Interannual hydrological variations and ecological phytoplankton patterns in Amazonian floodplain lakes

Cleber Nunes Kraus (1) , Marie-Paule Bonnet (2, 1) , Cristina Arantes Miranda (1) , Ina de Souza Nogueira (3) , Jérémie Garnier (1) , Ludgero Cardoso Galli Vieira (4)

1 LMI-OCE - Laboratoire Mixte International Observatoire des Changements Environnementaux
2 UMR 228 Espace-Dev, Espace pour le développement
3 UFG - Universidade Federal de Goiás [Goiânia]
4 UnB - Universidade de Brasilia [Brasília]

Amazonian aquatic environments are complex, and their interaction promotes heterogeneous environments that in turn make it difficult to describe the development of patterns. Amazonian floodplain lakes have different environmental and biological responses in similar water periods due to the interannual variation. We evaluated if the interannual variations in the physical-chemical structure and the phytoplankton community promote environmentally and biologically contrasted conditions between similar hydrological periods. Phytoplankton community structure has differences between periods, but these differences do not necessarily promote dissimilarities. Most of the phytoplankton species belong to the same functional groups. The compositions of species and functional groups between sample units inside lakes are variable and may or may not have significant differences in dissimilarity, but both periods are equally heterogeneous. Beta diversity has shown that the replacement of species and functional groups causes a high level of variation between sites, which maintain a high heterogeneity between periods. These variations have different responses for different scales turning the interpretation of patterns for these environments a problematic task. Hence, scale and inter-annual variability are factors that need to be carefully considered when setting standards to describe the ecological dynamics of floodplain lakes in the Amazonian system.

Mots clés: Amazonian wetlands; biodiversity; Beta diversity; Plankton; Freshwater; Ecology

Domaines: Biodiversité et Ecologie

Cleber Nunes Kraus, Marie-Paule Bonnet, Cristina Arantes Miranda, Ina de Souza Nogueira, Jérémie Garnier, et al.. Interannual hydrological variations and ecological phytoplankton patterns in Amazonian floodplain lakes. Hydrobiologia, 2019, 830 (1), pp.135-149. ⟨10.1007/s10750-018-3859-6⟩. ⟨hal-02136615⟩