Short-term successional dynamics of a macroalgal community in a stream from northwestern São Paulo State, Brazil
Data
2008-06-01
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Editor
Sociedade Botânica do Brasil
Resumo
Este estudo visou: descrever um evento de sucessão ecológica em curto período (70 dias) da comunidade de macroalgas após distúrbio artificial (remoção); avaliar se as características da estrutura da comunidade foram semelhantes antes e depois do período experimental; comparar o processo sucessional em dois trechos experimentais (parcialmente e totalmente perturbados, TPP e TTP), simulando distúrbios de médio (parcial) e grande impacto (completa remoção). Com relação ao tempo de colonização, Oedogonium sp. foi classificada como sucessional indiferente, enquanto Chaetophora elegans (Roth) C. Agarth e Batrachospermum delicatulum (Skuja) Necchi et Entwisle como sucessionais tardias para TTP; para TPP a única diferença foi que Oedogonium sp. foi classificada como sucessional tardia. Temperatura foi a variável mais influente para a maioria das espécies e variáveis biológicas, com aumentos de temperatura provavelmente favorecendo taxas de reprodução. Quanto à estratégia de vida Oedogonium sp. foi classificada como estrategista C-S, enquanto B. delicatulum e C. elegans como estrategistas S para os dois trechos. de maneira geral, a recuperação da estrutura da comunidade não foi completa ao final do período de sucessão. Este estudo de curto período foi consistente com o processo de sucessão determinístico, pois a trajetória de sucessão foi previsível, porque riqueza e abundância de espécies, formas de crescimento e estratégias de vida seguiram um padrão definido.
This investigation aimed to describe a short term (70 days) ecological succession event of a macroalgal community in a stream from northwestern São Paulo state (20º43'S; 49º13'W) after artificial disturbance (removal); evaluate if community structure characteristics were similar before and after the experimental period; compare the successional process of two experimental stream segments (partly and completely disturbed segments, PDS and CDS, respectively), simulating medium (partial) and high impact (complete removal) disturbances. In terms of colonization time, Oedogonium sp. was classified as successionally indifferent, whereas Chaetophora elegans (Roth) C. Agarth and Batrachospermum delicatulum (Skuja) Necchi et Entwisle were classified as late successional forms for CDS; for PDS the only difference was that Oedogonium sp. was classified as late successional. In terms of successional strategy, Oedogonium sp. was classified as a C-S strategist, whereas C. elegans and B. delicatulum were regarded as S strategists for both stream segments. Temperature was the most influential variable for most species and biological variables, with temperature increases probably favouring reproduction rates. In general, community structure recovery was not complete at the end of succession. This short-term study was consistent with the deterministic process of succession, since the succession trajectory was predictable, because species richness and abundance, growth forms and life strategies followed a definite pattern.
This investigation aimed to describe a short term (70 days) ecological succession event of a macroalgal community in a stream from northwestern São Paulo state (20º43'S; 49º13'W) after artificial disturbance (removal); evaluate if community structure characteristics were similar before and after the experimental period; compare the successional process of two experimental stream segments (partly and completely disturbed segments, PDS and CDS, respectively), simulating medium (partial) and high impact (complete removal) disturbances. In terms of colonization time, Oedogonium sp. was classified as successionally indifferent, whereas Chaetophora elegans (Roth) C. Agarth and Batrachospermum delicatulum (Skuja) Necchi et Entwisle were classified as late successional forms for CDS; for PDS the only difference was that Oedogonium sp. was classified as late successional. In terms of successional strategy, Oedogonium sp. was classified as a C-S strategist, whereas C. elegans and B. delicatulum were regarded as S strategists for both stream segments. Temperature was the most influential variable for most species and biological variables, with temperature increases probably favouring reproduction rates. In general, community structure recovery was not complete at the end of succession. This short-term study was consistent with the deterministic process of succession, since the succession trajectory was predictable, because species richness and abundance, growth forms and life strategies followed a definite pattern.
Descrição
Palavras-chave
life strategy, lotic ecosystem, macroalgae, succession, estratégia de vida, Ecossistema lótico, macroalga, sucessão
Como citar
Acta Botanica Brasilica. Sociedade Botânica do Brasil, v. 22, n. 2, p. 453-463, 2008.