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Although agricultural colluvial soils are important storage for soil organic carbon (SOC), the mechanisms underlying colluvial (cumulative soils) SOC stability have received little attention so far. In this study, we aim to understand to what extent the main controls on colluvial SOC stability differ from those observed in non‐colluvial soils. Paired soil profiles (non‐colluvial versus colluvial) were collected from five sites which differ in climate, soil geochemical background and cultivation history. Topsoil (0–10 cm) and subsoil (30–50 cm) were analysed for SOC fractions, mineral composition, potential soil respiration and radiocarbon content. Our analysis showed that for non‐colluvial soils, climate, cultivation history and weathering degree have significant effects on potential soil respiration. In contrast, for colluvial soils, the most influential factor for potential soil respiration was the rate of accretion and this was independent of climatic and geochemical context. Furthermore, accretion rates indirectly affected potential soil respiration by interacting with the degree of weathering of deposited soil. This changed the mineral matrix of colluvial soil settings and thereby may enhance soil mineral‐related SOC stabilisation mechanisms. Together, these results suggest that the dominant controls on SOC stability in colluvial soils differ from those in non‐colluvial soils, and the soil accretion rate is the most important control on colluvial SOC stability in agricultural systems. Highlights: The dominant controls on SOC stability in colluvial and non‐colluvial soils were compared.Climate and mineral weathering predominantly control SOC stability in non‐colluvial soils.In contrast, the accretion rate is the key factor controlling colluvial SOC stability.Accretion rate drives the role of mineral weathering in colluvial SOC stability. [ABSTRACT FROM AUTHOR]

In Mediterranean mountain agroecosystems, soil erosion associated with the development of ephemeral gullies is a common environmental problem that contributes to a loss of nutrient‐rich topsoil. Little is known about the influence of ephemeral gully erosion on particle size distribution and its effect on soil organic (SOC) and inorganic (SIC) carbon among different sized soil particles in agricultural soils. In this study, laboratory tests were conducted using velocity settling tube experiments to examine the effects of erosion on sediment particle size distributions from an incised ephemeral gully, associated with an extreme event (235 mm). We also consider subsequent deposition on an alluvial fan in order to assess the distribution of SOC and SIC concentrations and dissolved carbon before and after the extreme event. Soil fractionation was carried out on topsoil samples (5 cm) collected along an ephemeral gully in a cultivated field, located in the lower part of a Mediterranean mountain catchment. The results of this study showed that the sediment transported downstream by runoff plays a key role in the particle size distribution and transportability of soil particles and associated carbon distribution in carbonate rich soils. The eroding sediment is enriched in clay and silt‐sized particles at upslope positions with higher SOC contents and gradually becomes coarser and enriched in SIC at the end of the ephemeral gully because the finest particles are washed‐out of the study field. The extreme event was associated with an accumulation of dissolved organic carbon at the distal part of the depositional fan. Assessment of soil particle distribution using settling velocity experiments provides basic information for a better understanding of soil carbon dynamics in carbonate rich soils. Processes of soil and carbon transport and relationships between soil properties, erodibility and aggregate stability can be helpful in the development of more accurate soil erosion models. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Introduction: Holistic care of a critical patient should include approaching her/his family, as they are living specific needs caused by this critical situation. One of them is the information need. This study sets the elements that a nurse should take into account to effectively approach those information needs. Methods: It is a unifying review of the scientific production on this topic between 2007 and 2016. Twenty-three articles were included due to their contribution to understand the elements required to approach the needs described herein. Results: Six categories were defined to denote the elements for the nursing approach: information characteristics; assessment and identification of the information needs; essential skills in a nurse for approaching the information needs; family participation in the care so as to satisfy their information needs; conditions to approach the information needs; and type of information. Conclusions: These elements will make easier for a nurse to approach the family and will contribute to fulfil their information needs, to improve their quality of life, and enhance the quality standards in the health care. In addition, it contributes to the educative formation of health professionals thanks to the items based on the scientific evidence. [ABSTRACT FROM AUTHOR]

Abstract Several decades of intensive rainfed farming in Mediterranean mountains and later land abandonment has led to rapid land use and land cover changes. During recent centuries, the conversion of rangelands into croplands has increased the surfaces prone to erosion. In the southern Pre-Pyrenees, the process was reversed during the middle of the twentieth century, allowing the recovery of vegetation and subsequent variation in land cover. This work aims to assess how land use changes after generalised land abandonment affect some major soil properties related to soil quality. For this purpose, 98 replicate bulk soil samples were collected in a 23 km2 catchment that was mostly cultivated at the beginning of the last century. Soil samples were distributed over areas representing the main land uses (agricultural land, natural forest, pine afforestation and scrubland). Bulk density, stoniness, grain size, pH, carbonates, electrical conductivity, soil organic carbon (SOC), total nitrogen (TN), water retention capacity and magnetic properties (low frequency magnetic susceptibility (LF) and frequency dependence (FD)) were analysed in the samples from different land use areas. A past scenario was recreated using estimated data from the SPEROS-C model in order to evaluate changes in SOC over time. Furthermore, a multitemporal analysis of the Normalised Difference Vegetation Index of Landsat images was performed between 1972 and the present in order to assess the dynamics of revegetation. After land abandonment, 16.5% of the area remained as croplands, but afforestation and natural revegetation occupied 83.5% of the catchment. The highest mean value for SOC was found in the pine afforested area and the highest TN mean value was found in the natural forest. The lowest mean values for SOC and TN were recorded on the agricultural land. These results show the impact of soil changes produced by land use changes in fragile Mediterranean mountain agroecosystems. Graphical abstract Unlabelled Image Highlights • Changes in land use have resulted in differences in soil properties. • NDVI allows identifying vegetation cover variation developed after land use changes. • Spatial patterns of soil properties are highly conditioned by land use distribution. • Modelling SOC stocks along time is possible applying SPEROS-C model. • NDVI is directly related with the distribution of soil nutrients in the catchment. [ABSTRACT FROM AUTHOR]

Abstract: In the Mediterranean region, the long history of cultivation is associated with significant changes in the original landscape. Agricultural intensification and subsequent land abandonment and reforestation have significantly affected the hydrological behaviour and connectivity patterns of hydrological systems. Thus, information on the spatial distribution of land use/cover is essential for monitoring the runoff response to interpret catchment hydrology. A medium‐sized catchment of the central part of the Ebro Basin (NE Spain), representative of Mediterranean mountain agroecosystems, was selected to assess the effect of land use/cover changes during the last few decades on the hydrological network of the catchment. To this end, a topography‐based index, the ‘index of connectivity’, was applied to assess the effects of land use changes from 1957 to 2010. The sediment connectivity was estimated by using a geomorphometric approach to simulate how connectivity changes due to the different land covers. To improve this index, we used a combination of C‐factor, rugosity index and the novel application of a total aerial biomass equation over pine‐reforested areas as a weighting factor. A high‐resolution (1 × 1 m) digital elevation model was created by filtering and applying a multiscale curvature classification algorithm. The connectivity values show a decrease directly related to ~71% decrease of agricultural land. Understanding landscape patterns, changes and interactions of human activities is essential for land management in Mediterranean agroecosystems. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: In Mediterranean mountainous environments, the removal of natural vegetation for developing agriculture increased the surface areas prone to erosion in the past centuries. In Southern Pre‐Pyrenees, the process was inverted during the middle of the 20th century. This work aims to assess how land use changes after widespread land abandonment affect soil redistribution. For this purpose, 137Cs was used in a 23 km2 catchment that was mostly cultivated at the beginning of the past century. After land abandonment, 16.5% of croplands persisted but afforestation and natural revegetation occupy 83.5% of the catchment area. 137Cs massic activity and related soil properties—stoniness, grain size, and organic matter contents—were analysed in 98 bulk core samples. Physiographic characteristics—slope, altitude, and solar radiation—at the sampling points were determined by using Geographic Information Systems. Soil erosion and deposition rates were derived from 137Cs measurements after applying conversion models and were spatially interpolated to estimate the amount of net soil loss. In cropland soils, mean erosion (62.6 Mg ha−1 yr−1) and deposition rates (55.2 Mg ha−1 yr−1) were significantly higher than in the other land uses. The lowest mean erosion rates (2.4 Mg ha−1 yr−1) were found in natural forests and the lowest mean deposition (2.6 Mg ha−1 yr−1) in pine afforestation evidencing the soil stabilization achieved in the last decades due to revegetation. A sediment budget with the interpolated rates, result in a specific sediment yield of 4.15 Mg ha−1 yr−1. These results outline the impact of land use changes on soil redistribution in fragile mountain agroecosystems. [ABSTRACT FROM AUTHOR]

Fallout caesium-137 has been used to trace soil redistribution in abandoned fields located in the Central Spanish Pyrenees. A total of 28 fields with different lengths, slope angles and time since abandonment were selected on a representative south-facing slope of the Estarrún valley. The local reference inventory and the magnitude and spatial distribution of 137Cs inventories within these fields were documented and used as a basis for assessing patterns of soil redistribution. The local reference inventory was estimated to be 4,500 Bqm−2. Within the fields, the average 137Cs inventory at the top of the slope was 3,920 Bqm−2, and accumulation of soil at the bottom of the slopes was demonstrated by an average 137Cs inventory of 5,320 Bqm−2. Deviations from the reference inventory were highest for fields with the longest slopes that had been abandoned for less than 30 years. Here, increases in the 137Cs inventory, relative to the reference inventory, in excess of 20% were found at the bottom of the slopes. Considering all the fields and all geomorphic positions within the fields, the greatest 137Cs losses and gains were found in the fields with the longest duration of abandonment, indicating more intense soil redistribution. Irrespective of the timing of abandonment, the ranges of 137Cs inventories in the fields were found to be proportional to the water erosion index. The 137Cs technique demonstrated that patterns of sediment redistribution were closely related to the topographic and physiographic characteristics of the slopes. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Land management in agricultural lands has important effects on soil organic carbon (SOC) dynamics. These effects are particularly relevant in the Mediterranean region, where soils are fragile and prone to erosion. Increasing interest of modelling to simulate SOC dynamics and the significance of soil erosion on SOC redistribution have been linked to the development of some recent models. In this study, the SPEROS-C model was implemented in a 1.6-ha cereal field for a 150-year period covering 100 years of minimum tillage by animal traction, 35 years of conventional tillage followed by 15 years of reduced tillage by chisel to evaluate the effects of changes in land management on SOC stocks and lateral carbon fluxes in a Mediterranean agroecosystem. The spatial patterns of measured and simulated SOC stocks were in good agreement, and their spatial variability appeared to be closely linked to soil redistribution. Changes in the magnitude of lateral SOC fluxes differed between land management showing that during the conventional tillage period the carbon losses is slightly higher (0.06 g C m−2 yr−1) compared to the period of reduced till using chisel (0.04 g C m−2 yr−1). Although the results showed that the SPEROS-C model is a potential tool to evaluate erosion induced carbon fluxes and assess the relative contribution of different land management on SOC stocks in Mediterranean agroecosystems, the model was not able to fully represent the observed SOC stocks. Further research (e.g. input parameters) and model development will be needed to achieve more accurate results. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Exceptional rainfall events cause significant losses of soil, although few studies have addressed the validation of model predictions at field scale during severe erosive episodes. In this study, we evaluate the predictive ability of the enhanced Soil Erosion and Redistribution Tool ( SERT-2014) model for mapping and quantifying soil erosion during the exceptional rainfall event (~235 mm) that affected the Central Spanish Pyrenees in October 2012. The capacity of the simulation model is evaluated in a fallow cereal field (1.9 ha) at a high spatial scale (1 × 1 m). Validation was performed with field-quantified rates of soil loss in the rills and ephemeral gullies and also with a detailed map of soil redistribution. The SERT-2014 model was run for the six rainfall sub-events that made up the exceptional event, simulating the different hydrological responses of soils with maximum runoff depths ranging between 40 and 1017 mm. Predicted average and maximum soil erosion was 11 and 117 Mg ha−1 event−1, respectively. Total soil loss and sediment yield to the La Reina gully amounted to 16.3 and 9.0 Mg event−1. These rates are in agreement with field estimations of soil loss of 20.0 Mg event−1. Most soil loss (86%) occurred during the first sub-event. Although soil accumulation was overestimated in the first sub-event because of the large amount of detached soil, the enhanced SERT-2014 model successfully predicted the different spatial patterns and values of soil redistribution for each sub-event. Further research should focus on stream transport capacity. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The main sources of magnetic minerals in soils unaffected by anthropogenic pollution are iron oxides and hydroxides derived from parent materials through soil formation processes. Soil magnetic minerals can be used as indicators of environmental factors including soil forming processes, degree of pedogenesis, weathering processes and biological activities. In this study measurements of magnetic susceptibility are used to detect the presence and the concentration of soil magnetic minerals in topsoil and bulk samples in a small cultivated field, which forms a hydrological unit that can be considered to be representative of the rainfed agroecosystems of Mediterranean mountain environments.Additional magnetic studies such as isothermal remanent magnetization (IRM), anhysteretic remanent magnetization (ARM) and thermomagnetic measurements are used to identify and characterize the magnetic mineralogy of soil minerals. The objectives were to analyse the spatial variability of the magnetic parameters to assess whether topographic factors, soil redistribution processes, and soil properties such as soil texture, organic matter and carbonate contents analysed in this study, are related to the spatial distribution pattern of magnetic properties. The medians of mass specific magnetic susceptibility at low frequency (χlf) were 36.0 and 31.1 × 10−8 m3 kg−1 in bulk and topsoil samples respectively. High correlation coefficients were found between the χlf in topsoil and bulk core samples (r = 0.951, p < 0.01). In addition, volumetric magnetic susceptibility was measured in situ in the field (κis) and values varied from 13.3 to 64.0 × 10−5 SI. High correlation coefficients were found between χlf in topsoil measured in the laboratory and volumetric magnetic susceptibility field measurements (r = 0.894, p < 0.01). The results obtained from magnetic studies such as IRM, ARM and thermomagnetic measurements show the presence of magnetite, which is the predominant magnetic carrier, and hematite. The predominance of superparamagnetic minerals in upper soil layers suggests enrichment in pedogenic minerals. The finer soil particles, the organic matter content and the magnetic susceptibility values are statistically correlated and their spatial variability is related to similar physical processes. Runoff redistributes soil components including magnetic minerals and exports fine particles out the field. This research contributed to further knowledge on the application of soil magnetic properties to derive useful information on soil processes in Mediterranean cultivated soils. [ABSTRACT FROM AUTHOR]

• The contents and stocks of SOC showed a topography-induced spatial heterogeneity. • Topographic changes based on DEMs offers a robust estimation of soil redistribution. • Higher and significant SOC stocks were found in depositional sites than eroded ones. • Lower and significant SOC stocks were found in topsoils in 2014 than in 1998. • Higher and significant SOC stocks were found in subsoils in 2014 than in 1998. Assessing temporal changes in soil organic carbon (SOC) stocks is important when evaluating the SOC sequestration potential of soil management strategies. The monitoring of SOC stocks is challenging, particularly in eroding landscapes where erosion-induced changes in SOC stocks are superimposed on changes related to management. In this study we focused on the spatio-temporal variations of SOC in eroding cropland soils of the northeast of the peninsula of Jutland (Denmark) at field scale. We examined soil redistribution processes as control factors of SOC changes (ΔSOC) during a 16-year period by using soil data (both spatial and with depth) collected over two distinct periods in 1998 and 2014. Topographic changes between 1998 and 2014, derived from high resolution digital elevation models, were used to identify eroded, stable and depositional areas within the field. There was a predominance of soil loss, with 44% of the sampling points corresponding to eroded sites and 28% to depositional sites, while the remainder was considered as stable soils. Substantial erosion was detected and at the field scale, soil deposition equalled (29.7 ± 17.5 Mg ha−1 y−1) while soil erosion rates were lower with a mean of 25.8 ± 12.9 Mg ha−1 y−1. Comparing SOC stocks over the 16 year-period showed that on average, and when considering the whole soil profile, SOC contents and stocks were stable. However, this masked substantial dynamics that were related to erosion processes. Despite the occurrence of net soil erosion at the field scale, there was an overall increase in SOC storage of 1.88 Mg ha (SOC2014:SOC1998 ratio ≥ 1). Losses of SOC in topsoils (6%) and SOC gain (34%) in soil layers below the plough depth (25–45 cm) could be related to soil disturbances caused by tillage and the significant downward transport of topsoil SOC within the soil profile. Soil disturbances caused by tillage practices (i.e. soil management) and SOC transportation from topsoil to subsoil may be responsible for the downward movement of organic carbon and consequent SOC accumulation in subsoils. In addition the successive deposition and deep burial of SOC rich topsoils at depositional sites due to the effect of topography and slope position favours the enrichment of SOC in subsoils. It was estimated that as much as 11% of the sampling points changed from eroded to depositional sites and 15% of them varied from erosion to stable sites, and this might have favoured SOC accumulation. These results clearly show that understanding and quantifying soil redistribution processes is key to assess SOC temporal changes in agricultural soils. This is important to develop site-specific management strategies that improve SOC sequestration at local scale. [ABSTRACT FROM AUTHOR]

Patterns of erosion, transport and deposition of soil particles not only affect the distribution of mineral fraction of the soil but their organic components. The spatial variability of soil nutrients in Mediterranean mountain agroecosystems that combine complex land uses and abrupt topography is poorly documented despite emerging concerns on nutrients fate require understanding the potential impact of soil erosion on nutrients redistribution across landscapes. This study aims to assess at catchment scale the spatial patterns of soil organic and inorganic carbon (SOC, SIC), soil organic carbon fractions and total nitrogen (TN) in relation to land uses and soil redistribution. To this purpose we selected a well characterized endorheic catchment located in NE Spain where soil erosion and deposition rates derived from 137Cs measurements were previously documented and we mapped the distribution of cropland and rangeland areas. A grid of 100 × 100 m was established for collecting a total of 205 soil samples for nutrients and standard soil analyses. In both rangeland and cropland the patterns of SOC and TN stocks were clearly related to 137Cs inventories thus significantly lower nutrient stocks (SOC: 34.1 ± 18.6 Mg ha−1, TN: 2.9 ± 1.7 Mg ha−1) were found in erosional sites whereas higher stocks (SOC: 44.9 ± 24.2 Mg ha−1, TN: 3.9 ± 2.3 Mg ha−1) were recorded in depositional areas. In cropland the mean nutrients contents (SOC: 1.1 ± 0.8%, TN: 0.1 ± 0.1%) were significantly lower than in rangeland (SOC: 3.2 ± 2.1%, TN: 0.2 ± 0.1%). The highest C/N ratios (29) were found in rangeland, while in cropland they occurred in depositional areas with their values below 10 in the erosional sites. In turn, the SIC content (range 0.4 to 10.2%) was slightly lower at the depositional sites (4.9 ± 2.2%) but not significantly different from the erosional sites (5.1 ± 2.2%). Cultivated and steep slopes led to loss of soil and nutrients due to intense erosion processes also related to tillage and crop productivity. Our findings provide evidence that the combined effect of land use and soil redistribution exert an important control on the spatial distribution of nutrients, highlighting a significant decrease of SOC and TN stocks with increasing soil erosion in croplands. The information gained achieves a better understanding of soil nutrients dynamics and further knowledge for effective land management of mountain agroecosystems in the Mediterranean region. • Soil redistribution and land use are key factors on nutrients stock. • Highest SOC and TN stocks occur in cropland at depositional sites. • Labile carbon is more sensitive than stable fraction to soil erosion and land use. • Cropland lowlands are important sinks of soil inorganic carbon. • 137Cs data help to understand soil nutrients pools in Mediterranean agroecosystems. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) is a useful indicator of soil fertility that plays an important role in improving soil quality, increasing agronomic productivity and maintaining sustainability of agricultural systems. The use of hyperspectral data for SOC estimation offers a fast, cost-effective, and non-destructive alternative to conventional soil analyses. Spectral data analysis with multivariate statistical methods has been already successfully used to transfer soil reflectance data on quantitative estimation of SOC content. The spectral sensor type and calibration, and the data acquisition conditions are determinants of the quality and accuracy of the hyperspectral data. Therefore, our study aims to test the capability of the Vis-NIR-SWIR spectral information for the quantitative prediction of organic carbon content in Mediterranean soils by comparing laboratory-based spectroscopy and spectral data acquired in field conditions. We also test the effect of changes in solar illumination on the soil spectral reflectance by comparing soil spectral data under field conditions in different sky conditions.In 2017, soil samples were collected in a Mediterranean agricultural mountain landscape (NE Spain) where the main land uses are cropland, Mediterranean natural forest and scrubland and pine afforestation. We selected a dataset (n=73) that includes a wide range of SOC content from 2 to 71 g kg-1. Laboratory-based spectral data of the soil samples were acquired using an ASD FieldSpec 3 portable spectroradiometer (350 – 2500 nm wavelength range) in a dark room to avoid interference from stray light. An average value of 4 spectral measurements for each sample was used as the final spectral reflectance. In addition, multispectral data were acquired in field conditions with a RedEdge-M narrow-band multispectral camera. After spectral measurements, the SOC content (g kg-1) of all soil samples was measured at 550°C by dry combustion using a LECO RC-612 multiphase carbon analyser. These laboratory reference SOC measurements were coupled with the laboratory and field derived spectral measurements to explore the correlations between soil spectra and SOC. Results of partial least squares regression (PLSR) modelling of spectral data show that the tested multispectral narrow-bands were useful for SOC prediction with a satisfactory level of accuracy (root mean square error, RMSE = 1.15, ratio of performance to deviation, RPD = 1.44, R2 = 0.61) The spectral data provided by the tested multispectral camera can be successfully employed for SOC prediction in field conditions, providing an efficient method for fast acquisition of data also in the spatial domain, especially in the perspective of UAV applications. [ABSTRACT FROM AUTHOR]

Soil tillage and erosion promote the break up of soil structure and loss of carbon. Soilstructure is one of the main factors controlling the ability of soil to support plant growth, themovement of water and the cycling of carbon and nutrients. Therefore soil aggregation is animportant soil property for farmers. Soil aggregation affects soil organic carbon stabilizationand the ability of soils to resist erosion. Soil aggregate size distribution and stability representtwo indicators of soil physical quality that may change in response to soil redistributionprocesses.This study was performed to evaluate soil structural stability and aggregate-associated SOCdynamics in a Mediterranean mountain agroecosystem (NE Spain). The fieldwork wasconducted in 2017, and included the collection of topsoil samples (0-20 cm) fromcroplands after crop harvest at two contrasting slope positions representing eroded anddepositional sites. The main crops were winter cereals and soils with a mean value ofpH 8.5 and EC 0.11 dS m-1 and a silt loam texture are developed on sedimentaryrocks. Aggregate size separation and soil stability assessments were carried out onsoil replicates using a wet sieving method from Six et al. (2000). A total of 80 gair-dried soil samples (8 mm sieved) were fractionated through three sieves (2000, 250and 53 μm) into four aggregate-size classes: large macroaggregates (2000-8000μm), small macroaggregates (250–2000 μm), microaggregates (53-250 μm) andsilt-plus clay-sized particles (&#x003C;53 μm). Sand correction was performed for eachaggregate-size class. SOC contents in topsoils and in each aggregate fractions weremeasured by the dry combustion method and soil aggregate stability was expressedby the mean weight diameter (MWD, mm) and geometric mean diameter (GMD,mm).Different physical-chemical properties in topsoils were observed from the upper to thelower part of the slope. Large differences in SOC concentration and soil aggregationin topsoils between the eroded (mean SOC 2.4 g kg-1) and depositional (meanSOC 5.0 g kg-1) sites were found. The results showed an increase in the weightproportion (%) of all the aggregate size fractions at the lower part of the slope exceptfor the silt-plus clay-sized particles. MWD and MGD mean values were lower(0.40 mm and 0.39 mm) at the upper part of the slope compared to the lower part(0.98 mm and 0.53 mm). Topsoils at the depositional site had a better aggregatestructure and higher aggregate stability than those at the eroded site. This workcontributes to evaluate the effect of soil redistribution processes, responsible for themobilization and deposition of soil aggregates and associated soil organic carbon, on soilstructural stability which is crucial for maintaining soil productivity of Mediterraneanagroecosystems. Acknowledgements: This research was supported by the &#x0022;MOVE-IN Louvain&#x0022; IncomingPost-doctoral Fellowship (L.Quijano as a beneficiary), co-funded by the Marie Curie Actionsof the European Commission (MSCA-COFUND). [ABSTRACT FROM AUTHOR]

Abstract The present dominant trend of retreating and shrinking glaciers is leading to the formation of new soil in proglacial zones. The Cordillera Blanca located in the Peruvian Andes includes the Lake Parón catchment known for the Artesonraju Glacier and its rapid retreat, forming the largest proglacial lake in the region. This work aims to gain knowledge of soil and vegetation development on the most representative proglacial landforms existing in the Parón catchment. Previous research in proglacial environments suggests that soil properties might indicate different ages of ice retreat besides the normalised difference vegetation index (NDVI), which is known to be a powerful tool for assessing vegetation development. In the area surrounding Lake Parón up to the glacier tongue, an altitudinal transect (4200–4700 m a.s.l.) was established for sampling topsoils. A total of 40 surface soil samples (0–3 cm) were collected from the main glacial landforms, moraines, colluvium, glacio-fluvial terraces and alluvial fans, developed after different stages of glacier retreat. Soil organic carbon (SOC) and SOC fractions (active and stable), total nitrogen (TN) and 137Cs were analysed. A multitemporal analysis of NDVI was performed to assess the vegetation dynamics in the Parón catchment and over the different glacial landforms over time (1987–2018). The NDVI increase in recent decades indicates an expansion of vegetation cover and density. We compared NDVI values with the SOC and TN content to assess the relationships with vegetation growth in mountain soils. NDVI and the distribution of SOC and TN content show a positive correlation between vegetation evolution and the enrichment in soil nutrients that are more abundant in older moraines in coincidence with highest NDVI. These results outline the effect of shrinking mountain glaciers on generating new soils in parallel with the growth of vegetation. Graphical abstract Unlabelled Image Highlights • NDVI is related with soil organic carbon and nitrogen along temporal landform stages • Soil organic carbon and 137Cs mass activity are efficient markers of soil formation • Topsoil 137Cs and soil nutrients on landforms are related to stages of ice retreat • Older glacial landforms are enriched in soil nutrients and have higher vegetation cover • Temperature increase and glacier retreat are modifying the altitudinal vegetation line [ABSTRACT FROM AUTHOR]

This paper aimed to identify indicators of soil degradation in volcanic soils developed in the ecotone between the Andean Forests and the Patagonian steppe. The study area is located in the Percy River Basin, Argentine, on alluvial fans with volcanic soils. Sampling was conducted in two adjacent hillslopes where native forest was replaced by a rangeland with grass-shrub vegetation and a 32-years old Pinus radiata plantation. Sectioned and bulk soil samples were collected along three transects in each land cover up to 40 cm depth. Two forest patches of Maytenus boaria were selected as controls. Physical, chemical and magnetic properties were analyzed. Native forest soils were rich in silt fraction, organic matter and non-crystalline minerals, and presented the lowest values of magnetic susceptibility. Rangeland and plantation soils differed from forest soils in these properties. Soil changes were mainly associated to changes in mineralogy resulting from soil desiccation and to the selective removal of fine particles by erosion, together with differences in the effects of recent volcanic events on the soils. Changes in soils associated with land use affected key properties related to pedogenetic processes. Magnetic susceptibility, organic matter content, texture, and pH NaF were key for understanding soil degradation processes in this dynamic environment. [ABSTRACT FROM AUTHOR]

Many ice-free environments in Maritime Antarctica are undergoing rapid and substantial environmental changes in response to recent climate trends. This is the case of Elephant Point (Livingston Island, South Shetland Islands, SSI), where the glacier retreat recorded during the last six decades exposed 17% of this small peninsula, namely a moraine extending from the western to the eastern coastlines and a relatively flat proglacial surface. In the southern margin of the peninsula, a sequence of Holocene raised beaches and several bedrock plateaus are also distributed. A main issue in this environment is the role of glacier retreat and permafrost controlling the recently formed soils. To this purpose, a total of 10 sites were sampled along a transect crossing raised beaches and moraine materials following the direction of glacier retreat. At the selected sites surface samples were collected until 12 cm depth and sectioned at 3 cm depth intervals to analyse main properties, grain size, pH, electrical conductivity and carbonates. Besides, elemental composition and fallout (FRNs) and environmental radionuclides (ERNs) were analysed. To assess if profile characteristics within the active layer are affected by glacier retreat variations of organic carbon and carbon fractions and 137 Cs contents were examined. The presence of organic carbon (range: 0.13–3.19%), and 137 Cs (range: bdl–10.1 Bq kg − 1 ) was only found at the raised beaches. The surface samples had abundant coarse fractions in rich sandy matrix with increasing acidic pH towards the coast. Significant differences were found in the elemental composition and the radionuclides between the moraine and raised beaches. Soil forming processes are related to the time of exposure of the landforms after glacier retreat. The results obtained confirm the potential for using geomorphological, edaphic and geochemical data to assess the influence of different stages of glacier retreat in recent soils and sediments. [ABSTRACT FROM AUTHOR]

Mountain wetlands in Mediterranean regions are particularly threatened in agricultural environments due to anthropogenic activity. An integrated study of source-to-sink sediment fluxes was carried out in an agricultural catchment that holds a small permanent lake included in the European NATURA 2000 Network. More than 1000 yrs of human intervention and the variety of land uses pose a substantial challenge when attempting to estimate sediment fluxes which is the first requirement to protect fragile wetlands. To date, there have been few similar studies and those that have been carried out have not addressed such complex terrain. Geostatistical interpolation and GIS tools were used to derive the soil spatial redistribution from point 137 Cs inventories, and to establish the sediment budget in a catchment located in the Southern Pyrenees. The soil redistribution was intense and soil erosion predominated over soil deposition. On the areas that maintained natural vegetation the median soil erosion and deposition rates were moderate, ranging from 2.6 to 6 Mg ha yr − 1 and 1.5 to 2.1 Mg ha yr − 1 , respectively. However, in cultivated fields both erosion and deposition were significantly higher (ca. 20 Mg ha yr − 1 ), and the maximum rates were always associated with tillage practices. Farming activities in the last part of the 20th century intensified soil erosion, as evidenced by the 1963 137 Cs peaks in the lake cores and estimates from the sediment budget indicated a net deposition of 671 Mg yr − 1 . Results confirm a siltation risk for the lake and provide a foundation for designing management plans to preserve this threatened wetland. This comprehensive approach provides information useful for understanding processes that influence the patterns and rates of soil transfer and deposition within fragile Mediterranean mountain wetlands subjected to climate and anthropogenic stresses. [ABSTRACT FROM AUTHOR]

• Rainfall intensity affects infiltration rates in soils under different land uses. • Runoff, soil and associated nutrient losses vary under different land uses and intensities. • Soil sealing is the main driver force of runoff generation in agricultural and barren land. • Enrichment factors of nutrients differ under different rainfall intensities and land use. The aim of this research was to analyse the effect of rainfall intensity and slope on soil and nutrient losses by hydric erosion in soils with different hydrological characteristics. This research was carried out on soils collected from slopes with different land uses/covers (LU/LC) -forest, scrub, agricultural, afforested and barren land-, from a mountain area (Sierra de Santo Domingo in the South Pyrenean region), where intensive farming and land use changes including land abandonment and changes in soil cover have occurred. Soils were placed on erosion boxes (30 cm × 20 cm) and compacted to a bulk density similar to that measured in the field (slope values ranged between 10 and 20%). Soil properties such as organic matter content, soil texture and N and P contents were analysed (values used as concentration in the original soil). Soils were subjected to simulated rainfall with intensity values usually recorded in the area during storms. Runoff volumes were collected at 10 min intervals from the time that runoff was generated. The steady infiltration rate as well as the average runoff rates and soil losses were evaluated for each land use. In the runoff samples, sediment concentration and nutrients (N and P) were analysed using different aliquots. The comparative analysis of the results obtained under simulated rainfall in plots with soils from different land uses allowed determining the differences in contribution of each land use to soil and nutrient losses when they are subjected to similar rainfall intensities. The results showed that the maximum runoff rates were reached in agricultural soil and barren land after 40 min at low intensity and after about 20 min at high intensity. However, in soils under forest, scrub and afforestation, runoff rates were much lower for the same rainfall intensity and duration period. Soil sealing was the main factor reducing infiltration in the agricultural and in barren LU/LC soils, while in the other cases runoff was mainly produced after saturation. Soil losses were more than 10xtimes higher in barren land and in agricultural soils than in the other land uses. Nitrogen losses in agricultural soils were about 3 times higher than in forest, and scrub or in afforested LU/LC. Under high intensity rainfall, there was an enrichment ratio (ER) of nitrogen in the sediment in relation to the original soil, which was higher in scrub and agricultural lands (up to 1.33 and 1.32, respectively) than in the rest of land uses (1.1 on average). Phosphorous losses were mainly associated with soil particles and the land uses that gave rise to higher P losses was agricultural under any intensity, while P losses increased significantly in forest and afforested LU/LC at high intensity. The enrichment ratio (ER) was higher in agricultural soils (up to 1.82, increasing with intensity), forest and afforested LU/LC (1.33 and 1.16, respectively under high intensity) than in scrub (1.22) and barren lands (near 1). Information gained in this research can be of interest to manage mountain agroecosystems to limit N and P supply from headwaters to hydrological systems. [ABSTRACT FROM AUTHOR]

Fallout radionuclides, such as Caesium-137, were proven to be a valuable means for studying medium-term (c.a. 50 years) soil erosion processes. In order to gain knowledge on the spatial distribution of 137Cs in volcanic soils of Andean Patagonia, 137Cs reference inventories were established along a precipitation gradient. At the subhumid sector, patterns of 137Cs gain/loss associated with land use were also determined considering native forests under grazing, a degraded rangeland and a pine plantation. Along the rising rainfall gradient (750–1400 mm), pedogenesis of volcanic ash soils, non-crystalline mineral formation, organic matter content and soil porosity varied, increasing in moister areas. Radionuclide inventories varied along the edaphoclimatic gradient, reaching mean values of 192, 267 and 576 Bq m−2, at study areas with 750, 950 and 1400 mm of annual precipitation, respectively. The 137Cs inventory followed an exponential relationship with precipitation, which could be related to the presence of allophane as the colloidal material in the soils from the rainiest area. The penetration depth reached by 137Cs varied between 15 and 25 cm, according to rain amount and soil texture. Most of the 137Cs fallout was retained in the uppermost 10 cm of the profiles and an exponential decline of 137Cs with depth, highly related to organic matter contents, was found. At the subhumid study area, both 137Cs mass activity and inventory, significantly decreased under the different land uses, with respect to reference soils. Although the pattern of 137Cs gain/loss varied according to topography, soil properties (organic matter and porosity) and vegetation cover, showing eroding and aggrading profiles, most samples had 137Cs values lower than the reference value, suggesting loss of soil as a consequence of erosion processes. Furthermore, as much as 45%, 58% and 70% of sample points from native forests, plantation and rangeland, respectively, had 137Cs values below the limit of detection. In the study transects, the loss of the upper 15 cm of soil in the subhumid sector during the last 50 years, highly exceeding tolerable erosion rates, highlights the urgent need for applying effective soil conservation measures. Reference inventories, which vary according to the edaphoclimatic gradient, and the loss of the radionuclide in sites with anthropic intervention, show the potential for using 137Cs measurements for assessing erosion processes in the Patagonian Andean Region. • 137Cs inventory in Patagonia depends on precipitation and non-crystalline clays • 137Cs is mainly retained in the uppermost 10 cm of the soil profiles. • 137Cs along soil profiles is controlled by organic matter. • High 137Cs loss and erosion rates under different land uses in forest/steppe ecotone • 137Cs allows to assess erosion rates in Patagonian Andean Region. [ABSTRACT FROM AUTHOR]