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Changes in soil phosphorus (P) distribution and budget critically impact the sustainability of agricultural systems. Yet, few studies have examined the long-term evolution of cropland (and crop-specific) P budget and use efficiency (PUE) at a grid level. Here, we conducted a comprehensive evaluation of the cropland P budget and PUE and their human-environmental drivers in China during 1992–2018 at a spatial resolution of 0.1°. The results reveal a significant shift in China's cropland P budget from a deficit of −3.70 Tg P yr−1 in 1992 to a surplus of 0.31 Tg P yr−1 in 2018, mainly driven by increased fertilizer application and decreased soil erosion by water. The concurrent national average cropland PUE initially decreased from 0.51 in 1992 to 0.34 in 2003, but afterwards increased to 0.39 in 2015. An environmental-Kuznets-curve-like (EKC) relationship was identified between the national average P budget (inverted U-shaped) or PUE (U-shaped) and per capita GDP in China, with the turning point occurring in 2013 for the previous and at per capita GDP of US$8.85 k (constant 2017 US$) for the latter. But PUE had been well below a threshold of 0.40 at the national level after crossing the turning point and showed a considerable trend divergence among crops, particularly for cash ones. Spatially, northern and northwestern China exhibited high positive P budget but achieved relatively low PUE in the 2010s. Crop leaf area, irrigation, fertilizer input, and precipitation were identified as the most important factors determining the multi-year spatial pattern of P budget, while fertilizer input, temperature, and residue return played a dominant role in regulating PUE. Our findings highlight the need for a long-term commitment to regionalized and crop-specific synthetic management practices for controlling P inputs and minimizing P loss in the context of global change in China. [Display omitted] • Grid-level phosphorus budget and use efficiency are quantified for croplands and crops in China. • An environmental Kuznets-curve-like relationship exists between the national phosphorus budget or PUE and per capita GDP. • Crop-specific phosphorus use efficiency is calculated and divergent trends are found among different crops. • The critical environmental and anthropogenic factors influencing spatial patterns of P budget and PUE are clarified. [ABSTRACT FROM AUTHOR]

The Yanhe Watershed, emblematic of the loess hilly-gully landscape and ecological fragility in China's Loess Plateau, has experienced significant soil erosion and extensive soil-water conservation measures. To elucidate sediment dynamics and identify influencing factors in this region from 1960 to 2020, a novel multidimensional multiscale complexity analysis (MMCA) method was developed, based on entropy and complexity perspectives. This method integrated the refined composite multiscale fuzzy entropy (RCMFE) with multidimensional complexity analysis, offering a nuanced evaluation of sediment complexity and its implications for water resource management and ecological restoration. The findings revealed two distinct stages of sediment complexity variations: 1971–1988 and 2000–present. During the first period, the operation of the Wangyao Reservoir predominantly influenced sediment dynamics, initially reducing sediment complexity through sediment interception but later increasing it during discharge phases, particularly at larger scales. After 2002, extensive vegetation restoration efforts significantly reduced sediment complexity but raised concerns about long-term ecosystem resilience. Over the past decade, urbanization and climate change have exacerbated sediment instability, especially over semi-annual scales. This study advocates for management strategies that prioritize ecosystem sustainability and address the challenges posed by climate change and urbanization, facilitating improved soil and water conservation efforts in the Yanhe Watershed and similar regions in the Loess Plateau. • MMCA was proposed to analyze sediment complexity using RCMFE. • MMCA offers a novel way to explore driving mechanisms behind sediment dynamics. • Reservoir operations altered sediment complexity across various temporal scales. • Vegetation restoration reduced complexity but raised long-term resilience concerns. • Urbanization and climate change intensified sediment instability at larger scales. [ABSTRACT FROM AUTHOR]

United Nation Sustainable Development Goal 15.3 make a note of growing significance of management and restoration strategies for degraded land, and advocating globally for collaborative frameworks of innovative applied research and policy. Present study, quantified the impacts of the staggered contour trenching (SCT) technology in conjunction with silvi-pasture production system on regulating and provisioning ecosystem services of degraded mini-watersheds. Impacts of the SCT on hydrologic regulating ecosystem services were quantified by employing the paired watershed approach. Concept of watersheds with and without treatments was employed for computing non-hydrologic regulating and provisioning ecosystem services of the SCT in conjunction with silvi-pasture system. Results of analyses revealed that the SCT density of 505 trenches ha−1 had the highest reduction in the hydrologic regulating services namely, mean annual runoff event, runoff amount and soil loss, which were 35.5, 63.3, and 3.73%, respectively followed by 378, and 186 trenches ha−1. The highest improvement in the effective rainfall (9.9%) and effective rainfall efficiency (15.0%) was also with 505 trenches ha−1. The SCT density of 505 trenches ha−1 had retained silt 23.1 and 1.2 times higher than that of 378 and 186 trenches ha−1. The values of the post-treatment non-hydrologic regulating services of 505 trenches ha−1 were many folds higher compare to other trenching densities. Improvement in the non-hydrologic regulating services of the available -nitrogen, -potash and -potassium, and soil organic carbon values of the post-treatment of 505 trenches ha−1 were 36.7, 44.2, 25.8, and 25.0% than their pre-treatment values, respectively. Provisioning ecosystem services in term of the yields of the wood biomass of the Acacia nilotica and the Cenchrus ciliaris were the highest with 505 trenches ha−1 than the control (no trench) by 166.2 and 21.5%, respectively. Study indicated that 505 trenches ha−1 SCT density in the silvi-pasture production system was the best practices in conserving and maintaining the degraded land ecosystem services. These findings would be very supportive to the policy makers and degraded land managers for reclaiming and improving the sustainability and ecosystem functioning of the degraded land ecosystem for achieving the SDG 5.3 and maintaining the land degradation neutrality. [Display omitted] • Effects of three trenching densities on silvi-pasture system were analyzed. • Provisioning ecosystem service of system was the highest with 505 trenches ha−1. • Highest reduction of hydrologic regulating ecosystem services was with 505 trenches ha−1. • Post treatment non-hydrologic services of 505 trenches ha−1 were higher many folds. [ABSTRACT FROM AUTHOR]

Persistent soil erosion poses a significant threat to water quality, ecosystem viability and soil health in many regions of the world. Addressing this challenge requires a comprehensive understanding of local soil erosion rates, including the identification of vulnerable areas, to facilitate effective and integrated environmental management. In East Africa, however, many affected regions are data poor and lack measured hydrological data from which soil erosion estimates can be derived. This study used the physically based Revised Universal Soil Loss Equation (RUSLE) model to estimate the annual rate of soil erosion in the transboundary Sio-Malaba-Malakisi catchment, straddling Kenya and Uganda. Soil erosion events were quantified by integrating input factors derived from physical datasets using a Geographical Information System (GIS). The Analytical Hierarchy Process (AHP) technique was then used to assess the importance of selected physical factors influencing the soil erosion process in order to identify regions of increasing environmental vulnerability. The results obtained indicate a wide range of soil erosion rates across the region, with an estimated mean annual rate of 250 t ha−1 yr−1 for the whole catchment. Upstream areas characterized by intensive agricultural activity had erosion rates of up to 2000 t ha−1 yr−1, while downstream areas recorded erosion rates below 600 t ha−1 yr−1. Areas with intensive agriculture, unprotected soils, and a soil loss tolerance value above 12 t ha−1 yr−1 were found to be most vulnerable. Rainfall and vegetation cover were identified as key factors influencing erosion susceptibility. Regions with soil erosion rates above 50 t ha−1 yr−1 were identified as high priority regions for targeted soil and water conservation measures. The identification of vulnerability zones, including the classification of their severity, provides an opportunity to prioritize sustainable environmental management interventions; a process that can be replicated for such affected regions elsewhere. [Display omitted] • The integration of RUSLE, AHP and GIS improved the analysis of soil erosion risk and vulnerability. • More than 60% of the transboundary catchment area was classified as vulnerable to soil erosion. • Soil erosion estimation in transboundary regions provides opportunities for policy development. [ABSTRACT FROM AUTHOR]

Effective regulation of land-use activities in steepland areas is crucial to protect downstream ecologies and human life as intense rainfall disturbances become more frequent globally. In Aotearoa New Zealand extensive synchronous clear-cutting of Pinus radiata monocultures on steep convergent landforms, and associated earthworks, causes ongoing accelerated erosion, excessive sedimentation, and debris-laden landslides after adverse weather events. This study examines the implementation of national forestry regulations established in 2018, which also enable regional councils to create more stringent rules to protect aquatic ecosystems. All sixteen councils were surveyed in 2021 and 2022 for stringency in planning provisions; and four regions seriously affected by Cyclone Gabrielle in 2023 were resurveyed in 2024. The cyclone caused loss of human life and calamitous damage to housing, infrastructure, and productive land uses from floods exacerbated by clearcut logging debris. All councils had administratively adopted the national regulations into their existing freshwater and coastal resource management plans. Twelve councils retained existing rules that conflicted with the regulations, but these rules do not protect all regionally significant aquatic ecosystems nor minimise landslide risks. No council, except Gisborne, had instigated the expensive and lengthy statutory resource management plan change process, nor taken a 'strategic and principled' approach to develop more stringent regulations, such as tougher restrictions on clear-cutting, earthworks, and replanting on steep erosion-prone convergent landforms to protect aquatic ecosystems and vulnerable communities. The government did tighten the management of logging debris after the cyclone, but the national regulations remain ineffective in addressing clear-cut practices maladaptive to intense rainfall and continue to permit replanting on convergent landforms. The regulations need urgent amendment to require councils to develop and implement a strategic and principled approach to stringency to better protect aquatic ecosystems, human life, economic livelihoods, and public infrastructure. Water quality monitoring is also currently inadequate, as no council systematically monitors the effects of forestry activities on sedimentation rates, which inhibits the ability to compare across and between regions. Foresters are not required to monitor water quality, which also stymies assessments of compliance and policy effectiveness. Councils regularly monitor rivers, lakes, and estuaries, but rarely the effects of individual land uses. This means that sediment or other contaminants cannot be parsed to different land use activities, undermining attempts to set catchment limits. It can also take decades at current monitoring levels to defensibly show any water quality improvements after changes to land use regulations. The current environmental limits approach of setting individual water quality attribute targets is highly unlikely to drive changes to maladaptive and ecologically degrading land uses. A new environmental management approach is needed that prohibits or effectively constrains hazardous and adverse activities. • Intense rainfall elevates landslide risk after clear-cutting plantation forests on steeplands. • Restrictions on harvest area, earthworks and replanting can mitigate risks to local communities. • Neoliberal regulators may prefer flexible environmental standards over preventative rules. • Without monitoring by foresters or regulators, standards cannot be analysed for effectiveness. • Regulators may not have data to defend imposing more stringent rules on maladaptive practices. [ABSTRACT FROM AUTHOR]

Sloping farmland increases soil erosion, but little is known about how soil erosion impacts microbial structures and functions in sloping farmland. Using high-throughput sequencing, we conducted a six-year in-situ experiment with gradients of 0° (CK), 5° (S1), 10° (S2), and 15° (S3) to investigate the effects of sloping farmland on soil microbial diversities, compositions, and functions related to nitrogen and carbon resource acquisition. The results showed that the S1, S2, and S3 treatments significantly decreased SOM and NO 3 − levels by 33.0%∼47.3% and 37.0%∼49.6%, respectively, in comparison to the CK treatment. The S1, S2, and S3 treatments had similar impacts on diversities and compositions of bacterial and fungal communities. Moreover, the S1, S2, and S3 treatments had same enriched and depleted core microbiota. Long-term sloping cultivation filtered these core microbiota mainly by reducing SOM and NO 3 − and increasing AK and AP. Compared with the CK treatment, the S1, S2, and S3 treatments significantly reduced the relative abundances of potential functions of nitrogen fixation, hydrocarbon degradation, and fermentation by 46.9%∼54.5%, 74.7%∼83.5%, and 28.1%∼54.1%, respectively. Sloping treatments reduced functions related to nitrogen fixation and soil hydrocarbon degradation mainly because the loss of SOM reduced the relative abundances of core microbiota. Generally, long-term sloping cultivation reduced core microbiota related to nitrogen fixation and soil hydrocarbon degradation mainly due to the loss of SOM. Our findings provided implications for the management and reclamation of sloping farmland. • Long-term sloping cultivation significantly decreased soil organic matter by 33.0%∼47.3%. • Sloping gradients within 5°∼15° similarly impacted microbial diversities and functions. • Long-term sloping cultivation reduced nitrogen and carbon resource acquisition. [ABSTRACT FROM AUTHOR]

Cultivation of sloping land is a main cause for soil erosion. Conservation practices, such as soil and stone terraces, may reduce the impacts of erosion but their impacts on soil microbial diversity and functioning related to carbon (C) and nutrient metabolisms remain unclear. This study was conducted to evaluate the effects of slope gradients (5°, 8°, 15°, 25°) and conservation practices (cultivated, uncultivated, soil terrace, and stone terrace) on bacterial and fungal diversities, metagenomic and metabolomic functioning associated with basic soil properties. Our results showed that steep slopes at 25° significantly decreased soil pH, silt percentage, and bacterial and fungal abundances, but that soil and stone terraces increased soil organic C (SOC), silt and clay contents, and fungal abundance compared to sloping cultivated lands. In addition, soil and stone terraces increased both bacterial and fungal alpha diversities, and relative abundances of Crenarchaeota, Nitrospirota, and Latescibacterota, but reduced the proportions of Actinobacteriota and Patescibacteria, thus shifting microbial beta diversities, which were significantly associated with increased SOC and silt content. For metagenomics, soil and stone terraces greatly increased the relative abundance of functional genes related to Respiration, Virulence, disease and defense, Stress response, and nitrogen and potassium metabolisms, such as Denitrification and Potassium homeostasis. For soil metabolomics, a total of 22 soil metabolites was enriched by soil and stone terraces, such as Lipids and lipid-like molecules (Arachidonic acid, Gamma-Linolenic acid, and Pentadecanoic acid), and Organoheterocyclic compounds (Adenine, Laudanosine, Methylpyrazine, and Nicotinic acid). To sum up, soil and stone terraces could reduce some of the negative impacts of steep slope cultivation on soil microbial diversity as well as their metagenomic and metabolomic functioning related to C and nutrient metabolism useful for soil health improvement, potentially bolstering the impact of sustainable practices in erosion hotspots around the world. [Display omitted] • Steep slopes significantly decreased bacterial and fungal abundances. • Soil and/or stone terraces increased bacterial and fungal alpha diversities. • Terraces shifted microbial communities from oligotrophic to copiotrophic groups. • Microbes in terraces used more energy for self-growth or improving competitiveness. • Lipids and organoheterocyclic compounds were enriched by soil and stone terraces. [ABSTRACT FROM AUTHOR]

Sediment transport is a complex, multi-dimensional process. With the advancement in computing power and sophistication of computer applications over recent decades, it has become possible to conduct detailed analysis and simulations of soil erosion and sediment transport. The primary objective of this study was to examine and predict the potential influence of human activities on sediment transport. This was achieved by analyzing sediment transport in the Saskatchewan River beneath the E.B. Campbell Dam and in the Saskatchewan River Delta. The Hydrologic Engineering Center's-River Analysis System (HEC-RAS) was deployed to ascertain the sediment transport capacity and estimate erosion, sedimentation, and riverbed changes. Cross-sectional data, flow data, and sediment data were used in conjunction with HEC-RAS. The simulation results reveal that sediment transport below the E.B. Campbell Dam is limited, leading to notable sediment erosion. The selected study area has witnessed significant erosion during high-flow periods, particularly in the event of floods. Between 2012 and 2019, the riverbed elevation at the selected survey site decreased by approximately 0.45 m. The study findings corroborate that the Saskatchewan River and its delta have been impacted by human activities. Potential erosion and deposition below the E.B. Campbell Dam have been simulated for the selected site. The aim is to provide decision-makers or related stakeholders with insight into how dam operations can be adjusted to decrease erosion while sustaining hydrological, ecological, and environmental outcomes from human activities. • The Saskatchewan River and its delta have been influenced by human activities, climate changes, and their combined effects. • The sediment transport model via HEC-RAS evaluates the potential influences on riverbed erosion in the Saskatchewan River. • Riverbed erosion intensifies downstream of the E.B. Campbell dam. [ABSTRACT FROM AUTHOR]

Soil erosion is a critical process that leads to landscape degradation, compromising soil fertility and ecosystem functions. Forest ecosystems, with their intricate characteristics, play a pivotal role in mitigating soil erosion and providing soil retention ecosystem services (SRES). This study explores the impact of forest patch thresholds and critical points on soil erosion rates, focusing on 401 catchments in Poland using generalised additive models to identify thresholds and critical points in forest patches. Landscape metrics were applied to measure landscape structure, including shape, fractal dimension, contiguity, related circumscribing circles, and perimeter-area ratio indexes. These metrics, along with slope, rainfall, organic carbon content, water content, and clay ratio variables, were considered dependent variables in the models. The developed models have demonstrated reliable performance in estimating soil erosion rates, with a significant deviation explained from 80.5 to 81.1 for coniferous forest patches, 79.1 to 80.1 for broad-leave forest patches, and 80.9 to 81.4 for mixed forest patches at p < 0.05. In broad-leaved forests, three thresholds are identified in the shape index, which influence soil erosion rates in a complex manner. For coniferous forests, thresholds in the perimeter area ratio, related circumscribing circles, and contiguity indexes exhibit nonlinear relationships with soil erosion rates. Mixed forests show two thresholds in the related circumscribing circle and one in the fractal dimension index, affecting soil erosion rates differently. This research contributes significantly to understanding the interplay between forest patch shapes and soil erosion rates, providing decision support for land use planning. The identified thresholds and critical points offer valuable tools to enhance sustainable landscape functionality, emphasizing the importance of considering forest landscape structure in preserving soil retention ecosystem services. • Forest patch shape significantly influences soil erosion rates. • Three thresholds found in broad-leaved forests impact erosion rates. • Critical points in forest patch shapes influence soil retention. • Connectivity indexes affect erosion rates in coniferous forests. • The study offers valuable insights for sustainable land use planning. [ABSTRACT FROM AUTHOR]

Soil water repellency (SWR) exists in various soil ecosystems and can interrupt water infiltration and cause soil erosion. Anthropogenic land-use change can cause shifts in SWR and soil erosion resistance (SER) in sensitive soils. However, the direction and magnitude of these shifts in SWR and SER and their interrelations remain largely unclear. This study examined the changes in SWR, soil erodibility (K), and aggregate fractions in different land uses of a karst trough valley in southwest China. Soil samples were gathered from five land uses: cropland (CL), orchard (OP), secondary forest (SF), grassland (GL), and riverbank (RB), using a 1000 m × 1000 m grid, resulting in 210 sampling sites. Results showed that the water drop penetration time was significantly higher by 86.43%, 68.85%, and 71.47% in the SF, OP, and RB than in the CL, respectively (p < 0.05). The soil organic carbon (SOC) was the greatest in the SF and the lowest in the GL and CL (p < 0.05). The 1000–250 μm aggregate fraction, mean weight diameter (MWD), and geometric mean diameter (GMD) varied markedly among the different land uses (p < 0.05). The silt content, fractal dimension (D), and K were markedly lower in the RB than in the CL, OP, SF and GL (p < 0.05). The SWR had pronouncedly positive correlations with the SOC and 1000–250 μm aggregate fraction (p < 0.05). The K displayed a negative correlation with the GMD but a positive correlation with the D (p < 0.05). The structural equation modeling analysis revealed that the SOC was affected positively by the silt content and the 1000–250 μm aggregate fraction and negatively by the K. These factors directly regulated the SWR. Our results shed light on the mechanisms of land use changes impacting the SWR, SER and other soil properties in karst environments. [Display omitted] • Multisite SWR as affected by land use changes is studied in karst trough valley. • Cropland shows the lowest SWR while secondary forest has the highest one. • Land use markedly differs SOC, silt, K and 1000–250 μm micro-aggregate fraction. • Silt, K and 1000–250 μm micro-aggregate fraction jointly affect SOC, regulating SWR. • Decreasing soil erosion resistance can effectively reduce the occurrence of SWR. [ABSTRACT FROM AUTHOR]

Nearshore nourishments are a common intervention used to mitigate sediment deficits in coastal areas experiencing erosion problems. This coastal intervention involves placing nourished sediments in the submerged zone of the beach profile to form an artificial submerged sandbar which are then distributed by natural forces occurring in the coastal zone. Coastal processes that control the morphological evolution of coastal zones operate on several spatial and temporal scales (seconds to years) and can be divided into cross-shore and longshore components. Usually, the numerical models that simulate the evolution of cross-shore profiles due to sediment transport within the profiles, are related with short to medium-term events (days to months), and shoreline evolution models, that allow for long-term analysis (years to decades), are typically only considering longshore sediment transport. Describing all the processes in a single numerical model is complex and computationally demanding, and therefore, the numerical models are typically focused on specific processes, categorized by their temporal and spatial scales. This article presents a numerical study focused on medium to long-term numerical modelling of coastal zone evolution, examining the combined effects of cross-shore and longshore sediment transport processes of sediment transport. The model incorporates two simplified numerical models: LTC - Long Term Configuration, for shoreline evolution and CS-Model, for cross-shore sediment exchanges. Applied to nine different sandbar scenarios, model results revealed that disturbances in sandbar volume tend to return to equilibrium through cross-shore sediment transport processes. In situations that considered a constant sandbar volume alongshore, the longshore effects are null, because the volume entering in the coastal domain is equal to the volume leaving, and the sediment balance is only dependent of the cross-shore processes. Variable sandbar volume alongshore leads to impacts on shoreline position due to longshore sediment transport gradients generated by the sandbar disturbance. The results demonstrate the potential of the proposed combined model for medium to long-term projections, allowing for the interpretation of how physical aspects of nearshore nourishments evolve. These aspects include sandbar volume, shoreline position, berm width, and shoreline displacements induced by cross-shore and longshore sediment transport processes. These parameters aid in understanding sandbar-beach sediment dynamics, which is valuable for supporting coastal management, particularly in the development and design of shoreface sand nourishments, enabling the optimization of sand resources., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Urban and suburban development frequently disturbs and compacts soils, reducing infiltration rates and fertility, posing challenges for post-development vegetation establishment, and contributing to soil erosion. This study investigated the effectiveness of compost incorporation in enhancing stormwater infiltration and vegetation establishment in urban landscapes. Experimental treatments comprised a split-split plot design of vegetation mix (grass, wildflowers, and grass-wildflowers) as main plot, ground cover (hydro-mulch and excelsior) as subplot, and compost (30% Compost and No-Compost) as sub-subplot factors. Wildflower inclusion was motivated by their recognized ecological benefits, including aesthetics, pollinator habitat, and deep root systems. Vegetation cover was assessed using RGB (Red-Green-Blue) imagery and ArcGIS-based supervised image classification. Over a 24-month period, bulk density, infiltration rate, soil penetration resistance, vegetation cover, and root mass density were assessed. Results highlighted that Compost treatments consistently reduced bulk density by 19-24%, lowered soil penetration resistance to under 2 MPa at both field-capacity and water-stressed conditions, and increased infiltration rate by 2-3 times compared to No-Compost treatments. Vegetation cover assessment revealed rapid establishment with 30% compost and 60:40 grass-wildflower mix, persisting for an initial 12 months. Subsequently, all treatments exhibited similar vegetation coverage from 13 to 24 months, reaching 95-100% cover. Compost treatments had significantly higher root mass density within the top 15 cm than No-Compost, but compost addition did not alter the root profile beyond the 15 cm depth incorporation depth. The findings suggest that incorporating 30% compost and including a wildflower or grass-wildflower mix appears to be effective in enhancing stormwater infiltration and provides rapid erosion control vegetation cover establishment in post-construction landscapes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The continuous excessive application of phosphorus (P) fertilizers in intensive agricultural production leads to a large accumulation of P in surface soils, increasing the risk of soil P loss by runoff and leaching. However, there are few studies on the accumulation and loss of P from surface soil to deep soil profiles driven by shallow groundwater table (SGT) fluctuations. This study used the intensive cropland around 7 plateau lakes in Yunnan Province as an example and conducted in situ monitoring of P storage in the soil profile and SGT during the rainy season (RS) and dry season (DS) as well as simulation experiments on soil P loss. The aim was to study the spatiotemporal variation in P accumulation in the soil profile of cropland driven by SGT fluctuations in the RS and DS and estimate the P loss in the soil profile driven by SGT fluctuations. The results showed that fluctuations in the SGT promoted P accumulation from the surface soil to deeper soil. The proportions of P stored in various forms in the 30–60 cm and 60–100 cm soil layers in the RS were greater than those in the DS, while the average proportion in the 0–30 cm soil layer in the DS was as high as 48%. Compared with those in the DS, the maximum decreases in the proportion of P stored as TP and Olsen-P in the 0–100 cm soil layer in the RS were 16% and 58%, respectively, due to the rise in the SGT (SGT <30 cm), while the soil TP storage decreased by only 1% when the SGT was maintained at 60–100 cm. The critical thresholds for soil Olsen-P and TP gradually decreased with increasing soil depth, and the risk of P loss in deeper soil increased. The loss of soil P was increased by fluctuations in the SGT. Based on the cropland area around the 7 plateau lakes, P storage, and SGT fluctuations, the average loss intensity and loss amount of TP in the 0–100 cm soil layer around the 7 plateau lakes were estimated to be 25 kg/ha and 56 t, respectively. Therefore, reducing exogenous P inputs, improving soil endogenous P utilization efficiency and maintaining deep soil P retention are the basic strategies for preventing and controlling P accumulation and loss in deep soil caused by SGT fluctuations. • P accumulates obviously in surface soil in DS, while it accumulates into the deeper soil in RS. • Critical thresholds for soil Olsen-P and TP gradually decreased with increasing soil depth. • SGT fluctuations promote P accumulation from the surface soil to deeper soil. • Estimation of P loss in soil profile of croplands around plateau lakes driven by SGT fluctuations. [ABSTRACT FROM AUTHOR]

Vegetation restoration not only extensively reshapes spatial land use patterns but also profoundly affects the dynamics of runoff and sediment loss. However, the influence of vegetation restoration on runoff and sediment yield from a regional perspective are scarce. This study therefore focused on 85 sites within the "Grain for Green" Project (GGP) region on the Loess Plateau, to investigate the impacts of the GGP on soil erosion. The results revealed a notable reduction in sediment loss and runoff due to vegetation restoration. Since the inception of the GGP in 1999, approximately 4.1 × 106 ha of degraded lands have been converted into forestlands, shrublands, and grasslands, resulting in an average annual reduction of 1.4 × 109 m3 in runoff and a decrease of 3.6 × 108 t in annual sediment loss on the whole Loess Plateau, with the GGP contributing approximately 26.7% of the sediment reduction in the Yellow River basin. The reduced soil erosion has mainly been regulated by vegetation cover, soil properties (clay, silt, and sand), slope, and precipitation on the Loess Plateau. The insights gained offer valuable contributions to large-scale assessments of changes in soil erosion in response to vegetation reconstruction and enhance our understanding of the spatial configurations associated with soil erosion control measures. • Vegetation restoration extensively alters land use patterns and significantly impacts runoff and sediment dynamics. • Grassland balances runoff control and erosion reduction effectively. • Vegetation coverage, soil properties, slope, land-use changes, and precipitation determined runoff and sediment reduction, respectively. • The contribution of the "Grain for Green" Project (GGP) to sediment reduction in the Yellow River basin is approximately 26.7%. [ABSTRACT FROM AUTHOR]

Reducing soil erosion (SE) is crucial for achieving harmony between human society and the ecological environment. The cultivated land fragmentation (CLF), directly or indirectly, alters soil structure, diminishes its water-holding capacity, and escalates the risk of SE. Scientific assessment of the effect of CLF on SE can provide new insights into controlling of SE across watersheds in China. However, few studies have quantified the effect of CLF on SE. Therefore, we utilized land use change data in the Yangtze River basin from 2000 to 2020, measuring the levels of CLF and SE using Fragstats and InVEST models. The bivariate spatial autocorrelation model was employed to reveal the spatial relationship between CLF and SE. Additionally, we constructed a spatial Durbin model and introduced the geographically and temporally weighted regression model to analyze the role of CLF on SE. The south bank of the upper and middle reaches of the Yangtze River basin exhibited high CLF and SE. The bivariate spatial autocorrelation results showed a significant positive spatial correlation between CLF and SE. The spatial Durbin model results showed that CLF had a spatial spillover effect and time lag on SE, and the effect of CLF on SE had an inverted "N" curve. The study also confirmed that last SE and neighboring SE areas influenced local SE. Currently, CLF had a negative effect on SE in the Sichuan Basin, Yunnan-Guizhou Plateau, and the middle and lower Yangtze River Plain, and positively in Qinghai, Hunan, and Jiangxi provinces. These findings suggest that the government should enhance cross-regional and cross-sectoral cooperation and monitoring of cultivated land changes to prevent and control SE effectively. • Cultivated land fragmentation and soil erosion are increasing. • Cultivated land fragmentation has a dual spatio-temporal effect on soil erosion. • A nonlinear relationship between cultivated land fragmentation and soil erosion. • Cultivated land fragmentation inhibits soil erosion in a specific period. [ABSTRACT FROM AUTHOR]

The rapid expansion of laver (Porphyra yezoensis) cultivation on lower tidal flats has become integral to the local economy, yet it also raises concerns regarding its potential impact on the morphological evolution due to increasing human activities. This study utilizes integrated near-bed field measurements to assess morphological dynamics and quantify sediment erosion processes, highlighting the significant impact of laver harvest on tidal flat stability. Our results show that erosion and bed coarsening in the cultivated areas experienced a notable intensification immediately after harvest, with net erosion in cultivated areas reaching approximately -38.2 mm during the first tide post-harvest, markedly higher-more than an order of magnitude-compared to adjacent uncultivated areas. The erosion rate notably spiked with the average bed level change rate increasing to -13.8 × 10 -4  mm/s, compared to a rate of +0.3 × 10 -4  mm/s during the unharvest period. Subsequently, the cultivated areas entered a recovery phase with a deposition amount of +12.5 mm, while the net cumulative erosion thickness throughout the entire observation period was -25.2 mm. The cultivation method, characterized by consistent harvests every 10 days, means that even minor erosion from continuous harvests can escalate into significant degradation. This study suggests that long-term cultivation cycle practices may result in irreversible changes to the depositional environment, potentially jeopardizing the habitat viability and ecological function. Sustainable agricultural strategies, including site selection, infrastructure planning, monitoring environmental changes, ecological assessments and sustainable practices, are recommended to mitigate the negative impacts of cultivation on regional stability and preserve the coastal ecological balance., Competing Interests: Declaration of competing interest We declare on behalf of my co-authors that there is no conflict of interest exists in the submission of this manuscript, and manuscript is approved by all authors for publication., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Soil erosion is a significant environmental issue worldwide. It affects water quality, biodiversity, and land productivity. New Zealand government agencies and regional councils work to mitigate soil erosion through policies, management programmes, and funding for soil conservation projects. Information about cost-effectiveness is crucial for planning, targeting, and implementing erosion mitigation to achieve improvements in sediment-related water quality. While there is a good understanding of the costs of erosion mitigation measures, there is a dearth of literature on their cost-effectiveness in reducing sediment loads and improving water quality at the catchment level. In this study, we estimate the cost-effectiveness of erosion mitigation measures in meeting visual water clarity targets. The analysis utilizes the spatially explicit SedNetNZ erosion process and sediment budget modelling in the Manawatū-Whanganui Region and region-specific mitigation costs. The erosion mitigation measures considered in the analysis include afforestation, bush retirement, riparian retirement, space-planted trees, and gully tree planting. We modelled two scenarios with on-farm erosion mitigation implemented across the region from 2021 to 2100, resulting in a 48% and 60% reduction of total sediment load. We estimate the marginal costs to achieve the visual national bottom line for water clarity, as assessed by the length of waterways that meet the clarity targets. We also estimate the marginal costs of improving average water clarity, which can be linked with non-market valuation studies when conducting a cost-benefit analysis. We find that gully tree planting and space-planted trees are the most cost-effective mitigation measures and that riparian retirement is the least cost-effective. Moreover, cost-effectiveness is highly dependent on current land use and the biophysical features of the landscape. Our estimates can be used in cost-benefit analysis to plan and prioritize soil erosion mitigation at the catchment and regional levels. • The analysis utilizes the spatially explicit SedNetNZ model. • The cost-effectiveness of erosion mitigation to meet water clarity targets are estimated. • There is substantial variation of marginal costs across landscape. • Marginal abatement cost curves for improving water clarity are developed. [ABSTRACT FROM AUTHOR]

Anthropogenic reactive nitrogen (Nr) loss has been a critical environmental issue. However, due to the limitations of data availability and appropriate methods, the estimation of Nr loss from rice paddies and associated spatial patterns at a fine scale remain unclear. Here, we estimated the background Nr loss (BNL, i.e., Nr loss from soils without fertilization) and the loss factors (the percentage of Nr loss from synthetic fertilizer, LFs) for five loss pathways in rice paddies and identified the national 1 × 1 km spatial variations using data-driven models combined with multi-source data. Based on established machine learning models, an average of 23.4% (15.3–34.6%, 95% confidence interval) of the synthetic N fertilizer was lost to the environment, in the forms of NH 3 (17.4%, 10.9–26.7%), N 2 O (0.5%, 0.3–0.8%), NO (0.2%, 0.1–0.4%), N leaching (3.1%, 0.8–5.7%), and runoff (2.3%, 0.6–4.5%). The total Nr loss from Chinese rice paddies was estimated to be 1.92 ± 0.52 Tg N yr−1 in 2021, in which synthetic fertilizer-induced Nr loss accounted for 69% and BNL accounted for the other 31%. The hotspots of Nr loss were concentrated in the middle and lower regions of the Yangtze River, an area with extensive rice cultivation. This study improved the estimation accuracy of Nr losses and identified the hotspots, which could provide updated insights for policymakers to set the priorities and strategies for Nr loss mitigation. [Display omitted] • Data-driven models were combined with high-resolution multi-source data to estimate reactive nitrogen (Nr) losses. • The loss factors for five Nr loss pathways were updated. • Soil background losses accounted for 31% of the total Nr losses. • Three provinces in Central China were identified as Nr loss hotspots. • It is recommended that local soil and climate conditions be considered to develop Nr loss mitigation policies. [ABSTRACT FROM AUTHOR]

Straw incorporation has been considered as an effective environmental management application to improve soil erosion resistance (SER) and organic carbon sequestration. SER is useful to evaluate soil erosion subjected to concentrated flow. Nevertheless, few studies have been performed to examine how SER varied with the amount of straw incorporation on sloping croplands in high latitude and cool regions. In the current study, the fixed bed scouring tests were conducted in a large hydraulic flume using undisturbed soil samples taken from Hebei small watershed in the black soil region of Northeast China. The response of SER to different straw incorporation amounts (0, 1.125, 2.25, 4.5, 6.75, 9.0 and 13.5 t ha -1 ) was quantified after three months of straw decomposition. The major influencing factors and the corresponding mechanisms were determined. The findings demonstrated that rill erodibility firstly decreased exponentially with straw incorporation amount (R 2  = 0.93), while it slightly increased when straw incorporation amount was more than 9.0 t ha -1 . Critical shear stress firstly increased logarithmically (R 2  = 0.90) and then slightly decreased when the amount exceeded 9.0 t ha -1 . Compared to the treatment of 0 t ha -1 , rill erodibility reduced by 17.0%-92.8% and critical shear stress increased by 59.6%-127.2% across different treatments of straw incorporation. Rill erodibility had significant and negative correlations with soil organic matter content, aggregate stability, cohesion, root mass density, straw mass density and straw decomposition amount. The key mechanisms for promoting SER were derived by the direct and indirect effects of straw incorporation and its decomposition on soil physicochemical properties and crop roots. The amount of 9.0 t ha -1 was recommended as the optimum amount of straw incorporation in croplands in Northeast China. These findings are useful to understand how soil erosion resistance responds to the amount of straw incorporation and make rational environmental management policy for semi-humid and cool regions., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work. There is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled “Response of soil erosion resistance to straw incorporation amount in the black soil region of Northeast China”., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Soil erosion is a significant environmental issue worldwide, particularly in island regions where land resources are exceedingly scarce. Biological soil crusts play a crucial role in mitigating soil erosion, yet the precise effect and mechanism of biological soil crusts against erosion remain ambiguous. In this study, biological soil crusts at various developmental stages from a tropical coral island in the South China Sea were chosen to investigate the role of carbonic anhydrase in mitigating erosion. A cohesive strength meter, real-time quantitative PCR, and 16S rRNA gene high-throughput sequencing were employed to assess variations in soil antiscouribility as well as bacterial abundance and composition during the formation and development of biological soil crusts. Scanning electron microscopy was utilized to detect carbonates induced by bacterial carbonic anhydrase and elucidate their role in the solidification of sand particles. The findings indicate that the formation and development of biological soil crusts significantly enhance anti-scouribility. Comparison to those of bare coral sand, the shear stress increased from 0.35 to 1.11 N/m2 in the dark biocrusts. Moreover, significantly elevated carbonic anhydrase activity was observed in biological soil crusts, demonstrating a positive correlation with antiscouribility. In addition, there was a significant increase in bacterial abundance within the biological soil crusts. The enrichment of Cyanobacteriales and Chloroflexales potentially contributed to the increased carbonic anhydrase activity and antiscouribility. Furthermore, three cyanobacterial strains with carbonic anhydrase activity were isolated from biological soil crusts and subsequently confirmed to enhance sand solidification through microbial carbonate precipitation. This study presents initial evidence for the role of microbial carbonic anhydrase in enhancing the antiscouribility of biological soil crusts during their formation and development. These findings offer novel insights into the functional and mechanistic dimensions underlying the mitigation of soil erosion facilitated by biological soil crusts, which are valuable for implementing sustainable biorestoration and environmental management technologies to prevent soil erosion. [Display omitted] • Antiscourability and carbonic anhydrase activity enhanced during the formation and development of biological soil crusts. • Antiscourability was positive correlated with carbonic anhydrase activity. • Cyanobacteriales and Chloroflexales contribute to the augmentation of carbonic anhydrase activity. • Carbonic anhydrase-induced carbonates enhanced soil shear strength in biological soil crusts. [ABSTRACT FROM AUTHOR]

Soil loss is an environmental concern of global importance. Accurate simulation of soil loss in small watersheds is crucial for protecting the environment and implementing soil and water conservation measures. However, predicting soil loss while meeting the criteria of high precision, efficiency, and generalizability remains a challenge. Therefore, this study first used three machine learning (ML) algorithms, namely, random forest (RF), support vector machine (SVM), and artificial neural network (ANN) to develop soil loss models and predict soil loss rates (SLRs). These soil loss models were constructed using field observation data with an average SLR of 1756.48 t/km2 from rainfall events and small watersheds in the hilly-gully region of the Loess Plateau, China. During training, testing and generalizability stages, the average coefficients of determination from the RF, SVM, and ANN models were 0.903, 0.860, and 0.836, respectively. Similarly, the average Nash-Sutcliffe coefficients of efficiency from the RF, SVM and ANN models were 0.893, 0.791 and 0.814, respectively. These results indicated that MLs have superior predictive performance and generalizability, and broad prospects for predicting SLRs. This study also demonstrated that the RF model outperformed better than the SVM and ANN models. Therefore, the RF model was used to simulate the SLR of each small watershed in the Chabagou watershed. Our results showed the four-year (2017–2020) average annual SLR of the small watersheds ranged from 0.73 to 1.63 × 104 t/(km2∙a) in the Chabagou watershed. Additionally, the results also indicated the SLR of small watersheds under the rainstorm event with a 100-year recurrence interval was 4.4–51.3 times that of other rainfall events.Furthermore, this study confirmed that bare land was the predominant source of soil loss in the Chabagou watershed, followed by cropland land and grassland. This study helps to provide the theoretical basis for deploying soil and water conservation measures to realize the sustainable utilization of soil resources in the future. [Display omitted] • Three machine learning algorithms were first used to build soil loss models. • Random forest demonstrated the most favorable performance for soil loss modeling. • Soil loss caused by rainstorms was 4.4–51.3 times that of other rainfall events. • Bare land was the predominant source of soil loss. [ABSTRACT FROM AUTHOR]

Forest management practices play multifaceted roles in enhancing the geophysical properties that affect raindrop erosion in the watershed, and consequently, sediment deposition in the reservoir. The current work attempts to integrate empirical and physically-based modeling approaches to quantify the impacts of forest conservation on erosion risk and potential sediment accumulation in the mixed-forested Ogouchi Dam watershed in Japan. The reliability of the empirical model for estimating the total erodibility coefficient (TEr), as a function of various forest properties, was evaluated by applying the mathematical expression to multiple forest conditions and comparing the values to field-measured soil erosion rates. The spatial distribution of the empirically derived values showed that about 25.8% of the Government-managed forests and 45.1% of the private forests have higher risks of raindrop splash erosion compared to natural forests. The TEr value in each small Government-divided forest land (less than 5 ha) was then corresponded to the MUSLE management practice factor (MUSLE P) input in each hydrologic response unit (HRU) in the Soil and Water Assessment Tool (SWAT) model to create a sediment yield distribution map and to predict the amounts of sediment accumulation for different management scenarios. The spatial distribution of sediment yield for the base condition showed that 20.9% of the Government-managed forests and 61.6% of the private forests have higher probable amounts of sediment yield relative to the value simulated in the natural forest. A maximum cumulative sediment reduction of about 14.4% is likely attainable upon the complete control of the Government in the entire planted forest area. Overall, this study effectively utilized the field survey datasets to develop a robust empirical model for quantifying erosion risk and was able to couple the results to a GIS-based model that predicts the amounts of sediment yield under varying environmental conditions. • Quantified and mapped out erosion and sediment risks in a mixed-forested watershed. • A robust empirical model was used to parameterize input in a physically-based model. • Government-divided forest areas (<5 ha) were grouped into hydrologic response units. • Full Government control can reduce sediment accumulation in planted forests by 14.4%. [ABSTRACT FROM AUTHOR]

The drainage system is a key measure for regulating runoff nutrient losses on sloping farmlands. Confluence and diverging drainage systems are two drainage layouts representing natural water network systems and are widely distributed in sloping farmlands; however, the effects of these drainage systems on runoff nutrient losses in the sloped plots remain unclear. This study investigated the effects of different drainage systems on the characteristics of runoff nitrogen (N) losses in sloped plots using laboratory rainfall simulations. Three treatments, including bare slope (without drainage system, CK), confluence drainage system (T1), and diverging drainage system (T2), were used to compare the changes in concentrations and losses of total nitrogen (TN), dissolved nitrogen (DN), and particulate nitrogen (PN), and the DN:TN ratio in runoff under a combination of 1.8 mm min−1 rainfall intensity and three slope gradients (5°, 10°, and 15°). The results showed that the time to runoff was significantly delayed in T2 compared with that in CK and T1 across all slopes (p < 0.05). Accumulated runoff depth was considerably lower in T1 and T2 than in CK across all slopes (p < 0.05). The TN and PN concentrations in T1 were markedly lower than those in T2 on the 10° and 15° slopes (p < 0.05). The DN concentration in T1 was lowest at the 5° slope (p < 0.05). TN loss in T1 was 14.7–33.9% and 17.9–30.3% lower than those in CK and T2 across all slopes, respectively (p < 0.05). The PN loss in T1 was 56.7% and 53.3% lower than that in T2 on the 10° and 15° slopes, respectively (p < 0.05). DN loss in T1 was 39.3–72.5% lower than that in CK for all slopes (p < 0.05). DN:TN in T2 was lower than that in CK and T1 at the 10° and 15° slopes (p < 0.05). Our results confirm the effectiveness of drainage systems in reducing runoff nutrient losses in a sloped plot and demonstrate that the confluence drainage system is better at reducing N losses in runoff than diverging drainage systems. [Display omitted] • Effects of two drainage systems on runoff N loss were studied in the plot scale. • Drainage systems markedly reduce runoff depth relative to bare plots in all slopes. • Drainage systems considerably reduce TN loss relative to bare plots in all slopes. • Confluence drainage system reduces more TN loss than diverging drainage system. [ABSTRACT FROM AUTHOR]

Robust understanding of the fine-grained sediment cascades of temperate agricultural catchments is essential for supporting targeted management for addressing the widely reported sediment problem. Within the UK, many independent field-based measurements of soil erosion, sediment sources and catchment suspended sediment yields have been published. However, attempts to review and assess the compatibility of these measurements are limited. The data available suggest that landscape scale net soil erosion rates (∼38 t km−2 yr−1 for arable and ∼26 t km−2 yr−1 grassland) are comparable to the typical suspended sediment yield of a UK catchment (∼44 t km2 yr−1). This finding cannot, however, be reconciled easily with current prevailing knowledge that agricultural topsoils dominate sediment contributions to watercourses, and that catchment sediment delivery ratios are typically low. Channel bank erosion rates can be high at landscape scale (27 km−2 yr−1) and account for these discrepancies but would need to be the dominant sediment source in most catchments, which does not agree with a review of sediment sources for the UK made in the recent past. A simple and robust colour-based sediment source tracing method using hydrogen peroxide sample treatment is therefore used in fifteen catchments to investigate their key sediment sources. Only in two of the catchments are eroding arable fields likely to be important sediment sources, supporting the alternative hypothesis that bank erosion is likely to be the dominant source of sediment in many UK catchments. It is concluded that the existing lines of evidence on the individual components of the fine sediment cascade in temperate agricultural catchments in the UK are difficult to reconcile and run the risk of best management interventions being targeted inappropriately. Recommendations for future research to address paucities in measured erosion rates, sediment delivery ratios and suspended sediment yields, validate sediment source fingerprinting results, consider the sources of sediment-associated organic matter, and re-visit soil erosion and sediment cascade model parameterisation are therefore made. • Net soil erosion rates are approximately equal to catchment suspended sediment yields. • This is incompatible with most sediment originating from topsoils and low sediment delivery. • High bank erosion source contributions close the gap in sediment budgets. • The sources of mineral sediment were traced in 15 UK catchments. • Arable fields were suggested to be important sediment sources in only two of these. [ABSTRACT FROM AUTHOR]

Land desertification poses a significant challenge in the Brazilian semiarid region, encompassing a substantial portion of the country. Within this region, the detrimental effects of human activities, particularly unsuitable anthropic actions, have resulted in diminished vegetation cover and an accelerated rate of soil erosion. Notably, practices such as overgrazing and the conversion of native forests into pasturelands have played a pivotal role in exacerbating the process of land desertification. Ultimately, land desertification results in significant losses of soil organic matter and microbial diversity. To address this pressing issue and contribute to the existing literature, various land restoration practices, such as grazing exclusion, cover crops, and terracing, have been implemented in the Brazilian semiarid. These practices have shown promising results in terms of enhancing soil fertility and restoring microbial properties. Nonetheless, their effectiveness in improving soil microbial properties in the Brazilian semiarid region remains a subject of ongoing study. Recent advances in molecular techniques have improved our understanding of microbial communities in lands undergoing desertification and restoration. In this review, we focus on assessing the effectiveness of these restoration practices in revitalizing soil microbial properties, with a particular emphasis on the soil microbiome and its functions. Through a critical assessment of the impact of these practices on soil microbial properties, our research aims to provide valuable insights that can help mitigate the adverse effects of desertification and promote sustainable development in this ecologically sensitive region. • Land desertification in Brazilian semiarid negatively changes the soil microbial properties. • Restoring strategies improve the soil properties and microbial communities. • Molecular tools enhance understanding of soil microbiome under desertification and restoration. [ABSTRACT FROM AUTHOR]

Soil respiration (Rs) is a crucial ecological process of carbon (C) cycling in the terrestrial ecosystems, and soil erosion has a significant impact on its C budget and balance. However, the variations of Rs rate and their CO 2 efflux induced by erosion are currently poorly understood. To this end, four landscape positions (top, up, middle and toe) with different erosional and depositional characteristics were selected on a typical eroded slope in southern China to conduct field experiments, aiming to explore the effects of erosion and deposition on Rs among various sites. From March 2021 to February 2022, the in-situ Rs were measured using an automated soil respiration system, together with soil temperature at 5 cm depth (T s5) and water content at 10 cm depth (SWC 10). We initially constructed various Rs models across a one-year period, based on its relationships with T s5 and SWC 10. Subsequently, the seasonal changes of Rs at different erosional sites were simulated by the optimum models, and their annual CO 2 fluxes were further estimated. The results showed that Rs rates at all sites displayed a bimodal seasonal pattern, with the highest values in May and August. And the measured Rs of the eroding and depositional sites were 0.05–7.71 and 1.47–13.03 μmol m−2 s−1, respectively. Also, remarkably higher T s5 and SWC 10 were observed in depositional sites versus the eroding sites (P < 0.05). Additionally, Rs rates at all sites were positively correlated with SOC and T s5 , but negatively correlated with SWC 10. Herein, Rs models to single- and double-variable were established at different positions, and we found that the fitted R 2 and AIC differed on various sites, primarily in erosional and depositional sites. Furthermore, through the best-fitting models (higher R 2 and lowest AIC) we screened, the average Rs values of 3.03 and 4.46 μmol m−2 s−1 were quantitatively estimated for the eroding and depositional sites, respectively. Finally, it could be further assessed that the mean annual soil CO 2 –C efflux of eroded site (1104.14 g m−2) was significantly lower than that of depositional site (1629.46 g m−2). These findings highlighted the effect of erosion and deposition on Rs , which will facilitate a better understanding of C cycling in terrestrial ecosystems. • This study deployed models of soil environmental factors in southern China. • Soil respirations (Rs) of different erosion sites were measured and modeled. • Variations of Rs in various eroding sites were well predicted by the established models. • Rs averaged 2.95 and 4.96 μmol m−2 s−1 for eroded and depositional sites. • Soil CO 2 –C efflux of eroded and depositional sites were 1104.14 and 1629.46 g m−2. [ABSTRACT FROM AUTHOR]

Changes in the air temperature tend to indirectly affect soil erosion by influencing rainfall, vegetation growth, economic development, and agricultural activities. In this study, the partial least squares-structural equation model (PLS-SEM) was used to decouple the impacts of temperature change on soil erosion in Northeast China from 2001 to 2019, and the indirect effect of temperature change on the pathways of natural and socioeconomic factors was analyzed. The results showed that temperature increase in Northeast China caused an increase in soil erosion by increasing rainfall and promoting economic development. Under the pathway of natural factors, in spring, the promoting effect on soil erosion under the influence of temperature change on rainfall was greater than the inhibiting effect on soil erosion under by the influence of temperature change on vegetation. In summer, the opposite effect was observed. Under the pathway of natural factors, over time, the promoting effect of temperature increase on soil erosion increased by 22.7%. Under the pathway of socioeconomic factors, temperature change not only aggravated soil erosion by promoting economic development, but also indirectly increased investments in agriculture and water conservation by improving the economy, thus inhibiting soil erosion to a certain extent. Over time, the contribution of temperature change to soil erosion through socioeconomic pathway was reduced by 44.4%. When the pathway of natural factors is compared with that of socioeconomics factors, temperature change imposed a more notable effect on the change in soil erosion through the socioeconomic pathway, indicating that human activities are the driving factors with a greater effect on soil erosion. Based on this, reasonable human intervention is an important means to alleviate soil erosion aggravation caused by rising temperatures. • The impact of climate warming on soil erosion was decoupled using PLS-SEM. • Socioeconomic pathway has a greater impact on soil erosion than natural pathway. • Analyzed the spatiotemporal pattern of climate warming's indirect soil erosion impact. • Human intervention is crucial for mitigating soil erosion caused by climate warming. [ABSTRACT FROM AUTHOR]

Grassland degradation decreases ecosystem productivity and diminishes soil biodiversity, leading to the loss of beneficial microorganisms. Arbuscular mycorrhizal fungi (AMF) play a critical role in ecosystem functioning, being a key link between plant and microbial communities, soil, and vegetation. Here, we evaluated the potential of increasing the productivity of degraded grassland by AMF inoculation. A gradient of soil biodiversity: complete sterilization, low, moderate, and high biodiversity was established using the dilution-to-extinction approach. Grassland microcosms under greenhouse conditions were inoculated with three AMF taxa in an increasing diversity: no AMF, single AMF taxa, and all three AMF taxa together. The loss of soil biodiversity decreased plant community productivity, primarily due to reduced biomass of legumes and non-N 2 -fixing forbs. AMF inoculation raised plant community productivity by 190%, mainly attributed to the greater biomass of legumes and non-N 2 -fixing forbs. This positive effect of AMF inoculation was particularly pronounced on soils with low biodiversity, where soil mutualists were absent. The biomass of grasses remained independent of AMF inoculation. This differential responsiveness to mycorrhiza was mainly due to the distinctive plant traits of each plant functional group. Inoculating with a single AMF was more beneficial for plant biomass production than inoculation with multiple AMF under lower levels of soil biodiversity, probably due to high functional redundancy among AMF taxa. In conclusion, AMF inoculation reduced the adverse impact of soil degradation and biodiversity loss on plant biomass and vegetation development, highlighting the key roles and importance of AMF for grassland restoration. [Display omitted] • Soil biodiversity loss reduces plant productivity and shifts plant composition. • A diverse soil community benefits legumes and forbs more than grasses. • AMF mitigates the negative impacts of soil biodiversity loss on plant productivity. • Single AMF inoculation resulted in greater plant productivity than multiple AMF. [ABSTRACT FROM AUTHOR]

Evaluating the linkage between soil erosion and sediment connectivity for export assessment in different landscape patterns at catchment scale is valuable for optimization of soil and water conservation (SWC) practices. Present research attempts to identify the soil erosion susceptible (SES) sites in Kangsabati River Basin (KRB) using machine learning algorithm (decision trees, decision trees cross validation, CV, Extreme Gradient Boosting, XGB CV and bagging CV) taken thirty five variables, for investigating the linkage between erosion rates and sediment connectivity to assess the sediment export at sub-basin level employing connectivity index (IC) and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) sediment delivery ratio (SDR) model. Based on AUC of receiving operating curve in validation test, excellent capacity of extreme Gradient Boosting, XGB CV and bagging CV (0.95, 0.90) than decision tree and decision tree CV (0.78, 0.82), exhibits about 18.58 % of basin areas facing susceptible to very high erosion. Conversely, considering universal soil loss equation (RUSLE) parameters, InVEST-SDR model estimated about 64.24 % of soil loss rate occurred from high SES in where sediment export rate become very high (136.995 t/ha -1 /y -1 ). The IC result show that high sediment connectivity (<-4.4) measured in high SES of laterite and bare land in upper catchment, and double crop agricultural areas in lower catchment, while least connectivity (>-7.1) observed in low SES of dense forest, vegetation cover and settlement built-up areas. Pearson correlation matrix revealed that four landscape indices category i.e. edge metrics (p < 0.01), aggregation metrics (p < 0.001), shape metrics (p < 0.01-0.001) and diversity metrics (p < 0.01) signified the influence of landscape patterns on IC and SES. Accordingly, RUSLE, SDR and landscape matrices reveals that maximum sediment export rate associated with high connective delivery outlet and high SES in laterite, double crop and bare land due to simple landscape and greater homogeneity, whilst minimum export rate related with low connectivity and low SES in dense forest, vegetation cover and settlement built up area causes of fragmented landscape and spatial heterogeneity. Finally, findings could immense useful for formulating the optimizing measures of SWC in the watershed., Competing Interests: Declaration of competing interest We have declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Postfire restoration practices encompass those which aim to reduce negative wildfire impacts and to improve burned area rehabilitation. Contour-felled log debris (CFD) and log erosion barriers (LEB) are two techniques used worldwide on hillslopes after wildfires in order to avoid soil erosion. In this context, it is essential to evaluate how these restoration techniques can affect soil properties by increasing or decreasing wildfire impacts. The effects on several physico-chemical and biological soil parameters were here investigated by comparing three differently treated post-fire zones. Three randomly 20 × 20 m distributed plots were set up five years after wildfire in the burned and contour-felled log debris areas (CFD plots), three others in the burned and log erosion barriers area (LEB plots) and three others in the burned and unmanaged plots (BNa plots). Three more plots were set up in an unburned area close to the burned area (UB plots). The results revealed that LEB and, to a lesser extent CFD, improved postfire soil quality, which a priori favoured helped the recovery of ecosystem functions. Our results also indicate greater efficacy of LEB and CFD in retaining sediments by limiting loss of nutrients, which is considered essential to recover vegetation after a wildfire. Post-fire restoration plans should consider the use of LEB and CFD when aiming to favour ecosystem recovery processes after wildfires. • Hillslope treatments improve the microbiological soil properties. • Soil properties improvement is more clearly in log erosion barriers. • Contour-felled log debris and log erosion barriers generate higher SOM. • Log erosion barriers make higher nutrient content. [ABSTRACT FROM AUTHOR]

Abstract In the Mediterranean region, floods are expected to increase as a result of climate change and knowledge of soil erosion hot spots during exceptional rainfalls is required to support mitigation measures. This study quantifies the main sediment sources during an exceptional rainfall event in 2012 (235 mm) at the outlet of two catchments located in NE Spain. To this purpose, suspended sediments were collected during the flood event, complemented with entrapped sediments in mat taken one year after the event. We used fingerprinting methodology and applied the FingerPro unmixing model to estimate the contribution from main sources. The selected tracers clearly distinguished agricultural, rangeland, subsoil and channel banks as the four potential sources in both catchments. In the Vandunchil catchment, the 8 time-integrated suspended sediment samples revealed changes in source contribution during the 2-h sampling sequence. There were relatively high contributions from rangeland, agriculture and subsoil at the beginning of the sampling, representing 30, 40 and 35% of the total source contributions, respectively. Our records captured the delivery of pulses of eroded surface soil transported by runoff with direct connectivity to the stream. The sequence was followed by a sharp increase in channel bank contribution (up to 90%) in comparison to the other sources, reflecting streambank erosion and landslide occurrence, which manifested during the flood. In contrast, in the La Reina catchment, agricultural soils contributed the most (65%) and, together with subsoils (32%), were the main sources. These results reflect the effect of the higher connectivity and slope gradient of these cultivated fields of the La Reina catchment in comparison with those of the Vandunchil catchment. We discuss the possibility of using different properties, such as radionuclides, geochemistry and magnetic measurements, as tracers to distinguish between potential sources during an exceptional event in upland Mediterranean catchments. Our results support the use of fingerprinting techniques to determine variations in source contribution and sediment provenance during flood events, as extreme rainfalls are main drivers of sediment mobilization and key factors in changing landscapes. This is essential in identifying vulnerable hot spots, in which early-stage interventions are needed, and for helping policy makers with management of soil and water resources. Graphical abstract Image 1074 Highlights • Unique opportunity to capture soil response during an exceptional event of 235 mm. • Suspended sediment properties changed during the flood event. • Source contributions varied in response to the rainstorm in a short period. • Switch from soil sources to channel bank provenance was captured during the flood. • Land use and connectivity determined the suspended sediment provenance. [ABSTRACT FROM AUTHOR]

Abstract Soil erosion is the primary process driving land degradation. Using multiple scales of management to minimize soil erosion is crucial to achieve land degradation neutrality targets within the Sustainable Development Goals agenda. Land management (LM) influences both on-site and off-site erosion on the event-scale and over the long-term. However, each LM differs in effectiveness depending on the temporal scale considered. In order to understand how LM effects internal and external catchment dynamics, we apply LandSoil, a physically based landscape evolution model, to evaluate 7 LM scenarios over long- (30 years) and short-terms (event scale). LM scenarios included changes in land use and/or landscape structure. Under current LM, mean surface soil erosion was ∼0.69 ± 39·10−3 m over 30 years. In contrast, a single extreme event (435 mm/24 h) in January resulted in ∼0.62 ± 3·10−3 m loss and ∼0.04 ± 2·10−3 m if it occurred in October. Heterogeneous patterns of erosion and deposition developed after 30 years, whereas extreme events dominantly showed soil loss and high catchment connectivity. Effectiveness of LM in erosion mitigation and sediment trapping differed according to temporal and spatial scales for each scenario. We concluded that multiple temporal and spatial scales must be incorporated in order to adaptively manage land degradation and meet neutrality targets. Highlights • Internal and external catchment dynamics differ for long-term and extreme events. • Land degradation neutrality requires management efficiency for both time scales. • Combined land use, landscape structure and connectivity management is needed. • LandSoil model enables comparison of management efficiency on differing time scales. [ABSTRACT FROM AUTHOR]

Abstract Peat soils represent an important global carbon (C) sink, but can also provide a highly fertile medium for growing horticultural crops. Sustainable crop production on peat soils involves a trade-off between ensuring food security and mitigating typically high greenhouse gas (GHG) emissions and rates of soil C loss. An alternative approach to resource intensive field-based monitoring of GHG fluxes for all potential management scenarios is to use a process-based model driven by existing field data to estimate emissions. The aim of this study was to evaluate the suitability of the Denitrification-Decomposition (DNDC) model for estimating emissions of CO 2 , N 2 O and CH 4 from horticultural peat soils. The model was parameterised using climatic, soil, and crop management data from two intensively cultivated sites on soils of contrasting soil organic matter (SOM) contents (∼35% and ∼70% SOM content). Simulated emissions of CO 2 , N 2 O and CH 4 , and simulated soil physical and crop output values, were compared to actual GHG, soil and crop measurements. Model performance was assessed using baseline parameterisation (i.e. model defaults), then calibrated using pre-simulation and sensitivity analysis processes. Under baseline parameterisation conditions, DNDC proved poor at predicting GHG emissions and soil/crop variables. Calibration and validation improved DNDC performance in estimating the annual magnitude of emissions, but model refinement is still required for reproducing seasonal GHG patterns in particular. Key constraints on model functioning appear to be its ability to reliably model soil moisture and some aspects of C and nitrogen dynamics, as well as the quality of input data relating to water table dynamics. In conclusion, our results suggest that the DNDC (v. 9.5) model cannot accurately reproduce or be used to replace actual field measurements for estimation of GHG emission factors under different management scenarios for horticultural peat soils, but may be able to do so with further modification. Highlights • We applied the DNDC (Denitrification-Decomposition) model to arable peat soils. • DNDC simulated GHG emissions, crop yield and soil processes were not satisfactory. • DNDC modelling of soil moisture and soil C:N dynamics limited its functioning. • DNDC needs further improvement to capture GHG emissions at finer temporal scales. [ABSTRACT FROM AUTHOR]

Abstract Every year, gully erosion causes substantial damage to agricultural land, residential areas and infrastructure, such as roads. Gully erosion assessment and mapping can facilitate decision making in environmental management and soil conservation. Thus, this research aims to propose a new model by combining the geographically weighted regression (GWR) technique with the certainty factor (CF) and random forest (RF) models to produce gully erosion zonation mapping. The proposed model was implemented in the Mahabia watershed of Iran, which is highly sensitive to gully erosion. Firstly, dependent and independent variables, including a gully erosion inventory map (GEIM) and gully-related causal factors (GRCFs), were prepared using several data sources. Secondly, the GEIM was randomly divided into two groups: training (70%) and validation (30%) datasets. Thirdly, tolerance and variance inflation factor indicators were used for multicollinearity analysis. The results of the analysis corroborated that no collinearity exists amongst GRCFs. A total of 12 topographic, hydrologic, geologic, climatologic, environmental and soil-related GRCFs and 150 gully locations were used for modelling. The watershed was divided into eight homogeneous units because the importance level of the parameters in different parts of the watershed is not the same. For this purpose, coefficients of elevation, distance to stream and distance to road parameters were used. These coefficients were obtained by extracting bi-square kernel and AIC via the GWR method. Subsequently, the RF-CF integrated model was applied in each unit. Finally, with the units combined, the final gully erosion susceptibility map was obtained. On the basis of the RF model, distance to stream, distance to road and land use/land cover exhibited a high influence on gully formation. Validation results using area under curve indicated that new GWR CF RF approach has a higher predictive accuracy 0.967 (96.7%) than the individual models of CF 0.763 (76.3%) and RF 0.776 (77.6%) and the CF-RF integrated model 0.897 (89.7%). Thus, the results of this research can be used by local managers and planners for environmental management. Graphical abstract Image 1 Highlights • Three approaches ((a) CF and RF; (b) integrated CF-RF; and (c) combined GWR CF RF) used for GEZM. • A new methodological framework (GWR-RF-CF) was introduced for GEZM. • Geographically Weighted Regression was used to create several homogenous units. • GWR CF RF has higher prediction accuracy than other employed models. • GWR CF RF as a new approach can be used by decision makers for GEZM. [ABSTRACT FROM AUTHOR]

Abstract Assessment of watershed health and prioritization of sub-watersheds are needed to allocate natural resources and efficiently manage watersheds. Characterization of health and spatial prioritization of sub-watersheds in data scarce regions helps better comprehend real watershed conditions and design and implement management strategies. Previous studies on the assessment of health and prioritization of sub-watersheds in ungauged regions have not considered environmental factors and their inter-relationship. In this regard, fuzzy logic theory can be employed to improve the assessment of watershed health. The present study considered a combination of climate vulnerability (Climate Water Balance), relative erosion rate of surficial rocks, slope weighted K-factor, topographic indices, thirteen morphometric characteristics (linear, areal, and relief aspects), and potential non-point source pollution to assess watershed health, using a new framework which considers the complex linkage between human activities and natural resources. The new framework, focusing on watershed health score (WHS), was employed for the spatial prioritization of 31 sub-watersheds in the Khoy watershed, West Azerbaijan Province, Iran. In this framework, an analytical network process (ANP) and fuzzy theory were used to investigate the inter-relationships between the above mentioned geo-environmental factors and to classify and rank the health of each sub-watershed in four classes. Results demonstrated that only one sub-watershed (C15) fell into the class that was defined as 'a potentially critical zone'. This article provides a new framework and practical recommendations for watershed management agencies with a high level of assurance when there is a lack of reliable hydrometric gauge data. Graphical abstract Image 1 Highlights • We developed a novel framework to assess watershed health using the FANP approach. • The framework considers geo-environmental, topo-hydrological and climatic criteria. • Watershed health score (WHS) was proposed for the prioritization of sub-watersheds. • It provides practical recommendations for watershed management agencies. • It is applicable even in regions with a lack of reliable hydrometric gauge data. [ABSTRACT FROM AUTHOR]

Abstract Mulching has amply proven its effectiveness to mitigate post-fire soil erosion but its impacts on soil organic matter (SOM) quality and quantity continue poorly studied. The present study addressed this knowledge gap for a eucalypt plantation in central Portugal that had been burnt and, immediately after the wildfire, mulched with 13.6 Mg ha−1 of eucalypt logging residues some five years before. This was done by performing a range of analytical techniques (elemental and isotope analyses, analytical pyrolysis and 13C NMR spectroscopy) not only on the bulk soil samples but also on their humic acids (HAs) and free organic matter (FOM) fractions. While mulching reduced soil and SOM losses with 91 and 93%, respectively, it also improved SOM quality of the topsoil, in particular in terms of HAs and FOM. At 0–4 cm depth, both HAs and FOM contents were roughly twice as high in the mulched plots as in the control plots. The effects of mulching on the molecular composition of HAs and FOM fractions, however, varied markedly. Analytical pyrolysis (Py-GC/MS) revealed that mulching had led to a noticeable accumulation of labile, aliphatic SOM constituents such as carbohydrate-derived and alkyl compounds (fatty acids and n -alkanes) but that it hardly affected the composition of HAs. Even so, solid-state 13C NMR spectroscopy showed that mulching had resulted in a relative increase in aryl C in the FOM fraction, suggesting an enhanced preservation of the pyrogenic OM. Overall, the combined use of a range of analytical techniques allowed to conclude that, five years after their application, the forest logging residues had led to a greater preservation of the fire-derived pyrogenic OM (mainly aromatic compounds) in the topsoil as well as to higher contents of SOM's most labile molecular constituents (mainly carbohydrates and n -alkyl compounds). The former reflected the reduced erosion rates, while the latter was probably due to a combination of reduced erosion rates with the additional input of fresh organic matter. Highlights • 5 years after the fire, evidence of fire effects on SOM was limited to the upper soil. • Mulching increased organic carbon, HAs and FOM contents in the topsoil. • Mulching enhanced the labile fractions of SOM compounds (carbohydrates, n -fatty acids and n -alkanes). • Effect of mulching on HA molecular composition lasted less than five years. • Mulching contributed to the preservation of pyrogenic C in the topsoil. [ABSTRACT FROM AUTHOR]

Poor cementation between soil particles is a fundamental cause of soil erosion and desertification. In recent decades, many polymers have been used to cement soil particles and improve the physical and chemical properties of soils. The contributions of polymers with different structures and functional groups to soil improvement vary considerably. In this study, a mixture comprising polyacrylamide (PAM), sodium polyacrylate (PAAS), hydroxypropyl methylcellulose (HPMC), and polyvinyl alcohol (PVA) was investigated to meet the requirements of soil water retention, erosion resistance, and plant growth. The results showed that the time required for the modified soil to reach drought conditions was extended by 4–7 days. The PAM/HPMC, PAM/PVA and PAM/PAAS experimental groups reduced the erosion rate by 99.57%, 98.3% and 96.38%, respectively, compared to that of the control group. The belowground plant biomass was significantly increased by PAM/HPMC, PAM/PAAS, and PAM/PVA, with increases of 115.92%, 145.23%, and 205.67%, respectively. HPMC contributed more to the soil erosion resistance and water-holding capacity, PAAS improved the soil porosity substantially, and PVA significantly increased the plant biomass. The rigid structures of the polymer chains enhanced the structural stability of the soil, and the hydrophilic functional groups increased the hydrophilicity of the amended soil. This study indicates different polymers that may be used to improve soil properties. [Display omitted] • Cation exchange reactions increased the particle sizes of the soil aggregates. • Polymers with rigid structures improved the stabilities of the soil structures. • The time required to reach drought was extended by 4–7 days for the amended soils. • The polymers described herein increased the plant biomass by 205.67%. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) is essential for most soil functions. Changes in land use from natural land to cropland disrupt long-established SOC balances and reduce SOC levels. The intensive use of chemical fertilisers in modern agriculture accelerates the rate of SOC depletion. Domestic organic residues (DOR) are a valuable source of SOC replenishment with high carbon content. However, there is still a lack of knowledge and data regarding whether and to what extent DOR can contribute to replenishing SOC. This paper aims to unpack the potential of DOR as a SOC source. Total SOC demand and annual SOC loss are defined and calculated. The carbon flow within different DOR management systems is investigated in three countries (China, Australia, and The Netherlands). The results show that the total SOC demand is too large to be fulfilled by DOR in a short time. However, DOR still has a high potential as a source of SOC as it can mitigate the annual SOC loss by up to 100%. Achieving this 100% mitigation requires a shift to more circular management of DOR, in particular, more composting, and direct land application instead of landfilling and incineration (Australia and China), or a higher rate of source separation of DOR (The Netherlands). These findings form the basis for future research on DOR recycling as a SOC source. [Display omitted] • Carbon in domestic organic residues is not enough to replenish carbon in soils. • More than half of domestic organic residues are not recycled to soils. • In China and Australia, landfill is the main cause of carbon loss in the system. • In the Netherlands, incineration causes the major carbon losses. • Transition to composting of organic residues could mitigate soil carbon loss. [ABSTRACT FROM AUTHOR]

The rainfall runoff process is a critical factor in determining the transport of surface materials. Simulating the surface runoff process is fundamental to accurately characterize soil erosion and soil nutrient loss. This research aims to develop a comprehensive simulation model for rainfall-interception-infiltration-runoff under vegetation cover conditions. The model integrates three key components: a vegetation interception model, Philip's infiltration model, and a kinematic wave model. By combining these models, an analytical solution is derived to simulate slope runoff considering vegetation interception and infiltration during non-constant rainfall events. To validate the reliability of the analytical solution, a numerical solution was obtained using the Pressimann Box scheme method and compared with the analytical results. The comparison confirms the accuracy and robustness of the analytical solution (R2 = 0.984, RMSE = 0.0049 cm/min, NS = 0.969). Moreover, this study investigates the influence of two significant parameters, Int m and k , on the production flow process. The analysis reveals that both parameters exert a significant impact on the timing of production initiation and the magnitude of runoff. Specifically, Int m exhibits a positive correlation with runoff intensity, while k displays a negative correlation. This research introduces a novel simulation method that enhances our understanding and modeling of rainfall production and convergence under complex slope conditions. The proposed model provides valuable insights into rainfall-runoff dynamics, particularly in scenarios characterized by varying rainfall patterns and vegetation cover. Overall, this study contributes to advancing the field of hydrological modeling and offers a practical approach for quantifying soil erosion and nutrient loss under different environmental conditions. • A rainfall-interception-infiltration-runoff simulation model under vegetation cover was constructed. • An analytical solution for slope runoff is derived. • The maximum interception rate Int m was positively correlated with runoff intensity. [ABSTRACT FROM AUTHOR]

Soil erosion has become a worldwide problem that threatens the environment and the future of economic and social development. The purpose of this study is to investigate the contribution of steep slopes and gullies to erosion in high precipitation tropical areas of the Ethiopian highlands. A trapezoidal weir was installed at the head and tail of the gully to monitor the discharge and sediment concentration from 2017 to 2020. Sediment yield and runoff are heavily influenced by the amount and timing of precipitation. The coefficients of variation for total sediment loads ranged from 65.1 to 96.1% at the head and 17.1–78.1% at the tail; the lowest coefficients were found in 2018 and the highest in 2020. Furthermore, 85% of the sediment at the tail comes from the gully, according to the four-year sediment budget. Further, a hysteretic analysis of suspended sediment concentration and runoff revealed that hilly sediment sources are limited (clockwise), then sediment can be transported through the gully via bank failures (counterclockwise). Study findings contributed to a classification of runoff patterns and an investigation of suspended sediment dynamics. In the gully tail, sediment yield was higher than in the head, suggesting gully sediment contributed more to sediment yield than large upland catchments. As a result of the study, we have been able to develop practical recommendations for managing gully erosion in the future. • In northwest Ethiopia, gully erosion is the main cause of land degradation. • Gully erosion accounted for more than 85% of the total soil loss. • In four years of runoff and sediment data, different hysteretic loop types were identified. • Sediment yields varied consistently with measurement years. • Identifying sediment source areas can assist with gully management. [ABSTRACT FROM AUTHOR]

Planning multistage implementation plans, or roadmaps, based on the spatial distribution of a best management practice (BMP) scenario is essential for achieving watershed management goals under realistic conditions, such as stepwise investment plans that involve multiple stakeholders, including investors, economic and environmental beneficiaries. The state-of-the-art BMP roadmap optimization method can address this need for optimization but is over-specialized and complex to non-expert stakeholders. This study designed a user-friendly web-based participatory watershed planning system to assist a diverse group of stakeholders in reaching a consensus on optimal roadmaps. The participatory process of stakeholders includes iteratively proposing stepwise investment constraints, submitting roadmap optimization tasks, analyzing spatiotemporal results from multiple perspectives, and selecting preferred roadmaps. The proposed system design separates the participatory process of non-expert stakeholders from the specialized modeling process of constructing simulation-optimization tools for BMP roadmaps, which is done in advance by professional modelers and encapsulated as webservices on the server side. The webservices expose a small set of essential parameters to lower barriers to use. The interactive participatory process is presented to stakeholders through web browsers with an easy-to-use interface. The system design was evaluated by implementing an agricultural watershed planning system for soil erosion reduction and conducting a role-playing experiment involving three groups of stakeholders with different standpoints in proposing investment constraints. The experimental results show that the optimal roadmap sets exhibit progressive improvements across three-round optimizations started by different stakeholders, effectively capturing the varying perspectives of stakeholders and facilitating consensus-building among them. The idea of system design and example implementation can serve as a valuable reference for developing related user-friendly environmental decision support systems. [Display omitted] • System design meets practical watershed management needs for agreed-upon roadmaps. • System separates easy-to-use interface for non-expert users from specialized models. • Browser/Server system facilitates participatory processes of multiple stakeholders. • Users participate in proposing investment plans and electing optimized roadmaps. • Multi-stakeholder role-play experiment verifies system's validity and practicality. [ABSTRACT FROM AUTHOR]

This multidisciplinary research work evaluated the effects of soil erosion on grape yield and quality and on different soil functions, namely water and nutrient supply, carbon sequestration, organic matter recycling, and soil biodiversity, with the aim to understand the causes of soil malfunctioning and work out a proper strategy of soil remediation. Degraded areas in nineteen organically farmed European and Turkish vineyards resulted in producing significantly lower amounts of grapes and excessive concentrations of sugar. Plants suffered from decreased water nutrition, due to shallower rooting depth, compaction, and reduced available water capacity, lower chemical fertility, as total nitrogen and cation exchange capacity, and higher concentration of carbonates. Carbon storage and organic matter recycling were also depressed. The general trend of soil enzyme activity mainly followed organic matter stock. Specific enzymatic activities suggested that in degraded soils, alongside a general slowdown in organic matter cycling, there was a greater reduction in decomposition capacity of the most recalcitrant forms. The abundance of Acari Oribatida and Collembola resulted the most sensitive indicator of soil degradation among the considered microarthropods. No clear difference in overall microbial richness and evenness were observed. All indices were relatively high and indicative of rich occurrence of many and rare microbial species. Dice cluster analyses indicated slight qualitative differences in Eubacterial and fungal community compositions in rhizosphere soil and roots in degraded soils. This multidisciplinary study indicates that the loss of soil fertility caused by excessive earth movement before planting, or accelerated erosion, mainly affects water nutrition and chemical fertility. Biological soil fertility is also reduced, in particular the ability of biota to decompose organic matter, while biodiversity is less affected, probably because of the organic management. Therefore, the restoration of the eroded soils requires site-specific and intensive treatments, including accurately chosen organic matrices for fertilization, privileging the most easily decomposable. Restoring soil fertility in depth, however, remain an open question, which needs further investigation. [ABSTRACT FROM AUTHOR]

Nanotechnology is increasingly being used to remediate polluted soil and water. However, few studies are available assessing the potential of nanoparticles to bind surface particles, decrease erosion, and minimize the loading of water pollutants from agricultural surface discharge. To investigate this potential, we treated in situ field plots with two practical surface application levels of anionic polyacrylamide (PAM only) with and without nanomagnetite (PAM-NM), examined soil physical properties, and evaluated the impact of this amendment on contaminant sorption and soil erosion control. Polyacrylamide and PAM-NM treatments resulted in 32.2 and 151.9 fold reductions in Mn 2+ , 1.8 and 2.7 fold for PO 4 3- -P, and 2.3 and 1.6 fold for NH 4 + -N, respectively, compared to the control. Thus, we found that the combination of PAM and NM, had an important inhibitory effect on NH 4 + -N and PO 4 3- -P transport from soil—pollutants which can contribute substantially to the eutrophication of surface water bodies. Additionally, since the treatment, especially at a high concentration of NM, was effective at reducing Mn 2+ concentrations in the runoff water, the combination of PAM and NM may be important for mitigating potential risks associated with Mn 2+ toxicity. Average sediment contents in the runoff monitored during the rainfall simulation were reduced by 3.6 and 4.2 fold for the low and high concentration PAM-NM treatments when compared to a control. This treatment was only slightly less effective than the PAM-only applications (4.9 and 5.9 fold, respectively). We report similar findings for turbidity of the runoff (2.6–3.3 fold for PAM only and 1.8–2.3 fold for PAM-NM) which was caused by the effects of both PAM and NM on the binding of surface particles corresponding to an increase in aggregate size and stability. Findings from this field-based study show that PAM-modified NM adsorbents can be used to both inhibit erosion and control contaminant transport. [ABSTRACT FROM AUTHOR]

Farmers possess a wealth of knowledge regarding soil erosion and soil and water conservation (SWC), and there is a great demand to access it. However, there has been little effort to systematically document farmers' experiences and perceptions of SWC measures. Sustainable Land Management (SLM) has largely evolved through local traditional practices rather than adoption based on scientific evidence. This research aimed to assess soil erosion and performance of different SWC measures from the farmers' perspective by documenting their perceptions and experiences in Koga catchment, Ethiopia. To this aim, workshops were organised in three sub-catchments differing in slopes and SWC measures. Workshops included group discussions and field monitoring of erosion indicators and systematically describing the status of soil erosion, soil fertility and yield to assess the performance of SWC measures. Results show that farmers are aware of the harmful effects of ongoing soil erosion and of the impacts of mitigation measures on their farms. Sheet erosion was found to be the most widespread form of erosion while rill damage was critical on plots cultivated to cereals on steep slopes. The average rill erosion rates were 24.2 and 47.3 t/ha/y in treated and untreated farmlands, respectively. SWC reduced rill erosion on average by more than 48%. However, the impacts of SWC measures varied significantly between sub-watersheds, and farmers believed that SWC measures did not prevent erosion completely. Comparatively, graded stone-faced soil bunds revealed maximum desired impacts and were most appreciated by farmers, whereas level bunds caused water logging. Most traditional ditches were highly graded and begun incising and affected production of cereals. Despite the semi-quantitative nature of the methodology, using farmers' perceptions and experiences to document land degradation and the impacts of SWC measures is crucial as they are the daily users of the land and therefore directly affecting the success or failure of SWC measures. [ABSTRACT FROM AUTHOR]

As recreational visitation to the Sonoran Desert increases, the concern of scientists, managers and advocates who manage its natural resources deepens. Although many studies have been conducted on trampling of undisturbed vegetation and the effects of trails on adjacent plant and soil communities, little such research has been conducted in the arid southwest. We sampled nine 450-m trail segments with different visitation levels in Scottsdale's McDowell Sonoran Preserve over three years to understand the effects of visitation on soil erosion, trailside soil crusts and plant communities. Soil crust was reduced by 27–34% near medium and high use trails (an estimated peak rate of 13–70 visitors per hour) compared with control plots, but there was less than 1% reduction near low use trails (peak rate of two to four visitors per hour). We did not detect soil erosion in the center 80% of the trampled area of any of the trails. The number of perennial plant species dropped by less than one plant species on average, but perennial plant cover decreased by 7.5% in trailside plots compared with control plots 6 m off-trail. At the current levels of visitation, the primary management focus should be keeping people on the originally constructed trail tread surface to reduce impact to adjacent soil crusts. [ABSTRACT FROM AUTHOR]

Forest ecosystems sustain biota on the earth as they are habitat to diverse biotic species, arrests soil erosion, play a crucial role in water cycle, sequester carbon, and helps in mitigating the impacts of global warming. Large scale land use land cover (LULC) change leading to deforestation is one of the drivers of global climate changes and alteration of biogeochemical cycles with significant consequences in ecosystem services and biodiversity. This has necessitated the investigation of LULC by mapping, monitoring and modelling spatio-temporal patterns and evaluating these in the context of human-environment interactions. The current work investigates LULC changes with temperature dynamics of select protected areas in Western Ghats. The land use analyses reveal changes in the forest cover across Kudremukh National Park (KNP), Rajiv Gandhi Tiger Reserve (RTR), Bandipur Tiger Reserve (BTR). KNP region has lost evergreen forest cover during 1973–2016 from 33.46 to 27.22%, while BTR lost deciduous cover from 61.69 to 47.3% due to mining, horticulture plantations, human habitations, etc. The LST increase has impacted regeneration of species with the induced water stress, etc. CA-Markov modelling was used for forecasting the likely land uses in 2026 and validation was done through Kappa indices. Results highlight decline of evergreen cover in KNP (9%) and deciduous cover in RTR (2%) followed by BTR (3%) with further expansion of plantations, which will impact biodiversity, hydrology and ecology. Insights of LULC dynamics help natural resource managers in evolving appropriate strategies to ensure conservation of threatened biota in Western Ghats. [ABSTRACT FROM AUTHOR]

The extent of roads and other forms of linear infrastructure is burgeoning worldwide, but their impacts are inadequately understood and thus poorly mitigated. Previous studies have identified many potential impacts, including alterations to the hydrological functions and soil processes upon which ecosystems depend. However, these impacts have seldom been quantified at a regional level, particularly in arid and semi-arid systems where the gap in knowledge is the greatest, and impacts potentially the most severe. To explore the effects of extensive track, road, and rail networks on surface hydrology at a regional level we assessed over 1000 km of linear infrastructure, including approx. 300 locations where ephemeral streams crossed linear infrastructure, in the largely intact landscapes of Australia's Great Western Woodlands. We found a high level of association between linear infrastructure and altered surface hydrology, with erosion and pooling 5 and 6 times as likely to occur on-road than off-road on average (1.06 erosional and 0.69 pooling features km −1 on vehicle tracks, compared with 0.22 and 0.12 km −1 , off-road, respectively). Erosion severity was greater in the presence of tracks, and 98% of crossings of ephemeral streamlines showed some evidence of impact on water movement (flow impedance (62%); diversion of flows (73%); flow concentration (76%); and/or channel initiation (31%)). Infrastructure type, pastoral land use, culvert presence, soil clay content and erodibility, mean annual rainfall, rainfall erosivity, topography and bare soil cover influenced the frequency and severity of these impacts. We conclude that linear infrastructure frequently affects ephemeral stream flows and intercepts natural overland and near-surface flows, artificially changing site-scale moisture regimes, with some parts of the landscape becoming abnormally wet and other parts becoming water-starved. In addition, linear infrastructure frequently triggers or exacerbates erosion, leading to soil loss and degradation. Where linear infrastructure densities are high, their impacts on ecological processes are likely to be considerable. Linear infrastructure is widespread across much of this relatively intact region, but there remain areas with very low infrastructure densities that need to be protected from further impacts. There is substantial scope for mitigating the impacts of existing and planned infrastructure developments. [ABSTRACT FROM AUTHOR]

Riparian erosion is one of the major causes of sediment and contaminant load to streams, degradation of riparian wildlife habitats, and land loss hazards. Land and soil management practices are implemented as conservation and restoration measures to mitigate the environmental problems brought about by riparian erosion. This, however, requires the identification of vulnerable areas to soil erosion. Because of the complex interactions between the different mechanisms that govern soil erosion and the inherent uncertainties involved in quantifying these processes, assessing erosion vulnerability at the watershed scale is challenging. The main objective of this study was to develop a methodology to identify areas along the riparian zone that are susceptible to erosion. The methodology was developed by integrating the physically-based watershed model MIKE-SHE, to simulate water movement, and a habitat suitability model, MaxEnt, to quantify the probability of presences of elevation changes (i.e., erosion) across the watershed. The presences of elevation changes were estimated based on two LiDAR-based elevation datasets taken in 2009 and 2012. The changes in elevation were grouped into four categories: low (0.5 - 0.7 m), medium (0.7 – 1.0 m), high (1.0 - 1.7 m) and very high (1.7 – 5.9 m) , considering each category as a studied “species”. The categories’ locations were then used as “species location” map in MaxEnt. The environmental features used as constraints to the presence of erosion were land cover, soil, stream power index, overland flow, lateral inflow, and discharge. The modeling framework was evaluated in the Fort Cobb Reservoir Experimental watershed in southcentral Oklahoma. Results showed that the most vulnerable areas for erosion were located at the upper riparian zones of the Cobb and Lake sub-watersheds. The main waterways of these sub-watersheds were also found to be prone to streambank erosion. Approximatively 80% of the riparian zone (streambank included) has up to 30% probability to experience erosion greater than 1.0 m. By being able to identify the most vulnerable areas for stream and riparian sediment mobilization, conservation and management practices can be focused on areas needing the most attention and resources. [ABSTRACT FROM AUTHOR]

Fire plays a critical role in biodiversity, carbon balance, soil erosion, and nutrient and hydrological cycles. While empirical evidence shows that fuel reduction burning can reduce the incidence, severity and extent of unplanned fires in Australia and elsewhere, the integration of environmental values into fire management operations is not well-defined and requires further research and development. In practice, the priority for fuel reduction burning is effective mitigation of risk to life and property. Environmental management objectives, including maintenance of high quality water, reduction of CO 2 emissions and conservation of biodiversity can be constrained by this priority. We explore trade-offs between fuel reduction burning and environmental management objectives and propose a framework for optimising fuel reduction burning for environmental outcomes. [ABSTRACT FROM AUTHOR]

In addition to causing physical degradation and nutrient depletion, erosion of cultivated soils in the Amazon affects aquatic ecosystems through the release of natural soil mercury (Hg) towards lakes and rivers. While traditional agriculture is generally cited as being among the main causes of soil erosion, agroforestry practices are increasingly appreciated for soil conservation. This study was carried out in family farms of the rural Tapajós region (Brazil) and aimed at evaluating soil erosion and associated Hg release for three land uses. Soils, runoff water and eroded sediments were collected at three sites representing a land cover gradient: a recently burnt short-cycle cropping system (SCC), a 2-year-old agroforestry system (AFS) and a mature forest (F). At each site, two PVC soil erosion plots (each composed of three 2 × 5 m isolated subplots) were implemented on steep and moderate slopes respectively. Sampling was done after each of the 20 rain events that occurred during a 1-month study period, in the peak of the 2011 rain season. Runoff volume and rate, as well as eroded soil particles with their Hg and cation concentrations were determined. Total Hg and cation losses were then calculated for each subplot. Erosion processes were dominated by land use type over rainfall or soil slope. Eroded soil particles, as well as the amount of Hg and cations (CaMgK) mobilized at the AFS site were similar to those at the F site, but significantly lower than those at the SCC site (p < 0.0001). Erosion reduction at the AFS site was mainly attributed to the ground cover plants characterizing the recently established system. Moreover, edaphic change throughout AFS and F soil profiles differed from the SCC site. At the latter site, losses of fine particles and Hg were enhanced towards soil surface, while they were less pronounced at the other sites. This study shows that agroforestry systems, even in their early stages of implementation, are characterized by low erosion levels resembling those of local forest environments, thus contributing to the maintenance of soil integrity and to the reduction of Hg and nutrient mobility. [ABSTRACT FROM AUTHOR]