Relationships between long- and short-term records of lacustrine environments are examined using short and long cores obtained from Lake Baikal (Russia) and Lake Biwa (Japan). The connectivity and interactive availability of the environmental information is studied. Short surface cores from various points in Lake Baikal show similar trends in terms of environmental fluctuations. Similar trends in environmental changes are also observed from some short cores obtained from Lake Biwa. The environmental changes recorded in these cores are within the range of interglacial periods for both lakes. Examination of the sedimentation rate corresponding to short and long core information suggest that century-scale events and/or environmental changes may be detected from the longest sediment records at the Academician Ridge of Lake Baikal while decadal events and/or environmental changes may be detected from the long records of Lake Biwa.

The paper discusses geomorphological aspects of former appearances of huge lakes in the Valley of Great Lakes, the Valley of Gobi Lakes in northwestern and western Mongolia and in depressions of northeastern Mongolia, and partly in bounding Russia. The problem is far from its solution, despite a progress with dating of the lake sediments reflected in recent publications. In the paper, we analyze morphometry of high levels of the lakes visible on the satellite images as series of shorelines, which are very young, not older than the Holocene age. The investigated lakes are terminal basins collecting waters from the catchments of large rivers draining the Altai, Khangai, and Khentey Mountains; two of them form more complicated lake systems: of the Khyargas Lake including several transitional lakes, and of the Torei - Khukh lakes. The discussing reasons for these rises are obviously climatic with possible high influences of the deglaciation processes in the surrounding mountains.

Lithology and inorganic geochemical elements were investigated for a sediment core from Achit Lake, western Mongolia and the Chemical Index of Alteration (CIA) was calculated. Based on the results, the paleoclimatic changes in western Mongolia are reconstructed. The high content of SiO₂, Al₂O₃, TiO₂, Fe₂O₃, K₂O and Na₂O and the active layer of CIA are correlated with variable warm climate (climatic transitional period; from~13200 to 6400 and from~1600 to 0 cal yr BP). However, the high contents of easily soluble elements, such as MgO and CaO, with the inactive layer of CIA are corresponded to the cold climate (from ~22600 to ~13200 cal yr BP and from ~6400 to ~1600 cal yr BP). These lead to that geochemical elements of Lake Achit sediment and Chemical Index of Alteration are closely related to climatic changes in western Mongolia of the late Pleistocene and the Holocene.

Mongolia is located in the northern Central Asia, and provides an important key archive for research on the past environment in the region. To assess the regional paleoenvironment, this study analyzed a 10.5 m sediment core retrieved from Olgoy Nuur (Lake) in the west central part of Mongolia. The sedimentary features are investigated as environmental proxies, including whole and mineral grain size, water, organic matter, carbonate, amorphous silica contents, and variations in elements analyzed by X-ray fluorescence. The core was divided into three units based on lithology and analytical results: Unit I with clayey sediment, Unit II with silty sediment, and Unit III with sand and gravel. Principal component analysis (PCA) was applied to the 18 major and trace elements, and they were divided into terrigenous (Al, Si, K, Rb, Zr, Cd, and Pb as the first principal component, and Cr, Fe, Zn, and Ti as the second principal component), authigenic (Ca, Mn, and Sr), and melting (S and Br) inputs. PCA provided insight on the correlation between the sediment characteristics and elemental data. PCA variables demonstrated that lithogenic elements transported by the alluvial or aeolian processes are the principal component through the whole core. The PCA score showed a significant difference between Units I and II. In-lake chemical productivity, indicated by elements found in authigenic materials, was most active during the middle Holocene (upper part of Unit II) in the Olgoy Lake sediment.

The Kamchatka Peninsula and the Kuril Islands are located at the north-eastern Eurasian margin and hence are controlled by both continental and oceanic processes. The available records about the Holocene environmental dynamics, driving forces, and transfer mechanisms during different time scales are sparse. In this manuscript we provide a comparative study of the palaeoecological and neotectonic events reconstructed from different parts of the Kuril-Kamchatka region. Analysis of the available data has demonstrated spatial differences in timing and magnitude of the Holocene climatic episodes and strong influence of the local environmental processes including volcanic activities, that played an important role in development of vegetation and lake ecosystems. More multi-proxy qualitative and quantitative palaeoecological studies are needed to better document the regional pattern in palaeoclimatic events and to unveil the background mechanisms driving the successions of ecosystems in the Kuril-Kamchatka region.

Transport behavior of riverine suspended solids plays an important role in understanding biogeochemical cycles and carbon dynamics of river systems. The dynamics of particulate organic matter (POM) are susceptible to changing watershed environments in river systems. This study focuses on the relationship between riverine organic matter properties and land use in watersheds. The study was conducted in the Kumaki River system on the Noto Peninsula, in central Japan. The system consists of a forested headwater and upstream river area and of paddy fields along the midstream and downstream portions of the Kumaki River. The Nishiyachi River, which is one of main tributaries of the Kumaki River, has a paddy field located in the downstream watershed. River bottom sediment sampling was performed between June 2009 and April 2011 at four sites in the Kumaki River and one site in the Nishiyachi River. The C/N ratio andΔ¹⁴C of organic matter decreased along the river line, but the δ¹³C of organic matter and δ¹⁵N of total nitrogen increased. These results suggest that the distribution of forest and paddy fields in the watershed is reflected in the organic matter properties of river bottom sediments in each river watershed. Variation in the parameters at each sampling site appears to be affected by suspension, transport, and sedimentation of river suspended solids to different degrees as a result of rainfall events.

Sequential sampling and analyses of suspended and riverbed sediments with atmospheric radionuclides ⁷Be (T1/2=53 days), ²¹⁰Pb (T1/2=22.3 years), and ¹³⁷Cs (T1/2=30.2 years) make clear the sediment transport processes in the Kumaki River, central Japan. The ⁷Be/²¹⁰Pbex (excess ²¹⁰Pb) activity ratio of suspended and riverbed sediments revealed the following relation: atmospheric deposition (rainwater) > suspended sediment ≥ riverbed sediment. This relation implies that the riverbed sediment is older than the suspended sediment and it was formed by the accumulation of the suspended sediment during the normal flow condition and mixing with old sediments. The ¹³⁷Cs concentration in the riverbed sediment in the upstream area was clearly higher than that in the midstream area, while the concentration in the surface soil of the forest was much higher than that in the paddy field. This suggests that the riverbed sediment in the upstream area may be attributed to the forest soil and the paddy field contributes more to the midstream area, reflecting the land use difference in the Kumaki River catchment.