Elemental composition of peat profiles in western Siberia: Effect of the micro-landscape, latitude position and permafrost coverage

Bogdanov²,

et al. 2017

Water

Despite the importance of thermokarst (thaw) lakes of the subarctic zone in regulating greenhouse gas exchange with the atmosphere and the flux of metal pollutants and micro-nutrients to the ocean, the inventory of lake distribution and stock of solutes for the permafrost-affected zone are not available. We quantified the abundance of thermokarst lakes in the continuous, discontinuous, and sporadic permafrost zones of the western Siberian Lowland (WSL) using Landsat-8 scenes collected over the summers of 2013 and 2014. In a territory of 105 million ha, the total number of lakes >0.5 ha is 727,700, with a total surface area of 5.97 million ha, yielding an average lake coverage of 5.69% of the territory. Small lakes (0.5-1.0 ha) constitute about one third of the total number of lakes in the permafrost-bearing zone of WSL, yet their surface area does not exceed 2.9% of the total area of lakes in WSL. The latitudinal pattern of lake number and surface coverage follows the local topography and dominant landscape zones. The role of thermokarst lakes in dissolved organic carbon (DOC) and most trace element storage in the territory of WSL is non-negligible compared to that of rivers. The annual lake storage across the WSL of DOC, Cd, Pb, Cr, and Al constitutes 16%, 34%, 37%, 57%, and 73%, respectively, of their annual delivery by WSL rivers to the Arctic Ocean from the same territory. However, given that the concentrations of DOC and metals in the smallest lakes (<0.5 ha) are much higher than those in the medium and large lakes, the contribution of small lakes to the overall carbon and metal budget may be comparable to, or greater than, their contribution to the water storage. As such, observations at high spatial resolution (<0.5 ha) are needed to constrain the reservoirs and the mobility of carbon and metals in aquatic systems. To upscale the DOC and metal storage in lakes of the whole subarctic, the remote sensing should be coupled with hydrochemical measurements in aquatic systems of boreal plains.

Section: Stock Of Doc and Metals In Thermokarst Lakes Of The Wslmentioning

confidence: 70%

Section: Study Areamentioning

confidence: 99%

Size Distribution, Surface Coverage, Water, Carbon, and Metal Storage of Thermokarst Lakes in the Permafrost Zone of the Western Siberia Lowland

Bogdanov²,

et al. 2017

Water

“…The concentrations of 54 elements, including rare earths, were evaluated as the mean of 100-times scanned measurements. Details about the entire analytical procedure are available in Viers et al (2007Viers et al ( , 2013 and Stepanova et al (2015).…”

Section: Analytical Determinationsmentioning

confidence: 99%

“…The moss clone grown in bioreactors with fixed temperature, pH, light and composition of the culture medium (Beike et al, 2015) had a much more homogenous chemical composition than the field moss, exposed to changes in climatic conditions, element bioavailability, metabolic activity and growth rate (Bates, 2000;Stepanova et al, 2015).…”

Section: Fs-umentioning

confidence: 99%

Molecular and chemical characterization of a Sphagnum palustre clone: Key steps towards a standardized and sustainable moss bag technique

Palma

Pardo

Spagnuolo

et al. 2016

Ecological Indicators

a b s t r a c tThis work aimed to define the molecular and chemical signature of a S. palustre clone developed in the framework of the EU-FP7 Mossclone project to improve the standardization and reliability of the mossbag technique. The molecular characterization was performed by a set of DNA molecular markers (RAPD, ISJ, PCR-RFLP, sequencing and microsatellites) to tag the clone produced within the project. Molecular characterization also provided new DNA markers that can be applied in systematic analyses of Sphagnum, and gave new insights to implement well established techniques. The elemental composition of the clone was measured by ICP-MS analysis of 54 major and trace elements, with and without commonly applied pre-exposure treatments (oven devitalization and EDTA washing). Concentrations of almost all analyzed elements were significantly lower (from 10 to 100 times) in the clone than in conspecific field moss, apart from some elements (K, Mo, P and Na) deriving from the culture medium or EDTA treatment. Oven devitalization and EDTA washing did not significantly affect the clone composition. A comparison between the elemental composition of the clone with that of naturally growing Sphagnum species proved the particularly low elemental content of the clone. Therefore, in view of a rigorously standardized moss-bag protocol for the monitoring of persistent atmospheric pollutants, the use of the S. palustre clone, a biomaterial with very low and constant element composition, and homogenous morphological characteristics is strongly recommended.

“…The soil memory function is also shown by the Hydromull humus form that is more common on peat (that started their formation during the Atlantic period: 8000-5000 years ago). They are suitable to conserve pollen, spores, phytoliths, remnants of plants such as old wood that can testify the presence of different environment than the present one, so they can give evidence of global change in the past (Stepanova et al 2015). The peat soils have a large accumulation of organic matter.…”

Section: Histosols and Gleysolsmentioning

confidence: 99%

Climate change impacts on the Alpine ecosystem: an overview with focus on the soil

Chersich¹,

Rejšek²,

Vranová³

et al. 2015

J. For. Sci.

ABSTRACT:The Alpine ecosystem is very sensitive to climatic changes, which have an influence on glaciers, snow, vegetation and soils. The aim of this review is to illustrate the effects of global change on the Alpine soil ecosystem, which is an optimal marker to record them. The manuscript enhances our understanding of the global change effect on the Alpine environment: on morphology, on ice, on vegetation and points out how the cycles of soil nutrients equilibrium have been changed with a direct effect on soils that support plant species. The changes in cryosphere, glacier reduction and periglacial environment as glaciers retreat, decrease in the snow cover extent and earlier snowmelt, determine an effect on soils (on the structure, organic matter and humus forms, soil processes and soil types) from the top of the Alpine horizon to the bottom. The processes induced by climate change (such as erosion and tree line shifting) have a direct effect on water balance that can be observed on soil profile characters with an effect on upward migration, change in phenology, extensive losses of species. The equilibrium of the biogeochemical cycles has been changed and this has a direct effect on soils that support plant species.