Testate amoebae communities from some freshwater and soil habitats in China （Hubei and Shandong Provinces）

Seventy-eight species and forms of testate amoebae were identified from 29 freshwater and soil habitats in three territories of China （Shandong and Hubei Provinces）. Most abundant species from the genera Plagiopyxis, Centropyxis and Trinema represent the globally-distributed and eurybiont group of testate amoe- bae. The species richness was observed to be the lowest （7-12 species per biotope） in sandy sediments of the Yangtze River, but considerably higher （20-30 taxa） in soil environment. In the range of terrestrial habitats, the most remote communities from Laoshan Mountain in Shandong Province, China manifested the highest difference from others. On the other hand, communities originated in the most distant from industrial center places （Guifeng Mountain in Hubei Province, China） possess the most peculiar species composition including specific Gondwa- nian taxa （e.g. Nebela bigibbosa）. In sum, the results obtained provide the evidence that the community complexity and specificity reduce in the places located within areas that are highly populated and intensively visited by humans.

Postglacial incision-infill cycles at the Borisoglebsk Upland: Correlations between interfluve headwaters and fluvial network

The article discusses postglacial landscape transformation in the Northern Hemisphere Middle Pleistocene glaciation area located in the center of the Russian Plain.We attempted to verify the regional paleogeographic model by reconstructing the Late Pleistocene incision-infill cycles at the Eastern Borisoglebsk Upland based on a comparison of inactive interfluves headwaters and actual fluvial network palaeoarchives.The study was also aimed to determine the past extent of fluvial systems.Interdisciplinary research of the actual and buried topography,Ethology and pedogenic properties of surface deposits was carrid out with remote sensing data interpretation,DGPS survey,and detailed description of geological cores involved.The study was followed by analysis of grain size,chemical and organic contents,microstructure,and numerical dating.Integrating the available results,we propose a scenario of the fluvial network transformation at the Eastem Borisoglebsk Upland over the last 150 ka.At least four fluvial incision stages were determined while network extent has significantly changed through the Late Pleistocene.Three can be generally associated with the regional base level decrease-Late Moscow,Late Valdai and Late Holocene and accompanying isolation of the Nero Lake terraces of 130 m,100-105 m and 95-98 m.Incision stages were separated by landscape stability or aggradation periods those were asynchronous at the middle and upper parts of the fluvial network.The main agent of initial valley infill appears to be local lacustrine sedimentation altered by alluvial and colluvial deposition towards the second half of Valdai.Revealed landscape conditions variability emphasize the importance of comprehensive local correlations for regional retrospective models.