Biodiversity and the functioning of hypersaline lake ecosystems from Crimea Peninsula (Black Sea)
Golubkov, Sergey; Kemp, Richard; Golubkov, Mikhail; Balushkina, Evgenia; Litvinchuk, Larisa; Gubelit, Yulia
published: Jan 1, 2007
ArtNo. ESP141016901007, Price: 29.00 €
Environmental variables, biodiversity-productivity relationships and energy pathways were investigated in six shallow lakes of the Crimea with salinity ranging from 24 to 429 g/l. The research included estimations of primary production and total phosphorus concentrations, evaluation of species composition and abundance of planktonic and benthic organisms. There were considerable inter- and intra-annual fluctuations in the abiotic characteristics of the lakes. All lakes had a very high concentration of total phosphorus in the water (up to 5.6 gP/m3) due to a great influence of the watershed on the lakes. A high level of primary production (up to 14.9 gC m−2d−1) was found in most of the lakes. The lowest primary production was in the most saline lake with a dense population of the filtrator, Artemia sp. There were weak negative relationships between the species richness of phytoplankton and the salinity, but species richness of zooplankton and zoobenthos was strongly negatively related to salt concentration. Positive relationships were found between the total number of planktonic and benthic species and primary production of plankton. Grazing benthic energy pathways were dominant at salinities between 25 and 62.5 g/l. Greater levels of salinity led to the gradual reduction of benthic and to an increase of planktonic energy pathways. There were strong positive relationships between species richness and the primary production of phytoplankton. Three different mechanisms are discussed that provide an explanation for this result. They are energy allocation for osmoregulation at high salinities, complementarity in resource utilization of phytoplankton species and trophic-cascade interactions in ecosystems.