Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Variation in climate determines differences in the influence of abiotic variables on the phytoplankton community in tropical ecosystems

Fábio Portella Corrêa de Oliveira , Ariadne Moura , Dantas Ênio

Abstract

This study shows the influence of abiotic variables on phytoplankton in two different tropical climates. Samples were taken from tropical reservoirs, including six from tropical climate (As) and five from semi-arid climate (BSh). Phytoplankton samples were identified and biomass was quantified. Climatic and physicochemical variables were evaluated. We performed canonical analyses in order to observe the influence of abiotic variables on phytoplankton. In both As and BSh ecosystems, the physicochemical variables were significant, and the synergistic effect between variables and climatic conditions were more pronounced in BSh. Micronutrients had a significant role in structuring the phytoplankton community in both As and BSh. In As climate, Cylindrospermopsis raciborskii occurred under lower concentrations of zinc and copper, while in BSh, this species was present under higher concentrations of zinc. In As climate, Geitlerinema amphibium, Cyclotella meneghiniana, Planktothrix agardhii, and Microcystis aeruginosa were also associated with higher sodium concentrations in water, while in BSh, these species experienced lower rainfall. The climate determines the influence of abiotic variables on the phytoplankton community in an isolated and synergistic way. We showed that phytoplankton in tropical and semi-arid reservoirs is mostly regulated by nutrients whose influence varies according to the climate.

MF17079  Accepted 06 September 2017

© CSIRO 2017