Influence of ecological filters on phytoplankton communities in semi-arid solar saltern environments

Influência dos filtros ecológicos nas comunidades fitoplanctônicas em ambientes de salinas solares no semiárido

Objective

This study analyzed the influence of ecological filters (abiotic variables) on the phytoplankton community in hypersaline ecosystems.

Methods

The abiotic variables measured herein were: pH, water temperature, salinity, ammonium ion, total nitrogen, nitrite, nitrate, total phosphorus, and soluble reactive phosphorus. The phytoplankton community was studied for density, richness and Shannon-Wiener diversity index. Data were analyzed using analysis of variance, linear regression and Canonical correspondence analysis (CCA).

Results

In total, 110 taxa were identified in 3 solar salterns, distributed into 9 taxonomic classes, with the predominance of Cyanobacteria (41.8%) and Bacillariophyceae (22.7%). The species Pseudanabaena galeata was the only species sampled in all saline environments. Salinity significantly influenced the richness in the three salterns, Augusto Severo (F_(1,22) = 23.2, p <0.001), Francisco Menescal (F_(1,22) = 50.02, p <0.001) and Santa Clara (F_(1,22) = 66.33, p <0.001). The first two CCA axes explained 41.6% of total data variability, with a negative relationship with soluble reactive phosphorus for axis 2.

Conclusion

The study showed the influence of the dynamics of salterns ecosystems on the phytoplankton community structure. This is associated with filters developed by the environment, where the increasing salinity, temperature and precipitation of salts influence the composition of these organisms in the ecosystem.

environments hypersaline; salinity; algae; abiotic variables; richness