University of Isfahan Taxonomy and Biosystematics 3115-9001 10 34 2018 05 22 Investigation of the Flora and Diversity of Phytoplanktonic Algae in Yamchi Dam, Ardabil Province مطالعۀ فلور و تنوع جلبک‌های فیتوپلانکتونی سد یامچی، استان اردبیل 39 52 23541 10.22108/tbj.2019.108541.1053 EN Jamileh Panahy Mirzahasanlou Assistant Professor Department of Biology, Faculty of Basic Science, Gonbad Kavous University, Gonbad Kavous, Iran Zohreh Ramezanpour Assistant Professor International Sturgeon Research Institute, Rasht, Iran Javid Imanpour Namin Associate Professor Department of Fishery, Faculty of Natural Resources, University of Guilan, Somee Sara, Iran Journal Article 2018 01 27 <strong>Abstract</strong> <br />Phytoplanktons are primary producers in aquatic ecosystems, and form part of the basis of the food webs in these ecosystems. Yamchi dam was constructed on Balikhlu River (northwest of Iran). Considering that there was no study of phytoplankton in Yamchi dam, While phytoplanktons are important in understanding the biological function of lakes and detect changes in them, this investigation was carried out to study the floristic composition of phytoplanktons in this lake. In total, 62 Phytoplankton taxa were identified. These belong to 50 genera, 39 families and 9 classes of the algae. Among classes identified in this study, most species were designated to 3 classes: Bacillariophyceae with 23 sp. Chlorophyceae with 12 sp. and Cyanophyceae with 10 sp. Bacillariaceae and Scenedesmaceae each with 6 sp. are the largest families and <em>Nitaschia</em> with 4 sp. is the largest genus identified in the lake, respectively. In the present study, the highest value of diversity was observed in late spring and summer months, which was due to the conditions suitable for growth and co-occurrence of green algae and cyanobacteria, rather than the good quality of water in these months. The lowest values of the diversity index were calculated in the autumn, that the growth condition was suitable for diatoms, with the dominant species of <em>Stephanodiscus neostraea</em>. <br />  https://tbj.ui.ac.ir/article_23541_d419b6240c4f271c3664ed6d6796bb5b.pdf