Diel variation of phytoplankton functional groups in a subtropical reservoir in southern Brazil during an autumnal stratification period |
| |
Authors: | Vanessa Becker Luciana de Souza Cardoso Vera Lúcia M Huszar |
| |
Institution: | 1.Laboratório de Ficologia, Museu Nacional do Rio de Janeiro,Universidade Federal do Rio de Janeiro,S?o Cristov?o, Rio de Janeiro,Brazil;2.Instituto de Biociências, Dept. Botanica,Universidade Federal do Rio Grande do Sul,Porto Alegre,Brazil |
| |
Abstract: | A knowledge of diel variation and the vertical distribution of phytoplankton communities may contribute to a better understanding
of the driving factors of key species. Applying functional-group classification provides important information on the causes
of species selection in the pelagic community. The diel variation of phytoplankton functional groups was analysed during an
autumnal stratification period with the aim of understanding their changes in the vertical position related to light, mixing
regime and grazing pressure. Phytoplankton and zooplankton communities were sampled every 4 h during a 24-h period in a vertical
profile in a subtropical meso-eutrophic reservoir. Strong stratification during a 24-h cycle and a mixed clear epilimnion
with partial atelomixis marked the autumn season in the Faxinal reservoir, southern Brazil. The highest phytoplankton densities
and biomass were found during the second part of the day, a general pattern reported in the literature, and may be explained
by zooplankton dynamics. During the 24-h cycle, phytoplankton functional groups lacking a self-regulating capacity and those
able to regulate their vertical position were vertically segregated in the lake. The diel behaviour of both groups was driven
by the mixing regime (including atelomixis), light and zooplankton grazing pressure. |
| |
Keywords: | Atelomixis Grazing Man-made lake Phytoplankton dynamics Stratification 24-hour cycle |
本文献已被 SpringerLink 等数据库收录! |
|