Phytoplankton functional groups indicators of environmental conditions in floodplain rivers and lakes of the Paraná Basin

Abstract

Aim: The objective of this study was to evaluate the efficacy of phytoplankton functional groups as indicators of environmental conditions in floodplain rivers and lakes with different trophic state and connectivity degree to the Paraná River. Phytoplankton functional groups (FGs) cluster sensitive species to environmental variation and can be an alternative for environmental monitoring. Methods: Samples were performed quarterly from 2010 to 2013 in the Ivinhema, Paraná and Baia Rivers and in three lakes permanently connected to each river. Results: 419 taxa were identified, and those taxa that had values greater than 5% of the total biovolume were classified into FGs (P, C, A, B, MP, H1, W1, J, TD, L O , and N). The lakes presented higher biovolume and were more productive than rivers, especially in the dry periods. The rivers presented light limitation and low phytoplankton development. The FG L O was an indicator in rainy seasons. Both rivers and lakes were mostly oligotrophic. We registered FG indicators only for the lakes (A, B, C, E, L O , P, and W1) and mesotrophic environments (A, B, C, E, J, L O , and P). Conclusion: The FGs reflected the seasonal variation and the trophic state of environments in the upper Paraná River floodplain, mainly in the lentic environments. The species-environment relationship (FGs as indicators) was clearer in the lakes, probably because of the longer water retention that allows evidencing the response of the phytoplankton community to environmental factors. On the other hand, the absence of FGs as indicators in the rivers could be due to the high water flow that promotes dispersal stochasticity and masks the relationship between the environmental factors and the phytoplankton community. Thus, phytoplankton FGs proved to be a viable tool to evaluate the environmental conditions in a floodplain.

Morphology-based functional groups as the best tool to characterize shallow lake-dwelling phytoplankton on an Amazonian floodplain

“…Studies using single functional group approach to analyze floodplain phytoplankton have used FGs, such as in Brazil for the Upper Paraná River (Bovo-Scomparin and Train, 2008;Bovo-Scomparin et al, 2013;Zanco et al, 2017), Pantanal (Loverde-Oliveira and Huszar, 2007), the Araguaia River (Nabout et al, 2006;Nabout and Nogueira, 2007), in the Amazon basin (Huszar and Reynolds, 1997). In other countries still using FGs, for the middle stretch of the Paraná River in Argentina (Devercelli, 2006), for northern Australia, in Mary River (Townsend, 2006) for Cross River in Nigeria (Okogwu and Ugwumba, 2012) and for the shallow lake Sakadaṧ, situated on the floodplain of the Danube River in Croatia (Mihaljević et al, 2009;Mihaljević et al, 2010;Stević et al, 2013).…”

Phytoplankton Functional Groups Driven by Alternative States in a Tropical Floodplain Lake (Pantanal, Brazil)

“…These conditions were favorable to the diatom and zygnematophycean species of the functional group P (Aulacoseira spp., Aulacoseirales, Aulacoseiraceae and Closterium porrectum, Desmidiales, Closteriaceae), microplankton species and, in the case of diatoms, organisms adapted to live in turbulent environments, often turbid (Reynolds 1988, Sommer 1988) and eutrophic (Reynolds et al 2002, Padisak et al 2009. This group is usually also dominant in lotic environments (Bovo-Scomparin & Train 2008, Zanco et al 2017.…”

A functional deconstructive approach to mixotrophic phytoplankton responds better to local, regional and biogeographic predictors than species

“…The RFG Lo (represented mainly by dinoflagellates) was mainly associated with the rainy period. This group can tolerate nutrient losses caused by the water column stratification (Mihaljević et al ; Zanco et al ; Jati et al ) that can occur during the rainy period. In the Amazon floodplain lakes, this group was associated with the highest values of Z max and probable stratification of the water column.…”