Short-term successional dynamics of a macroalgal community in a stream from northwestern São Paulo State, Brazil

Abstract

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 (20°43'S; 49°13'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.