Erosion Loss Research Articles

Seasonal growth and senescence of seagrass alters sediment accumulation rates and carbon burial in a coastal lagoon

AbstractSeagrass meadows are important carbon sinks in the global coastal carbon cycle yet are also among the most rapidly declining marine habitats. Their ability to sequester carbon depends on flow–sediment–vegetation interactions that facilitate net deposition, as well as high rates of primary production. However, the effects of seasonal and episodic variations in seagrass density on net sediment and carbon accumulation have not been well quantified. Understanding these dynamics provides insight into how carbon accumulation in seagrass meadows responds to disturbance events and climate change. Here, we apply a spatially resolved sediment transport model that includes coupling of seagrass effects on flow, waves, and sediment resuspension in a seagrass meadow to quantify seasonal rates of sediment and carbon accumulation in the meadow. Our results show that organic carbon accumulation rates were largely determined by sediment accumulation and that they both changed non‐linearly as a function of seagrass shoot density. While seagrass meadows effectively trapped sediment at meadow edges during spring–summer growth seasons, during winter senescence low‐density meadows (< 160 shoots m−2) were erosional with rates sensitive to density. Small variations in winter densities resulted in large changes in annual sediment and carbon accumulation in the meadow; meadow‐scale (hundreds of square meters) summer seagrass dieback due to marine heatwaves can result in annual erosion and carbon loss. Our findings highlight the strong temporal and spatial variability in sediment accumulation within seagrass meadows and the implications for annual sediment carbon burial rates and the resilience of seagrass carbon stocks under future climate change.

Nature-Based Solutions in Coastal and Estuarine Areas of Europe

Momentum for sustainable and climate resilience solutions for coastal protection are growing globally given the pressing need to prevent further loss of biodiversity and ecosystems while meeting the climate change adaptation and mitigation goals. Nature-Based Solutions (NbS) represent an opportunity to align environmental and resilience goals, at a time of strained budgets in a global context and when short-term needs may run counter to long-term goals. In Europe, NbS fit the mandates of major EU environmental and climate change policies by restoring biodiversity and enhancing climate-resilience and carbon sequestration. Previous studies have compiled scientific evidence about hydro-meteorological hazards for the use of NbS. However, their implementation at scale is still lacking. As the knowledge and experience with NbS for adaptation to natural hazards and climate change increases, it becomes more important to draw lessons learned and insights for replicating and scaling up NbS, especially in coastal areas where their implementation is still limited compared to other environments. This study analyzed NbS case studies across European coastal and estuarine areas to draw key lessons, understand better the current status of implementation, and identify key challenges and gaps. From a total of 59 NbS case studies associated with flooding, erosion and biodiversity loss, results show an increase in NbS implementation since 1990s, but most rapidly between 2005 and 2015. Most of the case studies are hybrid solutions employing wetlands, predominantly located in the United Kingdom (UK) and the Netherlands. Funding of NbS is largely from public sources, and rarely come from a single or a private source. Three-quarters of the case studies reported monitoring activities, but more than half did not disclose quantitative results related to effectiveness against flooding and/or erosion. The need to improve coastal defenses was indicated as the main motivation for NbS implementation over traditional structures, while sustainability was the most mentioned additional reason. Although a variety of co-benefits and lessons learned was identified, clearer descriptions and enhanced details of such information are required. There is a need for tools and strategies to expand knowledge sharing of lessons learned to enable further replication of successful cases in other areas.

No-till farming: prospects, challenges – productivity, soil health, and ecosystem services

Globally, declining soil quality due to soil degradation is of great concern, and directly affects crop production, soil health and sustainability of natural resources. In conventional farming practices, the loss of fertile topsoil via runoff and erosion from arable land is a big concern. In addition, changes in land use and management practices result in loss of soil organic carbon (SOC) stock by −10–59%. The change from conventional till (CT) with residue burning/removal to no-till (NT) farming with residue retention/conservation agriculture (CA) practices have been recognised as important soil management practices for sustaining soil health and reversing land degradation. Worldwide, NT/CA practices are now being adopted on about 180 million ha (i.e. ∼14% of arable land). CA practices promote soil health by increasing organic carbon, and soil aggregation, thus improving infiltration and minimising erosion losses. In addition, CA has the potential to increase SOC sequestration, reduce greenhouse gas (GHG) emissions and help to mitigate global climate change. Among sustainable food production systems, CA is often advocated with a view to increase food production while conserving natural resources and SOC. This special issue ‘No-till farming: prospects, challenges – productivity, soil health, and ecosystem services’ addresses and critically reviews these important issues and aims to foster awareness of NT farming. The collection of 15 papers lucidly covers various facets of NT farming. A summary and salient findings of these papers are provided in this Editorial. NT farming is a promising practice, which not only improves soil physical, chemical and biological health but also enhances carbon sequestration, crop productivity and mitigates GHG emissions through appropriate crop residue and nutrient management strategies. The adage says ‘one size won’t fit all’ or ‘a single recipe will not solve all problem/challenges’, so we need to adopt site-specific NT systems for higher benefits and productivity and sustaining soil health.

The Clean Water Act and biosolids: A 45‐year chronological review of biosolids land application research in Colorado

The 1972 U.S. Clean Water Act set forth the generation of biosolids. In Colorado, biosolids land application research began in 1976 and continues today. Pastureland research suggested that sewage effluent could effectively be land applied to benefit aboveground plant growth and to polish water prior to reaching receiving waters. Forest wildfire-affected ecosystems can also benefit from biosolids applications; application rates of up to 80 Mg ha-1 can lead to greater plant establishment, soil microbial activity, and nutrient turnover and reduced nutrient and heavy metal concentrations in runoff below livestock and USEPA drinking water standards. Long-term (24-yr) observations in oil shale-mined lands showed that biosolids (up to 224 Mg ha-1 ) can have a positive effect on microbial-mediated nutrient cycling and, in turn, on aboveground plant community structure. Biosolids applications of up to 40 Mg ha-1 in high-elevation shrubland ecosystems, dominated by Mo-containing shale deposits, can aid in reducing imbalances between Mo and Cu in soils and plants; excessive plant Mo, when consumed by ruminants, can lead to molybdenosis. Biosolids and lime applications (both at 224 Mg ha-1 ) have been shown to improve long-term reclamation success on acid-generating, heavy metal-containing fluvial mine tailings. Thirty years of grazing land research, focused on soil and aboveground plant benefits, illustrate that soil health and plant productivity can be improved to the greatest extent at biosolids application rates close to 10 Mg ha-1 . Finally, 40 yr of dryland agroecosystem research (a) have helped identify biosolids N fertilizer equivalency (∼8kg N Mg-1 ) and thus dryland winter wheat application rates (e.g., 4.5-6.7 dry Mg ha-1 ); (b) have identified first-year mineralization rates of 25-32%; (c) dispute the "time bomb" theory by showing that plant metal uptake follows an exponential rise to a maximum; (d) showcase economic return to producers via increased wheat grain protein content; (e) suggest that biosolids-borne proteins and their degradation products are labile C and N sources; (f) have led to long-term tracking of micronutrients and heavy metals in soils and revealed that plants-soil concentrations will not lead to groundwater degradation and that plants are safe for human consumption; and (g) have shown that biosolids provide Zn, helping to overcome soil deficiencies and enhancing Zn biofortification in wheat grain. This latter point is important because ∼2 billion people globally suffer from Zn deficiencies. Forty-five years of research in Colorado have proven that biosolids can enhance environmental quality, improve soil health, and produce healthy food products.

UAV-based vegetation monitoring for assessing the impact of soil loss in olive orchards in Brazil

Vegetation cover is one of the most critical factors in soil erosion processes. Notably, olive orchards have been cultivated in shallow and sloping soils, with low vegetation cover and increasing the soil exposure to raindrop impact. In the tropics, considerable care is required to adequately use cover crops to control water erosion in new frontiers of olive plantations. In this context, we proposed a new technique to correlate the cover-management factor (C-factor) with vegetation indices from images obtained by unmanned aerial vehicle (UAV) and evaluate soil erosion losses under natural rainfall. We studied the relationship between different cover indices (vegetation cover index, non-photosynthetic vegetation cover index, and total cover index) with the C-factor of the USLE/RUSLE. This study was carried out in standard erosion plots with different vegetation cover systems associated with olive cultivation. UAV images were classified by Random Forest algorithm, and soil losses were quantified by sampling after each erosive rainfall event. Results showed a good performance in UAV image classification: average user's accuracy of 94% for vegetation class and 91% for bare soil. The Total cover index presented a better performance in predicting soil loss and determining the C-factor for exponential model (R2 = 0.87). UAV-based imaging demonstrates promising potential in monitoring vegetation cover crops and their impact on soil erosion. Total cover index performs better in estimating C-factor and predicting soil loss. However, the result of response surface analysis suggested that the association between total cover index and rainfall erosivity using second-order model presented the best prediction (R2 = 0.98), positive correlation between rainfall erosivity and C-Factor, and negative correlation between C-factor and total cover index and rainfall erosivity.

Effects of different wind directions on soil erosion and nitrogen loss processes under simulated wind-driven rain

“Wind-driven rain” is the main form of natural rainfall. Wind affects runoff, soil, and nutrient loss processes on slopes by changing rainfall characteristics. Wind direction is one of the main factors affecting the falling trajectory of raindrops, raindrop splash angle, and direction of the rainfall erosivity force. However, existing research on soil displacement and nitrogen loss driven by different wind directions and rainfall is still lacking. Based on a simulated wind-driven rain experiment, this study explored the influence of different wind directions (leeward, windward, and crosswind) on runoff, sediment yield, and nitrogen loss on slopes. The results showed that wind direction had a significant influence on runoff, sediment yield, and nitrogen loss in both runoff and sediment. The influence of wind direction on the slope runoff and sediment yield rates was leeward > crosswind > windless > windward. Compared with windless rainfall, the average runoff rate and sediment yield rate under leeward rainfall and crosswind rainfall increased by 6.17%–11.56% and 37.75%–41.58%, and 1.80%–2.40% and 13.31%–18.12%, respectively, while under windward rainfall, they decreased by 5.13%–7.38% and 7.86%–13.02%, respectively. Hydrodynamic parameters are physical parameters that characterize the process of sand-bearing shallow flow acting on surface soil particles. The mean flow velocity and unit stream power affected by the wind direction were ranked: leeward > windless > crosswind > windward. The mean flow velocity and unit stream power under leeward conditions were both 1.31 times those under windless conditions, indicating that leeward wind strengthened the erosion effect of the slope flow on the soil. The mean flow velocity and unit stream power caused by different wind directions may be the main reasons for soil erosion processes. The average nitrogen loss rate in runoff was ranked: windward > crosswind > windless > leeward. The law of nitrogen loss rate in the sediment is consistent with the regularity of the sediment yield rate in all wind directions, which increased respectively by 60.18%–163.86% and 19.39%–69.57% under leeward and crosswind conditions, respectively, and decreased by 10.23%–25.15% under windward conditions when compared to windless treatment. Therefore, when the intensity of wind-driven rain is constant, the impact of wind direction on slope runoff, sediment yield, and nitrogen loss is uncertain and may be either positive or negative. The angle between the raindrop movement direction and the runoff flow direction on the slope changes owing to the influence of different wind directions. This leads to changes in the slope infiltration rate, hydrological characteristics, and soil crusting process, and is one of the main reasons for the difference in soil erosion and nutrient loss rates.

Impact of Lacrimal Gland Extraction on the Contralateral Eye in an Animal Model for Dry Eye Disease.

PurposeAlthough there is still no consensus on the best animal model for dry eye disease research, a model based on lacrimal gland extraction (LGE) model is widely used. In this study, we aimed to investigate the histopathological changes taking place on the contralateral eye after unilateral LGE to determine whether it is useful as a control.MethodsSeven-week-old male C57BL/6 mice were divided into naive control, environmental chamber model, and LGE groups. Corneal fluorescein staining was scored to quantify the severity of damage. Morphological changes in the cornea, conjunctiva, and lacrimal gland (LG) were determined by hematoxylin and eosin staining and compared to those on naive control animals.ResultsCompared to naive subjects, the unilateral LGE model showed enhanced corneal erosion scores and loss of conjunctival goblet cells, not only on the ipsilateral but also on the contralateral side. These changes in the ocular surface became more pronounced in a time-dependent manner. Furthermore, loss of LG acinar cells and leukocyte infiltration were detected in the contralateral LGs of the LGE model.ConclusionsConsidering the changes observed in the ocular surface and LGs, the contralateral side of the LGE model may not offer proper control conditions for the experimental comparison of the effects of dry eye disease in vivo. There may be regulatory feedback or crosstalk system between both eyes activated in response to LGE.

Persistence of arable Chernozems and Chernic Rendzic Phaeozems in the eroded undulating loess plateau in Central Europe

Chernozems are considered to degrade under the temperate humid climate of Central Europe, particularly in the arable and undulating areas and, thus, exposed to erosion. The present study was carried out in the loess-covered Proszowice Plateau (southern Poland), which was found to have a continuous cover of chernozemic soils in the past. Ten soil profiles located in two neighbouring slope catenas have documented the sequence of chernozemic and non-chernozemic soils (Chernozems, Phaeozems, and Calcisols), impacted by water erosion under intense arable land use and spatially dependent on the relief intensity. Soils in elevated, strongly inclined (and, thus, intensely eroded) slope positions lost their mollic horizons and gained the features of Calcisols. However, soils in elevated, slightly inclined positions preserved the morphological and physicochemical features of Chernozems, even if their chernic horizons were thinned to a ploughing depth. Also the colluvial soils located on the short slopes, in close proximity to eroded hilltops, are saturated with secondary carbonates throughout the profile and retain their chernozemic features (Calcic Chernozems). Whereas, the colluvial soils located on the long, slightly inclined slopes, at a large distance to eroded hilltops, are deeply leached from carbonates and meet the criteria of Haplic Phaeozems (in well drained sites) or Gleyic Phaeozems (in poorly drained foothills and depressions). Moreover, the Chernic Rendzic Phaeozems with thick mollic/chernic horizons are present in elevated (thus expectedly eroded) parts of hills with thin loess overlying the limestone bedrock. The presence of chernic horizons in soils threatened by erosion indicates that the persistence of Chernozems and Chernic Rendzic Phaeozems is possible in undulating arable lands threatened by erosion in temperate humid climate of Central Europe if supported by sustainable agriculture, preventing soil erosion and organic matter loss from humus horizons.

Evaluating the Effectiveness of Mulching for Reducing Soil Erosion in Skid Trail Switchbacks

Forest operations can lead to increased runoff and soil loss on roads and skid trails. The aim of this study was to evaluate the effectiveness of two erosion control treatments applied to different segments of skid trails following six natural rainfall events. A total of 162 plots 10 m long by 4 m wide were established in a Hyrcanian deciduous forest to assess soil runoff and soil loss following ground-based harvesting traffic. The experimental setup consisted of three levels of traffic intensity (three, eight and 16 skidder passes), two levels of slope gradient (≤20% and >20%), three classes of curvature (narrow = high deflection angle, 60°–70°; wide = low deflection angle, 110°–130°, and straight trail segments), and three classes of mulch cover (bare soil, sawdust cover, and rice straw cover). Each treatment combination was replicated three times, yielding 972 soil samples. The average surface runoff volume and soil loss differed significantly between the switchbacks and the straight trail segments and depended strongly on the degree of curvature, with severity of adverse effects increasing with curve tightness. Mulch cover treatments had a significant ameliorating effect on the surface runoff volume and soil loss throughout the skid trail. The average runoff and soil loss from the skid trails treated with sawdust cover (SC) (0.24 g m-2 (mm) and 0.49 g m-2, respectively) were lower than on trails covered with rice straw (RSC) (0.45 g m-2 and 1.19 g m-2, respectively), which were, in turn lower than on untreated bare soil (BS) trail segments (0.70 g m-2 and 2.31 g m-2, respectively). Surface runoff volume was significantly positively correlated with soil loss and both were positively correlated with dry bulk density and rut depth and negatively correlated with litter mass, total porosity, and macroporosity. Surface cover is a successful measure for controlling erosion losses following skidding disturbances, particularly in the switchback curves of trails on steep slopes where erosion potential is high.

Applying Analytic Hierarchy Process for Identifying Best Management Practices in Erosion Risk Areas of Northwestern Himalayas

Despite the growing importance of soil and water conservation and watershed development projects as an approach to rural development and natural resource management, there has been relatively little research on devising site-specific best management practice (BMP) to check the soil erosion losses within permissible limits, especially in hilly regions. For a sustainable watershed management programme and implementation, site specific BMPs assume importance and hold the promise of making conservation planning and watershed management simpler and more effective. The study was attempted to develop a methodology to obtain BMPs, aiming to reduce the erosion losses in erosion risk areas of the northwestern Himalayas by employing Analytic Hierarchy Process (AHP). The AHP technique was employed to prioritise the potential technologies and select the BMP suitable for a particular land area. The prioritization of technologies was performed with four criteria viz. soil erosion resistance, cost, benefit, maintenance and environment friendliness of conservation measures. The soil erosion scenario of the study area located in the northwestern Himalayas was generated with each selected measure in a SWAT model using DEM, land use maps, a soil map and climate data of the study area. Then, the resultant erosion scenario of the conservation measures was compared and used for the AHP analysis. However, other criteria were assessed based on the judgement of a group of experts as well as farmers. In this study, four conservation measures, viz. Bench Terraces (BT), Vegetative Barrier (VB), Contour Farming (CF) and Zero Tillage + Live Mulch (ZL), were considered for BMP selection. Three scenarios, viz. experts’ judgement, farmers’ opinions and combined expert and farmer opinion, were analyzed to uncover the BMP for the different zones. The result revealed that experts and farmers unanimously preferred ZL as a BMP because of its low-cost implementation value and lower maintenance requirement while significantly controlling the erosion level as well as being environment friendly. The BT was the second most preferred technology for the study area. However, BMP was recommended for different zones having high to very severe erosion (soil loss > 10 t/ha/yr). Therefore, ZL was recommended for the areas with low altitude, whereas BT was recommended for the areas having high slopes because of its high capability for erosion control in the high slopping area. The methodology will act as a useful strategy for decision makers to prioritize the technology and recommend the best management for any region after considering suitable criteria. Future work may consider more criteria for inclusion to thus recommend the technology for a region in a more realistic way.

Problems of spatially distributed quantitative evaluation of soil erosion losses

Formulation of the problem. Water erosion of soils is the most widespread and dangerous soil degradation process in Ukraine. The development of an effective system of soil protection measures requires the use of spatially distributed mathematical models of soil erosion losses. This, in turn, highlights the problem of spatially distributed source data, which adequately reflect the spatial differentiation of factors of the erosion process, among which the main one is the relief. The purpose of the article. Assessing the adequacy of available spatially distributed source data, including cartographic and freely distributed global digital elevation models (DEMs), for spatially distributed quantitative assessment of soil erosion losses at the local level of territorial coverage is the aim of the article. Assessing from this point of view the scale of the original cartographic data, different global DEMs and their spatial resolution, as well as the degree of spatial generalization of the original data. Materials and methods. The solution of the set tasks was performed by the method of simulation modeling with the use of physical-statistical GIS-realized mathematical model of soil erosion-accumulation, developed at Odessa I. I. Mechnikov National University. Source data arrays were tested with DEMs SRTM90 and SRTM30 with a spatial resolution of 3 and 1 angular seconds, respectively, and AW3D30 with a spatial resolution of 1 angular second, as well as with cartographic DEMs based on topographic maps of scale 1:10000 and 1:25000. For testing the initial data, three test plots with an area of 2.67, 0.59 and 0.21 km2 were selected. The plots are located in the Balta district of Odessa region on the southern spurs of the Podolska upland. Results. It is established that freely distributed global digital elevation models SRTM and AW3D30 in the conditions of flat terrain do not always allow to adequately display the structure of slope runoff and, accordingly, to correctly perform calculations of soil erosion losses. The maximum deviation of the average soil erosion losses calculated for the test plots using global DEMs from the soil losses calculated using the reference DEM for SRTM30 and AW3D30 was 27%, for SRTM90 – almost 70%. The distribution of soil losses over the area of test plots obtained using different global DEMs differs even more. When using DEM based on topographic maps, reducing the scale of the original maps from 1: 10000 to 1: 25000 leads to a decrease in the average value of soil erosion losses by about 20% due mainly to reducing the magnitude and area of distribution of maximum soil losses, and on slopes of complex shape also due to changes in the area of accumulation zones. The degree of spatial generalization of the initial data significantly affects the results of the assessment of soil erosion losses both in relation to the average values and their distribution over the area. For small areas, the use of raster cells larger than 50 m is impractical. Scientific novelty and practical significance. It has been shown for the first time that in the conditions of flat terrain at the local level of spatial coverage, the freely distributed global DEM SRTM and AW3D30 are not always hydrologically correct. The reasons and conditions of violation of this correctness are specified. It has been established that the global DEM AW3D30 has local instrumental errors that may make it impossible to use it. The most realistic values of soil erosion losses are provided by DEM SRTM with a spatial resolution of 1 angular second.

Effects of Hydroxypropyl Methylcellulose (HPMC) on the Reinforcement of Sand by Microbial-Induced Calcium Carbonate Precipitation (MICP)

Microbial-induced calcium carbonate precipitation (MICP) is a new technology used for reinforcing soils through microbial mineralization. However, the existing MICP treatment technology is more suiTable for deeper soils due to its high permeability. In this study, HPMC, a cohesive material combined with Sporosarcina pasteurii-induced calcium carbonate precipitation was used to improve the surface layer of the soil. It was also tested in different contents of bacterial solutions and cementation solutions and with a different number of MICP treatments, and was analyzed and discussed by measuring the surface layer strength, calcium carbonate content generated in the crust, rainfall erosion resistance, wind erosion resistance, and ammonia retention rate of the specimens. The microstructure of the samples was investigated by XRD and SEM. It was shown that the addition of HPMC and increasing the number of MICP treatments were effective in the increase in the calcium carbonate content in the surface crust, but had no effect on the total amount of induced calcium carbonate. The combination of HPMC addition and MICP technology can effectively reduce rainwater scour loss and wind erosion loss, and increase its rainfall erosion resistance and wind erosion resistance. Rainfall losses were reduced by up to 30% in specimens treated with HPMC for MICP technology. When the wind speed was 12 m/s, the maximum mass loss rate of the specimens treated with HPMC for MICP was only 0.828%. The addition of HPMC can effectively improve the ammonia absorption rate and reduce the release of ammonia in the process of MICP technology, which is of great significance for environmental protection. The microstructure showed that the addition of HPMC and the increase in the number of treatments using MICP technology can make the surface structure of the specimens more compact, and the calcium carbonate can more effectively fill the pores and cement the soil particles, while the addition of HPMC may not change the calcium carbonate crystal type.

Fine root densities of grasses and perennial sugarcane significantly reduce stream channel erosion in southern China

Stream Channel (SC) erosion results in immense soil and nutrient losses and eutrophication of downstream lakes and rivers. Among other factors, the lack of vegetation cover within SCs and on adjacent soils can accelerate soil and nutrient losses. The combined impact of perennial sugarcane plantation and grass cover on increasing SC erosion losses have not been previously studied. Current study determined SC erosion and associated nutrient losses and clarified the effect of grass roots within SCs and the ratooned sugarcane grown on adjacent lands in Nala watershed in southern subtropics of China. Six SCs in two sub-watersheds (SW1 and SW2) surveyed after revegetation during 2019 were compared with initial survey conducted in 2017 and 2018. The SC erosion was significantly (P < 0.05) reduced by 84.2% (5.19 ± 2.16 Mg ha−1) in entire watershed in 2019 compared to 2018 (43.9 ± 15.2 Mg ha−1). It notably decreased by 99.23% and 96.50% in SC-1-3 at SW1 and SC2-3 at SW2, respectively. Total N and P losses decreased by 84.9% and 82.5%, respectively, in entire watershed. The decreases in SC erosion and nutrient losses are attributed to increasing vegetative cover (R2 = 0.7543, P < 0.001), and grass root densities of <1 mm (R2 = 0.7543, P < 0.001), 1–2 mm (R2 = 0.7051, P < 0.001) and >2 mm (R2 = 0.5746, P < 0.001). Principal component regression analysis confirmed that root densities of SC grasses, perennial sugarcane, and organic matter had positive impacts on controlling SC erosion and consequent nutrient losses.

An Anthropocene chronosequence study on upland soils in the northeastern USA

Intensive land use from agricultural activities fundamentally affects the physical structure and nutrient cycling of soils and can lead to increased erosion of sediment that gets stored downslope in legacy deposits. The northeastern USA provides the opportunity to study anthropogenic-induced changes to soils, with a well-documented ~300-year history of land modification. In this study, we investigate impacts on upland soils in northeast Connecticut at two sites used extensively in the 17–20th centuries that are now abandoned and forested along with two modern agriculture sites. We use stone walls present in LiDAR and aerial imagery from 1934 to 2019 to develop an Anthropocene chronosequence with four land use classes (T0, T1, T2, and T3) that vary in terms of duration of land use and time since abandonment. The two abandoned sites differ primarily in terms of average hillslope gradients, and we use transects at the steeper site to investigate the effect of catena position on sediment mobilization and downslope changes. Soil profiles within each class were described and sampled for standard soil analyses and trace metals using pXRF to address the processes of erosion and mixing in the soils. At both sites, A horizon thicknesses increase and B horizon thicknesses decrease with increasing land use duration. The consistent depth to the C horizon across all classes, lack of soil truncations and accumulation of sediment at the base of slopes, and inventories and patterns of Pb in soil profiles all suggest land use impacts led to soil mixing and redistribution along hillslope catenas, but no substantial erosion and soil loss. Therefore, depositional areas such as wetlands, floodplains and millponds in low relief deglaciated landscapes may not contain large quantities of legacy sediment. Furthermore, widely available LiDAR and aerial imagery datasets have the potential to scale up the chronosequence approach and soil impacts described here.

Can mulch be effective in controlling exotic grasses and promoting natural regeneration in ecological restoration?

Mulching use in agriculture has been known since 1802 as the practice of spreading dry leaves and straw on the soil to prevent erosion and water loss. Our study evaluated the mulch effectiveness in the establishment of regenerating seedlings and its contribution to the control of exotic grasses. The studies were carried out in an ecological restoration area in the municipality of Itapira-SP. The treatment with mulching consisted in chemical desiccation with glyphosate herbicide application, keeping the dry grass on the ground. In the control treatment, after chemical weeding, the grass was removed with manual mowing, exposing the soil. Eight months after implantation, we sampled all regenerating seedlings in 100 plots of 50 x 50 cm in each treatment. We considered as seedlings all individuals of tree species less than 100 cm tall. We calculated richness, abundance, similarity, and the relationship of the frequency of seedlings to the height of the mulch. We sampled eight species with 42 seedlings, with only one not identified. The highest abundance and species richness were found in the treatment with mulch (n = 34 individuals; eight species), the most abundant being Schinus terebinthifolia Raddi (14 individuals) followed by Solanum mauritianum Scop. (11 individuals), and Platypodium elegans Vog. (three individuals). The presence of exotic grasses was lower in the plots of the mulching (13%) compared to the control treatment (67%). The highest frequency of seedlings was obtained with mulch height from 21 to 37 cm. We suggest that adaptive management practices, such as the use of the mulching technique, can be implemented in ecological restoration areas, because they favor the natural regeneration of native seedlings and can contribute to the control of exotic grasses, but the height of the layer must be controlled.

Occurrence and erosion susceptibility of German Pelosols and international equivalents

AbstractBackgroundPelosols are the Soil of the Year 2022 in Germany, Austria and Switzerland. They represent soils with a high clay content (≥45%) in the diagnostic P horizon. Pelosols are nutrient‐rich, have a strong capacity for swelling and shrinking, have a challenging water balance with a high portion of nonplant available water and are affected by high traction. Such special characteristics make them challenging soils under agricultural management.AimsThe occurrence, land use management and soil erosion risk of Pelosols in Germany were investigated and compared to their clay‐rich soil counterparts on a global scale.MethodsWe intersected soil maps of the German and international digital soil mapping with soil erosion data.ResultsA high percentage (63%) of Pelosols in Germany are under agricultural use, from which two‐thirds are arable farming. Simultaneously, Pelosols have a high risk for soil erosion by water and are the fourth most endangered soil type compared to all soil types in Germany. The average soil erosion loss of Pelosols used for agricultural practices assessed by the Revised Universal Soil Loss Equation (RUSLE) is 2.24 t ha−1 year−1 compared to an average erosion loss of all agriculturally used soils in Germany of 1.65 t ha−1 year−1. From an international perspective, Pelosols in Germany are mostly mapped as haplic Cambisols or haplic Luvisols, as they do not necessarily meet the diagnostic properties of the clay‐rich Vertisol soil type. Most Vertisols are classified as Pelosols, but Pelosols do not necessarily fulfil the diagnostic criteria of Vertisols. Vertisols on a global scale have an even higher soil erosion risk than Pelosols in Germany (3.5 t ha−1 year−1).ConclusionsPelosols and Vertisols, despite their high percentages for agricultural use, have a high soil erosion risk compared to other soil types and thus need special care under agricultural use and adapted protective land use management.

Improvement of Pain Management by Nefopam in a Rat Adjuvant-Induced Arthritis Model.

IntroductionThe adjuvant-induced arthritis (AIA) model is widely used in research to investigate arthritis pathogenesis. Hind paw inflammation is the main outcome in this model with high loss of mobility function partly related to pain. However, analgesics such as non-steroidal anti-inflammatory drugs or opioid drugs interfere with the inflammation process related to arthritis, thus reducing their beneficial use in this model. Therefore, we investigated the effect of nefopam on arthritis development in order to improve pain management in the AIA model.MethodsFemale Lewis rats were randomly divided into two groups, and each group received an injection of Mycobacterium butyricum on defining day (D) 0. At D6, rats (n = 10) received nefopam (intraperitoneally or orally) or NaCl 0.9% IP or 1% sucrose in water (n = 5 for each). Rats were monitored with the arthritic index (AI) and ankle circumference. Pain was assessed by scoring based on behavioral indicators. Histology, RT-qPCR, and microcomputed tomography were performed.ResultsThe clinical parameter AI and ankle circumference were not different in both groups at various time points. However, pain score was significantly lower in the nefopam group at the early stage of the disease. At a later stage of the disease, inflammation was mildly lower whereas bone erosion and bone loss parameters increased in the nefopam group.ConclusionNefopam provided a slight reduction in the level of pain at the arthritis onset without reducing arthritis severity and bone loss in the rat AIA model. However, it should be administrated orally for a shorter period to avoid inflammation reduction in the long run.

Priorities for UK soils

The predominance of agriculture in the UK is a major factor determining the main soil threats and priorities. The main soil degradation processes are compaction, erosion and soil organic matter loss, while soil contamination and sealing is also a significant issue. Agricultural land take threatens soil ecosystem services but receives little attention. An urgent need to tackle climate change has resulted in a new direction for land use and soil policy.

Effect of copper mining on vegetation disturbances in and out of Oyu Tolgoi mining site

Since 2005, the mining sector has been a vital part of Mongolia's economy. This sector is one of Mongolia's most important sources of revenue. Primary outputs of Mongolia's mining industry are copper, gold, and coal. On the other hand, mining has a negative impact on the environment causing soil erosion, noise pollution, water pollution, and biodiversity loss. The Oyu Tolgoi copper mine is located in a semi-arid zone in the Mongolian Gobi. The impact of mining was investigated by sampling eight plots both in and out of this giant mining site. Vegetative cover, species richness, biomass, and basal gap of perennial plants were compared within and outside the perimeter of the Oyu Tolgoi mining site. The mining sites have a harmful impact on the environment. According to our findings vegetation cover, species richness, biomass, and perennial plant gaps were not different between the paired plots outside and inside of the mining site. Mining activities had little effect on vegetation, according to the findings.

Assessment of Land Use and Land Cover Changes on Soil Erosion Using Remote Sensing, GIS and RUSLE Model: A Case Study of Battambang Province, Cambodia

Soil erosion causes land degradation which negatively impacts not only natural resources but also livelihoods of people due to low agricultural productivity. Cambodia is prone to soil erosion due to poor agricultural practices. In this research we use Battambang province as a case study to quantify impact of land use and land cover change (LULC) on soil erosion. This study assessed the impact from LULC changes to soil erosion. LULC change maps were analyzed based on Landsat satellite imagery of 1998, 2008, and 2018, computed in QGIS 6.2.9, while the soil erosion loss was estimated by the integration of remote sensing, GIS tools, and Revised Universal Soil Loss Equation (RUSLE) model. The results showed that the area of agricultural land of Battambang province significantly increased from 44.50% in 1998 to 61.11% in 2008 and 68.40% in 2018. The forest cover significantly decreased from 29.82% in 1998 to 6.18% in 2018. Various soil erosion factors were estimated using LULC and slope. Based on that, the mean soil loss was 2.92 t/ha.yr in 1998, 4.20 t/ha.yr in 2008, and 4.98 t/ha.yr in 2018. Whereas the total annual soil loss was 3.49 million tons in 1998, 5.03 million tons in 2008, and 5.93 million tons in 2018. The annual soil loss at the agricultural land dramatically increased from 190,9347.9 tons (54%) in 1998 to 3,543,659 tons (70.43%) in 2008 and to 4,267,439 tons (71.91%) in 2018 due to agricultural land expansion and agricultural practices. These losses were directly correlated with LULC, especially agricultural land expansion and forest cover decline. Our results highlight the need to develop appropriate land use and crop management practices to decrease land degradation and soil erosion. These data are useful to bring about public awareness of land degradation and alert local citizens, researchers, policy makers, and actors towards land rehabilitation to bring the area of land back to a state which is safe for increasing biodiversity and agricultural productivity. Measures to reduce or prevent soil erosion and the use of conservation agriculture practices, along with water and soil conservation, management, agroforestry practices, vegetation cover restoration, the creation of slope terraces, and the use of direct sowing mulch-based cropping systems should be considered.