Environmental factors that drive zooplankton diversity in Neo-Tropical Savannah Lagoons.

Renan Rezende, Claudia Padovesi

Resumo


Abstract: Zooplankton is an important community in aquatic ecosystems due to its linkage between primary producers and secondary consumers also playing a key role in cycling of organic materials. Aim: Therefore, our objective was to evaluate the effects of physicochemical variables of the water on the diversity of zooplankton community in seven small tropical lagoons of Brazilian savannah. Methods: Zooplankton samples were taken using a bucket and filtered 200 L by a 64 µm-mesh-plankton-net, and preserved for subsequent identification. Water temperature, dissolved oxygen, pH, electrical conductivity, turbidity, chlorophyll-a, ammonium, nitrate, nitrite, total phosphorus, and soluble reactive phosphorus were measured. Results: The nitrogen and phosphorus are limiting in savannah lentic systems for the zooplankton. The turbidity and ammonium values found were the major factors responsible for structuring this community highlighting the importance of other factors. The higher α diversity was positively associated with aquatic macrophytes (increase of niches and refuge), whereas closed lagoons with geographic proximity increase the similarity in species composition, decreasing the β diversity. Conclusions: We conclude that the deterministic processes (niche theory), due to species have different ecological requirements, are different responses to environmental gradients and increase the diversity in heterogenic lentic systems.

Palavras-chave


α diversity, β diversity, nutrients, habitat heterogeneity, lentic systems



Licença Creative Commons
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional.

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