Accelerated Soil Erosion Research Articles

Productive conservation at the landslide prone area under the threat of rapid land cover changes

Abstract Landslides often occur in the study area as a continuation of the erosion process on very thick soil from a series of volcanic ash deposition during the Tertiary and Quaternary periods. Rapid land cover changes from agricultural land into settlement increase runoff significantly causing accelerated soil erosion. Soil conservation approaches using parameters to reduce surface runoff and soil loss are less acceptable in agricultural society. Soil conservation methods aimed at reducing runoff and soil loss are not widely embraced in agricultural communities, efforts in soil conservation must be economically beneficial. Vegetative-based erosion control is the most suitable option for the agricultural communities. However, there needs to be improvements in terms of plant arrangement that is adapted to the spatial arrangement of slopes and is focused on zones along rills and gullies. Selection of tree species planted for erosion control that have the value of increasing economic income is the key to the success of planned soil and water conservation efforts.

Sediment load assessments under climate change scenarios and a lack of integration between climatologists and environmental modelers

Increasing precipitation accelerates soil erosion and boosts sediment loads, especially in mountain catchments. Therefore, there is significant pressure to deliver plausible assessments of these phenomena on a local scale under future climate change scenarios. Such assessments are primarily drawn from a combination of climate change projections and environmental model simulations, usually performed by climatologists and environmental modelers independently. Our example shows that without communication from both groups the final results are ambiguous. Here, we estimate sediment loads delivered from a Carpathian catchment to a reservoir to illustrate how the choice of meteorological data, reference period, and model ensemble can affect final results. Differences in future loads could reach up to even 6000 tons of sediment per year. We suggest there must be a better integration between climatologists and environmental modelers, focusing on introducing multi-model ensembles targeting specific impacts to facilitate an informed choice on climate information.

Historical Hazard Assessment of Climate and Land Use–Land Cover Effects on Soil Erosion Using Remote Sensing: Case Study of Oman

Human activities, climate change, and land-use alterations accelerated soil erosion in recent decades and imposed significant threats to soil fertility and stability worldwide. Understanding and quantifying the spatiotemporal variation of soil erosion risks is crucial for adopting the best management practices for surface soils conservation. Here, we present a novel high-resolution (30 m) soil erosion framework based on the G2 erosion model by integrating satellite and reanalysis datasets and Machine Learning (ML) models to assess soil erosion risks and hazards spatiotemporally. The proposed method reflects the impacts of climate change in 1 h time resolutions and land use in 30 m scales on soil erosion risks for almost 4 decades (between 1985 and 2017). The soil erosion hazardous maps were generated/evaluated using Extreme Value Analysis (EVA), utilizing long-term annual soil erosion estimations/projections to aid policymakers in developing management strategies to protect lands against extreme erosion. The proposed framework is evaluated in the Sultanate of Oman, which lacks soil erosion estimation/assessment studies due to data scarcity. Results indicate that soil erosion has increasing perilous trends in high altitudes of the Sultanate of Oman that may cause substantial risks to soil health and stability.

Predicting soil erosion risk using the revised universal soil loss equation (RUSLE) model and geo‐spatial methods

AbstractAnthropogenic activities like overgrazing, deforestation and mismanaged land use accelerate soil erosion (SE), causing nutritional and organic matter loss. In this study, we predicted the annual rate of soil loss in the Salt Range, extending south from the Pothohar plateau, Pakistan, using the Revised Universal Soil Loss Equation (RUSLE). The RUSLE model parameters and erosion probability zones were estimated using remote sensing and Geo‐Spatial methods. The annual average soil loss rates were calculated by considering five geo‐environmental factors, that is, slope length and steepness (LS), rainfall erosivity (R), cover management (C), soil erodibility (K), and conservation practice (P) range from 0–559 527, 1404–4431, 0–1, −0.14 to 1.64, and 0.2–122 respectively. This research determined that the yearly average rate of SE in the Salt Range varies from over 50 to above 350 . The distribution of land area across different SE probability zones reveals that a small portion (2.11%) is classified as High, a moderate portion (7.13%) falls under the category of Moderate, while the majority (90.7%) is classified as Low in terms of proneness towards erosion. The land devoid of vegetation and characterized by steep slopes is especially prone to SE. The Salt Range is highly vulnerable to SE risk due to climatic variations and improper land use practices. The result provides a spatial distribution of SE across the salt range, utilized for management planning processes and conservation at the policy level among decision‐makers and land‐use planners.

Lake level fluctuations and varve preservation – The sediment record from Lake Suminko (Poland) reflects European paleoclimatic changes

We present a reconstruction of Holocene lake-level fluctuations at Lake Suminko, a eutrophic hardwater lake in northern Poland. The lake contains annually laminated (varved) sediments, forming a unique archive of past hydroclimatic variability. Employing a combination of sedimentological and geochemical methods, we demonstrate that sediment core sections with well-preserved varves and lower Ca/Fe ratios correspond to periods of higher water levels associated with colder and wetter climatic conditions. We identify twelve periods of lake level high stands, consistent with other lake sediment records from western Poland and Europe, as well as with North Atlantic IRD events. Pollen data and geochemical proxies confirm negligible human impact on the lake during most of the Holocene, except for the last 500 years when accelerated soil erosion related to landscape opening and agricultural activities occurred. Therefore, we conclude that Holocene lake-level fluctuations at Lake Suminko are primarily controlled by climatic conditions regulating water availability and groundwater supplies to the lake. Our study also highlights the potential of varve preservation as a useful indicator of lake-level changes.

RUSLE‐based scenarios for sustainable soil management: Case studies from Romanian Subcarpathians

AbstractSoil erosion is one of the major threats to soil sustainability and a global environmental issue causing serious losses of the fertile upper layer of soil, affecting land productivity. Among natural processes and human activity factors, the highest sensitivity of soil loss rate is related to climate changes, as well as land cover/land use transformations. The aim of our paper is to assess the efficacy of various land cover and land use management practices under current climate conditions, as a decision‐making indicator in searching for sustainable soil‐use solutions. The approach is focused on two complementary case studies from the non‐arable hilly area of Romanian Subcarpathians and it is based on aggregating and processing Earth Observation (EO) techniques together with the Revised Universal Soil Loss Equation (RUSLE) equation. The workflow follows three stages: (1) the assessment of the present‐day status of soil erosion, as baseline scenario; (2) the analysis of historical soil erosion dynamics within the last 35 years; and (3) the prediction of soil loss rates in different scenarios of changed conditions related to land cover management and support practices against erosion. The results demonstrate the effectiveness of human interventions in soil erosion prevention, mitigation, or conservation. Soil‐improving management through vegetative measures and soil practices, like grazing management and mulching/manure application, together with forest recovery on eroded slopes may reduce soil loss rates by 50%–70%. However, abandoning the land and allowing the environment to change uncontrollably is a regional‐specific strategy that could accelerate soil erosion on the slopes that are already affected, while decelerating on the others by forest and shrubs regrowth. The significance of our research is related to the identification of the optimal soil use strategies that balance the local communities' economic interests with the effectiveness of sustainable soil management practices, thereby assisting in the achievement of the UN Sustainable Development Goals (SDGs) as indicators for a sustainable future.

Response of soil quality degradation to cultivation and soil erosion: A case study in a Mollisol region of Northeast China

Soil degradation is endangering agricultural and ecological sustainability in the Mollisol region of Northeast China. Cultivation and soil erosion are the primary drivers degrading soil quality. However, few studies have comprehensively quantified the effects of cultivation and soil erosion on soil quality degradation in Mollisols. Therefore, three sampling sites with similar landscapes, erosion environments and agricultural management practices were selected. The cultivation chronosequence was determined using a space-for-time substitution approach, including 1) forestland without cultivation (0 yr, stage I), 2) farmland with few cultivation years (< 20 yr, stage II), and 3) farmland with many cultivation years (> 80 yr, stage III). Soil erosion was quantified using the caesium-137 (137Cs) and black soil thickness. Sixteen soil physicochemical indicators were analyzed, and soil quality and its degradation were evaluated using an integrated soil quality index (SQI) and a soil degradation index (SDI), respectively. The results showed that soil erosion was profoundly accelerated by cultivation. Soil organic carbon (SOC), bulk density (BD), mean weight diameter (MWD) and soil erodibility (K) factor were selected to develop the SQI. The SQI was higher in stage I (0.61±0.05) than in stages II (0.49±0.06) and III (0.52±0.03) and decreased with increasing soil erosion rate, implying that cultivation and soil erosion exacerbated the degradation of soil quality. Furthermore, cultivation and soil erosion contributed 16.0–51.1% and 2.0–18.4% to the changes in soil quality, respectively, and their combination further amplified the impacts (8.4–61.5%). Cultivation and accelerated soil erosion driven by cultivation led to the degradation of soil quality; the former controlled the degradation processes mainly by decreasing the MWD, and the latter induced soil quality degradation by reducing the SOC and increasing the K factor. These findings are important for advancing our understanding of the driving forces and mechanisms of soil degradation in the Mollisol region.

Soil erosion in the United States: Present and future (2020–2050)

Brought on by anthropogenic actions, accelerated soil erosion inflicts extreme changes in terrestrial and aquatic ecosystems. These field-scale (30 m) changes have neither been fully surveyed in the present, nor predicted for a probable future. Water-driven soil erosion (i.e., sheet and rill erosion) rates across the contiguous United States were estimated for the present, and then predicted for the future using three alternative Shared Socioeconomic Pathway and Representative Concentration Pathway (SSP-RCP) scenarios (2.6, 4.5, and 8.5) of the Coupled Model Intercomparison Project Phase 6 (CMIP6). The G2 erosion model which is integrated with Machine Learning (ML) and Remote Sensing (RS) techniques were used to estimate soil erosion based on gauge observations of long-term precipitation, and climate and land use land cover (LULC) scenarios. The baseline model (2020) estimated soil erosion rates of 2.32 Mg ha−1yr−1 under current conservation agriculture practices (CPs). Maintaining current CPs, future scenarios predict an 8 % to 21 % increase in soil erosion under different combinations of SSP-RCP climate and LULC change scenarios. The findings of this study can help policy makers for future conservation planning on maintaining soil fertility, mitigating environmental impacts, and promoting food security.

Effects of the conversion of natural tropical rainforest to monoculture rubber plantations on soil hydrological processes

Abstract Rubber plantations have increased significantly under unprecedented economic growth in tropical areas, which leads to soil degradation and thereby alters soil hydrological processes. However, our understanding of how forest conversion affects soil hydrological processes remains unclear. Here, we collected soil samples from secondary forests (SF) and rubber plantations (RP) to determine the soil hydrological characteristics. We found the topsoil (0–20 cm) water retention in SF was higher than that of RP but displayed the contrast pattern in a deeper soil layer (20–60 cm). Meanwhile, the soil infiltration rates among the two vegetation types decreased significantly with infiltration time, with higher stable soil infiltration rates in SF than those in RP. Moreover, soil properties were also impacted by the forest conversion, such as the topsoil capillary porosity (CP) and total porosity (TP) in SF were higher than those of RP but contrasted in a deep soil layer. In comparison, the topsoil bulk density (BD) in SF was lower than that of RP, but contrasted in the deep soil layer and reached a significant level in the 0–10 and 40–50 cm (P &amp;lt; 0.05). Overall, the soil water retention was mainly determined by the CP, which could explain 31.56% of the total variance in soil water retention, followed by TP (26.57%) and soil BD (26.47%), whereas soil texture exerts a weak effect on soil water retention. Therefore, we can conclude that the conversion of tropical rainforest into rubber plantations may accelerate soil erosion owing to its lower topsoil water retention and soil infiltration rates.

Soil Erosion Modeling Using the Revised Universal Soil Loss Equation and a Geographic Information System in a Watershed in the Northeastern Brazilian Cerrado

Soils have an important task in maintaining vegetation cover and natural resources on Earth and are indispensable to societies. However, the accelerated soil erosion has become an environmental problem related to land settlement for agricultural practices and forestry and is linked to population growth. This study aimed to evaluate soil erosion in a watershed downstream of Parnaíba river, northwest of Piauí state, in the Brazilian Cerrado using geotechnology products and tools in order to understand the soil loss and map the potential erosion and actual erosion through qualitative and quantitative results to support the management and planning of the watershed in an effective and efficient way. As a modeling tool, this research used the Revised Universal Soil Loss Equation (RUSLE). The potential erosion ranged from very low to very high. The soil loss obtained by the integration of natural physical factors with land use (anthropic action) resulted in soil loss corresponding to the category slight (0–0.01 t.ha−1.year−1) to extremely high (&gt;100 t.ha−1.year−1). The areas with the greatest soil loss were identified in land uses linked to pasture, exposed soil, and cultivated land. It was also possible to identify erosion features in the field, indicating the need to implement soil conservation practices.

Sensitivity of source sediment fingerprinting to tracer selection methods

Abstract. In a context of accelerated soil erosion and sediment supply to water bodies, sediment fingerprinting techniques have received an increasing interest in the last 2 decades. The selection of tracers is a particularly critical step for the subsequent accurate prediction of sediment source contributions. To select tracers, the most conventional approach is the three-step method, although, more recently, the consensus method has also been proposed as an alternative. The outputs of these two approaches were compared in terms of identification of conservative properties, tracer selection, modelled contributions and performance on a single dataset. As for the three-step method, several range test criteria were compared, along with the impact of the discriminant function analysis (DFA). The dataset was composed of tracer properties analysed in soil (three potential sources; n = 56) and sediment core samples (n = 32). Soil and sediment samples were sieved to 63 µm and analysed for organic matter, elemental geochemistry and diffuse visible spectrometry. Virtual mixtures (n = 138) with known source proportions were generated to assess model accuracy of each tracer selection method. The Bayesian un-mixing model MixSIAR was then used to predict source contributions on both virtual mixtures and actual sediments. The different methods tested in the current research can be distributed into three groups according to their sensitivity to the conservative behaviour of properties, which was found to be associated with different predicted source contribution tendencies along the sediment core. The methods selecting the largest number of tracers were associated with a dominant and constant contribution of forests to sediment. In contrast, the methods selecting the lowest number of tracers were associated with a dominant and constant contribution of cropland to sediment. Furthermore, the intermediate selection of tracers led to more balanced contributions of both cropland and forest to sediments. The prediction of the virtual mixtures allowed us to compute several evaluation metrics, which are generally used to support the evaluation of model accuracy for each tracer selection method. However, strong differences or the absence of correspondence were observed between the range of predicted contributions obtained for virtual mixtures and those values obtained for actual sediments. These divergences highlight the fact that evaluation metrics obtained for virtual mixtures may not be directly transferable to models run for actual samples and must be interpreted with caution to avoid over-interpretation or misinterpretation. These divergences may likely be attributed to the occurrence of a not (fully) conservative behaviour of potential tracer properties during erosion, transport and deposition processes, which could not be fully reproduced when generating the virtual mixtures with currently available methods. Future research should develop novel metrics to quantify the conservative behaviour of tracer properties during erosion and transport processes. Furthermore, new methods should be designed to generate virtual mixtures closer to reality and to better evaluate model accuracy. These improvements would contribute to the development of more reliable sediment fingerprinting techniques, which are needed to better support the implementation of effective soil and water conservation measures at the catchment scale.

Wind Erodibility and Particulate Matter Emissions of Salt‐Affected Soils: The Case of Dry Soils in a Low Humidity Atmosphere

AbstractArid and semiarid ecosystems around the world are often prone to both soil salinization and accelerated soil erosion by wind. Soil salinization, the accumulation of salts in the shallow portions of the soil profile, is known for its ability to decreases soil fertility and inhibit plant growth. However, the effect of salts on soil erodibility by wind and the associated dust emissions in the early stages of soil salinization (low salinity conditions) remains poorly understood. Here we use wind tunnel tests to detect the effects of soil salinity on the threshold velocity for wind erosion and dust production in dry soils with different textures treated with salt‐enriched water at different concentrations. We find that the threshold velocity for wind erosion increases with soil salinity. We explain this finding as the result of salt‐induced (physical) aggregation and soil crust formation, and the increasing strength of surface soil crust with increasing soil salinity, depending on soil texture. Even though saline soils showed resistance to wind erosion in the absence of abraders, the salt crusts were readily ruptured by saltating sand grains resulting in comparable or sometimes even higher particulate matter emissions compared to non‐saline soils. Interestingly, the salinity of the emitted dust is found to be significantly higher (5–10 times more) than that of the parent soil, suggesting that soil salts are preferentially emitted, and airborne dust is enriched of salts.

Spatial Planning Decision Based on Geomorphic Natural Hazards Distribution Analysis in Cluj County, Romania

Spatial planning decisions form the basis of territorial progress by enhancing the resilience and opportunities for local and regional development. Therefore, decisions made as a result of multidisciplinary studies based on GIS assessment of all involved factors can provide a real and up-to-date image of the analyzed territory. In this context, geomorphic processes are among the factors restricting development, affecting built-up areas, transport infrastructure, and economic activities. This paper assesses geomorphic processes at the level of Cluj County, Romania, which mainly consist of active landslides that directly impact the accessibility of communities and their degree of safety, while accelerated soil erosion severely affects the output of land used for agriculture. GIS technology and a semi-quantitative model for determining the landslide hazard were used to classify landslides across occurrence probability classes. This methodology was implemented in Romania through Government Decision no. 447/2003. The USLE model was used to determine the soil erosion. As a result, the territory of Cluj County, which is the study area of this paper, was entirely included in one of the classes of risk concerning active geomorphic processes. Another important aspect consisted of categorizing transport infrastructure according to risk classes. A population risk assessment was also performed, taking into account the degree of accessibility of the territorial emergency department in the event that such hazards and processes occur. These results form the basis of proposals to efficiently plan the county territory, adapting decisions to the present trends in the evolution.

Long-term Tillage Practices Impact Soil Aggregation and Climate Resilience in Tunisian Field Cropping Systems

Soil degradation poses a major challenge for agricultural and socio-economic development in Tunisia. The conventional intensive cultivation practices commonly used by farmers cause rapid depletion of soil organic matter, which is adversely affecting the physio-chemical properties of soil and is accelerating soil erosion. The decrease in soil organic carbon stocks is a major factor aggravating the impacts of climate change.

Landscape Pattern of Sloping Garden Erosion Based on CSLE and Multi-Source Satellite Imagery in Tropical Xishuangbanna, Southwest China

Inappropriate soil management accelerates soil erosion and thus poses a serious threat to food security and biodiversity. Due to poor data availability and fragmented terrain, the landscape pattern of garden erosion in tropical Xishuangbanna is not clear. In this study, by integrating multi-source satellite imagery, field investigation and visual interpretation, we realized high-resolution mapping of gardens and soil conservation measures at the landscape scale. The Chinese Soil Loss Equation (CSLE) model was then performed to estimate the garden erosion rates and to identify critical erosion-prone areas; the landscape pattern of soil erosion was further discussed. Results showed the following: (1) For the three major plantations, teas have the largest degree of fragmentation and orchards suffer the highest soil erosion rate, while rubbers show the largest patch area, aggregation degree and soil erosion ratio. (2) The average garden erosion rate is 1595.08 t·km−2a−1, resulting in an annual soil loss of 9.73 × 106 t. Soil erosion is more susceptible to elevation and vegetation cover rather than the slope gradient. Meanwhile, irreversible erosion rates only occur in gardens with fraction vegetation coverage (FVC) lower than 30%, and they contribute 68.19% of total soil loss with the smallest land portion, indicating that new plantations are suffering serious erosion problems. (3) Garden patches with high erosion intensity grades and aggregation indexes should be recognized as priorities for centralized treatment. For elevations near 1900 m and lowlands (&lt;950 m), the decrease in the fractal dimension index of erosion-prone areas indicates that patches are more regular and aggregated, suggesting a more optimistic conservation situation.

Soil erosion triggered by the archeological excavation and conservation of trenches. The case of “Cerro de las Trincheras” in Bailén (Jaén, Spain)

Gully erosion is a landform developed due to accelerated soil erosion rates. Gullies can be identified by human impacts on geomorphological processes, as well as hydrological and erosional systems. In Spain, the trenches or "trincheras" from the Spanish Civil War (1936-1939) are considered of archaeological interest for several reasons. At Cerro de las Trincheras in Bailén (Jaén, Spain), a trench was built during the Spanish Civil War. In 2020, an archaeological excavation took place to restore the ruins, triggering the development of gullies and rills and a decrease in vegetation quality. We present a first approximation of the variations in vegetation cover and the decrease in quality (using NDVI, the normalized difference vegetation index) due to the trench acting as a gully (1956, 2005-2020) and the increase in rills and gullies after the excavation. We strongly advocate for future archaeological excavations to include a protocol (soil mapping, vegetation survey, and hydrological connectivity index) to reduce soil degradation and prevent damage to vegetation and associated ecosystems, thereby curbing the increase in soil erosion rates.

Soil Erosion in Extensive versus Intensive Land Uses in Areas Sensitive to Desertification: A Case Study in Beira Baixa, Portugal

The occurrence of long periods of drought followed by extreme episodes of rainfall and ineffective soil conservation practices are the main causes of soil erosion in the Mediterranean region. The objective of this paper is to assess and compare the hydrological and erosional responses related to land use changes in agricultural landscapes that are sensitive to erosion and that are a result of the significant replacement of traditional land uses. Such changes are characterized by the replacement of extensive olive groves associated with pastureland by intensive almond production, where deep plowing and heavy machinery are required. In each sampling site, runoff initiation, runoff coefficient, and soil loss were evaluated under simulated rainfall (55 mm h−1), at plot scale (0.25 m2), at the end of the hot and dry summer period. Slope gradient, soil texture, bulk density, soil organic matter content, soil water content, and plant cover were also determined. The results showed the impact of recently planted intensive almond orchards (IAOs) on accelerating soil erosion risk compared with the extensive traditional olive groves (EOGs), although runoff initiation and discharge are very similar between the studied land uses. The mean values recorded for soil loss and sediment concentration were 118 g m−2 h−1 and 12 g m−2 h−1 and 3.1 g L−1 and 0.7 g L−1, respectively, for IAOs and EOGs. Our results also demonstrated that maintaining a vegetation cover is a determining factor for the prevention and control of soil erosion, especially in IAOs, where retaining high percentages of natural plant-residue mulch layers (&gt;70%) reduced soil loss by about 70% in this study.

Quantification of Mountainous Hydrological Processes in the Aktash River Watershed of Uzbekistan, Central Asia, over the Past Two Decades

Estimation of hydrological processes is critical to water resource management, water supply planning, ecological protection, and climate change impact assessment. Mountains in Central Asia are the major source of water for rivers and agricultural practices. The disturbance of mountain forests in the region has altered the hydrological processes and accelerated soil erosion, mudflow, landslides, and flooding. We used the SWAT (Soil and Water Assessment Tool) model calibrated and validated with remote sensing data to quantify the mountainous hydrological processes in the Aktash River watershed (ARW) of Uzbekistan, Central Asia. Simulations showed that the daily surface runoff and streamflow closely responded to daily precipitation. Groundwater discharge reached its maximum in winter because of snowmelt. The wet months were from July to December, and the dry months were from January to June. The magnitudes of the seasonal hydrological processes were in the following order: fall &gt; summer &gt; winter &gt; spring for precipitation and surface runoff; summer &gt; spring &gt; fall &gt; winter for evapotranspiration (ET); winter &gt; spring &gt; fall &gt; summer for snowmelt; fall &gt; winter &gt; summer &gt; spring for water yield and streamflow; and winter &gt; fall &gt; spring &gt; summer for groundwater discharge. The Mann–Kendall statistical test revealed a significant increasing trend for the annual precipitation (τ = 0.45, p &lt; 0.01) and surface runoff (τ = 0.41, p &lt; 0.02) over the past 17 years from 2003 to 2019. Compared to rangeland, forested land decreased monthly and annual average surface runoff by 20%, and increased monthly and annual average groundwater recharge by about 5%. Agricultural land had much higher unit-area values (mm/km2/y) of ET, groundwater recharge, and water yield than those of urban, forest, and range lands. Our research findings provide useful information to farmers, foresters, and decision makers for better water resource management in the ARW, Central Asia, and other mountain watersheds with similar conditions.

Substantially Enhanced Landscape Carbon Sink Due To Reduced Terrestrial‐Aquatic Carbon Transfer Through Soil Conservation in the Chinese Loess Plateau

AbstractSoil conservation is of global importance, as accelerated soil erosion by human activity is a primary threat to ecosystem viability. However, the significance and role of soil conservation in reshaping landscape carbon (C) accounting has not been comprehensively integrated in the terrestrial C sink. Here, we present the first integrated assessment of the modified terrestrial C sink and aquatic C transport due to soil conservation for the semiarid Chinese Loess Plateau (CLP), the world's most vulnerable region to soil erosion. We show a surprisingly low terrestrial‐aquatic C transfer that offset the terrestrial net ecosystem productivity by only 7.5%, which we attribute to the effective implementation of soil conservation practices. Despite the highest soil erosion, the semiarid CLP acts as effective C sink at 43.2 ± 22.6 g C m−2 year−1, which is comparable to temperate forest in absorbing atmospheric CO2. Moreover, C burial in reservoirs has created an additional anthropogenic C sink of 2.9 ± 1.1 g C m−2 year−1. Our findings indicate that effective soil conservation can significantly increase landscape C sequestration capacity. The co‐benefits of soil conservation in erosion control and C sequestration have important implications for policy makers in other regions undergoing increasing erosion intensity to pursue environmental sustainability.

Climate-smart forestry in the world’s drylands: A review of challenges and opportunities

Land degradation and desertification are widespread across the world’s drylands. These processes are substantially affected by climatic change, with long-term and severe droughts on the one hand, and high intensity rainstorms and devastating floods on the other hand. Simultaneously, land-use change and mismanagement practices have led to processes of accelerated soil erosion, depletion of soil organic carbon pools, and the degradation of extensive drylands. Forestry has been accepted as an effective means for restoring degraded drylands, and for attaining a range of regulating, provisioning, supporting, and cultural ecosystem services. Specifically, forestry is widely perceived as an effective means for soil erosion control, organic carbon sequestration, microclimate improvement, and climate change mitigation. However, forestry in drylands often proves to generate substantial environmental challenges, resulting in deterioration of ecosystem functions and health. The objective of this essay is to review the challenges and opportunities induced by dryland afforestation and reforestation, and highlight the need to attain climate-smart strategies for establishing and managing these land-uses. Particularly, tree species invasion and allelopathy, which are common in dryland forestry projects, jeopardize species richness and diversity of native vegetation communities. Further, the challenges linked with tree invasiveness necessitate predicting the distribution of potentially invasive species and foreseeing their impacts on the recipient ecosystems under projected climate change scenarios. The effect of allelopathy is significant under limited water availability conditions and is expected to be determined by the expanding drylands and intensifying aridity worldwide. Therefore, judicious selection of tree species should not only focus on ones with high water-use efficiency, low flammability, high pest resistance, and fast growth, but also on low invasiveness and allelopathic capacities. Insights of this essay may be used by land managers, stakeholders, and policy makers involved in environmental development of drylands.