Teste da teoria neutra utilizando distribuição de abundância de espécies = Species Abundance Distributions (SAD) de algas perifiticas.

Abstract

In addition to playing an empirical role in establishing a close characterization of ecological communities, species abundance distribution enables the comparison of different communities with a compact description of structures. Several models seek proper understanding of this distribution. Yet, only two models are currently more common: log-series and log-normal. Studies on these patterns raise theories seeking an improved understanding. In this context, Hubbell proposes a neutral model (Unified Neutral Theory) under dynamic zero-sum known as zero-sum multinomial (ZSM) species abundance distribution model bringing renewed understanding and discussion. Since the neutral theory is expressly related to communities of non-motile organisms, the periphytic algal community represents an excellent group to have patterns and ecological theories investigated. Thereby, the objective of this study is the assessment of periphytic algal community structure supported by the Neutral Theory. Data include samples of petioles from three stands of the Eichhornia azurea (Sw.) Kunth aquatic macrophyte (n=45). The zero-sum assumption was not reached and the non-neutral model (log-normal distribution) fit more satisfactorily. Hence, in the context of our results we present two conclusions: the periphytic algal community dynamics cannot be regarded as neutral and the structuring was not through ecological drift. Our study reveals the relevance of periphytic algal communities as object of study for ecological theories and concepts and the necessity of expanding the number of samplings as well as substrates.