Phytoplankton richness and abundance in response to seasonality and spatiality in a tropical reservoir

Lyza Christine Dos Santos Moura,Cláudia Alves De Souza,Silvia Moreira Dos Santos,Jascieli Carla Bortolini,Carlos Roberto Alves Dos Santos

doi:10.1590/s2179-975x11419

Lyza Christine Dos Santos Moura, Cláudia Alves De Souza + Show 3 more

Open Access

https://doi.org/10.1590/s2179-975x11419

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Abstract

Abstract: Aim Species richness and abundance are important elements in understanding communities’ dynamics. In this way we evaluated the spatial and temporal variation of phytoplankton richness and density in a tropical reservoir, and its main drivers. We tested whether the temporal variability of the hydrological cycle influences the phytoplankton, in addition to testing the main environmental variables that influence richness and density. Methods Data from environmental variables and phytoplankton were sampled in different regions of João Leite reservoir, Goiás, Brazil, during a dry and rainy period, and were analyzed by Principal Component Analysis, Student's t-test and Bioenv. Results We recorded distinct environmental scenarios between the dry and rainy period, with temporal differences in richness. Sixty-two taxa were recorded, with cyanobacterial predominance in both hydrological periods and in the lentic reservoir regions. Water temperature, pH, electrical conductivity, dissolved oxygen, turbidity, and nutrient concentrations were the main drivers of phytoplankton richness and density in our study. Conclusions The richness and abundance of species directly reflect the determining factors in the structure of communities, generating important information about ecosystem functions. Therefore, understanding the environmental variability on phytoplankton richness and abundance in tropical reservoirs is essential, since the construction of reservoirs influences aquatic biodiversity and the provision of ecosystem services.

Highlights

Biodiversity is heterogeneously distributed throughout the world, with biological communities vary in space and time (Soininen et al, 2018)
PH, electrical conductivity, dissolved oxygen, turbidity, and nutrient concentrations were the main drivers of phytoplankton richness and density in our study
The Ribeirão João Leite basin is an environmental protection area (EPA), the area is subject to intense human impact, as more than 60% of the land is occupied by cattle ranching, with a coverage of only 30% of native vegetation (Carneiro et al, 2010)

Summary

Introduction

Biodiversity is heterogeneously distributed throughout the world, with biological communities vary in space and time (Soininen et al, 2018). Studies have responded to the need to address the extent of biodiversity change and its drivers (Hillebrand et al, 2018). Associated with richness, the distribution of phytoplankton species abundance is an accurate indicator of community structure and is especially useful when site data are compared (Borics et al, 2021). These measures provide essential information about the organization and structure of the community in relation to the availability of resources and the environmental variability in the aquatic ecosystem

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