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The identification of the spatial distribution of soil trace-elements and the contribution of different sources to the sediment yield is necessary for a better watershed and river water quality management. Until now, less attention has been paid to comprehensive assessments of sediment sources and soil trace-elements with respect to the suspended sediment production. The present study aimed at modelling the spatial distribution of soil trace-elements, quantifying the sediment sources apportionment and relating the landforms to polluted soils. Different techniques and approaches such as the Nemerow pollution index, machine learning algorithms (Random Forest (RF), generalised boosting methods (GBM), generalised linear models (GLM) and sediment fingerprinting were applied to the Kan watershed. A total of 79 soil samples having different Nemerow index values were considered for spatial modelling. Using statistical methods (Range test, Kruskal-Wallis and discrimination function analysis), an optimal set of tracers was selected. An unmixing model was applied to calculate the relative contribution of landforms for eight rainfall events. The results of the soil trace-element mapping showed that RF had the best performance with an accuracy of 83%. The evaluation of polluted soil areas showed that the landforms 'steep hills' and 'valley' contributed the most with 51% and 27% in the riparian zone, respectively. In addition, these landforms give a high contribution to sediment production in late-winter-spring events (29%) with a GOF (goodness of fit) of 0.65. The landform 'plain' had the highest contribution (28%) in sediment yield with a GOF of 0.72 in early-winter events. This means that the valley and steep hill landforms accelerate the transport of trace-elements across the watershed. Interestingly, the contribution of landforms varies during the year. Overall, the new proposed approach enables to better trace the origin of suspended sediments and trace-elements discharge into the river environment.

Germination of 2000-year-old seeds of Phoenix dactylifera from Judean desert archaeological sites provides a unique opportunity to study the Judean date palm, described in antiquity for the quality, size, and medicinal properties of its fruit, but lost for centuries. Microsatellite genotyping of germinated seeds indicates that exchanges of genetic material occurred between the Middle East (eastern) and North Africa (western) date palm gene pools, with older seeds exhibiting a more eastern nuclear genome on a gradient from east to west of genetic contributions. Ancient seeds were significantly longer and wider than modern varieties, supporting historical records of the large size of the Judean date. These findings, in accord with the region's location between east and west date palm gene pools, suggest that sophisticated agricultural practices may have contributed to the Judean date's historical reputation. Given its exceptional storage potentialities, the date palm is a remarkable model for seed longevity research.

Assuming a positive outcome of the parliamentary procedure for laws and, thus, the transformation of the official cadastre for buildings and land into a soil cadastre (urban, extra-urban and cadastre for the conservation of natural or semi-natural soil diversity) would start a new era for pedology. Finally, after many decades of activity to expand soil culture in Italy, almost all Italian families would be in contact with a soil specialist. Land use and redefined plots would be handled with greater care and responsibility. Experts in agricultural and forestry and biodiversity conservation would have a new impetus in their activity. Furthermore, economists will also have to address new issues. The aim of this work was to analyse how to meet the needs of a future Cadastre with respect to soil information both from a descriptive (Cadastral Certificate) and a cartographic point of view and to outline a practical guideline for future technicians who will be in charge of maintaining and updating the soil information system. To this end, we used the area of Caccamo (Sicily) and its soilscape as an example to put this concept into practice. On the one hand, this contribution aims at stimulating the start of a scientific-technical debate and, on the other hand, to give practical indications for the solution of the problem., EQA - International Journal of Environmental Quality, Vol 39 (2020)

Humus forms are a distinctive morphological indicator of soil organic matter decomposition. The spatial distribution of humus forms depends on environmental factors such as topography, climate and vegetation. In montane and subalpine forests, environmental influences show a high spatial heterogeneity, which is reflected by a high spatial variability of humus forms. This study aims at examining spatial patterns of humus forms and their dependence on the spatial scale in a high mountain forest environment (Val di Sole/Val di Rabbi, Trentino, Italian Alps). On the basis of the distributions of environmental covariates across the study area, we described humus forms at the local scale (six sampling sites), slope scale (60 sampling sites) and landscape scale (30 additional sampling sites). The local variability of humus forms was analyzed with regard to the ground cover type. At the slope and landscape scale, spatial patterns of humus forms were modeled applying random forests and ordinary kriging of the model residuals. The results indicate that the occurrence of the humus form classes Mull, Mullmoder, Moder, Amphi and Eroded Moder generally depends on the topographical position. Local-scale patterns are mostly related to micro-topography (local accumulation and erosion sites) and ground cover, whereas slope-scale patterns are mainly connected with slope exposure and elevation. Patterns at the landscape scale show a rather irregular distribution, as spatial models at this scale do not account for local to slope-scale variations of humus forms. Moreover, models at the slope scale perform distinctly better than at the landscape scale. In conclusion, the results of this study highlight that landscape-scale predictions of humus forms should be accompanied by local- and slope-scale studies in order to enhance the general understanding of humus form patterns., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe; 1128

The paleoclimate during the Early Eocene in Maritime Antarctica is characterized by cool conditions without a pronounced dry season. Soils formed on volcanic material under such climate conditions in modern analogue environments are usually Andosols rich in nanocrystalline minerals without pedogenic smectite. The paleosols formed on volcanic material on King Georges Island are covered by basalts, dated by 6 new 40Ar/39Ar datings to 51–48 Ma, and are rich in smectite. A pedogenic origin of the smectites would suggest a semi-arid rather than a wet non-seasonal humid paleoclimate. To investigate the origin of the smectites in these paleosols we used X-ray diffraction and microscopic techniques. Minor mineralogical changes between the volcanic parent material and the paleosols and a homogenous distribution of smectites throughout the paleosol horizons indicate that these smectites were mainly inherited from the pyroclastic parent material, which was altered prior to surficial weathering. Nevertheless, the mineralogical properties, such as degree of crystallinity and octahedral site occupancy, of these smectites were modified during the ancient soil formation. Our findings highlight that trioctahedral smectites were a product of deuteric alteration of pyroclastic rocks and were progressively transformed to dioctahedral smectites during weathering in a soil environment on King George Island.

The rapidly collapsing glacial systems of the Alps produced a large number of melt-water lakes and mires after the Last Glacial Maximum (LGM) in the Late Glacial period. The Rhone-Aare-glacier system gave rise to large moorlands and lakes in the region of the Three Lakes Region of Western Switzerland. When moorlands are formed, they are efficient sinks of atmospheric carbon, but when transformed to agricultural land they are significant C sources. In addition, mires can be used as archives for reconstructing landscape evolution. We explored in more detail the dynamics of the landscape of the Three Lakes Region with a particular focus on the formation and degradation of mires. The Bernese part of the Three Lakes Region developed to become—after the optimisation of the water-levels of the Swiss Jura—the vegetable belt of Switzerland. The situation for agriculture, however, has now become critical due to an overexploitation of the peatland. Until c. 13 ka BP the entire region was hydrologically connected. An additional lake existed at the western end of the plain receiving sediments from the Aare river. Around 13 ka BP, this lake was isolated from the Aare river and completely silted up until c. 10 ka BP when a mire started to form. In the valley floor (‘Grosses Moos’), the meandering Aare and the varying level of the nearby lake of Neuchâtel caused a spatio-temporally patchy formation of mires (start of formation: 10–3 ka BP). Strong morphodynamics having high erosion and sedimentation rates and a high variability of the chemical composition of the deposited material prevailed during the early Holocene until c. 7.5 ka BP. The situation remained relatively quiet between 5 and 2 ka BP. However, during the last 2000 years the hydrodynamic and geomorphic activities have increased again. The optimisation of the Swiss Jura water-levels during the nineteenth and twentieth centuries enabled the transformation of moorland into arable land. As a consequence, the moorland strongly degraded. Mean annual C-losses in agricultural land are c. 4.9 t ha−1 and c. 2.4 t ha−1 in forests. Because forests limit, but not stop, the degradation of mires, agroforestry might be tested and propagated in future as alternative land-use systems for such sensitive areas.

The increasing atmospheric CO2 concentration is a consequence of human activities leading to severe environmental deteriorations. Techniques are thus needed to sequester and reduce atmospheric carbon. One of the proposed techniques is the transformation or construction of new soils into which more organic carbon can be sequestered and CO2 be consumed by increased weathering. By using a chronosequence of new and transformed soils on crushed limestone (0–48 years) in a Mediterranean area (Sicily), we tried to quantify the amount of organic carbon that could be additionally sequestered and to derive the corresponding rates. A further aim was to trace chemical weathering and related CO2 consumption and the evolution of macropores that are relevant for water infiltration and plant nutrition. Owing to the irrigation of the table grape cultivation, the transformed soils developed fast. After about 48 years, the organic C stocks were near 12 kg m-2. The average org. C sequestration rates varied between 68 and 288 g m-2 yr-1. The C accumulation rates in the transformed soils are very high at the beginning and tend to decrease over (modelled) longer time scales. Over these 48 years, a substantial amount of carbonate was leached and reprecipitated as secondary carbonates. The proportion of secondary carbonates on the total inorganic carbon was up to 50%. Main mineralogical changes included the formation of interstratified clay minerals, the decrease of mica and increase of chloritic components as well as goethite. The atmospheric CO2 consumption due to silicate weathering was in the range of about 44–72 g C m-2 yr-1. Due to the high variability, the contribution of chemical weathering to CO2 consumption represents only an estimate. When summing up organic C sequestration and CO2 consumption by silicate weathering, rates in the order of 110–360 g C m-2 yr-1 are obtained. These are very high values. We estimated that high sequestration and CO2 consumption rates are maintained for about 50–100 years after soil transformation. The macropore volume decreased over the observed time span to half (from roughly 10 to 5 %). The transformation of soils may even amend their characteristics and increase agricultural production. Due to the relatively sandy character, enough macropores were present and no substantial compaction of the soils occurred. However, great caution has to be taken as such measures can trigger deterioration of both soil ecosystem services and soil quality., Geoderma, 402, ISSN:0016-7061, ISSN:1872-6259

The relationship between the spatial variability of soil elements, weathering and erosion rates can be very complex. Topography, abruptly-changing elevation gradients and slopes of varying geological composition exert an important influence on weathering trajectories and erosion. This complex interconnectivity is only rarely addressed in weathering studies. The main objectives of this investigation are, therefore, to relate weathering and erosion to various and geomorphic units in a dry-alpine and threshold landscape having steep slopes (Kan catchment, Tehran Province, Iran). A number of common weathering indices were tested using a genetic algorithm. The best indices are the (K + Na)/Ti ratio, the WIP (weathering index according to Parker), and the PI (product index according to Ruxton). However, the recently suggested 4Si-M+-R2 and M-F-Wmin systems discriminate weathering trends more accurately. Our results show that these soils have a low to moderate weathering stage. Weathering trajectories point to the active formation of kaolinite and oxyhydroxides. River sediments are slightly more weathered and contain the most-weathered topsoils and suggest erosion in the catchment is predominantly due to topsoil removal. Chemical weathering is influenced by the dominant geomorphic units (unconsolidated deposits of the Quaternary and solid bedrock) and landform features (combination of altitude and slope). Aspect does not appear to have a significant impact on weathering. Denudation (~erosion) rates were determined using meteoric 10Be since the fluvial sediments did not contain enough quartz for in situ 10Be analyses. This procedure has higher uncertainties due to difficulties in estimating the depositional flux of meteoric 10Be. Due to tectonic uplift, the erosion rates are very high. To maintain a soil layer, soil production rates must be also high. Although annual precipitation is relatively low, slope and soil dynamics seem particularly high, which leads to a fast turnover of the soil material and maintains the weathering intensity at a rather low to intermediate level.

Vast areas in the Mediterranean are characterised by evaporite deposits of the Messinian crises (c. 6–5.3 Ma BP). During this period, large deposits were built up in shallow lagoon-like systems and are now found in southern Italy, Albania, Cyprus and Turkey. So far, soil formation on evaporites has been studied predominantly in subarid to arid environments. Although the formation of soils has received new significance, little is known about the evolutional trajectories on evaporites of the Mediterranean. We therefore studied soil formation in the Caltanissetta basin (Sicily) where evaporites are most widespread. The lithologies included the sequence: marine clay deposits, laminated marl (diatomite; Tripoli sediments), Calcare di Base (limestone), detritic deposits, gypsum (selenite). The chemical signature (immobile elements, rare earth elements) indicated that they all have a similar origin. Surprisingly, both an increasing Corg and carbonate content in the soils caused a decrease in the δ 13C signal in carbonates and in part in the bulk soil. The low δ 13C and δ 18O values of carbonates in the parent material indicate a high rock-water (or meteoric water) interaction that has occurred during sedimentation and diagenesis. Organic matter was oxidised into the shallow lagoon-like systems and its carbon incorporated in the limestone. Elemental leaching from silicates during pedogenesis was most intense in the soils that developed on clays and Tripoli sediments. Vertisols and Mollisols have evolved, together with a high amount of oxyhydroxides (non-crystalline and crystalline forms) and kaolinite. Only weak soil formation was recognisable at sites having gypsiferous parent material. The presence of a high amount of selenite hindered a more advanced evolution. The soils developed on detritic and gypsiferous material exhibited some palygorskite that was inherited from the parent material. At sites having selenite or limestone, shallow Aridisols or Mollisols are found. Weathering is weakly pronounced, e.g. indicated by a high proportion of trioctahedral minerals. Besides inheritance from the parent material, smectite and kaolinite are also actively formed in the soils with increasing weathering. Plagioclase and mica are the main sources of smectite and K-feldspar is a main source of kaolinite neo-formation. The evaporite deposits vary greatly within short distances causing a high spatial diversity of soils. Consequently, soil quality strongly varies, which challenges agricultural use. Well-developed soil profiles and advanced weathering stages are only possible when marine clays, Tripoli sediments or detritic deposits are the parent material. Limestone (Calcare di Base) and gypsiferous sediments (selenite) strongly limit soil formation and mineral transformation.

Soil chronosequences in Alpine areas have often been applied to trace physical, mineralogical and chemical soil properties over time. How the soil pore system of undisturbed soils evolves, however, has not yet been clarified. We therefore investigated two soil chronosequences in the Swiss Alps spanning a time period from a few decades up to the Early Holocene/Late Pleistocene. One soil sequence developed on siliceous parent material in the Sustenpass (proglacial area of the Stein glacier), with soils aged from 30a to 10 ka while the second developed on calcaric parent material in the Klausenpass, with soils aged from 110a to 14 ka (proglacial area of the Griess glacier). We hypothesised that the overall pore size of the topsoil and consequently the relative proportion of macropores decrease with increasing soil age. The pore size characteristics were determined by using X-ray computed tomography. Independent of the parent material (calcareous vs siliceous), macroporosity decreased with time. The greatest changes seemed to occur between the Little Ice Age (LIA) and about 3–4 kyr of soil evolution. Vegetation composition and the functional richness of the plant community exert an influence on soils that developed on siliceous parent material by giving rise to more small pores. Besides pore sizes, pore characteristics also changed with time. In general, the tortuous structure of the soils became more complex with time. The evolution of the pore characteristics such as tortuosity, number and length of pore networks seem also to be related to biologic factors such as root properties, plant species and soil organic matter composition. It remains, however unanswered how these time-dependent biologic factors interact with and influence in detail the pore network. This aspect certainly merits investigation in greater detail in the future.

Recent studies have demonstrated that soils formed on pyroclastic ash deposits are much more common in the Mediterranean area than previously assumed. These soils are an important key to understanding past volcanic events and landscape evolution. Chronological information in soils of Quaternary volcanic events, however, remains still poorly understood in southern Italy. Using a multi-method forensic approach, we explore the origin and age of volcanic deposits (soils) in Sicily and Calabria. The geochemical signature of the soil was compared to the chemical fingerprint of the magmas of potential source areas of southern Italian volcanoes. The results indicate that the investigated soils on the Nebrodi (Sicily) and Sila (Calabria) mountains were both impacted by materials having a high-K calc-alkaline series volcanism. The Aeolian Islands (in particular Lipari and Vulcano) are the most likely source of origin, but contributions also from the Etna (particularly the Biancavilla ignimbrites and Plinian eruptions) occurred. Weathering and leaching processes, along with a potential contribution from the underlying non-volcanic bedrock, has altered the main chemical composition of soils, often precluding direct relation to potential source areas. Immobile elements and their ratios (e.g. the Nb/Y vs Zr/Ti plot) or trace elements (Co, Th) and rare earth elements (laser ablation ICP-MS analyses of glass particles, volcanic clasts and pumice-like materials) gave precious hints of the origin of the volcanic deposits. Radiocarbon dating of the H2O2 resistant soil organic fraction indicates a minimum age of 8–10 ka of the soils. The weathering index WIP (weathering index according to Parker) and the chemical composition of volcanic glasses and clasts were tested as proxies for the age of the volcanic deposits and time for soil formation. The soils and landscape are characterised by multiple volcanic depositional phases for the last about 50 ka in the Sila mountains and about 70 ka or more in the Nebrodi mountains. Chemical-mineralogical analyses enabled the detection of deposition phases during the Pleistocene and also Holocene. The multi-method approach enabled the identification of potential source areas, provided a tentative age estimate of the start (and in part duration) of ash deposits and therefore improved our understanding of volcanic landscape evolution.

Deadwood is known to significantly contribute to global terrestrial carbon stocks and carbon cycling, but its decay dynamics are still not thoroughly understood. Although the chemistry of deadwood has been studied as a function of decay stage in temperate to subalpine environments, it has generally not been related to time. We therefore studied the decay (mass of deadwood, cellulose and lignin) of equal-sized blocks of Picea abies wood in soil-mesocosms over two years in the Italian Alps. The 8 sites selected were along an altitudinal sequence, reflecting different climate zones. In addition, the effect of exposure (north- and south-facing slopes) was taken into account. The decay dynamics of the mass of deadwood, cellulose and lignin were related to soil parameters (pH, soil texture, moisture, temperature) and climatic data. The decay rate constants of Picea abies deadwood were low (on average between 0.039 and 0.040y(-1)) and of lignin close to zero (or not detectable), while cellulose reacted much faster with average decay rate constants between 0.110 and 0.117y(-1). Our field experiments showed that local scale factors, such as soil parameters and topographic properties, influenced the decay process: higher soil moisture and clay content along with a lower pH seemed to accelerate wood decay. Interestingly, air temperature negatively correlated with decay rates or positively with the amount of wood components on south-facing sites. It exerted its influence rather on moisture availability, i.e. the lower the temperature the higher the moisture availability. Topographic features were also relevant with generally slower decay processes on south-facing sites than on north-facing sites owing to the drier conditions, the higher pH and the lower weathering state of the soils (less clay minerals). This study highlights the importance of a multifactorial consideration of edaphic parameters to unravel the complex dynamics of initial wood decay.

The importance of gradual erosion relative to landsliding depends predominantly on the slope angle. One factor of critical influence in landsliding along with slope angle and slope shape is the soil depth. Understanding soil depth development on steep topography is fundamental for understanding and predicting the occurrence of landsliding at threshold landscapes. We develop a model to predict soil depth that addresses both threshold and gradual processes. If erosion is a gradual process, soil depth increases until the soil production rate no longer exceeds the erosion rate, and steady state is reached. The predicted soil depth (x) is proportional to the ratio of the infiltration to the erosion rate. Identifying a predictive result for erosion as a function of slope angle (S) allows a test of both the erosion and soil production models with field observations. The same theoretical approach to soil production should be applicable when the principal erosion process is shallow landsliding. After landslides, soil recovery initially follows our predicted power law increase in time, though with increasing time background erosion processes become important. At a time equal to a landslide recurrence interval, the soil depth can exceed the steady state depth by as much as a factor 2. By comparing predicted and observed x(S) results, we show that the accessed result for erosion as a function of slope angle is accurate. Soils deeper than the depth predicted at the landslide recurrence interval are beyond the stability limit. This result suggests an important practical relevance of the new soil production function.

At mid-latitudes, the transition from the Pleistocene to the Holocene was characterised by distinct and partially abrupt climatic changes. Also during the Holocene, climatic perturbations, with sometimes cold-dry conditions, have occurred. How land surfaces and soil development processes in high-mountains respond to these climatic oscillations is so far only poorly known. We traced the responses of surfaces in the alpine settings of the Wind River Range (Wyoming, US) by using a large mire as natural archive. This enabled us to reconstruct environmental conditions and ecosystem changes during the Holocene in this montane area. Although adjacent moraine deposits display 10Be exposure ages from the Last Glacial Maximum up to MIS16 or even older, the accessible sediment deposits covered only the Holocene (via radiocarbon dating). By applying a geoforensic approach and deriving sedimentation rates, major climatic signals were detected. A higher deposition (and consequently erosion) rate and thus a higher rate of geomorphic activity was measured for the known cold periods 9.4–10.2 ka BP, 4.2 ka BP and 2.5 ka BP. During the LIA, especially rapid aggradation of organic matter organic matter took place here. Rates of chemical weathering and soil formation seem to have been relatively low until about 5–6 ka BP but have since increased during the Late Holocene. This would fit previous observations of increasing moisture conditions after the mid-Holocene aridity period. In contrast to several other studies, no clear signs of major disturbances (erosion, weathering) during the 8.2 ka event could be observed. Together with the low levels of chemical weathering found here, we do not see any evidence that the climate was more humid during this period. Compared to previous findings, more humid conditions seemed to have returned earlier, i.e. about 5 kyr BP. In general, this landscape displayed a patchy pattern of reaction to environmental changes, as all events were not recorded in each mire profile., Geomorphology, 371, ISSN:0169-555x, ISSN:1872-695X

Recent modeling and comparison with field results showed that soil formation by chemical weathering, either from bedrock or unconsolidated material, is limited largely by solute transport. Chemical weathering rates are proportional to solute velocities. Nonreactive solute transport described by non-Gaussian transport theory appears compatible with soil formation rates. This change in understanding opens new possibilities for predicting soil production and depth across orders of magnitude of time scales. Percolation theory for modeling the evolution of soil depth and production was applied to new and published data for alpine and Mediterranean soils. The first goal was to check whether the empirical data conform to the theory. Secondly we analyzed discrepancies between theory and observation to find out if the theory is incomplete, if modifications of existing experimental procedures are needed and what parameters might be estimated improperly. Not all input parameters required for current theoretical formulations (particle size, erosion, and infiltration rates) are collected routinely in the field; thus, theory must address how to find these quantities from existing climate and soil data repositories, which implicitly introduces some uncertainties. Existing results for soil texture, typically reported at relevant field sites, had to be transformed to results for a median particle size, d50, a specific theoretical input parameter. The modeling tracked reasonably well the evolution of the alpine and Mediterranean soils. For the Alpine sites we found, however, that we consistently overestimated soil depths by ~45%. Particularly during early soil formation, chemical weathering is more severely limited by reaction kinetics than by solute transport. The kinetic limitation of mineral weathering can affect the system until 1 kyr to a maximum of 10 kyr of soil evolution. Thereafter, solute transport seems dominant. The trend and scatter of soil depth evolution is well captured, particularly for Mediterranean soils. We assume that some neglected processes, such as bioturbation, tree throw, and land use change contributed to local reorganization of the soil and thus to some differences to the model. Nonetheless, the model is able to generate soil depth and confirms decreasing production rates with age. A steady state for soils is not reached before about 100 kyr to 1 Myr

The European Alps are a geomorphologically active region and experience a number of gravity-driven hillslope processes. Soil and landscape formation in the Alps has consequently undergone several minor and major traceable changes of developmental trajectories during the Holocene. Soil development is hypothesised to be often non-linear with time and characterised by stages of progressive and regressive evolution caused by upbuilding (formation, profile deepening) and erosion (profile shallowing). Several cold and warm climate phases are identified during the Holocene but it is largely unknown which effects these might have had on slope processes. By using datable moraines ( 10 Be) and mires ( 14 C), we have constructed a temporal framework for these processes. Using the geochemical imprint of mires in the Alpine setting of the Goschener-valley of the Central Swiss Alps, we reconstructed general (mostly erosional) landscape processes for the last ca. 10 ka. As this is the type locality for the Goschener cold phase, we assumed that this phase (Goschener cold phase I and II ~ 1.5 and ~ 2.5 ka BP) should have left easily recognizable traits. After deglaciation (11–12 ka BP), soil evolution was progressive. Beginning around 8 ka BP, we detect a distinct increase in erosion here, together with a vegetation change (towards tundra vegetation) and the highest measured rates of carbon sequestration. Other phases of high geomorphic activity were recognised ca. 5–6 ka BP, 4 ka BP and, to a lesser extent, 1–3 ka ago. The cold phase at 5–6 ka BP corresponds to a less distinct change in vegetation and lessened erosion. Human impact is increasingly obvious since about 2.4 ka BP which overlaps with the Goschener cold phase. Nonetheless, erosion processes were not extraordinarily high during this period and a climate effect cannot be distinguished. We detect evidence of increasing human disturbance (regressive soil evolution) for about the last 1 ka. We also detect an increase in dust flux during the last ca. 4–5 ka, presumably due to the landscape change(s) in the Sahara during this time.

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 100cm. 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 clearly—similarly to the European Alps—that 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.

The aim of this work was to detect imprints on soil properties from former Islamic land use (9th to 11th century) using a multi-method, soil-chemical approach. Four soil profiles (with buried horizons) found in the vicinities of former Islamic settlements in Sicily were analysed for phosphorus (total, organic and inorganic), nitrogen (total, NO 3 − and NH 4 + ), carbon compounds (δ 13 C, lipids, polycyclic aromatic hydrocarbons (PAH) and functional groups), physical and chemical C-fractions and the state of soil weathering. Two soil profiles contained ceramic sherds from the Islamic period. Inorganic nitrogen forms, phosphorous and the PAH content indicated strong impacts from traditional agriculture and/or burning. Radiocarbon dating of soil organic carbon (SOC) fractions from buried horizons showed that distinct changes must have occurred during the Islamic epoch. The isotopic composition of SOC indicated that land use was probably different in earlier times. C 4 plant cultivation was expected but surprisingly lipid analyses did not confirm this. A high amount of aliphates and low C/N ratio indicated a good, long-term SOC stabilisation under the native conditions combined with Islamic land use. The irrigation of the soils probably increased the production of weakly-crystalline Fe forms that helped to stabilise SOC. The multi-method approach was very helpful in deciphering human-induced processes. Although a full proof for each parameter is not given, former Islamic land-use seems to have distinctly affected the soils – not only locally but probably also in other areas of Sicily, Northern Africa, Near East and Iberian Peninsula.

An important result of the past few decades of soil–geomorphic research is the awareness of the major role of dust and related carbonate precipitates in arid soils. The temporal evolution of soils developed on outwash terraces is still a matter of debate particularly regarding the type of evolution: progressive evolution and constant rates vs complex and/or interval-accumulation rates (progressive or regressive evolution possible). Soils on a chronosequence of outwash terraces just outside and downstream of canyon mouths of the Wind River Range (USA) were analysed for carbonate accumulation, organic carbon and poorly-crystalline pedogenetic oxyhydroxides stocks and pathways of chemical weathering. The soils and their carbonate stocks in the fine earth fraction (< 2 mm) can be used as a relative dating tool and appear to correlate with regional glacial chronostratigraphy [Pinedale (c. 20 ky), Bull Lake (with two different units around 160 and 260 ky) and Sacagawea Ridge (c. 660 ky)]. Carbonate stocks of soils on these terraces increase with increasing soil age, but at generally decreasing rates. A quasi-steady state situation, however, was not reached before 1 My. The time-split approach showed that CaCO3 accumulation rates were the highest during marine isotope (MIS) cold stages (2.13 g CaCO3/m2/y), presumably due to a sparse vegetation cover during MIS2 (Pinedale) and 8 (lower Bull lake). Compared to organic carbon (c. 8–10 kg Corg/m2), the inorganic carbon stocks of the fine earth fraction were much higher (c. 60 kg Cinorg/m2). Although the dominant pedogenic process here appears to be carbonate accumulation, chemical weathering and elemental leaching also are significant. Weathering data were obtained using immobile elements and rare earth elements (REE) as tracers. Chemical weathering and related leaching were particularly notable for Na originating from plagioclase. In addition, pedogenetic Al and Mn oxyhydroxides accumulate (220 and 32 g/m2, respectively, after 660 ky). These form at relatively low rates, however, when compared to moister and cooler conditions at higher altitudes in the Wind River Range. Due to the dry climate under which the terrace soils formed (annual precipitation 32 cm/yr− 1), weakly crystalline and amorphous Fe-oxyhydroxide is rapidly transformed into crystalline forms (hematite) over time. Consequently, the stocks of weakly crystalline and amorphous Fe-oxyhydroxide was significantly lower in the ~ 660 ky soils (50 g/m2) than in the Holocene soils (1000 g/m2). The development of soils on Quaternary outwash terraces in this region is controlled through the rates of aeolian influx over time as modified by glacial/interglacial climate variations rather than by moisture availability. Consequently, carbonate accumulation rates in these soils are ‘influx limited’ rather than ‘moisture limited’.

Only scarce information is available on how organic C is incorporated into the soil during the decay and how (micro) climate influences this process. Therefore, we investigated the effect of exposure and elevation on the organic litter decomposition and C-stabilisation in acidic soils of an Alpine environment. An experiment with artificially 13C labelled Norway spruce needles was carried out at north- and south-exposed sites between 1200 and 2400 m a.s.l. in the Italian Alps using mesocosms. After 1 year, the 13C recoveries of the bulk soil were 18.6% at the north-facing slopes and 31.5% at the south-facing slopes. A density fractionation into a light (LF; ≤1.6 g cm−3) and a heavy fraction (HF; >1.6 g cm−3) of the soil helped to identify how the applied substrate was stabilised. At the northern slope, 10.5% of the substrate was recovered in the LF and 8.1% in the HF and at the south-facing slope 22.8% in the LF and 8.1% in the HF. The overall 13C recovery was higher at the south-facing sites due to restricted water availability. Although the climate is humid in the whole area, soil moisture availability becomes more important at south-facing sites due to higher evapotranspiration. However, at sites >1700 m a.s.l, the situation changed, as the northern slope had higher recovery rates. At such altitudes, temperature effects are more dominant. This highlights the importance of locally strongly varying edaphic factors when investigating the carbon cycle.