Influence of Biogenous Elements on Components of the Lake Baikal Plankton Community

✍ Scribed by Silow, E. A. ;Stom, D. J. ;Basharova, N. A. ;Belyaev, A. A. ;Buntina, N. A. ;Burlakova, O. A. ;Dzuban, T. A. ;Ermakova, E. N. ;Zausaeva, N. A. ;Spivak, A. I. ;Khramtzova, T. G. ;Shahova, G. V. ;Sheveleva, N. G. ;Shestakova, N. A.

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 284 KB
• Volume: 19
• Category: Article
• ISSN: 0323-4320
• DOI: 10.1002/aheh.19910190607

✦ Synopsis

Influence of Biogenous Elements on Components of the Lake Baikal Plankton Community

Summary: Fertilization experiments in mesocosms of 1 ... 2,000 1 containing up to 0.32 mg/l P and 1.7 mg/l N in summer and in winter did not show any significant changes of the hydrochemical conditions and in the bacterio-plankton. C02-assimilation (14-C method) is reduced by circa 10 by nutrient doses, whereas the chlorophyll concentration increases significantly due to addition of P and N a t the same time in summer, a decrease taking place in winter. The different courses of development are connected with different reactions of individual species of phytoplankton.

Investigation procedure

We have selected a method of mesocosms (GRIGORIEVA et el.) widely practised in hydrobiology. We have employed mesocosms of 1 1 volume (daily (24 h) experiments), 16, 500 and 2000 1. The experiments were carried out subglacially and in summer. The procedure of the experiments has been described earlier (ISCHIDA and MITAMURA).

The following indices were determined : total numbers of saprophytic bacteria, bacteria growing on a medium with N H & ! l and nitrates, heterotrophic and autotrophic assimilation of radioactive sodium bicarbonate, chlorophyll-a concentration, quantities and species composition of phyto-and zooplankton, content of phosphates, total phosphorus, ammonia, nitrate and total nitrogen, COD, oxygen and carbon dioxide content, BOD5, p H and Eh, conductivity. phosphorus nitrogen phosphorus nitrogen phosphorus nitrogen after 24 h 0.