https://vital.lib.tsu.ru/vital/access/manager/Index en-us 5 https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000518079 Wed 05 Dec 2018 10:15:21 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000996387 Tue 14 Feb 2023 15:56:35 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000895290 Tue 07 Jun 2022 10:50:26 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001133427 Thu 25 Apr 2024 10:02:13 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001009377 30 %, regardless of season) variations between day and night. The CH4 concentrations and fluxes increased in the order “spring ≤ summer < autumn” and ranged from 1 to 15 μmol L−1 and 5 to 100 mmol m−2 d−1, respectively. The CO2 concentrations and fluxes (range from 100 to 400 μmol L−1 and 1 to 4 g C m−2 d−1, respectively) were positively correlated with dissolved and particulate organic carbon, total nitrogen and bacterial number of the water column. The CH4 concentrations and fluxes were positively correlated with phosphate and ammonia concentrations. Of the landscape parameters, positive correlations were detected between riparian vegetation biomass and CO2 and CH4 concentrations. Over the six-month open-water period, areal emissions of C (>99.5 % CO2; <0.5 % CH4) from the watersheds of 11 rivers were equal to the total downstream C export in this part of the WSL. Based on correlations between environmental controllers (watershed land cover and the water column parameters), we hypothesize that the fluxes are largely driven by riverine mineralization of terrestrial dissolved and particulate OC, coupled with respiration at the river bottom and riparian sediments. It follows that, under climate warming scenario, most significant changes in GHG regimes of western Siberian rivers located in permafrost-free zone may occur due to changes in the riparian zone vegetation and water coverage of the floodplains.]]> Thu 16 Nov 2023 11:51:49 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000896010 10%). The leachates and the depression water were enriched in trace elements, whereas the thermokarst lake and the river demonstrated a decrease in concentration of Fe (−39 and −94%, respectively), Al (−9 and −85%), and Mn (−10 and −79%) during FTC. Overall, the observations demonstrated an increase in aliphatic low molecular weight organic matter (OM), and the precipitation of Fe, Al hydroxides and organo-mineral particles. Therefore, enhanced of frequency of FTC can favour the release of metals and toxicants from acidic OM-rich surface waters and maintain stable OM-metals-colloids in large lakes and rivers, thus regulating aquatic transport of DOC and metals from soils to the Arctic Ocean.]]> Thu 16 Jun 2022 13:20:51 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000659755 Thu 04 Jul 2019 10:25:17 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000624644 season > watershed size. The effect of the latitude was minimal in spring for most TE but highly visible for Sr, Mo, Sb and U. The main factors controlling the shift of river feeding from surface and subsurface flow to deep underground flow in the permafrost-bearing zone were the depth of the active (unfrozen) seasonal layer and its position in organic or mineral horizons of the soil profile. In the permafrost-free zone, the relative role of carbonate mineral-bearing base rock feeding vs. bog water feeding determined the pattern of trace element concentration and fluxes in rivers of various size as a function of season. Comparison of obtained TE fluxes in WSL rivers with those of other subarctic rivers demonstrated reasonable agreement for most trace elements; the lithology of base rocks was the major factor controlling the magnitude of TE fluxes. The climate change in western Siberia and permafrost boundary migration will affect essentially the elements controlled by underground water feeding (DIC, alkaline-earth elements (Ca, Sr), oxyanions (Mo, Sb, As) and U). The thickening of the active layer may increase the export of trivalent and tetravalent hydrolysates in the form of organo-ferric colloids. Plant litter-originated divalent metals present as organic complexes may be retained via adsorption on mineral horizon. However, due to various counterbalanced processes controlling element source and sinks in plants – peat – mineral soil – river systems, the overall impact of the permafrost thaw on TE export from the land to the ocean may be smaller than that foreseen by merely active layer thickening and permafrost boundary shift.]]> Thu 03 May 2018 16:49:28 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001139591 Mon 27 May 2024 15:57:04 KRAT ]]> https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000901388 Mon 17 Oct 2022 14:24:10 KRAT ]]>