Spatial changes in carbon and nitrogen stable isotopes of the planktonfood web in a saline lake ecosystem

摘要

We investigated spatial changes in the isotope ratios of the plankton food web in Lake Chany, Siberia, Russia, especially at an estuarine transition zone of the lake. The delta super(13)C values of particulate organic matter (POM) varied among the sampling sites, and increased with increasing pH of the lake water. This may reflect a shift by phytoplankton from using CO sub(2) to using bicarbonate for photosynthesis with increasing pH. The delta super(13)C values of zooplankton community also changed at each site along with those of the POM. This was indicative of carbon isotope changes of plankton food webs between the stations along an environmental gradient.