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Location of the study sites (soils and peat bog) in the southeastern part of the Altai Mountains (border region: Russia/Mongolia/China). Impression of the environment and sampling sites together with a typical soil profile
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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 condit...
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... The present work focuses on cold alpine soils of the Results Keywords and Clay discussion minerals The . Organic soils carbon have a . Oxyhydroxides Holocene age. . Altai Mountains (Siberia, Russia). Permafrost is widespread The Permafrost results . showed Water availability astonishingly . Weathering clearly — similarly to the and often occurs at a depth of about 100 cm. The area is European Alps — that the north-facing soils have a higher characterised by extremely cold winters and cool summers: weathering state. This is expressed by lower pH values, higher the aim was consequently to find out whether weathering oxalate and dithionite extractable Fe, Al, Mn and Si contents, could be more intense on thermally less unfavoured condi- higher C and N concentrations and stocks when compared to tions or whether the abundance of water could be a more the south-facing sites. No statistically significant differences important factor. with respect to weathering indexes could be detected. Materials and methods We investigated 10 soils in a very The geochemical evolution of the soils seems to be en- small area close to a local glacier tongue. Five of the investi- hanced at north-facing sites, even though very severe climatic gated soils were south-facing and the other five north-facing. conditions prevail. Furthermore, biodegradation seems to be The soils have the same parent material (mica-rich till), alti- less pronounced on north-facing compared to south-facing tude, topography and soil age. The vegetation is alpine grass- sites as poorly degraded organic matter is accumulated. This land that is partially intersected with some juniper and mosses. gives rise to more organic ligands that promote metal binding Soil chemical properties such as organic C, N, soil organic and their subsequent eluviation along the soil profile. matter quality (using DRIFT), pH value, (oxy)hydroxides, Conclusions We consequently must assume that weathering total elemental contents (XRF) and soil micromorphology is not limited by low temperatures in the active layer but is and mineralogy (using diagnostic treatments and XRD) were rather controlled by soil moisture that seems to be higher determined. The age constraint of the site was given by during the warmer period in the north-facing soils. geomorphic studies together with 14 C dating of a nearby peat bog and the stable organic matter fraction of the soils. 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 14 C dating of a nearby peat bog and the stable organic matter fraction of the soils. Keywords Clay minerals . Organic carbon . Oxyhydroxides . Permafrost . Water availability . Weathering Precipitation and temperature particularly influence soil properties by affecting the type and rates of chemical, biological and physical processes (Dahlgren et al. 1997; Birkeland 1999). Vegetation growth and decomposition, which depend on temperature and the other environmental factors, influence weathering reactions through the production of acidity and organic ligands that may promote chemical weathering and subsequent elemental leaching. Weathering rates, in general, are not only driven by climate as known from the paradigm of Dokuchaev (1883) and, in an extended form, of Jenny (1941). Consequently, differences between north- and south-facing sites should be better assignable to thermal differences. The investigated field sites (2,380 m asl) are located in the southeastern part of the Altai Mountains (border region: Russia/ Mongolia/China) at 49°49.159 ′ N, 87°50.912 ′ E and are found in an extended proglacial area of the Sophiysky Glacier of the South Chuya Ridge (Fig. 1). The tendency of glacier degra- dation since the end of the 19th century is to be at an average rate of 15 – 20 m per year (Ostanin et al. 2004). The Sophiysky Glacier has retreated 18 m per year over the last 100 years; the altitude of its tongue was 2,485 m asl in 2000 (Agatova et al. 2002). In the Altai Mountains, meteorological stations are mostly found at altitudes <1,000 m asl. Only two are at>2,000 m asl (located in highland) and four are at an altitude between 1,000 and 2,000 m asl. The annual variation of temperature is in general strongly pronounced. In the highlands, the absolute minimum temperature is around − 50 to − 56 °C (Marinina and Samoilova 1987). The nearest meteorological station is Kosh-Agach (1,830 m asl) that is situated about 55 km east of the investigation site where a minimum air temperature of − 62 °C was recorded in 1969 (Narozhniy and Zemtsov 2011). Average soil surface temperature in January there is − 30 °C. As an average over the last few decades, a snow cover was measured there for 131 days per year (Osokina et al. 1993). Average snow cover is quite low with 10 cm (which enhances the production of permafrost). According to the geobotanical zonation (Ogureeva 1980), the studied area belongs to the alpine – tundra altitudinal ...
Citations
... Globally, a 10 • C increase in temperature doubles the rate of many biological and biochemical processes (Schaetzl & Anderson, 2005). However, in proglacial landscapes, several studies have associated some aspects of soil development to be faster in colder local temperatures (Egli et al., 2015;Egli et al., 2006). Notably, Egli et al. (2015) found a faster accumulation of organic matter on colder and therefore wetter north-facing slopes in the Altai mountains (Siberia, Russia). ...
... However, in proglacial landscapes, several studies have associated some aspects of soil development to be faster in colder local temperatures (Egli et al., 2015;Egli et al., 2006). Notably, Egli et al. (2015) found a faster accumulation of organic matter on colder and therefore wetter north-facing slopes in the Altai mountains (Siberia, Russia). They associated the higher organic matter to a reduced microbial activity due to a colder and wetter environment that decreases the rate of organic matter decomposition . ...
... Our results are consistent with Szymański et al. (2019) who reported that soils occurring at wet sites exhibit lower total N contents than dry sites within proglacial areas along the northeastern coast of Sørkappland. Similarly, previous studies have associated higher organic matter to a reduced microbial activity due to a cold and wetter environment, which decreases the rate of organic matter decomposition (Egli et al., 2015). ...
Climate warming has accelerated the retreat of mountain glaciers worldwide, exposing new areas to weathering, vegetation colonization, and soil formation. In light of probable climate changes such as warming and new extremes, understanding the factors that control soil organic carbon (SOC) and nitrogen build-up is crucial to comprehend proglacial soils and ecosystem formation. To this end, we examine the evolution of SOC, nitrogen (total N and NH4+), and phosphorus (available P) along nine 120-year chronosequences of deglacierization distributed between the European Alps and Tropical Andes. Our dataset includes geochemical analyses of 188 soil samples, in situ soil temperature data for the period 2019–2022, and hydrographic variables. Although time controls proglacial soil development at all sites, our study highlights distinct pedogenesis dynamics between proglacial landscapes depending on the micro and macro environmental context. Differences in soil development were strongly driven by growing degree days (GDD), maximum soil temperature, and parent material. Notably, we identified a positive effect of GDD on SOC and N (total N and NH4+), while our results indicate a negative effect of maximum soil temperature on SOC and NH4+, suggesting that overly high temperatures reduce microbial mineralization and organic matter input to the soil matrix. We reported the presence of higher initial SOC, total N, and NH4+ in the Andean sites than in the Alps sites, suggesting enhanced soil development at the Andean locations. This comparative study suggests the relative importance of maximum temperature and initial site conditions (e.g., parent materials, glacier biomes) during proglacial pedogenesis. Our findings highlight that soil temperature modulates pedogenesis in a complex way and suggest avoiding simply associating greater soil development with higher soil temperature in proglacial landscapes.
... The region is characterized by a cryoarid, permafrost-affected environment (Permafrosthydrogeological map). Within mountain ranges, including the Akkol valley, unconsolidated sediments are frozen from a depth of about 0.8-1.5 m (Egli et al. 2015). The thickness of the active layer has increased over the past 20 years. ...
... The postglacial Holocene period shows different stages of soil formation in the region at various altitudes-from the basin floors up to the heads of valleys (Egli et al. 2015;Bronnikova et al. 2018). At the highest positions, humid and relatively warm Early Holocene stage of forest pedogenesis, as well as a Late Holocene (last 3-4 ka) cold humid phase, presumably under mountain tundra and/or alpines, are recorded. ...
... All these post-LIA process contributes to the penetration of modern OM into the lower horizons of the soil profile. On the landslides along the front of the Historical moraine, where no obvious traces of permafrost degradation, 14 C ages of humus horizon of surface soil at a depth of 15-30 cm fall within the time interval 1. [Egli et al. 2015]), and even at a depth of 12-15 cm, 14 C ages of humus horizon are about 0.4 cal kBP (SOAN-9683, section 4) and 3.5 cal kBP (UZN 6103; Egli et al. 2015). So, in spite of the modern 14 C age obtained for soil at 27-34 cm on the surface of the Historical moraine (section 3), we argue that pedogenesis began here before LIA. ...
The available paleosol and paleowood data from the head of the Akkol trough valley, South Chuya range, indicates a climatically driven glacier dynamic in the Russian Altai. Radiocarbon dating of paleosols and paleotree fragments help determine the beginning of the Neoglacial in this high mountain region in the middle of the Holocene. New data limit the advance of the Sofiysky glacier at that time by the front of the Historical moraine. Less so than during the Historical stage (2.3–1.7 cal kBP), glacial activity 5–4 cal kBP is also supported by rapid reforestation. The Akkem moraine in trough valleys of the Russian Altai accumulated prior to the Holocene. The limitations and difficulties of radiocarbon dating of paleosols should be considered when interpreting the dating results.
... Both chronosequences demonstrate that the FRI only started to have an effect on soil evolution when the vegetation was already well established, i.e., sometime between 160 and 3000 years of soil development. Before that, the physical site properties and the climate (mainly the precipitation, [127]) are the stronger drivers. The small-scale topography of the moraines (indentations offer protection from wind and erosion and have a higher retention of moisture [128]), inhomogeneity in the mineralogical and chemical composition of the parent material, and soil texture drive the soil formation and are therefore responsible for the high spatial variability of mountainous soils. ...
... Such medial position may refer to a break and retreatment of the meltwater stream, already after the deposition of the lower part of the cover layer (30-45 cm). The following micro features also indicate the fluvial sedimentation of the cover layer, showing changes in the stream direction and velocity: 1) predomination of rounded and semirounded mineral grains in the cover layer instead of random roundness in the glacial till ( Fig. 3; 5 A, B; 6 A, B); 2) high density of the contact zone between the cover layer and the glacial till; intercalations of the glacial till and the cover layer (Fig. 5 C-F), due to water erosion (Yezhova, 2014); 3) slightly subhorizontal orientation of the mica plates that becomes almost random near the upper boundary of the glacial till (Fig. 3 C; 5B), which, according to Egli et al. (2015), indicates lower stream velocity near the border with 2Bt1 horizon. ...
Retisols are the most spread soil in the boreal forests of the Russian Plain. Their features are usually linked to the Holocene pedogenesis. However, Retisols formed in the bipartite sediments of Moscow age (sandy cover layer on top of the glacial till) could have experienced pedogenic and cryogenic impact much earlier, starting from the last Interglacial. The subdivision of relic and modern features is still incomplete. In our work, OSL datings together with micromorphological studies indicate that the cover layer was formed by local rewashing of the glacial till during the deglaciation of the Moscow glacier. GPR investigation shows the mantle bedding of the cover layer and proves the stability of uplands and slopes since deposition, which confirms their exposure to long time pedogenesis. Detailed morphology, micromorphology, microtomography, clay mineralogy and AMS dating confirm the presence of polygenetic modern and relic features in the profile of Retisols. Within the cover layer, pedogenesis resulted in a set of embedded soil profiles that have been formed in balance with the modern environment. In the glacial till pedogenesis is mostly exhibited on the ped faces as a set of multi-layered clay and clay-humus coatings. Based on AMS dating of the inner layer of the clay infilling, it was argued that clay illuviation had started during the last interglacial (MIS5e) and continued through the Holocene. The studied soils should be considered as surface paleosols (polygenetic soils) with the palimpsest type of soil memory, reflecting environmental evolution during the last interglacial-glacial cycle and the Holocene.
... Both chronosequences demonstrate that the FRI only started to have an effect on soil evolution when the vegetation was already well established, i.e., sometime between 160 and 3000 years of soil development. Before that, the physical site properties and the climate (mainly the precipitation, [127]) are the stronger drivers. The small-scale topography of the moraines (indentations offer protection from wind and erosion and have a higher retention of moisture [128]), inhomogeneity in the mineralogical and chemical composition of the parent material, and soil texture drive the soil formation and are therefore responsible for the high spatial variability of mountainous soils. ...
Soil development and erosion are important and opposing processes in the evolution of high-mountainous landscapes, though their dynamics are not fully understood. We compared soil development between a calcareous and a siliceous chronosequence in the central Swiss Alps at high altitudes, which both cover soil formation over the Holocene. We calculated element mass balances, long-term erosion rates based on meteoric 10 Be and we determined the rates of soil formation. We also analyzed the shifts in the mineralogical composition, weathering indices, the particle size distribution , carbon stocks and oxalate extractable Fe, Al, and Mn. The siliceous soils had high chemical weathering rates at the early stage of soil formation that strongly decreased after a few millennia. The development of calcareous soil was characterized by high carbonate losses and a shift to finer soil texture. Soil erosion hampered the upbuilding of soil horizons in the early stages of soil development , which led to a delay in soil and vegetation development. This study shows how soil formation drivers change over time. In the early stages of soil development, the parent material predominantly drives soil formation while at later stages the vegetation becomes more dominant as it influences surface stability, hydrological pathways, and chemical weathering that determine water drainage and retention.
... Baltensweiler et al., 2020;Mousavi et al., 2019;Piikki and Söderström, 2019). In most cases, aspects of landscape position are no longer only used to characterize relief but also as a proxy to characterize other soil forming factors, such as in the Altai mountains in Russia where microclimatic differences between north-and south-facing topographic elements cause soil differences (Egli et al., 2015), or in situations where elevation is a proxy for the age of marine or river terraces (Marijn van der Meij et al., 2016;Sauer et al., 2010). We thus define soil-landscape relations here as relations between landscape position and soil properties, through the activity of multiple soil forming factors. ...
Landscape position co-determines soil formation, and hence soil properties are related to landscape position. In many landscapes, the importance of landscape position is large, and thus relations between soil properties and landscape position are strong. This is particularly true for agricultural landscapes, where tillage has smoothed over local variation in soils. It is less true for some forested landscapes, where local impacts of trees on soil formation have increased local variation. This raises the question whether soil-landscape relations are strong in natural grassland, with neither trees nor plowing. We answer this question for hillslopes in a natural grassland in the American Great Plains by quantifying soil-landscape relations and soil spatial autocorrelation based on a dataset of 100 soil observations. We find that soil-landscape relations are weak, even when accounting for topographic features specific for the study site, and that short-range variation in soil properties is about as large as long-range variation. We conclude that non-tree related natural processes disrupt the formation of clear catenas, and hypothesize that these include small burrowing mammals and infilling of parent-material fractures with finer material.
... The more rapid soil development (in particular the accumulation of clay) on siliceous bedrock increases the soil moisture retention capacity (Figure 11; #1 in Figure 1), which promotes vegetation and soil development (Egli et al., 2015). This thus represents a positive feedback. ...
Lateral subsurface stormflow (SSF) is the most important runoff generation mechanism for most hillslopes in temperate climates. It is influenced by pedological, biological, and topographic factors that change during landscape evolution, but so far little is known about how SSF changes over long‐time scales. Therefore, we conducted sprinkling experiments on a silicate and carbonate moraine chronosequence in the Swiss Alps. Each chronosequence consisted of four moraines ranging between a couple of decades and ∼13,500 years in age. On each moraine, we installed three plots and measured shallow SSF in a trench. We added tracers (δ²H and NaCl) to the sprinkling water to identify mixing and flow pathways in the subsurface. The coarse and drainable sediments on the young moraines provoked more frequent and larger SSF responses than for the old moraines. There was no SSF during the sprinkling experiments on the older moraines at the calcareous study area, but SSF occurred during larger natural rainfall events. The pre‐event water fractions in SSF were higher for the old moraines than the young moraines due to the increase in silt, clay, and soil organic matter content, and subsequent increase in the amount of water stored in the soil. The results of this study suggest that soil and vegetation development affect SSF characteristics and help—together with the results for overland flow (companion paper; Maier & van Meerveld, 2021, https://doi.org/10.1029/2021WR030221)—to improve hydrological models and our understanding of the changes in near‐surface runoff generation processes during the first millennia of landscape evolution in Alpine areas.
... Buntig, 1983), frost cracked quartz (e.g. Egli et al., 2015), slightly humified organic matter (e.g. Egli et al., 2015), normal nodules of iron and manganese (e.g. ...
... Egli et al., 2015), slightly humified organic matter (e.g. Egli et al., 2015), normal nodules of iron and manganese (e.g. Szymanski et al., 2015), and subhorizontal planes (e.g. ...
... Thus, the use of soil micromorphology as a tool for past permafrost reconstructions cannot be constrained only to pure cryogenic fabrics, but must also involve other micromorphological features related to environmental changes (such as the spodic features in this study case), allowing for a more comprehensive reconstruction of the complex pedogenic settings (e.g. Kovda et al., 2009;Egli et al., 2015;Sedov et al., 2016;Sheinkman et al., 2016;Kovda et al., 2017;DiPietro et al., 2018) in which cryogenic fabrics were/are developed. ...
Podzols developed on glacial and periglacial features provide the opportunity to reconstruct permafrost past limits and related paleoclimatic variations using micromorphological analysis.
Analyzing 10 thin sections on 8 soils classified as Podzol in two study areas in the Central Italian Alps (Stelvio Pass area and Val Cantone area), we have been able to find different microstructures or pedofeatures (i.e., granular, platy, subangular blocky microstructures, silt cappings on coarse mineral grains) induced by processes related to permafrost conditions like gelifluction and ice lenses segregation. The type and the frequency of these micropedological traits allowed us to determine the lowest limit of past permafrost at 2228 m a.s.l. in Stelvio Pass area and 2347 m a.s.l. in Val Cantone area, respectively ca. 400 m and 330 m lower than today.
Moreover, the analysis of paleoprecipitation and paleotemperature derived from various proxy data and the age of soil pedogenesis allowed us to identify four different phases of podzolization dated to: 13.5–11.5 ka (I phase), 11–9.7 ka (II phase), 9.3–8 ka (III phase), and 7.7–7.3 ka (IV phase).
Reconstructed paleoprecipitation and paleotemperature of the four phases of podzolization also allowed us to determine that in Val Cantone there were two different permafrost aggradation periods that were synchronous to podzolization while in Stelvio Pass area one additional permafrost aggradation period that occurred at 7.7–7.3 ka.
... Peats are presented in the central parts of the Chuya and Kurai intermountain depressions along the Chuya river and in the trough valleys of surrounding ridges. The soils were formed and buried repeatedly during the Holocene at different altitudes-from the basins' floor up to the head of trough valleys [43][44][45][46]. All those buried paleosols have mollic horizons, which are well developed and rich in organic carbon. ...
... It should be noted that in 1898, Sapozhnikov described the presence of ancient moraines in front of the lake [1]. Nevertheless, later, both ancient and young moraines of the Sofiysky glacier were considered as a single complex, attributed to the LIA [25,26,43,60,62,63]. Near the moraine complexes of the Aktru and Historical stages, the mouth of the right tributary opens into the Akkol valley. ...
... When a fragment of the left slope collapsed, landslide mass disintegrated into a number of bodies that blocked the valley almost completely (the width of the valley does not exceed 300-350 m in this location). The petrographic composition, which is different from the rocks of the axial part of the South Chuya range, the lack of rounded fragments, and absence of substrate between them, do not allow considering these landforms as moraines (as, for example, was supposed by Egli et al. [43]. At the same time, the landslide overlaps eroded moraine deposits composed of rock material transported from the axial parts of the range. ...
Analysis of new chronological data, including 55 radiocarbon, 1 OSL, and 8 dendrochronological dates, obtained in the upper reaches of trough valleys within the Katun, North Chuya, South Chuya, and Chikhachev ranges, together with the 55 previously published ones, specifies climatically driven glacier dynamic in the Russian Altai. Available data refute the traditional concept of the Russian Altai Holocene glaciations as a consecutive retreat of the Late Pleistocene glaciation. Considerable and prolonged warming in the Early Holocene started no later than 11.3–11.4 cal kBP. It caused significant shrinking or even complete degradation of alpine glaciers and regeneration of forest vegetation 300–400 m above the modern upper timber limit. Stadial advances occurred in the middle of the Holocene (4.9–4.2 cal kBP), during the Historical (2.3–1.7 cal kBP), and the Aktru (LIA thirteenth–nineteenth century) stages. New radiocarbon ages of fossil soils limited glaciers expansion in the Middle Holocene by the size of the Historical moraine. Lesser glacial activity between 5 and 4 cal kBP is also supported by rapid reforestation in the heads of trough valleys. Glaciers advance within the Russian Altai, accompanied by accumulation of the Akkem moraine, could have occurred at the end of the Late Pleistocene.
... Both may have increased humidity and impacted seasonal runoff patterns in the valley. A recent study has argued that it is predominantly water availability that determines weathering and the accumulation of organic matter in the soil of alpine regions (Egli et al., 2015). ...
Factors governing the spatiotemporal soil development on a deglaciated area of Pindari Glacier in the Indian Central Himalaya were investigated over a timespan of 170 years. Glacier retreat exposed sediments to weathering, decarbonation, illuviation, acidification and melanisation. The spatiotemporal scales of soil transformation in this proglacial environment are significantly greater than in other chronosequences in the alpine environment. The accumulation of SOC and N in the oldest moraine is reflected in high accumulation rates of 52.6 g C m–2 year–1 and 4.8 g N m–2 year–1 in the 20-cm deep soil layer. Reference data from the topsoil of the rhododendron woodlands indicate that the oldest moraine topsoil is close to reaching some sort of a steady state. At least 100 years was required to stabilise the soil cover in most of the proglacial area. The results highlight the importance of rapid glacier retreat as well as inhibited weathering due to plant succession in soil formation, under impact of local climate characterized by high precipitation, temperatures and moisture delivery.
