This paper aims to study the composition and some ecological aspects of the phytoplancton of one of the artificial lakes located at "Chico Mendes" Botanical Garden, Goiânia, Goiás, midwest region of Brazil. The floristic and some ecological aspects were analised. The samples were collected during the following periods: dry, begining of the rainy season and rainy. Besides the phytoplancton, some abiot parameter were mensured (pH, oxygen, temperature, nitrate, nitrite, alkalinity, chlorite, turbity, BDO e precipitation), 77 taxa belonging to taxonomic classes were recognized and 37 taxa was recorded for the first time to State of Goiás. Chlorophyceae was the most representative class. During rainy period the greatest richness was registered, with 11 abundant taxa. In contrast, at the begining of the rainy season the highest phytoplanktonic density was observed (13,590 ind/ml) with 18 abundant taxa, in special Nephrochlamys allantoidea (Chlorophyceae) and Phacus dangeardi (Euglenophyceae). The water was warm (24º-26º), lightly acid through alkalin and meso to oligotrophic.
Phitoplancton; floristics; ecologicals aspects
