07 Phytomass and Specifi c Diversity of Macrophyte Vegetation in the Middle Reach of the Yenisei River Tatiana A. Zotina* Institute of Biophysics SB RAS, 50/50, Akademgorodok, Krasnoyarsk, 660036, Russia Received 03.08.2013, received in revised form 17.06.2013, accepted 15.01.2014 Phytomass and specifi c diversity of macrophytes of the Yenisei River on the stretch from Krasnoyarsk to the mouth of the Angara River were estimated. <...> The investigation showed that littoral macrophyte vegetation clearly differs in specifi c composition and biomass in the deep water (H>0,8 m) and shallow water (H<0,7 m) zones. <...> Potamogeton lucens principally dominates in deep-water communities; several dominating species are noticed in the shallow-water zone (P.perfoliatus, P.pectinatus, Elodea canadensis and some other species). <...> Phytomass loss observed in the two dominating species of pondweed, P. lucens and P.perfoliatus, during the season of vegetation was 3.1±3.4 % (n=17) and 11.6±7.8 % (n=37), respectively. <...> The estimated Shannon-Margalef index (based on dry biomass) revealed higher specifi c diversity of the shallow-water macrophyte vegetation as compared to the deep-water one on the majority of sampling sites, but the mean values did not differ statistically (0,90±0,78 и 0,53±0,55, n=15). <...> The biomass and diversity of macrophytes of the Yenisei River did not change considerably at different distances away from the sources of technogenic pollution of the river. <...> All rights reserved * Corresponding author E-mail address: t_zotina@ibp.ru # 73 # Tatiana A. Zotina. <...> Phytomass and Specifi c Diversity of Macrophyte Vegetation in the Middle Reach <...>