Hydroecological Controls on Algal Community Dynamics and Trophic Status in Freshwater Habitats

ABSTRACT This study was conducted in the southern slopes of the Greater Caucasus and is aimed at the mapping of the algal diversity and the ecological integrity of several lotic and lentic systems across the Ismayilli territory. Through a stringent morpho‐taxonomic screening, we were in a position to recorded 52 different algal taxa; they were classified into five major divisions: Charophyta, Chlorophyta, Cyanobacteria, Bacillariophyta and Euglenophyta. One of the most interesting changes was in the summer, when Bacillariophyta acquired a leading position, probably in direct consequence of the increase of clear water and the increase of solar radiation. We also discovered that the frequent occurrence of pollution‐resistant genera such as Oscillatoria spp., Euglena spp. and Scenedesmus quadricauda , and spike in values of Palmer Index at some of the stations, is a good indicator of moderate organic enrichment. Alternatively, the current survival of sensitive taxa, including Chara vulgaris L., confirms the high level of water purification in many sites leading to localized oligotrophic circumstances. We also find that there is a strong seasonal and spatial change in community makeup with the value of the Shannon‐Weaver index ranging between 0.463 and 2.164. To offer some statistical support to these findings, we discovered that the scores on the Palmer Index have significant positive correlations ( α = 0.05, n = 17) with both EC and TDS. Interestingly, the EC and TDS values were almost perfectly synchronized ( r = 0.97), which depicts a highly close hydrochemical interaction.