Responses of different phytoplankton functional attributes to the spatio-temporal heterogeneity in a large subtropical shallow lake

Luciane Oliveira Crossetti, Lacina Maria Freitas-Teixeira, Juliana Elisa Bohnenberger, Uwe Horst Schulz, Lúcia Ribeiro Rodrigues, David da Motta-Marques

Resumo


Aim: Analyzes of biological communities that take into account only the identification and quantification of the species and their relative contributions, most of the time, do not reflect their ecological functions, especially considering the wide spatial and temporal variation of large shallow lakes. This study aimed at understanding the influence of environmental spatio-temporal heterogeneity on the functional structure of phytoplankton in an subtropical large shallow lake. Methods: Seasonal samplings were carried out in 2010 and 2011, in 19 sampling sites distributed along the entire length and width of the system, comprising the littoral and pelagic zones of the north, central and southern regions of Lake Mangueira. This large shallow lake (Zmax = 7 m, Zmean = 2.6 m) is 90 km long and 3-10 km wide. Abiotic variables and phytoplankton functional attributes (volume, maximum linear dimension, life forms and functional groups) were analyzed as measures of functional diversity. Results: The results showed that there was no spatial organization of the functional attributes of the phytoplankton community in the studied period. Colonial non-flagellated organisms, organisms with cellular volume between 103 and 104 μm3 and greater than 104 μm3, and with maximum linear dimension between 21 and 50 μm prevailed in all zones and regions studied. Phytoplankton functional groups responded to resource variation, especially increasing their variety and contribution in spring and summer periods, segregating the north of the lake, regardless of the studied zones (pelagic and littoral). Conclusions: Phytoplankton functional structure in Lake Mangueira was not spatially organized. The prevalence of relatively large organisms and the spatial homogeneity observed in the functional structuring of the phytoplankton community of Lake Mangueira reflected the influence of the hydrodynamics of this extensive shallow lake for the development of the local biota.


Palavras-chave


functional traits, size, functional groups, littoral zone, pelagic zone

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

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