Environmental fluctuations of the Lake Chany complex in western Siberia based on NOAA images

The Lake Chany complex, located in Western Siberia, consists of the large shallow lakes with an average depth of about 2m. The lake area fluctuates according to water level that depends closely on the amount of inflow( snow-melt) and the evaporation, since the lake complex has no outflow river. Based on NOAA/AVHRR satellite normalized difference vegetation index (NDVI) data of the ice-free periods in 2000 and 2001, we evaluated the seasonal changes in the lake area and the surroundingu vegetations of the Lake Chany complex. In late April or early May, the maximum lake area was abserved and the lake area decreased drastically until late May or early June. Then, the lake area decreased gradually from early June to late August. The lake area in August was about 70% of the maximum. Then, the area tends to increase by early October. Compared with the ground truth in August 2001, the seasonally fluctuated areas on NOAA images corresponded to the vast vegetations with several km in width of reed (Phragmites communis) stands which seem to be influenced by the inflow of snow meltwater and the growth of reeds.Article信州大学山地水環境教育研究センター研究報告 2: 1-4(2004)departmental bulletin pape

Preliminary studies on carbon and nitrogen stable isotope ratios analysis of food web in Lake Chany of Western Siberia

Lake Chany is an inland moderately saline lake in Western Siberia. Itconsists of three lakes, Bolshye (Large) Chany, Malye (Small) Chany and Yarkul Pool. Field survey of Lake Chany was carried out at four parts of the lake with different salinity to analyze their food web structures using carbon and nitrogen stable isotope as natusral tracers. The intruding river rigion (St.1) and Malye Chany (St.2) wwkth low salinity (0.9%), the central part of Bolshye Chany (St.3) with salinity of 5.7% and the innermost part of Bolshye Chany (St.4) with the highest salinnity of 6.3% were selected as study sites. Comparison of the isotope ratios of benthis incertebrate (Chironomidae; Diptera) among the sampling sites showed the lowest δ13C and δ15N values at St.1 and highest values at St.4. The benthic invertebrates at St.3 showed similar δ13C and δ15N values to those of St.4 and St.1, respectively. Similar trends but different values of the isotope raions among the sampling stations were observed in zooplankton, POM and sediment samples, indicationg the initial substances of the food chains were different at different parts of the lake.Article信州大学山地水環境教育研究センター研究報告 2: 21-24(2004)departmental bulletin pape

Isotopic evidence for the spatial heterogeneity of the planktonic food webs in the transition zone between river and lake ecosystems

Resources and organisms in food webs are distributed patchily. The spatial structure of food webs is important and critical to understanding their overall structure. However, there is little available information about the small-scale spatial structure of food webs. We investigated the spatial structure of food webs in a lake ecosystem at the littoral transition zone between an inflowing river and a lake. We measured the carbon isotope ratios of zooplankton and particulate organic matter (POM; predominantly phytoplankton) in the littoral zone of a saline lake. Parallel changes in the δ 13C values of zooplankton and their respective POMs indicated that there is spatial heterogeneity of the food web in this study area. Lake ecosystems are usually classified at the landscape level as either pelagic or littoral habitats. However, we showed small-scale spatial heterogeneity among planktonic food webs along an environmental gradient. Stable isotope data is useful for detecting spatial heterogeneity of habitats, populations, communities, and ecosystems

Spatial changes in carbon and nitrogen stable isotopes of the plankton food web in a saline lake ecosystem. Hydrobiologia 571: 395–400

Abstract 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 d 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 2 to using bicarbonate for photosynthesis with increasing pH. The d 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