels caused almost complete loss of the macroalgal community attached to the substratum and provided a strong pressure against its immediate re-establishment. After this disturbance, a weekly sampling program from May 1999 to January 2000 was established to investigate macroalgal recolonization. The community changed greatly throughout the succession process. The number of species varied from one to seven per sampling. Global abundance of macroalgal community did not reveal a consistent temporal pattern of variation. In early succession stages, the morphological form of tufts dominated, followed by unbranched filaments. Latter succession stages showed the almost exclusive occurrence of gelatinous forms, including filaments and colonies. The succession trajectory was mediated by phosphorus availability in which community composition followed a scheme of changes in growth forms. However, we believe that deterministic and stochastic processes occur in lotic ecosystems, but they are dependent on the length of time considered in the succession analyses.