Author/Editor     Simčič, Tatjana; Brancelj, Anton
Title     Intensity of mineralization processes in mountain lakes in NW Slovenia
Type     članek
Source     Aquat Ecol
Vol. and No.     Letnik 36, št. 3
Publication year     2002
Volume     str. 345-54
Language     eng
Abstract     The potential and actual intensity of mineralization in sediments of fourteen mountain lakes and one subalpine lake in NW Slovenia have been measured. Potential mineralization was measured as the intensity of the electron transport system (ETS) activity of microzoobenthos and microbial communities and the actual mineralization as the oxygen consumption of respiration processes, both measured at a standard temperature of 20 degres. The lakes are of different trophic levels and some exhibit seasonal anoxia. All but one are hardwater lakes. Two layers of sediment cores from the deepest point of the lakes were analysed: a surface layer and one below 15 cm. Significant differences among different lakes in their ETS activity and oxygen consumption in the surface and lower layers of sediment were observed. ETS activities and oxygen consumption rates were higher in the surface layers of all the lakes. From the three unvestigated deterministic factors (temperature, lake depth and total phosphorus in the water column) on sediment metabolism ETS activity in the surface layer correlated significantly with total phosphorus and lake depth, but oxygen consumption rate showed a significant correlation only with total phosphorus. The relationship between oxygen consumption and ETS activity was also investigated. ETS activities correlated with oxygen consumption rates according to the equation logR=0.421 logETS+0.898 (r=0.82;N=30; p<0.001). The R/ETS ratio was lower at the sediment surface than in the layers deeper than 15 cm. It is concluded that ETS activity and oxygen consumption are good indicators of the intensity of the metabolic activity and mineralization in lake sediments. As the characteristics of lakes and some environmental factors influence the ETS activity and the oxygen consumption differently, the same R/ETS ratio should not be used as conversion factor in calculations for different lakes.
Descriptors     FRESH WATER
GEOLOGIC SEDIMENTS
ELECTRON TRANSPORT
ZOOPLANKTON
OXYGEN CONSUMPTION
TEMPERATURE
PHOSPHORUS
SEASONS
WATER POLLUTANTS
ANALYSIS OF VARIANCE