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High-elevation and cold regions have harsh natural conditions with low temperatures and intense ultraviolet radiation, which impede plant growth and maintenance. Therefore, soil and water conservation vegetation restoration models are of great significance. In this study, a site condition analysis was performed based on three main limiting factors, including climatic and meteorological, soil, and topographic and geomorphological factors, providing a basis for vegetation restoration. The study area was divided into different site types. After investigating the situation of nurseries distributed in places such as Tibet, Qinghai, and Sichuan, trees, shrubs, and grasses with ecological characteristics similar to those of the local vegetation, including strong stress resistance, good soil and water conservation benefits, and well-established artificial cultivation practices, were selected as alternative vegetation for late-stage planting of indigenous tree species. Combining the results of site condition analysis and site type classification, the configuration of trees, shrubs, and grasses for different off-site condition types and the corresponding greening methods are discussed, providing a scientific reference for ecological restoration in high-elevation and low-temperature regions. [ABSTRACT FROM AUTHOR]

Vegetation restoration plays a crucial role in conserving soil and water, as well as rehabilitating ecosystems, by enhancing soil properties and vegetation attributes. The evaluation of the ecological consequences among different vegetation restoration types can be achieved by clarifying the impacts on carbon, water and nutrient storages. In this study, we selected four typical vegetation restoration types (Pinus tabuliformis forest (PTF), Platycladus orientalis forest (POF) and Robinia pseudoacacia forest (RPF) as typical planted forests, and the natural secondary forest (NSF) as the control treatment) in the eastern Loess Plateau of China. The soil properties (at 0–200 cm depth) and vegetation attributes (including arborous, shrubs and herbaceous plants) were measured, as well as calculated soil carbon, water and nutrient storages, with a total of 1600 soil samples and 180 vegetation survey plots. The partial redundancy analysis (pRDA) and correlation analysis were also used to analyze the contributions and relationships among environmental factors, soil eco-hydrology and nutrient supplement services in different forestry ecosystems. The results indicate the following: (1) NSF has the lowest soil bulk density (1.21 ± 0.184 g·cm−3). Soil properties varied significantly at vertical scales, and had obvious surface accumulation. (2) Soil moisture storages were better in natural forests than those in planted forests, with more drastic changes in soil moisture dynamics. (3) The soil carbon, nitrogen, and phosphorus storages significantly differed among four vegetation types, with the highest carbon storages in PTF (207.75 ± 0.674 t·ha−1), the highest nitrogen storages in POF (5.54 t·ha−1), and the highest phosphorus storages in RPF (4.33 t·ha−1), respectively. (4) Soil carbon storages depend primarily on the coupling effect of soil properties and precipitation, while nutrient storage is mainly influenced by soil properties. The results quantify the significant differences in soil water, carbon, and nutrient storage across various vegetation restoration types, and reveal the individual and combined contributions of environmental factors, providing new insights into the mechanisms driving these differences. These findings offer practical guidance for the sustainable management of forest ecosystems and the optimization of ecological restoration strategies on the Loess Plateau. [ABSTRACT FROM AUTHOR]

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Water resources sustainability is an increasing concern, requiring accurate estimates of the hydrological processes involved. This study evaluates the impacts of climate change (CC) and land use (LU) in a river basin in the Brazilian semi-arid. Using the Soil & Water Assessment Tool (SWAT), calibration/ validation was carried out based on limited measurements for discharge and using complementary remote sensing information for evapotranspiration (ET), as well as experimental data for soil moisture (SM). The evapotranspiration data used for calibration were obtained from the MOD16A2 product, at sub-basin scale. Principal component analysis was used to evaluate the interaction between variables. To assess the impacts of CC e and LU two scenarios were investigated: S1 – LU map without insertion of Permanent Preservation Areas (PPA), and S2 – with insertion of PPA. The Regional Climate Models (RCM) Eta-MIROC5 and Eta-HADGEM-ES for the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios were adopted. The SWAT model adequately represented evapotranspiration, with Nash-Sutcliffe coefficient (NS) of 0.67 for calibration, and 0.74 for validation. For wet periods, the SM simulated values were similar to the experimental measurements with a coefficient of determination (R²) of 0.68. Complementary information for evapotranspiration and soil moisture across sub-basins successfully allowed consistent spatially distributed hydrological variables to be simulated. The model performance for validation using ET data was higher (NS = 0.77) compared to previous streamflow-only calibration strategies for flow (NS = 0.42) and soil moisture (NS = 0.46). Under the CC scenarios, natural vegetation restoration would compensate reductions in water availability. [ABSTRACT FROM AUTHOR]

[Objective] This study was aimed to explore the characteristics of soil organic carbon and moisture content under different vegetation restoration types and their relationships, and to provide a scientific basis for the selection of vegetation restoration models in the Mu Us sandy land. [Methods] Different vegetation restoration types, including natural restoration of grassland and various plants such as Artemisia desertorum, Salix psammophila, A. desertorum S. psammophila mixed (shrub-shrub mixed), Pinus sylvestris, S. psammophila P. sylvestris mixed (tree-shrub mixed), in the Mu Us sandy land, were studied. Bare sand was used as the control. The effects and correlations of different vegetation restoration types on carbon and water in the 0-5.0 m soil profile were analyzed. [Results] (1) Vegetation restoration increased, with S. psammophila P. sylvestris mixed, P. sylvestris, Grassland, A. desertorum S. psammophila mixed, A. desertorum S. psammophila mixed, and A. desertorum showing decreasing trends, with significant accumulation effects observed within the 0—0.2 m soil depth. As soil depth increased, the organic carbon content of all vegetation types gradually decreased. Within the depth range of 0.8—2.2 cm, A. desertorum, S. psammophila, and A. desertorum S. psammophila mixed exhibited carbon loss. (2) Different vegetation restoration types showed varying degrees of soil moisture deficit in deep soil layers, primarily concentrated at 1—3.0 m soil layer, with S. psammophila P. sylvestris mixed showing the most severe deficit, followed by P. sylvestris, A. desertorum S. psammophila, S. psammophila, Grassland, A. desertorum. (3) Roots were identified as the main factors influencing soil organic carbon content and moisture consumption. Soil organic carbon content exhibited a negative correlation with soil moisture within the 0—5.0 m soil depth range. [Conclusion] Vegetation carbon storage was achieved at the expense of utilizing deep soil moisture, with S. psammophila P. sylvestris mixed exhibiting the lowest water consumption per unit of fixed carbon. The study suggests that S. psammophila P. sylvestris mixed exhibits favorable effects in vegetation restoration from the perspective of soil carbon retention and water retention in the Mu Us sandy land.

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Rocky desertification is a devastating process in Karst areas of Southwest China and induces serious fragmentation in ecosystems. Therefore, vegetation restoration and the scientific evaluation of soil quality are key restorative strategies in these areas. In this study, a natural closed forest and a disturbed forest with three restoration models, including an evergreen broad-leaved forest, mixed forest, and deciduous forest, were investigated in Huanjiang County. More than nineteen soil properties (including physical, chemical, and biotic properties) were analyzed across treatments, and principal component analyses (PCA) were combined with a minimum data set (MDS) applied to evaluate the soil quality. Our study sought to identify a vegetation restoration model to improve the soil quality in this area. We demonstrated that soil physical and chemical properties, microbial biomass, and enzyme activities significantly differed across all of the models. Soil water content, capillary porosity, total porosity, organic carbon, total phosphorus, available phosphorus, and urease activity were high in the mixed forest, leading to better physical soil properties. Also, relatively high soil total nitrogen, total potassium, available nitrogen, available potassium, microbial biomass C and N, catalase, sucrose, and alkaline phosphatase levels were observed in the deciduous broad-leaved forest, resulting in improved soil chemical properties. Based on the minimum data set (MDS) method, six indicators, including non-capillary porosity, organic carbon, total phosphorus, pH, microbial biomass nitrogen, and urease activity, were selected to evaluate the soil quality across the models. Our data showed that, among the five models, the deciduous broad-leaved forest had the highest soil quality index (0.618), followed by the mixed forest (0.593). Stepwise regression analysis showed that soil organic carbon explained 79.9% of the variations in the soil quality indices, suggesting it was a major factor affecting the soil quality. Thus, vegetation restoration models mainly comprised of native tree species effectively improved the soil quality in Karst rocky desertification areas, with deciduous broad-leaved forests displaying the best effects, followed by mixed forests. [ABSTRACT FROM AUTHOR]

Vegetation primarily draws water from soil moisture (SM), with restoration in drylands often reducing SM storage (SMS). However, anomalies have been detected in the Beijing–Tianjin Sand Source Region (BTSSR) of China via the Global Land Data Assimilation System (GLDAS) and Gravity Recovery and Climate Experiment (GRACE). This study quantified the sources of increased SMS in drylands to elucidate the effects of vegetation restoration on SMS. The results indicated the following: (1) In vegetated drylands, 46.2% experienced a significant increase in SMS while 53.8% remained stable; both were positively correlated with the normalised difference vegetation index (NDVI). (2) The increase in SMS was accompanied by a decrease in groundwater storage (GWS), as indicated by the significant correlation coefficients of −0.710 and −0.569 for SMS and GWS, respectively. Furthermore, GWS served as the primary source of water for vegetation. (3) The results of the redundancy analysis (RDA) indicated that the initial vegetation, the driver of the observed trend of increased SMS and decreased GWS, accounted for 50.3% of the variability in water storage. Therefore, to sustain dryland ecosystems, we recommend that future vegetation restoration projects give due consideration to the water balance while concurrently strengthening the dynamic monitoring of SMS and GWS. [ABSTRACT FROM AUTHOR]

Soil moisture is crucial to vegetation restoration in karst areas, and climate factors and vegetation restoration are key factors affecting changes in soil moisture. However, there is still much controversy over the long‐term changes in soil moisture during vegetation restoration. In order to reveal the changes in soil moisture during vegetation restoration, we conducted long‐term positioning monitoring of soil moisture at 0–10 and 10–20 cm on secondary forests sample plot (SF, tree land) and shrubs sample plot (SH, shrub land) in karst areas from 2013 to 2020. The results showed that the aboveground biomass of SF and SH increased by 50% and 240%, respectively, and the soil moisture of the SF and SH showed an increasing trend. When shrubs are restored to trees in karst areas, the soil moisture becomes more stable. However, the correlation coefficients (R2) between the annual rainfall and the annual average soil moisture of SF and SH are 0.84 and 0.55, respectively, indicating that soil moistures in tree land are more affected by rainfall. The soil moisture of shrubs and trees are relatively low during the months of alternating rainy and dry seasons. Rainfall has a very significant impact on the soil moisture of tree land, while air temperature and wind speed have a significant impact on the soil moisture of tree land, but the soil moistures of shrub land are very significantly affected by rainfall and relative humidity. Therefore, during the process of vegetation restoration from shrubs to trees, the main meteorological factors that affect soil moisture changes will change. The results are important for understanding the hydrological processes in the ecological restoration process of different vegetation types in karst areas. [ABSTRACT FROM AUTHOR]

Planting alfalfa is one of the biological measures to manage the Pisha stone area in the Yellow River Basin, where soil erosion is serious, and the ecosystem is extremely fragile. The characteristics and driving factors of plant-soil ecological stoichiometry during the planting process of the loess layer (LL) (0-90 cm) and Pisha stone layer (PSL) (90-180 cm) were studied to reveal the limiting factors of plant-soil nutrients and the driving mechanism of ecosystem evolution in this area. In this study, the correlation between the contents of carbon (C), nitrogen (N), phosphorus (P), and their ratios in alfalfa and soil with different planting years (2, 5, 8, and 10 yr) was measured. Plant-soil C, N, and P stoichiometry characteristics were explored to analyze the influence mechanisms of fallow years and soil layers. The results showed that the changes of C, N, and P in alfalfa were similar to those of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) in LL. Alfalfa C/N was significantly positively correlated with soil C/P and N/P. Alfalfa growth is limited by N in the early stages and P in the middle and late stages, which can provide a theoretical basis for vegetation restoration and soil erosion management in the Pisha stone region. This study investigated the stochastic properties of the alfalfa-soil continuum and its fluctuations with the planting year. [ABSTRACT FROM AUTHOR]

In the Loess Plateau, gaining insights into the water storage and soil retention functions of diverse vegetation types, especially, in the semi‐arid watersheds is crucial for identifying the key factors necessary to ensure sustainable development and achieve land degradation neutrality. In this study, five different land use types such as forest, shrub, artificial grass, and natural grasslands were surveyed from 2014 to 2020. Meanwhile, bare land was also used as a control plot. The trade‐off between erosion mitigation and water consumption indicator was quantified based on the ecosystem services perspective benefits. Our results showed that there are significant differences among different land use types (p < 0.05): natural grassland > shrubs > artificial grassland > forests. Vegetation restoration was able to change the soil particle size distribution, increasing clay and silt content, and decreasing sand particles. During the growing season, surface soil water storage decreased in all land use types coinciding with the higher decrease in the control plot. The change in surface water storage in the forest was the most stable, with a decrease of 0.13 mm. The trade‐off between erosion mitigation and water consumption indicator was less than 0 for all vegetation types, which indicates a synergistic effect on soil conservation and water storage benefit. Our results demonstrated that shrubs can register the most balanced benefit of water storage and soil preservation. This is a solid basis for the selection of specific vegetation types and the optimization of the watershed landscape in the middle reaches of the Yellow River, characterized by vulnerable areas due to aridification. [ABSTRACT FROM AUTHOR]

Under the background of climate change, vegetation restoration in arid area ecosystem is faced with great challenges, which has important research value and is also an important research direction of ecology. In this paper, CiteSpace software was used to carry out data mining and econometric analysis on the research progress of vegetation restoration in arid area ecosystem. Besides, the number of papers published under this topic, the trend of change, the main research strength and the development path of the research topic were presented. The study found that (1) the overall volume of papers showed a significant growing tendency on the whole, and generally experienced three growth stages of slow, steady and rapid growth. The research hotspots were different at different stages. At present, the research mainly focuses on clustering topics such as “soil moisture”, “abandoned farmland”, “biological soil skinning” and “layered soil”, and the cross-study of engineering, hydrology, geosciology and other related disciplines is increasing day by day. (2) China, the United States and Spain were the countries with the largest number of publications, and the Chinese Academy of Sciences was the research institution with the largest number of publications. Li Xinrong and others constituted the core group of authors under the research topic. (3) The strategies of vegetation restoration in response to drought stress and the changing rules of the structure and function of different restored ecosystems under the background of climate change may be the research hotspots of vegetation restoration in arid areas in the near future. [ABSTRACT FROM AUTHOR]

In arid and semi-arid sand dune ecosystems, belowground bud bank plays an important role in population regeneration and vegetation restoration. However, the responses of belowground bud bank size and composition to sand burial and its induced changes in soil environmental factors have been rarely studied. In arid sand dunes of Northwestern China, we investigated belowground bud bank size and composition of the typical rhizomatous psammophyte Psammochloa villosa as well as three key soil environmental factors (soil moisture, total carbon and total nitrogen) under different depths of sand burial. Total buds and rhizome buds increased significantly with increasing burial depth, whereas tiller buds first increased and then decreased, with a peak value at the depth of 20-30 cm. Soil moisture increased significantly with sand burial depth, and was positively correlated with the number of all buds and rhizome buds. Soil total carbon concentration first increased and then decreased with sand burial depth, and total nitrogen concentration was significantly lower under deep sand burial than those at shallow depths, and only the number of tiller buds was positively correlated with soil total nitrogen concentration. These results indicate that soil moisture rather than soil nutrient might regulate the belowground bud bank of P. villosa, and that clonal psammophytes could regulate their belowground bud bank in response to sand burial and the most important environmental stress (i.e., soil moisture). These responses, as the key adaptive strategy, may ensure clonal plant population regeneration and vegetation restoration in arid sand dunes. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Soil & Water Conservation is the property of Bulletin of Soil & Water Conservation Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: To solve the withering of Hippophae rhamnoides plantation in the feldspathic sandstone areas of Inner Mongolia and to promote the regeneration, rejuvenation, and sustainability of H. rhamnoides forests. Methods: We stumped aging H. rhamnoides trees at the ground heights of 0, 10, 15, and 20 cm (S1, S2, S3, and S4, respectively) and utilized unstumped trees as the control (CK). We then analyzed the effects of the different stump heights on the roots and the root microenvironment of H. rhamnoides and the relationship between the roots and the root microenvironment in the stumped H. rhamnoides. Results: The root fractal features, root branching rate, root length, root soluble proteins, soil moisture content, and soil nutrients among the different treatments were ranked as S3>S2>S1>S4>CK (P < 0.05). The root topological index, root proline, and malondialdehyde among the different treatments were ranked as S3

Purpose: Vegetation restoration types influence the physicochemical properties and near-surface characteristics of soil and likely affects soil resistance. However, variations in the characteristics of soil resistance under different vegetation restoration types have not been characterized in the severely eroded subtropical regions of South China. The objective of this study was aimed to identify the mechanism of soil resistance under different vegetation restoration types and simulate the prediction equation. Materials and methods: This study examined four typical vegetation restoration types that were restored by artificial planting forest (AF), orchard (AO), scrubland (AS) and grassland (AG) and compared them with unrestored eroded land (EL) as a control. The soil detachment rate was measured by scouring the soil with steel cutting rings with flowing water under five shear stress intensities (3.40–18.11 kPa). This study quantified the effects of typical types of vegetation restoration on soil resistance in severely eroded subtropical regions of South China by identifying the major factors and simulating a prediction equation. Results: The results showed that the eroded land had the maximum soil detachment rate (0.474 kg m−2 s−1), and then was the most easily detached. It was followed sequentially by the artificial grassland, the artificial scrubland, the artificial orchard and the artificial forest. The soil detachment rate was negatively correlated with clay content, capillary porosity, soil organic matter content, soil cohesion (p < 0.01) and soil initial water content (p < 0.05), and it was a positively correlated with silt content (p < 0.01). Near-surface characteristics also inhibited the soil detachment process to some extent. A similar trend was observed for rill erodibility, which was dominated mainly by soil organic matter content, root surface density and sand content (NSE = 0.806). The critical shear stress was significantly positively related to soil cohesion and biological crust thickness (NSE = 0.632). Conclusions: Based on the Water Erosion Prediction Project (WEPP) model, the soil detachment rate was simulated from easily measured factors, such as sand content, soil organic matter content, soil cohesion, biological crust thickness and root surface density (R2 = 0.812, NSE = 0.827). This observation provides a reference regarding the soil–water erosion process in severely eroded subtropical regions in South China. [ABSTRACT FROM AUTHOR]

Vegetation restoration measures have been increasingly employed to alleviate rocky desertification in karst ecosystems. However, the comprehensive effects of these interventions on soil properties and soil organic carbon (SOC) remain poorly understood. Herein, we gathered 644 paired observations from 68 studies and conducted a meta-analysis to quantify the performance of different vegetation restoration measures including moss (MS), grassland (GL), cash crop (CP), shrub (SH), and secondary forest (SF) through soil properties and SOC. Our results demonstrated significant effects of MS, GL, CP, SH, and SF on soil biotic and abiotic factors, each with distinct response characteristics. Particularly, MS significantly enhanced all soil properties (excluding a slight decrease in soil pH by 10.8%). Moreover, MS, GL, CP, SH, and SF could elevate SOC by 32.1%, 17.6%, 24.9%, 59.2%, and 48.7% respectively. Utilizing random forest and linear regression models, we identified primary drivers for SOC in MS, GL, CP, SH, and SF as soil moisture content, arbuscular mycorrhizal fungi, soil microbial phosphorus, total nitrogen, and β-1,4-glucosidase, respectively. This meta-analysis underlined the varied effects of vegetation restoration measures on soil properties and advocates for restoration measures that prioritize plant productivity and reduce soil temperature during the karst rocky desertification restoration process. Additionally, this study underscores the pivotal role of vegetation rehabilitation in environmental conservation and carbon sequestration of ecologically vulnerable regions. • Vegetation enhancing carbon sequestration in rocky desertification areas. • Moss enhances SOC sequestration by improving soil moisture. • Soil microorganisms dominate the impact of vegetation restoration on SOC. [ABSTRACT FROM AUTHOR]

• Soil bulk density and soil porosity are important factors influencing runoff and soil loss. • Grass + Fish-scale pits measures are most effective in reducing understorey soil erosion. • The aboveground component was much better at preventing soil erosion than the root. • Near soil-surface characteristics influenced by vegetation restoration have a weaker effect on runoff than on soil loss. Vegetation restoration affects soil erosion by altering near soil-surface characteristics and hydrodynamic mechanisms. However, the regulatory mechanisms of vegetation restoration in reducing soil erosion under forests are not fully clear. Five soil and water conservation measures (SWCM) with different vegetation structures and characteristics were used in the pure forest of Pinus massoniana which included the grass and shrub, grass, grass and shrub + level furrow, grass, shrub and trees and grass + fish-scale pits, to analyze the impact of vegetation restoration on near soil-surface characteristics and soil erosion. The data were analyzed using Structural Equation Modeling (SEM) to find the key indicators affecting soil erosion under forest. The findings revealed that, as opposed to the control plots (CK), there were significant alterations in the near soil-surface attribute following the application of SWCM. These changes were characterized by an increase in soil porosity, soil water content, soil nutrient content, root biomass, litter, and vegetation cover, and a decrease in soil compaction, disintegration coefficient, and bulk density, with the most significant improvement occurring in 0–10 cm soil layer. The SWCM significantly reduced soil erosion, with runoff and soil loss reduction ranging from 60.46 % to 74.09 % and 67.62 % to 79.99 %, respectively. Structural equation models revealed the influence of SWCM on soil erosion. Specifically, soil water content and litter had a favourable influence on reducing soil erosion, root biomass had a direct positive impact on soil erosion, and vegetation cover directly leads to a reduction in soil erosion. Soil physical properties primarily influenced soil erosion through their effect on vegetation cover. Combining bioengineering and vegetation measures is superior at enhancing soil structure, improving nutrient content, and decreasing soil erosion compared to single vegetation measures. It is recommended to combine bioengineering with vegetation strategies to effectively curb understory forest erosion and enhance soil quality in pine forests. [ABSTRACT FROM AUTHOR]

As a crucial aspect of terrestrial ecosystems, water plays a key role in soil hydrological cycling and ecological management. However, limited knowledge exists on how soil water varies along rock fragment content (RFC) beneath plants. In this study, we investigated soil water content (SWC) and relative soil water deficit (DSWC) with four RFC levels ranging from 0 to 75 % (V/V) under four native species, including A. vestita , B. brachycarpa , C. szechuanensis , and S. davidii , and their relationships with soil physical properties and plant functional traits. Results showed that an increase in RFC significantly decreased SWC (except A. vestita) at soil depth of 10–50 cm and altered its vertical trend from unimodal to increasing under each plant. Notable differences in SWC between the wet and dry seasons in 75 % RFC disappeared under A. vestita and B. brachycarpa , suggesting that the RFC changed the spatiotemporal patterns of the SWC. DSWC generally decreased as soil depths deepened under A. vestita with shallow roots, in contrast to increasing under other deep-rooted species (B. brachycarpa , C. szechuanensis , and S. davidii). The seasonal variance of DSWC basically decreased with soil depth. This indicated that the plants generally deceased SWC, particularly in the wet season, and the effect depended on interspecific traits. SWC and DSWC had closely relationships with soil physical properties and plant performing. We suggest that varying RFC indirectly impacted soil water not only via altering soil structure and temperature, but also by shaping plant characteristics (especially root distribution and architecture), mediating plant effect on the spatiotemporal dynamics of SWC. [ABSTRACT FROM AUTHOR]

• Rainfall infiltration on the greening CLP is less studied in the non-growing season. • 3-year, 10-min soil moisture data were collected in paired catchments on the CLP. • Growing season favored deeper, faster rainfall percolation and preferential flow. • Non-growing season showed restrained infiltration depth and velocity. • Factors controlling infiltration varied between growing and non-growing seasons. Rainfall infiltration into hillslopes on the Chinese Loess Plateau (CLP) undergoes noticeable changes during the growing season following long-term revegetation. However, infiltration patterns during the non-growing season have been understudied. In this study, we monitored soil moisture over three years (May 2016-December 2018) at 10-minute intervals, spanning five soil depths (10, 20, 40, 60, and 100 cm). Monitoring was conducted in both a forestland catchment and an adjacent grassland catchment on the CLP, with two monitoring sites per catchment: one downhill in the gully, and the other uphill on the slope. Our findings reveal pronounced seasonal variations in meteorological conditions and vegetation index. We observed divergent rainfall infiltration patterns and their governing factors between the growing (May to October) and non-growing seasons (November to April). During the growing season, rainfall facilitated a quicker response with shorter lag time (23.34 h vs. 56.84 h in the non-growing season) and noticeable soil moisture increments (up to 35.7 % cm3/cm3 vs. only up to 6.4 % cm3/cm3). The wetting depth often extended to 40–100 cm (compared to 10–40 cm in the non-growing season), with a higher wetting front velocity (17.44 mm/h vs. 6.24 mm/h) and an increased occurrence frequency of preferential flow (19.77 % vs. 9.72 %). The impact of rainfall amount and peak intensity on infiltration was more pronounced during the non-growing season, whereas, in the growing season, infiltration was additionally influenced by antecedent moisture conditions and vegetation type. Notably, in the growing season, the enhanced soil moisture recharge due to rainfall infiltration exceeded the rise in evapotranspiration, resulting in higher soil water storage. The findings of this study shed new light on seasonal infiltration dynamics on the greening CLP, contributing valuable insights into hillslope hydropedological processes post-revegetation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Vegetation restoration on the Loess Plateau increased the extend and depth of infiltration. • Vegetation restoration on the Loess Plateau has altered the pattern of uniform water infiltration, resulting in a distinct preferential flow in the infiltration processes. • Mixed-mode afforestation is better than single-dominant-species afforestation to promote precipitation infiltration. • The preferential flow phenomenon was more pronounced in the natural secondary forest than that in plantation forests. In order to improve the fragile ecological environment, the Loess Plateau region of China has implemented a large number of long-term forest vegetation restoration projects. Infiltration, as an important part of the hydrological cycle, is also changing with vegetation restoration, and a comprehensive study of these changes is an essential aspect of evaluating the effectiveness of vegetation restoration. In the study, three typical forest vegetation types in the Loess Plateau were selected to investigate and analyse infiltration characteristics and infiltration patterns by staining tracer experiments. The results showed that (1) vegetation restoration increased the extend and depth of infiltration. (2) The extent of infiltration in mixed plantation forest of Pinus tabulaeformis and Robinia pseudoacacia was better than that in pure Pinus tabulaeformis plantation forest. (3) Vegetation restoration resulted in more pronounced preferential flow phenomenon in the infiltration processes. (4) The preferential flow phenomenon was more pronounced in the natural secondary forest than in plantation forests, especially if the amount of infiltrated water was low. (5) The extent of infiltration was mainly influenced by the infiltration water volume, soil water content, and total soil porosity; and the degree of preferential flow development was mainly influenced by the infiltration water volume, soil organic matter, and root distribution. At present, vegetation restoration on the Loess Plateau can play a role in promoting precipitation infiltration, and mixed-mode afforestation is better than single-dominant-species afforestation to fulfil this function of forests. [ABSTRACT FROM AUTHOR]

• Evaluating the effect of afforestation on deep soil environment within level ditch. • Shrubs of different planting years caused the difference in deep soil water storage. • Positive effect of slope on soil carbon/nitrogen storage reduced with soil depth. Vegetation restoration can sequester more carbon to address global climate change and conserve biodiversity to maintain soil ecological functions. The combination of engineering measures and afforestation is a prominent strategy to restore degraded slope ecosystems. Engineering measure alters slope topography and reconstructs the microtopography which is differed completely from other positions; however, the studies about the effects of afforestation on the deep soil environment within microtopography are still unclear. In this study, the changes of the soil water in the different layers of 0–4 m and the soil carbon and total nitrogen in that of 0–1.2 m in the level ditch combined with C. korshinskii planted for 17 years (17y), 28 years (28y), and 36 years (36y) were analyzed, and naturally restored slope was used as the control (CK). The results showed that compared with CK, the soil water storage (0–4 m) under 17y, 28y, and 36y was significantly decreased by 22.9 %, 26.8 %, and 36.5 %, respectively. The soil water storage (2–3 m) under 28y and 36y was evidently decreased by 29.0 % and 41.7 % compared with 17y, and the one (3–4 m) under 36y was significantly decreased by 13.8 % and 21.5 % compared with 17y and 28y, respectively. The soil carbon/nitrogen storage (0–1.2 m) was decreased by 40.5 %/41.7 % under 17y and was increased by 20.6 %/22.4 % under 28y compared with CK, the one under 28y and 36y was significantly higher 103 %/110 % and 81.5 %/82.8 % than that under 17y. Based on stepwise regression analysis, shrub volume and slope significantly impacted water storage and carbon/nitrogen storage, respectively. The significant differences in the effects of C. korshinskii of different planting years on soil water storage were mainly found in deeper layers. Our findings provide insight into the alterations of the deep soil environment within the microtopography reconstructed by engineering measures in the context of vegetation restoration. [ABSTRACT FROM AUTHOR]

Vegetation of oak forests of Polissia is a synthetic and very sensitive indicator of ecological conditions of habitats. After continuous fellings of the main use, there are significant changes in the floristic composition and coenotic structure of vegetation. To preserve biodiversity, the dynamics of soil moisture (Hd), soil acidity (Rc) and the amount of mineral nitrogen in the soil (Nt) were studied on the basis of complete geobotanical descriptions of time series of forest areas with oak forests using phytoindication methods (scoring). It is established that a sharp change in soil parameters occurs immediately after the completion of felling and removal from the plantation of the main edificator - the stand. In the process of vegetation restoration, after the creation of forest oak crops, there is a gradual restoration of soil parameters. Thus, soil moisture (Hd) has the lowest values in plantations before the period of crown closure – 10.70±0.21 points, which increases significantly after the stand formation. The best-formed vegetation in oak forests of wet soils is characterized by 90-year-old cenoses in which there is a decrease in soil moisture to a minimum value – 10.30±0.12 points. The lowest soil acidity (Rc) is characteristic of maternal 120-year-old biogeocenoses – 9.50±0.10 points, the highest – 7.90±0.20 points – for 3-year-old groups. The amount of mineral nitrogen (Nt) in the soil is in the range – from 4.50±0.15 (biennial forest crops) to 4.90±0.15 points (100-year-old and 120-year-old oak biogeocenoses). Thus, during the restoration period of oak forests, the return of soil parameters to the initial values’ level characteristic of the maternal subclimax plantations is observed. In the future, research on the main trends in the restoration of environmental parameters of soils after continuous fellings and the development of methods of their use for practical purposes are promising.

Vegetation restoration is the primary method used to prevent soil erosion and improve the ecological environment. The objective of this study was to explore how vegetation and soil properties changed over time in natural and artificial vegetation types. We conducted vegetation surveys in four permanent plots over 12 years (2007–2018) and measured soil properties in 2007, 2013, and 2016. The results showed that the change in species composition in natural vegetation was a continuous and progressive process. After approximately ten years of natural herb restoration, trees began to appear and formed sparse forests. In artificial vegetation, the species composition of the undergrowth varied under Robinia pseudoacacia forests during restoration years, and was dominated by Poaceae and annual plants that could tolerate shade and drought. Species composition was stable under Caragana korshinskii shrubs, where the undergrowth was dominated by perennial plants that were similar to natural vegetation. In different vegetation types, species richness, diversity, and herb community cover fluctuated, while the succession rate decreased with the number of restoration years. The soil moisture condition was better in natural vegetation than in artificial vegetation, and could be maintained near the stable field capacity. The soil moisture was supplemented to 280 cm in R. pseudoacacia forests and 320 cm in C. korshinskii shrubs in a year with extreme rainfall, but the dry soil layer returned in the following years. Soil nutrients improved over time, especially in artificial vegetation, which appears to be better than natural vegetation. In general, natural vegetation improved plant community and soil properties. Artificial vegetation only improved soil nutrients, but caused soil desiccation which is difficult to recover. Therefore, the natural vegetation restoration model of sparse forest grassland was better than artificial vegetation model.

Soil moisture is essential for vegetation restoration in arid and semi‐arid regions. Ascertaining the vertical distribution and transportation of soil moisture under different vegetation types has a profound effect on the ecological construction. In this study, the soil moisture at a depth of 500 cm for four typical vegetation types, including Robinia pseudoacacia, Caragana korshinskii, Stipa bungeana, and corn, were investigated and compared in the Zhifanggou watershed of the Loess plateau. Additionally, hydrogen and oxygen stable isotopes were detected to identify the transport mechanism of soil moisture. The results showed vertical distribution and transportation of soil moisture were different under different vegetation types. Depth‐averaged soil moisture under S. bungeana and corn generally increased along the profile, while C. korshinskii and R. pseudoacacia showed weakly increasing and relatively stable after an obvious decreasing trend (0–40 cm). The soil moisture under R. pseudoacacia was lower than that under other vegetation types, especially in deep layer. However, the effect of R. pseudoacacia on soil moisture in the topsoil (< 30 cm) could be positive. For R. pseudoacacia (160–500 cm), C. korshinskii (0–500 cm), and S. bungeana (0–100 cm), the soil moisture declined with increased in vegetation age. Planting arbor species such as R. pseudoacacia intensified the decline of soil moisture on the Loess Plateau. The capacity of evaporation fractionation of soil moisture followed the sequence: corn > S. bungeana > R. pseudoacacia > C. korshinskii. The δ18O values in soil water fluctuated across the profile. The δ18O values changed sharply in upper layer and generally remained stable in deep layer. However, in middle layer, the vertical distribution characteristics of the δ18O values were different under different vegetation types. We estimated that piston flow was the main mode of precipitation infiltration, and the occurrence of preferential flow was related to vegetation types. These results were helpful to improve the understanding of the response of deep soil moisture to vegetation restoration and inform practices for sustainable water management. [ABSTRACT FROM AUTHOR]

Soil water, nitrogen, and organic matter contents are among the main limiting factors for successful vegetation restoration on degraded slopes in arid and semi‐arid areas. Combining slope engineering measures for revegetation is considered an effective eco‐rehabilitation practice used to restore degraded slopes. However, a single slope measure is insufficient to efficiently utilize runoff and sediments to improve soil water, nitrogen, and organic matter for revegetation. In this study, four treatments were implemented on a hilly slope in a temperate continental semiarid area slope engineered with fish‐scale pits (semicircle‐shaped pit, 1.0 m in diameter, 0.5 m in radius, and 0.2 m deep), namely: with gravel mulching (GM), straw mulching (SM), infiltration hole (IH), and without other measures (CK). The effects of the combined measures on soil water, nitrogen, and organic matter contents were analyzed over 4 years. The results showed that the soil water storage (0–100 cm) showed no significant differences among all treatments; however, the soil (100–260 cm) of GM/SM/IH treatment increased by 11.65%/8.62%/7.10% compared with CK (p < 0.05). The soil organic matter and nitrogen (0–100 cm) under IH were 73.34%/81.29%/98.32% and 77.37%/80.27%/85.31% higher than CK/SM/GM, respectively (p < 0.05). Overall, IH is the most effective measure for increasing nitrogen and organic matter, and it is equally effective with GM and SM to increase the water replenishment of deep soils in semiarid areas. Our findings provide the combined measures to combat soil water, nitrogen, and organic matter deficits for slope revegetation in arid and semiarid areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Vegetation restoration decreased deep soil water storage in the Loess Plateau. • Revegetation increased steady infiltration but reduced initial and mean rates. • Soil infiltration rates exhibited gradual decline trends along the slope. • The effect of vegetation type on infiltration was higher than slope position. • Soil water and clay content were key factors influencing infiltration rates. Vegetation restoration effectively mitigates soil erosion and improves soil properties, but in drylands, it can lead to soil water scarcity and disrupt ecological balance. Until now, limited research has examined the combined effects of vegetation restoration type and topography on soil water and infiltration in the Loess Plateau of China. Here, we investigated soil water content (SWC), soil water storage (SWS), soil infiltration rates and related soil properties in typical forestland, shrubland, and grassland across five slope positions on steep slopes, and compared them with cropland. The results indicated that vegetation restoration significantly decreased SWS compared to cropland. Across the entire 0–500 cm depth, reductions were observed at 30.9 %, 33.2 %, and 20.8 % for forestland, shrubland, and grassland, respectively, with forestland and shrubland demonstrating a more pronounced decrease, particularly in deeper soil layers. Shrubland had the lowest SWS on the upper, middle, and top slopes, while forestland showed the lowest SWS on the lower and foot slopes. In terms of infiltration, vegetation restoration generally increased steady infiltration rate but resulted in reduced initial and mean infiltration rates (except for shrubland). Shrubland had the highest infiltration rates, followed by forestland, while grassland had the lowest rates. Soil infiltration rates decreased gradually along the slope, indicating that the impact of vegetation restoration on soil infiltration improvement weakened with lower slope positions. Vegetation restoration type had a stronger direct and total effects on infiltration than slope position. Yet, the indirect influence of slope position through clay content and SWC outweighed that of vegetation restoration type. Our findings highlight the comprehensive assessment of the eco-hydrological effects of vegetation restoration is essential for identifying suitable species and designing optimal spatial distribution, ultimately maximizing the ecological benefits of the restoration. These insights can offer valuable guidance for ecological restoration and land management in fragile dryland ecosystems. [ABSTRACT FROM AUTHOR]

BackgroundChina’s so-called Three North Shelterbelt Program (3NSP) has produced a vast area of lined forest reconstruction in the semi-arid regions. This study uses the lined rain-fed Pinus sylvestris var. mongolica (PSM) sand-fixing forest in the eastern part of Mu Us Sandy Land in Northwestern China as an example to investigate the ecohydrological process in this region. Rain gauges, newly designed lysimeters and soil moisture sensors are used to monitor precipitation, deep soil recharge (DSR) and soil water content, where DSR specifically refers to recharge that can reach a depth more than 200 cm and eventually replenish the underneath groundwater reservoir.ResultsThis study shows that there are two obvious moisture recharge processes in an annual base for the PSM forest soil: a snowmelt-related recharge process in the spring and a precipitation-related recharge process in the summer. The recharge depth of the first process can reach 180 cm without DSR occurring (in 2018). The second process results in noticeable DSR in 2018. Specifically, the DSR values over 2016–2018 are 1, 0.2, and 1.2 mm, respectively. To reach the recharge depths of 20, 40, 80, 120, 160, and 200 cm, the required precipitation intensities have to be 2.6, 3.2, 3.4, 8.2, 8.2, and 13.2 mm/d, respectively. The annual evapotranspiration in the PSM forest is 466.94 mm in 2016, 324.60 mm in 2017, and 183.85 mm in 2018.ConclusionThis study concludes that under the current precipitation conditions (including both dry- and wet-years such as 2016–2018), water consumption of PSM somewhat equals to the precipitation amount, and PSM has evolved over years to regulate its evapotranspiration in response to annual precipitation fluctuations in Mu Us Sandy Land of China.

Background: China's so-called Three North Shelterbelt Program (3NSP) has produced a vast area of lined forest reconstruction in the semi-arid regions. This study uses the lined rain-fed Pinus sylvestris var. mongolica (PSM) sand-fixing forest in the eastern part of Mu Us Sandy Land in Northwestern China as an example to investigate the ecohydrological process in this region. Rain gauges, newly designed lysimeters and soil moisture sensors are used to monitor precipitation, deep soil recharge (DSR) and soil water content, where DSR specifically refers to recharge that can reach a depth more than 200 cm and eventually replenish the underneath groundwater reservoir. Results: This study shows that there are two obvious moisture recharge processes in an annual base for the PSM forest soil: a snowmelt-related recharge process in the spring and a precipitation-related recharge process in the summer. The recharge depth of the first process can reach 180 cm without DSR occurring (in 2018). The second process results in noticeable DSR in 2018. Specifically, the DSR values over 2016–2018 are 1, 0.2, and 1.2 mm, respectively. To reach the recharge depths of 20, 40, 80, 120, 160, and 200 cm, the required precipitation intensities have to be 2.6, 3.2, 3.4, 8.2, 8.2, and 13.2 mm/d, respectively. The annual evapotranspiration in the PSM forest is 466.94 mm in 2016, 324.60 mm in 2017, and 183.85 mm in 2018. Conclusion: This study concludes that under the current precipitation conditions (including both dry- and wet-years such as 2016–2018), water consumption of PSM somewhat equals to the precipitation amount, and PSM has evolved over years to regulate its evapotranspiration in response to annual precipitation fluctuations in Mu Us Sandy Land of China. [ABSTRACT FROM AUTHOR]

Soil moisture is one of the restricting factors in the humid karst areas, which feature strong spatial heterogeneity. However, current research about the effects of vegetation restoration on soil moisture content have mainly focused on plot scale and slope scale, while these effects still remain unclear at regional scale in this area. Taking Southwest China as a case study and based on the land parameter data record (LPDR) and enhanced vegetation index (EVI) data set during 2002–2018, this study analyzed the spatiotemporal variation characteristics of vegetation and soil moisture content, and evaluated the effects of vegetation restoration on regional soil moisture content dynamics in paired years with similar precipitation conditions. The results showed that the EVI generally increased at a rate of 0.035/10a during 2002–2018, while the soil moisture was dominated by a drying trend at a variation rate of −0.0006 (cm3/cm3)/10a. The increasing trend of EVI accounted for 90.90% across the study area, whereas the decreasing trend of soil moisture accounted for 51.66%, and the increasing trend of soil moisture accounted for 48.34%. In addition, the decreasing trend of soil moisture coupled with an increasing trend of EVI distributed in most of the study area, especially in the homogenous limestone area. Our results demonstrate that there were remarkable vegetation restoration efforts in a series of ecological restoration projects, which resulted in a drying trend of the regional soil moisture content in the humid karst areas. The results suggest that it is necessary to consider reasonable vegetation planting density and suitable revegetation types to balance the relationship between vegetation water consumption and soil moisture supplementation in vegetation restoration practice in the humid karst areas. [ABSTRACT FROM AUTHOR]

To explore the impact of land- use change on the long- term soil water balance in Northern China's Loess Plateau, we used the H ydrus-1 D model to simulate the soil water dynamics at depths of 0--4 m under the scenario of arable land-alfalfa land-natural grassland located in the Liudaogou watershed. The evolution characteristics of hydro logical variables including soil water storage, deep seepage and evapotranspiration were quantified from 1981 to 2050. The results showed that soil water fluctuated with rainfall levels during arable land periods, with 88% of the annual precipitation consumed through evapotranspiration, and 11 % was lost to deep seepage. The first stage of soil water change during the alfalfa land period was 1--6 years after plantation, during this period, evapotranspiration accoun ted for 108 % of the annual rainfall, leaving the soil water in a negative balance. And the soil water storage of 0--4 m decreased at a rate of 52 mm/a. The second stage was 7- 13 years after plantation, almost all rainfall was consumed by evapotranspiration. Eight years after alfalfa land transitioned into natural grassland, annual evapotranspiration de creased by 31 %, and soil water storage gradually recharged at 45 mm/ a. Subsequently, 92% of the annual rainfall was used for evapotranspiration, with the remaining 8% was lost to deep seepage. The soil water remained in a rela tively stable state. These indicated that the soil water balance modes varied under different vegetation types. Planting vegetation with high-water-consumption could cause negative balance of soil water and led to serious soil desiccation, which then had a negative effect on soil water supply. However, the formed dry soil layer could be completely re stored by changing the vegetation type. [ABSTRACT FROM AUTHOR]

Gully erosion has been considered as one of the main forms of soil erosion on the Loess Plateau of China. To control soil and water loss and improve the eco-environmental quality of the Loess Plateau, the Chinese government implemented the “Grain for Green” project in 1999 to restore vegetation on steep slope farmlands. Although the project has been implemented for two decades, soil erosion on the loess hilly region caused by extreme rainstorms is still serious. Therefore, the controlled effects of vegetation restoration on gully formation and soil erosion on loess hillslopes under extreme rainstorms need to be evaluated. Moreover, the effect of land use change on the morphology of gullies and gully volume estimation under extreme rainstorms is poorly understood. Given these issues, the Chabagou watershed (a typical watershed in the Loess Plateau of China) suffered by an rainstorm (called “7·26” rainstorm) was selected as the study area of gully erosion. Four small basins in the Chabagou watershed were selected from the upper, middle, and lower reaches, respectively, to explore the morphological characteristics and derive volume estimation models of three land uses (farmland, fallow land, and abandoned land) under extreme rainstorm. A total of 140 gullies were investigated, including 45 gullies on farmland, 66 gullies on fallow land and 29 gullies on abandoned land. The gully length was measured by the laser rangefinder and the gully was divided into three sections (upper, middle and lower) by a 50-m tape. In each section, the top width, bottom width and the depth of the gully were measured using a steel tape. The measuring times was adjusted according to the gully length to ensure the measuring accuracy. The measured cross-sectional parameters (i.e. width and depth) of the three sections were averaged as the eventual width and depth of each section, and the gully volumes of the three sections were summarized to be the amount of gully erosion. The results showed that: 1) the gullies less than 20 m on farmland, fallow land and abandoned land accounted for 55.6%, 34.8% and 44.8%, respectively. The averaged gully depth on farmland was 110 cm, which was 18.3%, and 19.2% higher than those on fallow land and abandoned land, respectively. The width-depth ratios of gully on farmland and fallow land were 0.87 and 0.84, respectively, and their cross sections were characterized by the wide and shallow shape, but the crossed section of the gully on abandoned land was closed to squared shape (width-depth ratio was 1.01). 2) The lowest gully erosion volume was found on abandoned land, which was 47.8% and 28.3% lower than that of farmland and fallow land, respectively, indicating that vegetation restoration can effectively contain gully erosion under extreme rain. 3) Gully erosion volume of farmland on upslope was largest, followed by downslope and mid-lope, while fallow land and abandoned land showed an increasing trend along the slope. For the three types of land use, the widening rate of gully on the upslope was greater than that on the downslope, but the opposite was found on the mid-slope. 4) The significant (P<0.001) power functions could express the relationships between gully erosion volume and gully length and/or gully cross-sectional area on farmland, fallow land, and abandoned land, and the cross-sectional area was a more effective parameter for estimating gully volume. This study results can provide important information for predicting the gully erosion of different land use types and controlling gully erosion in the hilly area of the Loess Plateau. [ABSTRACT FROM AUTHOR]

Birds are a key constituent of the coastal ecosystems. They have been identified as vital ecosystem engineers that modify both the abiotic and biotic factors through their behavior processes. Understanding the ecosystem engineering effect of birds is of importance to undergo restoration based on ecosystem process in coastal vegetation systems. Field surveys were conducted to investigate the effect mechanisms of the foraging-associated hollows of birds on the vegetation resilience in a degraded coastal saltmarsh vegetation ecosystem, in the Yellow River Delta, Northern China. Our results showed that the foraging-associated hollows of birds could play an important role in changing microtopography, improving edaphic environment and promoting vegetation establishment. Compared with the degraded flat microtopography areas without birds influence, the soil hardness and the soil salinity in the foraging-associated hollows of birds are significantly lower, while the soil moisture content, and the soil carbon and nitrogen nutrition content in the foraging- associated hollows of birds are significantly higher. Additionally, the foraging- associated hollows of birds could function as effective traps to improve the seed retention, seedling establishment and plant survival, which could effectively promote the recovery of Suaeda salsa. Our study highlights that foraging- associated engineering processes of birds modifying the microtopography should be considered as an important implication, for using artificial microtopography to increase the potentials of vegetation restoration in degraded coastal saltmarsh ecosystems. [ABSTRACT FROM AUTHOR]

Vegetation restoration has returned a large number of steep slope farmlands to forests and grasslands, and effectively controlled soil erosion in the Loess Plateau. In the loesstableland and gully region of the Loess Plateau, loess-tableland, hill-slope and gully-slope are widely distributed. Geomorphological location and land use may lead to differences in soil properties and vegetation root systems, and thus affect soil erodibility. However, few studies have been conducted to explore the impact of vegetation restoration at different geomorphological locations on soil erodibility, and the relationships between soil erodibility and influencing factors. This study was carried out in the Nanxiaogou watershed in the loesstableland and gully region of the Loess Plateau. The undisturbed topsoil (0-20 cm) of farmland, grassland, shrub land and woodland was sampled on loess-tableland, hill-slope and gully-slope (no farmland on gully-slope). The comprehensive soil erodibility index (CSEI) was obtained by weighted sum method. The results indicated that: (1) The significant difference in CSEI was found among different geomorphological locations. The CSEI of gully- slope was 8.1% and 77.7% higher than those of hill- slope and loess- tableland, respectively. (2) As for the loesstableland, the CSEI of grassland, shrub land and woodland decreased by 21.1%, 29.2% and 28.8%, respectively compared with that of farmland. For the hill- slope and gully- slopes, the CSEI of woodland was lower than that of other land use types. (3) The CSEI had significantly negative correlations with clay content, sand content, soil capillary porosity, root weight density, root mean diameter, root length density and root surface area density, but significantly positive correlations with silt content and soil bulk density. Multivariate linear stepwise regression indicates that silt content, root mean diameter and soil bulk density are the most important factors influencing CSEI, among which silt content has the greatest direct influence on CSEI, while root mean diameter exerts negative influence on CSEI through direct or indirect effects. This study suggests that shrubs should be the preferred vegetation for vegetation restoration on the loess- tableland. Revegetation with arbor as dominant community may be more effective in controlling soil and water loss on hill-slope and gully-slope. [ABSTRACT FROM AUTHOR]

• Soil moisture content varied with soil depth, upslope distance, vegetation type, and time. • Soil organic carbon and moisture were lowest in Robinia pseudoacacia plantations. • Grassland showed lower soil moisture loss and greater organic carbon sequestration. • On the Loess Plateau, afforestation within grassland may enhance ecosystem services. Large-scale afforestation is considered controversial as an ecosystem renewal strategy for the Loess Plateau of China, since it may increase soil organic carbon (SOC) but may also exacerbate water shortages. In our study, we aimed to clarify how afforestation and slope affect soil moisture content (SMC) and SOC and their interaction particularly for deep hillslope profiles on long hillslopes, in terms of the trade-off between soil moisture and organic carbon. This study investigated SMC and SOC density (SOCD) from 0 to 400 cm hillslope depth profiles at 20 m intervals uphill to 100 m in the May and October (the beginning and end of the growing period, respectively) from 2015 to 2017. The three sampling sites were located in Robinia pseudoacacia plantation, natural forest, and natural grassland as the control. Soil moisture deficit and SOC sequestration of plantation were compared to those of grassland, and the trade-off between SMC and SOCD was evaluated. The results showed that SMC and SOCD were the lowest in the Robinia pseudoacacia plantation, indicating that the plantation exhibited a greater soil moisture deficit and SOC loss than the grassland. In the plantation and natural forestland, the subsoil (100–400 cm) exhibited greater soil moisture deficit and SOC loss than the soil (0–100 cm). SOCD increased while SMC decreased with upslope distance for all hillslope layers in both plantation and natural forestland. The downslope sites exhibited more severe soil moisture deficit, and greater SOC loss than the upslope sites. Natural grassland exhibited low water depletion and high SOC sequestration. Further, the downslope plantation sites exhibited the lowest root mean square deviation for the relationship between SMC and SOCD. Based on these findings, a vegetation restoration strategy involving afforestation of downslope patches within a contiguous grassland matrix may achieve high-level maintenance of ecosystem services. These findings provide a theoretical basis for vegetation restoration on the Loess Plateau. [ABSTRACT FROM AUTHOR]

• Soil moisture dynamics were compared between artificial and natural recovery. • The soil moisture content in planted forest was the lowest at various locations. • Planted forest exhibited the slowest response speed of soil moisture to storm events. • The occurrence frequency of preferential flow in planted forest was the lowest. The global trend of vegetation "greening" in the context of ecological restoration necessitates an urgent assessment of ecosystem services. As essential components of ecosystem services, the hydraulic functions of soil in infiltrating and retaining water following vegetation restoration remain unclear, especially in subtropical mountainous and hilly areas with complex topographies. From 2018 to 2021, soil moisture data collected at five-minute intervals were monitored for three restoration strategies in a hilly catchment of China's Three Gorges Reservoir area. The restoration strategies included planted forest (PF) and natural restoration (naturally regenerated forest, NF; deforested pasture, DP). The soil moisture response to rainfall under these strategies was evaluated using several metrics, including the time difference between peak rainfall intensity and peak soil moisture response (T p2p), cumulative infiltration, and occurrence frequency of preferential flow (PRF). The results showed that the average soil moisture content (SMC) of PF was significantly (p < 0.05) lower than that of NF and DP in both dry and wet seasons, regardless of upslope or downslope location. However, the topographic position affected the difference in average SMC between DP and NF. At the downslope location, the average SMC of DP (0.39 cm3 cm−3) was significantly higher than that of NF (0.33 cm3 cm−3). Conversely, at the upslope location, the average SMC of DP (0.27 cm3 cm−3) was lower than that of NF (0.30 cm3 cm−3). These findings suggested that PF had a lower amount of soil water storage than NF and DP, which was supported by the lowest cumulative infiltration in PF during storm events. The response of soil moisture to storms in PF (T p2p = 3.1 h) was slower than that in NF (T p2p = 1.9 h) and DP (T p2p = 2.5 h). This was consistent with the lower occurrence frequency of preferential flow in PF (PRF = 19.2 %) than NF (PRF = 39.2 %) and DP (PRF = 32.9 %). Therefore, longer response time and less preferential flow indicated that the PF had a relatively poor soil moisture responsiveness to storm events. Accordingly, this study highlights the insufficiency of afforestation in soil water infiltration and retention compared to natural restoration, meriting consideration when assessing soil hydraulic functions in vegetation restoration areas. [ABSTRACT FROM AUTHOR]

The priming effect stands as a critical factor influencing the balance of soil organic carbon (SOC). Following vegetation restoration, the carbon (C) pool stability in Platycladus orientalis forests (PO) varies, and the priming effect resulting from exogenous C addition also differs significantly. Here, we selected PO with restoration ages of 10, 15, and 30 years in the rocky mountainous area in northern China and conducted measurements of soil properties, microbial communities, microbial necromass C (MNC), SOC fractions, and the priming effect characteristics to explore the main influencing factors of the priming effect, especially the microbiological mechanisms. Our results showed that the ratio of mineral-associated organic C to particulate organic C increased. The characteristics of the priming effect showed the same pattern, and there was a significant positive correlation between the C pool stability and the priming effect. The diversity of the fungal communities increased with increasing vegetation restoration age, and the content and proportion of fungal necromass C (FNC) also increased synchronously, reaching the maximum value in the soil of PO that had been restored for 30 years. In addition, the soil water content and total nitrogen indirectly affected the priming effect by influencing the microbial communities. In summary, the results suggested that vegetation restoration can enhance the C pool stability by promoting an increase in soil FNC, thereby producing a positive priming effect. This can help deepen our understanding of the SOC mineralization changes induced by fresh C input following vegetation restoration and provides a theoretical basis for better explaining the C cycle between soil and atmosphere under the vegetation restoration models in the future. • Vegetation restoration enhanced C pool stability and had a time-accumulated effect. • Higher C pool stability tend to generate stronger priming effect. • Soil fungal communities and necromass C led to different priming effect. [ABSTRACT FROM AUTHOR]

The vegetation coverage on the Loess Plateau (LP) of China has clearly increased since the implementation of the Grain for Green Project in 1999, but there is a debate about whether the improved greenness was achieved at the expense of the balance between the supply and demand of water resources. Therefore, developing reliable indicators to evaluate the water availability is a prerequisite for maintaining ecological sustainability and ensuring the persistence of vegetation restoration. This study was designed to evaluate water availability on the LP during 2000–2015, using the evaporative stress index (ESI) derived from a remote sensing dataset. The relative dependences of the ESI on climatic and biological factors (including temperature, precipitation and land cover change) were also analyzed. The results showed that the leaf area index (LAI) in most regions of the LP showed a significant increasing trend (p < 0.05), and larger gradients of increase were mainly detected in the central and eastern parts of the LP. The evapotranspiration also exhibited an increasing trend in the central and eastern parts of the LP, with a gradient greater than 10 mm/year. However, almost the whole LP exhibited a decreased ESI from 2000 to 2015, and the largest decrease occurred on the central and eastern LP, indicating a wetting trend. The soil moisture storage in the 0–289-cm soil profiles showed an increasing trend in the central and eastern LP, and the area with an upward trend enlarged with the soil depth. Further analysis revealed that the decreased ESI on the central and eastern LP mainly depended on the increase in the LAI compared with climatic influences. This work not only demonstrated that the ESI was a useful indicator for understanding the water availability in natural and managed ecosystems under climate change but also indicated that vegetation restoration might have a positive effect on water conservation on the central LP.

Soil erosion occurs extensively across China, leading to severe degradation of the land and ecosystem services. However, the spatial and temporal variations in soil erodibility (k) and the distribution of soil erosion across land use types and slopes remain unclear. We synthesized the results from 325 sites published in 152 literatures to analyze the factors affecting the k, such as land use type, climate, topography, soil, and vegetation restoration age. The results showed that areas with slopes >25° had a larger k factor (k = 0.1047) than did those with slope <6° (k = 0.0637) or 6–25° (k = 0.0832). The k from 2006 to 2011 (k = 0.0725) was higher than that from 1999 to 2005 (k = 0.058) and that from 2012 to 2016 (k = 0.0631). The k value initially increased with vegetation restoration age and then gradually decreased. Land use also had an impact on the k factor, with the k factor of cropland (k = 0.0697) being higher than that of grassland (k = 0.0663) but lower than that of forest (k = 0.0967). Across China, North Shaanxi, Heilongjiang, and South Guizhou, which are located in the Loess Plateau in Northwest China, the Black Soil region of Northeast China, and the Karst areas in Southwest China, respectively, were the three most severely eroded regions due to hydraulic erosion, frost‐thaw erosion, and high‐intensity erosion, respectively. Overall, the most important factors affecting the k were soil characteristics, followed by topography and climate. Among them, soil nitrogen and precipitation were the two most critical factors influencing the k. Key Points: Grassland had lower soil erodibility than had cropland and forestlandNorth Shaanxi, Heilongjiang, and South Guizhou were the three most severely eroded regionsPrecipitation and soil N play critical roles in controlling soil erosion [ABSTRACT FROM AUTHOR]

Purpose: Deep soil moisture has been considered to be critical for plant survival in water-limited ecosystems. The limited precipitation on the semi-arid Loess Plateau is the only water source for soil moisture and is unevenly distributed throughout the year. Characterizing the seasonal changes in deep soil moisture in relation to land use types and structures is important for the sustainability of vegetation restoration in this region.Materials and methods: A total of 27 experimental sites along seven transects were selected in the Jiegou catchment on the semi-arid Loess Plateau. These sites were covered by five land use types: native grassland, traditional farmland, abandoned farmland, and 5-year and 7-year Robinia pseudoacacia (RP) forestlands. Soil moisture measurements were conducted during three seasons (spring, summer, and fall) at soil depths of 0 to 5 m in 0.2-m increments, and 2025 disturbed soil samples were collected to determine the gravimetric soil moisture content using the oven-dry method (24 h at 105 °C). The depth-averaged soil moisture was compared among different seasons and land use types using one-way ANOVA and significance tests.Results and discussion: Among the seasons, the depth-averaged soil moisture had the following order: fall > spring > summer. In the shallow layers (above 2 m), soil moisture in summer was significantly lower than that in spring and fall (p < 0.05). The vertical distribution characteristics of soil moisture (0-5 m) were similar among the land use types during each season but different among the seasons for each land use type. In general, the depth-averaged values of soil moisture among the land use types were on the order of native grassland > farmland > forestland. This finding indicated that afforestation drastically decreased deep soil moisture, particularly in summer. Furthermore, the different land use structures significantly influenced the spatial distribution of deep soil moisture during each season.Conclusions: This study highlights the seasonal changes in both shallow and deep soil moisture under various land use types, which provides insights into the sustainable use of deep soil moisture and rational land use management on the semi-arid Loess Plateau of China. [ABSTRACT FROM AUTHOR]

Afforestation brings lots of water‐related benefits, including reducing soil erosion and improving water conservation, simultaneously; it is considered to be a land use activity, which threatens water resources security. Characterizing the response of soil moisture to revegetation is important for the sustainability of water and plants on the Loess Plateau of China. In this study, we conducted a meta‐analysis of 1,262 observations from 66 published studies to evaluate the effect of land use on the soil moisture of forest, shrubland, and grassland regions at a depth of 5 m in different ecological zones of the Loess Plateau. The results indicated that (a) Soil moisture content (SMC) decreased after land use conversion in all three ecological zones and was inconsistent among different soil layers. (b) Except for other grassland species, changes in the response size for soil moisture were not significant among any tree species, including Pinus tabuliformis, Robinia pseudoacacia, other forest species, Caragana korshinskii, other shrubland species, and Medicago sativa. (c) Soil moisture changes varied with different restoration types and ages. (d) The change in response to precipitation was not significant, whereas the change in response to temperature was significant. In addition, the responses of the initial soil moisture levels exhibited a negative correlation with revegetation. These results indicate that it is vital for scientific afforestation in the Loess Plateau to complement local climate conditions and soil properties. [ABSTRACT FROM AUTHOR]

Abstract In water-restricted erosive mountains environments, large-scale vegetation plantation and diverse terracing measures have been widely used as the most powerful ecological-restoration tools to control water erosion and improve local degraded ecosystems, further enhancing the complexity of terracing, vegetation, and soil water relationships. In this study, 70 sampling sites across different hillslopes were selected and used for biweekly soil water measurement in a typical loess hilly catchment of China. The most typical terracing measures (broad bench terraces-BBT, narrow bench terraces-NBT, level ditch terraces-LDT, counter-slope terraces-CST, and half-moon terraces-HMT) and introduced vegetation types (wild peach, apricot, arborvitae, poplar, and Chinese pine) were included in the study. Based on multi-site measurements, the effects of terracing and vegetation on the profile of soil moisture dynamics at a depth of 2 m were analyzed. Results show that terracing generally has a very positive role in soil water enhancement. Compared with slope risers, terracing can increase soil moisture by 0.87% (±0.82%) to 37.71% (±9.01%), which benefits ecological restoration. However, the effects of various terracing measures on soil water differed. BBT measures were the most powerful in soil water recharge, with an incremental ratio of 21.88%, which is 4.94, 5.95 and 4.21 times that of CST (5.19%), LDT (4.43%) and NBT (3.68%), respectively. The existence of different plant communities can increase the uncertainties and complexities of soil water status. Introduced trees and shrubs generally induce a greater reduction in soil water than do natural plants in similar environmental conditions. The few remaining original hillslopes covered by natural grasses can better preserve soil water, because of large differences in water use strategies between planted and natural species. Such findings are expected to provide important references for the proper selection of terracing and artificial vegetation toward enhancing the efficiency of water conservation and ecological restoration in dry and degraded regions. Graphical abstract Unlabelled Image Highlights • Vegetation plantation and terracing are key tools for ecosystem restoration in drylands. • Terracing has a very positive role in soil water enhancement in the water-restricted regions. • Terracing increases soil moisture by 0.87% to 37.71%, which benefits ecosystem restoration. • Broad bench terraces are the most powerful in soil water recharge. • Plantings of vegetation in terraces increase the complexities of soil water responses. [ABSTRACT FROM AUTHOR]

Soil nitrogen (N) accumulation enhances carbon (C) sequestration and subsequently the restoration of degraded ecosystems, but the changes in soil N properties after vegetation restoration in such ecosystems are poorly understood. We collected data from 358 fixed points in the karst catchment in China to determine the trends, magnitude, and mechanisms of soil N sequestration after 10 years of revegetation. The revegetation types were tillage fields that were abandoned or were converted to pasture, planted forest, or converted to mixed pasture and forest and pasture lands that were abandoned (P_Aban) or converted to mixed pasture and forest (P_Mix). The changes in soil N density (g m−2) over time were insignificant, and only P_Aban, P_ Mix, and the overall catchment experienced significant increases in soil N concentration (g kg−1). Structural equation modeling indicated that bedrock exposure affected the change in soil N concentration (∆NC) and the soil N sequestration value (∆ND) via affecting the change in soil C concentration, by directly affecting bulk density, soil depth, and Ca2+. The soil C:N ratio increased significantly, and the increase in soil N was slower than that of C, suggesting a decoupling of soil C and N accumulation in the initial stage of revegetation. ∆ND was significantly related to the change in soil C:N ratio, indicating that the coupling between soil C and N may be constrained by insufficient soil N sequestration during revegetation. These findings suggest that the restoration of degraded karst ecosystems requires an increase in soil N input early during vegetation restoration. [ABSTRACT FROM AUTHOR]

• In-situ tests in five sands with different vegetation coverages and types. • Deep percolation (DP) directly measured by a DP recorder. • DP in mobile sand more sensitive to rainfalls of > 10 mm and high-intensity. • Increases in vegetation coverages and forest selection reduced DP and soil water. Deep percolation (DP) determines the sustainable utilization of regional groundwater resources and provides large hydrological benefits to ecosystems in semiarid sandy regions. However, studies involving DP variability have rarely conducted in-situ tests with different vegetation coverages (VC) and vegetation types using direct measurements. This study measured soil moisture and DP for four years in five plots, with DP measured using a deep percolation recorder: mobile sand (MS) as the control group; Artemisia ordosica semifixed (AOSF) with VC of 30%–35% and Artemisia ordosica fixed (AOF) with VC of 70%–75% (AOSF and AOF stand ages: 30–40 years), representing different vegetation coverages; and Salix psammophila fixed (SPF) and Pinus sylvestrix var. Mongolica fixed (PSMF) with the same VC of 45%–50% (SPF and PSMF stand ages: 30 years), representing different vegetation types. The effects of sand-fixing vegetation on DP and soil water were evaluated using the relative extractable soil water (RESW) and soil water storage deficit metrics. DP occurrence in MS was closely related to rainfall amounts of > 10 mm and high-intensity rainfall rather than the total annual rainfall. Increases in vegetation coverages and forest selection significantly reduced DP and RESW compared with MS. DP in the shrub plot (SPF) was significantly higher than that in the forest plot (PSMF). Plants utilized water from different sources among the sandy land types: the shallow (0–80 cm) and deep layers (80–200 cm) in PSMF and AOF, and only from the shallow layer in AOSF and SPF. However, compared with MS, soil water storage deficit occurred to varying degrees in each plot. This study can provide a scientific reference for the restoration of the ecology and water cycle in sandy regions. [ABSTRACT FROM AUTHOR]

Mountainous regions of the globe experience landslides due to heavy rainfall and unplanned construction on slopes. Geojute is adopted globally as a landslide rehabilitation measure, but its impact on natural vegetation development is poorly understood. The present study was conducted to examine the impact of geojute application on vegetation restoration, ecology and carbon stock in a recently occurred landslide, during 2012. The results revealed that the geojute application improved the richness, diversity, density and basal area of plant species at the landslide site. Likewise, biomass production, carbon stock and carbon sequestration of plant species was observed significantly higher in geojute treatments compared to control (without geojute treatment). Moreover, significant improvement in soil moisture was recorded beneath the geojute treatments. Further, results showed that the geojute is highly effective in controlling soil erosion at the landslide site. The findings of this study revealed ecological and environmental benefits of geojute application in term of improvement in vegetation recovery processes, species diversity and carbon sequestration at the landslide site. The scientific outcome of this study can be helpful for planning the rehabilitation measures in landslide affected regions of the globe. [ABSTRACT FROM AUTHOR]

Abstract: The Chinese Loess Plateau (CLP) is a unique Critical Zone with deep loess deposits, where soil moisture is primarily replenished by seasonal monsoon rainfall. However, the role of vegetation, coupled with complex topography, on rainwater infiltration on the CLP, especially after long‐term revegetation for controlling erosion, is inadequately quantified. Over the growing season of 2016, we monitored soil moisture at the 30‐min interval at 5 depths (10, 20, 40, 60, and 100 cm) in an afforested catchment and a nearby catchment with natural regrowth of grasses. Two monitoring sites were established in each catchment, one in the downhill gully and the other in the uphill slope. We found that vegetation, topography, and rainfall attributes together determined rainwater infiltration and soil moisture replenishment. An accumulated rainfall amount of 9 mm was required to trigger soil moisture response at 10‐cm depth at the 2 grassland sites and the forestland uphill‐slope site whereas 14 mm of rainfall was required for the forestland gully site covered by dense undergrowth and trees. Rainfall events with larger sums and higher peak intensities permitted rainwater infiltration to deeper soil depths. However, no rain recharged soil moisture to 100‐cm depth during the monitoring period. The forestland uphill‐slope site showed the deepest wetting depth (up to 60‐cm depth), fastest wetting‐front velocity (up to 4 cm/hr below 10‐cm depth), and the most significant soil moisture increase (up to 15% cm 3 cm−3 increase at 10‐cm depth) after rainfall in the growing season. The grassland gully site had the highest soil water storage, whereas soil moisture was depleted the most at the forestland gully site. Findings of this study reveal the transient dynamics of soil moisture after rainfall on the CLP, which signifies the role of revegetation on rainwater infiltration in the loess Critical Zone. [ABSTRACT FROM AUTHOR]

Knowledge of the soil water and stoichiometrical characteristics (SC) during long-term natural vegetation restoration is essential for managing the restoration of vegetation. To evaluate the response of soil water storage (SWS), soil organic carbon (SOC), total nitrogen content (TN) and total phosphorous content (TP) to long-term natural vegetation restoration (∼160 a), we examined the soil moisture and SC in areas with different restoration ages located in the central part of the Loess Plateau, China. Our results showed that the SWS decreased significantly with vegetation restoration and that the C:P ratio, N:P ratio, TN and TP increased significantly. The SWS increased gradually, whereas the SOC, C:P ratio, N:P ratio, TN and TP in each restoration stage decreased significantly with increasing soil depth in the 0–60 cm soil layer. These parameters tended to be stable in the soil layer below 60 cm. Vegetation acts as a link between SWS and soil SC, and they interact with each other indirectly. SWS and SWC showed an significant positive relationship ( P  < 0.01), whereas SWS and SOC, TN, TP, C:P ratio, and N:P ratio showed significant negative relationships ( P  < 0.01), thus, SOC, TN and TP are the key chemical factors affecting SWS.. These results could help estimating the productivity and sustainability of semiarid ecosystems and improve future eco-environmental reconstructions. [ABSTRACT FROM AUTHOR]