10 research outputs found
On the Problems of Correlating the Pleistocene Glacial Deposits in the Russian Altai with Siberian Stratigraphic Scales
Using Dendrochronological Analysis for Dating Earthquake-Triggered Landslides (By the Example of SE Altai, Russia)
Environmental context and adaptations of prehistoric and early historical occupation in the Southern Altai (SW SiberiaâEast Kazakhstan)
Fluctuation of glaciers in the southeast Russian Altai and northwest Mongolia Mountains since the Little Ice Age maximum
Reconstruction of the Late-glacial and Holocene history of Lake Oron (Eastern Siberia, Russia) based on high-resolution reflection seismic data
Lignite coal burning seam in the remote Altai Mountains harbors a hydrogen-driven thermophilic microbial community
Microclimate affects soil chemical and mineralogical properties of cold alpine soils of the Altai Mountains (Russia)
Purpose: The present work focuses on cold alpine soils of the Altai Mountains (Siberia, Russia). Permafrost is widespread and often occurs at a depth of about 100 cm. The area is characterised by extremely cold winters and cool summers: the aim was consequently to find out whether weathering could be more intense on thermally less unfavoured conditions or whether the abundance of water could be a more important factor.
Materials and methods: We investigated 10 soils in a very small area close to a local glacier tongue. Five of the investigated soils were south-facing and the other five north-facing. The soils have the same parent material (mica-rich till), altitude, topography and soil age. The vegetation is alpine grassland that is partially intersected with some juniper and mosses. Soil chemical properties such as organic C, N, soil organic matter quality (using DRIFT), pH value, (oxy)hydroxides, total elemental contents (XRF) and soil micromorphology and mineralogy (using diagnostic treatments and XRD) were determined. The age constraint of the site was given by geomorphic studies together with 14C dating of a nearby peat bog and the stable organic matter fraction of the soils.
Results and discussion: The soils have a Holocene age. The results showed astonishingly clearlyâsimilarly to the European Alpsâthat the north-facing soils have a higher weathering state. This is expressed by lower pH values, higher oxalate and dithionite extractable Fe, Al, Mn and Si contents, higher C and N concentrations and stocks when compared to the south-facing sites. No statistically significant differences with respect to weathering indexes could be detected.
The geochemical evolution of the soils seems to be enhanced at north-facing sites, even though very severe climatic conditions prevail. Furthermore, biodegradation seems to be less pronounced on north-facing compared to south-facing sites as poorly degraded organic matter is accumulated. This gives rise to more organic ligands that promote metal binding and their subsequent eluviation along the soil profile.
Conclusions: We consequently must assume that weathering is not limited by low temperatures in the active layer but is rather controlled by soil moisture that seems to be higher during the warmer period in the north-facing soils