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The quantitative assessment of the impact of vegetation restoration on evapotranspiration and its components is of great significance in developing sustainable ecological restoration strategies for water resources in a given region. In this study, we used the Priestley-Taylor Jet Pro-pulsion Laboratory (PT-JPL) to simulate the ET components in the Helong section (HLS) of the Yellow River basin. The effects of vegetation restoration on ET and its components, vegetation transpiration (Et), soil evaporation (Es), and canopy interception evaporation (Ei) were separated by manipulating model variables. Our findings are as follows: (1) The simulation results are compared with the ET calculated by water balance and the annual average ET of MODIS products. The R2 of the validation results are 0.61 and 0.78, respectively. The results show that the PT-JPL model tracks the change in ET in the HLS well. During 2000–2018, the ET, Ei, and Es increased at a rate of 1.33, 0.87, and 2.99 mm/a, respectively, while the Et decreased at a rate of 2.52 mm/a. (2) Vegetation restoration increased the annual ET in the region from 331.26 mm (vegetation-unchanged scenario) to 338.85 mm (vegetation change scenario) during the study period, an increase of 2.3%. (3) TMP (temperature) and VPD (vapor pressure deficit) were the dominant factors affecting ET changes in most areas of the HLS. In more than 37.2% of the HLS, TMP dominated the change affecting ET, and vapor pressure difference (VPD) dominated the area affecting ET in 30.5% of the HLS. Overall, the precipitation (PRE) and VPD were the main factors affecting ET changes. Compared with previous studies that directly explore the relationship between many influencing factors and ET results through correlation research methods, our study uses control variables to obtain results under two different scenarios and then performs difference analysis. This method can reduce the excessive interference of influencing factors other than vegetation changes on the research results. Our findings can provide strategic support for future water resource management and sustainable vegetation restoration in the HLS region. [ABSTRACT FROM AUTHOR]

Ecological sluices were constructed along the Tarim River to supplement the ecosystem's water supply. However, the impact of water regulation by these sluices on the surface water area (SWA) and its relationship with the vegetation response remain unclear. To increase the efficiency of ecological water use, it is crucial to study the response of SWA to water control by the ecological gates and its relationship with vegetation restoration. We utilized the Google Earth Engine (GEE) cloud platform, which integrates Landsat-5/7/8 satellite imagery and employs methods such as automated waterbody extraction via mixed index rule sets, field investigation data, Sen + MK trend analysis, mutation analysis, and correlation analysis. Through these techniques, the spatiotemporal variations in SWA in the middle reaches of the Tarim River (MROTR) from 1990–2022 were analyzed, along with the relationships between these variations and vegetation restoration. From 1990–2022, the SWA in the MROTR showed an increasing trend, with an average annual growth rate of 12.47 km2 per year. After the implementation of ecological gates water regulations, the SWA significantly increased, with an average annual growth rate of 28.8 km2 per year, while the ineffective overflow within 8 km of the riverbank notably decreased. The NDVI in the MROTR exhibited an upward trend, with a significant increase in vegetation on the northern bank after ecological sluice water regulation. This intervention also mitigated the downward trend of the medium and high vegetation coverage types. The SWA showed a highly significant negative correlation with low-coverage vegetation within a 5-km range of the river channel in the same year and a significant positive correlation with high-coverage vegetation within a 15-km range. The lag effect of SWA influenced the growth of medium- and high-coverage vegetation. These findings demonstrated that the large increase in SWA induced by ecological gate water regulation positively impacted vegetation restoration. This study provides a scientific basis for water resource regulation and vegetation restoration in arid regions globally. [ABSTRACT FROM AUTHOR]

Active vegetation restoration plays an important role in the improvement in soil organic matter (SOM), including the carbon (C), nitrogen (N) and phosphorus (P) sequestration of degraded mining ecosystems. However, there is still a lack of understanding of the key drivers of SOM pool size and dynamics in active vegetation restoration. For this study, soil was collected from five different sites (Xiaoxian, Dingyuan, Chaohu, Tongling and Dongzhi), four habitats (platforms, slopes, steps and native areas) and two soil layers (0–20 cm and 20–40 cm) in limestone mines of Anhui province to quantify the spatial distribution of SOM contents and their stoichiometric characteristics and influential factors. It was found that the top soil in Chaohu had the highest significant C, N and P contents in the ranges of 14.95–17.97, 1.74–2.21 and 0.80–1.24 g/kg, respectively. Comparing the stoichiometric ratios of the different sites revealed significant differences in C:N and N:P ratios, but C:P ratios were relatively consistent. In particular, the C:N and C:P ratios in deep soil were higher than those in top soil, whereas the N:P ratio in deep soil was lower than that in top soil, suggesting that soil N is a major limiting factor in the top soil. The SOM content did not differ significantly between the three reclaimed habitats, but was significantly higher than that in the native habitat, suggesting that mine restoration has significantly enhanced SOM accumulation. Further analysis showed that nutrient availability and enzyme activity are important factors affecting soil C, N and P content in top soil, while the relationship gradually weakens in deep soil. This was attributed to active anthropogenic management and conservation measures during the early stages of reclamation. This study shows that the ecological recovery of the mining area can be enhanced by implementing differentiated vegetation planting strategies and anthropogenic management on different habitats in the mining area. [ABSTRACT FROM AUTHOR]

The Grain for Green Project (GGP) is a major national initiative aimed at ecological improvement and vegetation restoration in China, achieving substantial ecological and socio-economic benefits. Nevertheless, research on vegetation cover trends and the long-term restoration efficacy of the GGP in the Loess Plateau remains limited. This study examines the temporal–spatial evolution and sustainability of vegetation cover in this region, using NDVI data from Landsat (2000–2022) with medium-high spatial resolution. The analytical methods involve Sen's slope, Mann–Kendall non-parametric test, and Hurst exponent to assess trends and forecast sustainability. The findings reveal that between 2000 and 2022, vegetation coverage in the Loess Plateau increased by an average of 0.86% per year (p < 0.01), marked by high vegetation cover expansion (173 × 103 km2, 26.49%) and low vegetation cover reduction (149 × 103 km2, 22.83%). The spatial pattern exhibited a northwest-to-southeast gradient, with a transition from low to high coverage levels, reflecting a persistent increase in high vegetation cover and decrease in low vegetation cover. Approximately 93% of the vegetation cover in the Loess Plateau showed significant improvement, while 5% (approximately 31 × 103 km2) displayed a degradation trend, mainly in the urbanized and Yellow River Basin regions. Projections suggest that 90% of vegetation cover will continue to improve. In GGP-targeted areas, high and medium-high levels of vegetation cover increased significantly at rates of 0.456 ×103 km2/year and 0.304 × 103 km2/year, respectively, with approximately 75% of vegetation cover levels exhibiting positive trends. This study reveals the effectiveness of the GGP in promoting vegetation restoration in the Loess Plateau, offering valuable insights for vegetation recovery research and policy implementation in other ecologically fragile regions. [ABSTRACT FROM AUTHOR]

The Bulianta Coal Mine is among the problematic coal mining areas in China that is still creating environmental damage, especially associated with soil destruction. Therefore, a scientific investigation was conducted to establish a scientific basis for evaluating the impact of planted forest on soil physical and chemical properties, as well as the ecological benefits following 15 years of vegetation restoration in the area. The soil physicochemical characteristics and distribution of organic carbon storage in the 0–80 cm layer soils of Pinus sylvestris forests, Prunus sibirica forests, and Hippophae rhamnoides forests restored after 5, 10, and 15 years were investigated. The immersion method was used to determine soil porosity and density followed by the determination of soil indicators, and a statistical ANOVA test was applied to examine the differential effects of different vegetation types and restoration years on soil properties. The results clearly demonstrated the following: (1) The recovery of vegetation was achieved after a period of 15 years, with the average bulk density of the 0–80 cm soil layer as follows: P. sylvestris forest (1.513 g·cm−3) > P. sibirica forest (1.272 g·cm−3) > H. rhamnoides forest (1.224 g·cm−3), and the differences among different forest types were statistically significant (p < 0.05). (2) In planted forests, soil nutrients were predominantly concentrated in the 0–20 cm layer, while soil carbon storage exhibited a decline with an increasing soil depth. (3) The soil carbon storage across the three forest types was as follows: P. sylvestris forest (45.42 t·hm−2) > P. sibirica forest (44.56 t·hm−2) > H. rhamnoides forest (41.87 t·hm−2). In summary, during the ecological vegetation restoration process in the Bulianta Core Mine, both P. sylvestris forest and P. sibirica forest exhibit superior carbon storage capacities compared to H. rhamnoides forest, as well as more effective soil improvement outcomes. [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]

Abstract: In the context of the large-scale management of the Loess Plateau and efforts to reduce water and sediment in the Yellow River, this study focuses on a typical watershed within the Loess Plateau. The potential for vegetation restoration in the Kuye River Basin is estimated based on the assumption that vegetation cover should be relatively uniform under similar habitat conditions. The potential for terrace restoration is assessed through an analysis of topographic features and soil layer thickness, while the potential for silt dam construction is evaluated by considering various hydrological and geomorphological factors. Based on these assessments, the overall potential for soil erosion control in the watershed is synthesized, providing a comprehensive understanding of target areas for ecological restoration within the Kuye River Basin. The study demonstrates that the areas with the greatest potential for vegetation restoration in the Kuye River Basin are concentrated in the upper and middle reaches of the basin, which are in closer proximity to the river. The total potential for terracing is 1013.85 km2, which is primarily distributed across the river terraces, farmlands, and gentle slopes on both sides of the riverbanks. Additionally, the potential for the construction of check dams is 14,390 units. The target areas for terracing measures in the Kuye River Basin are primarily situated in the middle and lower reaches of the basin, which are in closer proximity to the river. Conversely, the target areas for forest, grass, and check dams, as well as other small watershed integrated management measures, are predominantly located in the hill and gully areas on the eastern and southern sides of the basin. The implementation of the gradual ecological construction of the watershed, based on the aforementioned objectives, will facilitate the protection, improvement, and rational utilization of soil, water, and other natural resources within the watershed. [ABSTRACT FROM AUTHOR]

Fenced enclosures, a proven strategy for restoring degraded grassland, have been widely implemented. However, recent climate trends of warming and drying, accompanied by increased extreme rainfall, have heightened soil erosion risks. It is crucial to assess the long-term effectiveness of fenced enclosures on grassland restoration and their impact on soil physicochemical properties and water infiltration capacity. This study investigated the effects of enclosure duration on soil organic matter, aggregate composition and stability, and infiltration capacity in Yunwu Mountain Grassland Nature Reserve, comparing grasslands with enclosure durations of 2, 14, 30, and 39 years. Results showed that grasslands enclosed for 14, 30, and 39 years had infiltration rates increased by 20.66%, 152.03%, and 61.19%, respectively, compared to those enclosed for only 2 years. After 30 years of enclosure, soil quality reached its optimum, with the highest root biomass, soil organic matter, aggregate stability, and a notably superior infiltration rate. The findings suggest that long-term fenced enclosures facilitate grassland vegetation restoration and enhance soil infiltration capacity, with the most significant improvement observed at the 30-year enclosure milestone, followed by a gradual decline in this effect. [ABSTRACT FROM AUTHOR]

Understory vegetation constitutes an essential component of the ecosystem within the coal mining area, disclosing the correlation between plant species composition and soil properties throughout the multi-year restoration process, and offering a theoretical framework for ecological restoration and reconstruction in the northwest wind-blown sand mining area. We investigated the coupling and coordination degree between the composition of understory vegetation and soil in Pinus sylvestris forests, Hippophae rhamnoides forests, and Prunus sibirica forests at different restoration stages (5 years, 10 years, 15 years) using field survey methods and indoor separation techniques. The results clearly indicate that: (1) After 15 years of recovery, a total of 32 species of herbs appeared in different plantations, belonging to 8 families and 21 genera, of which Artemisia scoparia had the highest importance value (42.85); (2) Significant differences were observed in herb diversity, soil physicochemical properties, and their relationships among different plantations (p < 0.05); (3) The vegetation–soil coupling coordination index of the plantations was as follows: P. sibirica forest (0.5111) > P. sylvestris forest (0.5069) > H. rhamnoides forest (0.4932). The vegetation status of the H. rhamnoides forest is a state of vegetation lagging development type of intermediate-level coordinated development, while the vegetation status of the P. sibirica forest and the P. sylvestris forest is barely harmonious. The status of the P. sibirica forest and P. sylvestris forest is better than that of H. rhamnoides forests. It is essential to enhance the management measures implemented in the Bulianta mine area. Appropriate tending, particularly the regulation of soil nutrients, might be more conducive to the restoration of vegetation and the improvement of forest ecosystem services in the mining area. [ABSTRACT FROM AUTHOR]

Coastal saline soils are an important soil resource that, when restored, can enhance arable land and preserve the natural ecology. With the aim of improving the use of coastal saline soils, we conducted a spot survey at Bohai coastal saline land to investigate the differences in soil properties between different vegetation types. The soil physical and chemical properties of various vegetation types, including Aeluropus sinensis, Imperata cylindrica, Tamarix chinensis, Lycium chinense, Hibiscus moscheutos, Helianthus annuus, Gossypium hirsutum, and Zea mays, were examined at two depth layers: 0–20 cm and 20–40 cm, and in two seasons, spring and autumn. The soil properties were compared with bare land as a control. The results indicated that the electrical conductivity, total soil salt content, sodium adsorption ratio, and bulk density of soils with vegetation cover were lower than those with bare land. On the other hand, soil pH, organic matter content, mean weight diameter, and saturated hydraulic conductivity were higher. The redundancy analysis results revealed a substantial positive correlation between soil pH, saturated hydraulic conductivity, water content, mean weight diameter, and organic matter content, as well as a significant positive correlation between soil electrical conductivity, total soil salt content, sodium adsorption ratio, and bulk density. Soil pH, saturated hydraulic conductivity, water content, mean weight diameter, organic matter content, and soil electrical conductivity, total soil salt content, sodium adsorption ratio, and bulk density were negatively correlated. The results of the structural equation model and variance decomposition showed that soil organic matter and bulk density were the key factors affecting the degree of soil salinization, and compared with their independent effects, their combined effect on soil salinization was greater. This study's conclusions can provide a point of reference for further research on the mechanisms of soil improvement and desalinization in coastal saline land. [ABSTRACT FROM AUTHOR]

Vegetation restoration is an effective measure to cope with global climate change and promote soil carbon sequestration. However, during vegetation restoration, the turnover and properties of carbon within various aggregates change. The effects of plant source carbon input on surface soil and subsurface soil may be different. Thus, the characteristics of carbon components in aggregates are affected. Therefore, the research object of this study is the Robinia pseudoacacia forest located in 16–47a of the Loess Plateau, and compared with farmland. The change characteristics of organic carbon functional groups in 0–20 cm, 20–40 cm, and 40–60 cm soil layers were analyzed by Fourier near infrared spectroscopy, and the relationship between the chemical structure of organic carbon and the content of organic carbon components in soil aggregates was clarified, and the mechanism affecting the distribution of organic carbon components in soil aggregates was revealed in the process of vegetation restoration. The results show the following: (1) The stability of surface aggregates is sensitive, while that of deep aggregates is weak. Vegetation restoration increased the surface soil organic carbon content by 1.97~3.78 g·kg−1. (2) After vegetation restoration, the relative contents of polysaccharide functional groups in >0.25 mm aggregates were significantly reduced, while the relative contents of aromatic and aliphatic functional groups of organic carbon were significantly increased. The opposite is true for aggregates smaller than 0.25 mm. (3) With the increase in soil depth, the effect of litter on organic carbon gradually decreased, while the effect of root input on the accumulation of inert carbon in deep soil was more lasting. [ABSTRACT FROM AUTHOR]

Understanding the effects of short-term artificial revegetation on preventing soil degradation in erosion gullies of black soil areas is essential to choosing the most suitable species of vegetation for controlling the development of erosion gullies. A field experiment with short-term artificial revegetation with herbaceous species (Medicago sativa L., Glycyrrhiza pallidiflora Maxim., Elytrigia repens (L.) Desv. ex Nevski, Rheum palmatum L., Asparagus officinalis L., Trifolium repens L., Bromus inermis Leyss., Elymus dahuricus Turcz.) and a runoff scouring test were conducted in a typical erosion gully in a black soil area. Soil erosion, physicochemical characteristics, and shoot/root characteristics were measured to evaluate the effects of short-term artificial revegetation. Short-term artificial revegetation significantly decreased (p < 0.05) sediment yield by 91.1% ± 7.2% compared with that of bare soil. Soil total nitrogen (TN), total potassium (TP), available phosphorus (AP), cation exchange capacity (CEC), water-stable aggregates > 0.25 mm (WR0.25), and aggregate mean weight diameter (MWD) and mean geometric diameter (GWD) were significantly correlated with vegetated treatments, indicating they were factors sensitive to short-term artificial revegetation. Except for total potassium (TK), the other soil characteristics decreased in vegetated treatments. In addition to increasing TK, vegetated treatments also increased soil available nitrogen (AN)/TN ratios in the short term. The overall effects of different herbaceous species on soil and water conservation, soil quality, and vegetation growth were evaluated, and Trifolium repens L. is the most suitable for preventing soil degradation in an erosion gully. The results of this study will provide a reference for the restoration and protection of the ecological environment in black soil areas with gully erosion. [ABSTRACT FROM AUTHOR]

In recent years, the problem of ecosystem degradation caused by human activities has become increasingly serious. Vegetation restoration is a key means to solve this problem, which has increased. To address the suitability and structural optimization of vegetation restoration in the Loess Plateau (China), the MaxEnt model was used to quantify the impacts of environmental and human activities on the planting suitability of vegetation restoration species at the raster scale. Three layers of trees, shrubs, and herbs with 12 common vegetation restoration species were selected. The factor index system was constructed by combining climatic, ecological, and socio-economic data, and the MaxEnt model predicted land suitability. It was found that human activities significantly increased the unsuitable planting area. This especially affected Robinia pseudoacacia in the tree layer and Amorpha fruticosa in the shrub layer. High and medium suitable areas were mainly sparsely populated areas with close water sources. Through maximum suitability optimization, it was identified that the overall spatial distribution of the three layers in the study area was relatively consistent, and the structural dominance of trees + shrubs + herbs and single herbs in the vertical structure was obvious; these were concentrated in the southwestern and northeastern parts of the study area, respectively. In addition, organic content (OC) and distance from the road to woodland (RW) were the dominant factors affecting land suitability, with a contribution rate of more than 50% and up to 80%. These results provide a scientific basis for optimizing planting structures. They are of significant theoretical and practical significance in guiding vegetation restoration work. [ABSTRACT FROM AUTHOR]

Landslides caused by earthquakes bring about dramatic changes in soil erodibility. In order to understand the change characteristics of soil erodibility during a vegetation restoration period after the 5.12 Wenchuan earthquake, a non-landslide area, landslide area, and transition area in Leigu Town, Beichuan County were selected as research areas. Field soil sampling, geostatistics, and spatial interpolation were used to explore the spatiotemporal changes in soil physicochemical properties and soil erodibility during a natural restoration in 2013 (5 years after the earthquake) and in 2022 (14 years after the earthquake). The results showed that the comprehensive soil erodibility index (CSEI) was mainly composed of five soil factors, which were soil pH, soil total nitrogen (TN), mean weight diameter of soil aggregates (MWD), fractal dimension of soil water stable aggregates (D), and soil erodibility (Kepic). The CSEI of the landslide area was slightly lower than that of the non-landslide area. The CSEI was gradually increasing during the process of natural restoration after earthquake. From 2013 to 2022, the increase rates of the CSEI were 6.9%, 10.0%, and 41.5% for the landslide area, non-landslide area, and transition area, respectively. Along attitude segments, the spatial distribution of soil erodibility in 2022 is more uniform than that in 2013. The higher value of CSEI was located in the upper part of research areas. The spatial distribution of the CSEI in 2013 and 2022 appeared as a moderate autocorrelation. The variable ranges of CSEI in 2013 and 2022 were about 20 m. In the early stage of vegetation restoration, soil and water conservation engineering was recommended in the landslide area. [ABSTRACT FROM AUTHOR]

Understanding the evolution of land use change and its drivers is vital in keeping the fragile balance between human activities and nature. The present study employs remote sensing data from between 1990 and 2020 during the Grain-for-Green Project (GGP) in Luochuan county, Shaanxi Province, which offers 30 years of continuous data on precipitation, temperature, population, and GDP. Here, the combined method of supervised classification with manual visual interpretation was adopted for building a high-precision spatial distribution information database, in order to explore the links existing between the change features of land use, distribution, and spatial pattern, and the interference of local socio-economic development and natural factors before and after the GGP. According to the results, during the past three decades, Luochuan county has undergone large changes in land use types, displaying distinct features and regional disparities. Geographically, the north of Luochuan county is predominantly forest and grassland, while farmland is mostly in the south of Luochuan county. In 1990, farmland dominated this county; however, after 2000, forest and grassland areas expanded. Notably, the implementation of the GGP significantly influenced changes in grassland and forest areas. With the development of modernization, Luochuan county's land use structure has gradually equilibrated, with increased uniformity in the distribution of various land use types. Obviously, the shift in land use from 1990 to 2020 primarily correlates with mean annual temperature, annual precipitation, total population, and GDP. Furthermore, regression analysis revealed that during the initial decade of the GGP, natural factors primarily drove land use changes. However, after the GGP, the conversion rate from farmland to forest and shrubland/grassland escalated, and population growth was the continual external force driving the expansion of forest and grassland. Despite substantial economic benefits from land development and utilization in Luochuan county during the past 30 years, certain human economic activities have posed significant pressure on regional agricultural development and sustainable land resource use. Overall, this study helps our government to enhance national land management and planning through a targeted method, also providing a reference for analyzing land use change processes within same areas. [ABSTRACT FROM AUTHOR]

The Chinese government has implemented numerous ecological policies in Qinghai Province aimed at protecting and restoring the natural ecosystem. Yet, amid global climate change, the precise effects of these policies on ecological improvement remain ambiguous. There is an urgent need for a comprehensive evaluation of the effects of these policies at a regional scale and an analysis of the changes in policy implementation stages to optimize the strategic direction of regional ecological policies. In this study, using mathematical statistics and spatial analysis, we analysed the spatial and temporal characteristics of the Normalized Difference Vegetation Index (NDVI) in Qinghai Province from 2000 to 2023. Further, by systematically reviewing ten major ecological policies currently or previously implemented in the region, we explored the response of vegetation restoration to these policies through both horizontal and vertical evaluations by reasonably delineating the policy study sub-zones. The study identified distinct stages of policy implementation—regreening, stabilizing, and natural recovery—and correlated these stages with the efficacy of policy impacts. Our findings indicate significant vegetation coverage improvements across Qinghai Province over the past two decades, with all ecological policies positively influencing the environment. The main contribution of this study is that it comprehensively evaluates the impact of multiple ecological policies on vegetation restoration at the regional scale, providing a reference for the formulation and adjustment of subsequent ecological policies. [ABSTRACT FROM AUTHOR]

Natural soil and vegetation recovery following human disturbance is the primary means of restoring degraded ecosystems globally. However, it remains unclear how vegetation recovery in the tropical karst areas of China affects the soil physicochemical properties. Here, we investigated the impacts of natural vegetation recovery on soil physicochemical properties at different soil depths in tropical karst areas in southwestern China, using a space–time substitution method. We found that with the natural vegetation recovery, soil bulk density (SBD) decreased. Soil pH initially decreased and then increased, reaching its lowest value during the shrubland stage. There was a significant increase in other soil physicochemical factors. In the soil profiles, SBD tended to increase with depth. The pH, total potassium (TK), total phosphorus (TP), and exchangeable calcium remained relatively stable across the different soil layers. TK, TP, available phosphorus, SBD, total nitrogen, pH, exchangeable magnesium, and available potassium significantly contributed to the soil physicochemical properties. Soil physicochemical properties were predominantly directly affected by litter and biological factors, albeit indirectly influenced by topographic factors. Our study provides crucial insights into karst soils and their relationship with vegetation recovery, which are pivotal for steering vegetation restoration and soil amelioration in karst areas. [ABSTRACT FROM AUTHOR]

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]

Road construction and strip mining in mountainous regions inevitably causes the destruction of vegetation and soil, leading to large ranges of exposed slopes. Although soil spray-sowing has become a promising method to accelerate community assembly in humid regions, the application of microbial fertilizers and shading in slope recovery during soil spray-sowing are rarely reported in dry-hot valleys. This study compared the effectiveness among artificial seeding, arch column + planting bags, and soil spray-sowing by slope restoration trials in the Yuanjiang dry-hot valley, southwest China. Additionally, we explored the effect of slope degrees, shade, and microbial fertilizers on seedling survival and growth after soil spray-sowing. Results indicated that soil spray-sowing displayed better species survival and growth performance than artificial seeding and arch column + planting bags. The richness, density, and height of seedlings dropped dramatically with the increasing of slope degrees after soil spray-sowing, especially when the slope degree was greater than 1. Although shading observably improved the species density, it inhibited the growth of Albizia julibrissin and Crotalaria pallida. Moreover, microbial fertilizers Penicillium chrysogenum and Bacillus aryabhattai markedly enhanced the density and growth of species Azadirachta Indica, Cajanus cajan, Indigofera cassioides, and Sophora xanthanth. Soil spray-sowing, combined with shading and microbial fertilizers, contributes to species survival and growth when the slope degree is less than 1.73 and the soil spray-sowing process coincides with the rainy season, which provides the theoretical basis and technical support for ecological restoration in the dry-hot river valley. [ABSTRACT FROM AUTHOR]

Plantation is an economical and effective method of ecological restoration, which is also a common means to increase soil organic carbon (SOC) content. However, the effects of vegetation types on SOC accumulation and δ13C distribution during ecological restoration are still not clear. Therefore, we evaluated the soils under four types of restoration measures: plantation (PL, dominated by Olea europaea 'Leccino'), grasslands [GLs, Setaria viridis], croplands [CLs, Zea mays] and shrublands (SLs, Lycium chinense Mill), after 11-year restoration. SOC and the natural stable carbon isotope abundance in four recovery modes were determined, while amino sugars (ASs) and lignin phenols (LPs) were used as biomarkers to identify microbial- and plant-derived carbon, respectively. The results showed that SOC, AS, and LP decreased with the increasing of soil depth, and SOC and LP showed the same trend in topsoil (0–20 cm). ASs in subsoil (40–50 cm) were significantly higher in GLs than that in CLs and the PL, while fungi residue carbon in GLs was significantly higher in subsoil. The δ13C in topsoil was mainly affected by plant factors, especially by litter. With the increasing soil depth, the effect of plants on δ13C decreased, and the effect of microorganisms increased. Vegetation types could affect SOC and δ13C by influencing plant inputs in topsoil. In the subsoil, differences in microbial compositions under different vegetation types could affect δ13C enrichment. The study revealed the effects of vegetation types on SOC accumulation and δ13C distribution during ecological restoration, emphasized that vegetation types can affect SOC accumulation by influencing the plant input of topsoil and the microbial compositions in subsoil, and provided a reference for the development of management policies in restoration areas. [ABSTRACT FROM AUTHOR]

Bacteria, fungi, and protists occupy a pivotal position in maintaining soil ecology. Despite limited knowledge on their responses to managed vegetation restoration strategies in karst regions, we aimed to study the essential microbial communities involved in the process of vegetation restoration. We compared microbial characteristics in four land use types: planted forests (PF), forage grass (FG), a mixture of plantation forest and forage grass (FF), and cropland (CR) as a reference. Our findings revealed that the richness of bacteria and protists was higher in FF compared to PF, while fungal richness was lower in both PF and FF than in CR. Additionally, the bacterial Shannon index in FF was higher than that in CR and PF, while the fungal and protist Shannon indices were similar across all four land use types. Significant differences were observed in the compositions of bacterial, fungal, and protist communities between FF and the other three land use types, whereas bacterial, fungal, and protist communities were relatively similar in PF and FG. In FF, the relative abundance of bacterial taxa Acidobacteria, Firmicutes, and Gemmatimonadetes was significantly higher than in PF and CR. Fungal communities were dominated by Ascomycota and Basidiomycota, with the relative abundance of Ascomycota significantly higher in FF compared to other land use types. Regarding protistan taxa, the relative abundance of Chlorophyta was higher in FF compared to CR, PF, and FG, while the relative abundance of Apicomplexa was higher in CR compared to FF. Importantly, ammonium nitrogen, total phosphorus, and microbial biomass nitrogen were identified as key soil properties predicting changes in the diversity of bacteria, fungi, and protists. Our results suggest that the microbial community under FF exhibits greater sensitivity to vegetation restoration compared to PF and FG. This sensitivity may stem from differences in soil properties, the formation of biological crusts and root systems, and management activities, resulting in variations in bacterial, fungal, and protist diversity and taxa in PF. As a result, employing a combination restoration strategy involving plantation forest and forage grass proves to be an effective approach to enhance the microbial community and thereby improve ecosystem functionality in ecologically fragile areas. [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]

Biochar, as a soil amendment, has been widely confirmed to increase soil carbon sequestration. However, how biochar addition affects soil carbon changes during the vegetation restoration process is still unclear, which constrains our ability to explore biochar's application in the technology of soil carbon sequestration in forests. We conducted an incubation experiment on biochar and dissolved organic matter (DOM) addition to soil at three stages of revegetation (degraded land (DS), plantation forest (PS), and secondary natural forest (NS) in Changting County in Fujian province, China) to investigate the effects of vegetation restoration, biochar, DOM, and their interaction on soil CO2 emission and its relative mechanisms. We found that the accumulative release of CO2-C in the NS and PS soils was 7.6 and 6.8 times higher, respectively, in comparison to that from the DS soil. In the DS, biochar addition significantly increased the accumulative release of CO2-C, soil pH, NH4+-N content, qCO2, phenol oxidase, and peroxidase activities. Peroxidase activities were positively correlated with the accumulative release of CO2-C, and oxidase was the most important direct factor influencing the accumulative release of CO2-C in the DS. However, the accumulative release of CO2-C, soil NH4+-N content, qCO2, β-glucosidase, and N-acetylglucosaminidase activities was significantly reduced after the application of biochar in the PS and NS. These two hydrolases were positively associated with the accumulative release of CO2-C, and hydrolase was the most vital direct factor influencing the accumulative release of CO2-C from the PS and NS soils. The positive effect of DOM addition on CO2 emission under biochar application declined with a vegetation restoration age increase. Our results indicated that biochar could alter microbial physiological processes, inhibit qCO2 and hydrolase activities, and further decrease CO2 emission in relatively fertile soil from the PS and NS; but in the relatively barren soil from the DS, biochar might promote CO2 emission by stimulating microorganisms to enhance qCO2 and oxidase activities. [ABSTRACT FROM AUTHOR]

The study employed the PML (Penman–Monteith–Leuning) model to simulate the evolution law of long-sequence evapotranspiration in the mountainous region of the Luan River basin. Additionally, this study conducted a quantitative analysis to determine the effect of restoration on evapotranspiration water consumption. From 1981 to 2020, the results indicated that there were significantly less fluctuations in precipitation in the mountainous region of the Luan River basin than there were fluctuations in discharge. The restoration of vegetation in the mountainous region of the Luan River basin caused a mean annual growth rate of 3.47 mm in evapotranspiration. A linear positive correlation was observed between the evapotranspiration and vegetation NDVIs (normalized difference vegetation indexes) in mountainous regions. Specifically, for each 0.01 increase in the NDVI, there was an approximate 8.3 mm increase in evapotranspiration. When comparing the time periods of 1995–2001 and 2002–2020, it was observed that evapotranspiration increased by 70 mm. Furthermore, the evapotranspiration rate in the southeastern region exhibits significant variation, peaking at over 50 mm per year. In contrast, the northwest experiences variations of less than 10 mm per year. A quantitative analysis of the relationship between the evolution of mountain evapotranspiration and the response law of vegetation restoration is presented in this study; this information can be used as a guide when developing practical vegetation restoration strategies. [ABSTRACT FROM AUTHOR]

The clarification of the impact of human activities on vegetation in mining areas contributes to the harmonization of mining and environmental protection. This study utilized Geographically and Temporally Weighted Regression (GTWR) to establish a quantitative relationship among the Normalized Difference Vegetation Index (NDVI), temperature, precipitation, and Digital Elevation Model (DEM). Furthermore, residual analysis was performed to remove the impact of natural factors and separately assess the impact of human activities on vegetation restoration. The experiment was carried out in Shangwan Mine, China, and following results were obtained: (1) During the period of 2000 to 2020, intensified huan activities corresponded to positive vegetation changes (NDVI-HA) that exhibited an upward trend over time. (2) The spatial heterogeneity of vegetation restoration was attributed to the DEM. It is negatively correlated with NDVI in natural conditions, while under the environment of mining activities, there is a positive correlation between NDVI-HA and DEM. (3) The contribution of human activities to vegetation restoration in mining areas has been steadily increasing, surpassing the influences of temperature and precipitation since 2010. The results of this study can provide important references for the assessment of vegetation restoration to some extent in mining areas. [ABSTRACT FROM AUTHOR]

The implementation of the Grain for Green Project has increased vegetation coverage and provided suitable habitats and food resources for soil fauna, thereby promoting the development of soil faunal communities. Studying seasonal variations in soil fauna communities in different vegetation areas can improve our understanding of the mechanisms that drive soil fauna recovery. We selected five typical artificially restored vegetation habitats, including Populus simonii (POS), Pinus tabulaeformis (PIT), Caragana korshinskii (CAK), Stipa bungeana (STB), and Medicago sativa (MES), and one farmland (Zea mays, FAL) habitat on the Loess Plateau. In this study, soil fauna communities and environmental factors were investigated during spring (May), summer (August), and autumn (November). Among the habitats, the STB habitat had the largest seasonal variation in soil faunal density (from 1173 ind·m−2 in May to 10,743 ind·m−2 in August), and the FAL habitat had the smallest (from 2827 ind·m−2 in August to 5550 ind·m−2 in November). Among the restored vegetation habitats, Acarina (44.89–88.56%) had the highest relative abundance of all taxa. The redundancy analysis (RDA) results showed that among the factors driving seasonal variation in soil animal communities, temperature (47.41%) was the most important, followed by precipitation (22.60%). In addition, the dominant groups, Acarina and Collembola, played an influential role in seasonal variations in soil faunal density. Temperature mainly determined the seasonal variations in soil faunal communities. Seasonal factors should be considered when conducting soil fauna research, as they contribute to biodiversity conservation and regional ecological management in the Loess Plateau. [ABSTRACT FROM AUTHOR]

Frequent spontaneous combustion activities restrict ecological restoration of coal waste dumps after reclamation. Effective monitoring of vegetation restoration is important for ensuring land reclamation success and preserving the ecological environment in mining areas. Development of unmanned aerial vehicle (UAV) technology has enabled fine-scale vegetation monitoring. In this study, we focused on Medicago sativa L. (alfalfa), a representative herbaceous vegetation type, in a coal waste dump after reclamation in Shanxi province, China. The alfalfa aboveground biomass (AGB) was used as an indicator for assessing vegetation restoration. The objective of this study was to evaluate the capacity of UAV-based fusion of RGB, multispectral, and thermal infrared information for estimating alfalfa AGB using various regression models, including random forest regression (RFR), gradient boosting decision tree (GBDT), K-nearest neighbor (KNN), support vector regression (SVR), and stacking models. The main results are as follows: (i) UAV multi-source data fusion improved alfalfa AGB estimation accuracy, although the enhancement diminished with the increasing number of sensor types. (ii) The stacking model consistently outperformed RFR, GBDT, KNN, and SVR regression models across all feature fusion combinations. It achieved high accuracy with R2 of 0.86–0.88, RMSE of 80.06–86.87 g/m2, and MAE of 60.24–62.69 g/m2. Notably, the stacking model based on only RGB imagery features mitigated the accuracy loss from limited types of features, potentially reducing equipment costs. This study demonstrated the potential of UAV in improving vegetation restoration management of coal waste dumps after reclamation. [ABSTRACT FROM AUTHOR]

This study aims to investigate the impact of vegetation restoration on soil humus and aggregate stability within the karst region of Southwest China. This study focused on soils at five vegetation succession stages (abandoned land, grassland, shrub rangeland, shrubland, and secondary forest) in the typical karst region, and the aggregate stability was determined using wet sieving and the Le Bissonnais method. Simultaneously, the Pallo method and separation extraction were used to determine the humus composition, aiming to analyze the distribution of humus content in the soil aggregates and its effect on aggregate stability. The results revealed the following: (1) The mean weight diameter of soil aggregates significantly increased with vegetation restoration stages. Soil water-stable aggregates at each vegetation stage mainly included particles over 2 mm in size. (2) The humic acid and fulvic acid contents consistently increased with vegetation restoration, and the precipitation quotient value of the humification degree showed an increasing trend. At each vegetation restoration stage, the percentage of each humus component was, from highest to lowest, as follows: insoluble HM, fulvic acid, humic acid, clay-bound HM, and iron-bound HM. (3) Through stepwise regression analysis, humic acid content in >2 mm aggregates, fulvic acid and clay-bound HM contents in 1–2 mm aggregates, and insoluble HM content in <0.25 mm aggregates were the dominant factors affecting soil aggregate stability in the karst region. These results aim to provide novel insights for a more in-depth comprehension of the restoration and rehabilitation of vegetation within the karst region of Southwest China, thereby laying a robust foundation for scientific theories and further investigations. [ABSTRACT FROM AUTHOR]

The coastal wetlands in the Yellow River Delta play a vital role in the ecological function of the area. However, the impact of primary restoration on microbial communities is not yet fully understood. Hence, this study aimed to analyze the bacterial and archaeal communities in the soil. The results indicated that Marinobacter and Halomonas were predominant in the bacterial community during spring and winter. On the other hand, Muribaculaceae and Helicobacter were prevalent during the core remediation of soil, while Inhella and Halanaerobium were predominant in non-vegetation-covered high-salinity soil. The bacterial Shannon index showed significant differences in vegetation-covered areas. For archaea, Salinigranum, Halorubrum, and Halogranum were dominant in vegetation areas, while Halolamina, Halogranum, and Halorubrum were prevalent in non-vegetation areas. The colonization of Suaeda salsa led to differences in the composition of bacteria (22.6%) and archaea (29.5%), and salt was one of the significant reasons for this difference. The microflora was more diverse, and the elements circulated after vegetation grounding, while the microbial composition in non-vegetation areas was similar, but there was potential competition. Therefore, vegetation restoration can effectively restore soil ecological function, while the microorganisms in the soil before restoration provide germplasm resources for pollutant degradation and antimicrobial development. [ABSTRACT FROM AUTHOR]

The photovoltaic industry is developing rapidly because of its renewable energy and other advantages. However, the installation of this infrastructure may affect soil, vegetation, and carbon dynamics, making it is necessary to carry out vegetation restoration work at a plant's location in the later stages of its construction. For this reason, three types of artificial vegetation were selected (Pinus sylvestris var. mongolica, Astragalus membra-naceus var. mongholicus and Medicago sativa) as research objects in an ecological photovoltaic power plant in Northern China, to study the changes in soil organic carbon storage (SOCS), carbon:nitrogen ratios (C:N) and C:phosphorus ratios (C:P) at different soil depths and for different vegetation types. Natural vegetation plots undisturbed by the construction of the power plant were used as a control. Seven years after revegetation, we found that the storage and content of soil organic carbon in all three artificial vegetation plots were notably lower compared to the control. Nevertheless, the soil's organic carbon content for Medicago sativa plots increased was significantly higher by 1.2 g·kg−1 compared to Pinus sylvestris var. mongolica and A. membranaceus var. mongholicus plots, while organic carbon storage increased significantly by 3.55 t·ha and 7.15 t·ha. SOCS, C:N, and C:P concentrations in the 0–20 cm soil layer exhibited a significantly higher value in comparison to those of the 20–40 cm soil layer. As the soil depth increased, all the concentrations declined gradually. Vegetation type and soil depth, as well as their interaction, had a significant impact on soil carbon storage, C:N, and C:P. The study area was restricted by the availability of P. In general, vegetation restoration is a beneficial ecological practice for soil restoration at photovoltaic power stations. It is believed that planting alfalfa can accelerate the improvement of soil carbon with an extension of vegetation recovery time. In order to restore the balance of nutrients for plants, it is necessary to avoid human interference at the later stage, and to supplement phosphorus as soon as possible to minimize phosphorus limitation at the later stage of vegetation growth, which is of great importance to increasing the likelihood of success in reclaiming disturbed land. [ABSTRACT FROM AUTHOR]

Purple soils are greatly representative of ecologically fragile soils in southern China, yet the impact of vegetation restoration processes on the nitrogen (N) availability in purple soil ecosystems is still unclear. In this study, the soil nutrient content, available N fractions (including microbial biomass N (MBN), ammonium N (NH4+-N), nitrate N (NO3−-N), and total dissolved N (TDN)), and enzyme activities (including urease (URE), nitrate reductase (NR), and nitrite reductase (NIR)) involved in N mineralization and immobilization were investigated across the three vegetation-restoration measures: Camellia oleifera monoculture, Camellia oleifera ryegrass intercropping, and Camellia oleifera intercropping with weeds. The results showed that the Camellia oleifera monoculture mode considerably enhanced the accumulation and availability of soil N and modified the proportion of available N fractions in arable land situated on purple soil slopes, compared to the intercropping mode, the physical, chemical, and microbiological properties of soil demonstrated more pronounced effects due to the Camellia oleifera monoculture vegetation-restoration measures. However, soil nutrient loss is faster on set-aside land and in crop monocultures, and intercropping restoration measures are more beneficial for soil and water conservation under timely fertilization conditions. The soil URE, NR, and NIR activities and MBN content in the Camellia oleifera monoculture model were significantly higher than in the control check sample. Soil N transformation occurs through the combined influence of chemical and biological processes. The relationships between the activities of the three soil enzymes studied and the contents of various components of soil nutrients and effective N displayed significant differences. Notably, URE had a highly significant positive correlation with TOC. There is a strong positive correlation between NR and TN, NIR and TDN, NO3−-N, and NH4+-N. Our findings suggest that vegetation restoration improved the soil N availability and its enzyme activities in purple soils, making an essential contribution to the restoration and sustainability of purple soil ecosystem functions. [ABSTRACT FROM AUTHOR]

Soil quality is a very important indicator used to assess ecosystem restoration states in terms of vegetation recovery and establishment. Evaluating the soil quality of different vegetation restoration types in mountainous areas of Beijing and identifying their influencing factors would provide a scientific basis and be helpful for vegetation restoration in the future. Six vegetation types (or communities), including Platycladus orientalis (L.) Franco pure forest (POP), Pinus tabulaeformis Carr. pure forest (PTP), Platycladus orientalis–Pinus tabulaeformis mixed forest (PPM), Platycladus orientalis coniferous and broadleaved mixed forest (POCB), Pinus tabulaeformis coniferous and broadleaved mixed forest (PTCB), deciduous broadleaved mixed forest (DBMF), and one area of non-afforested land (NF), with similar stand conditions were selected and fourteen factors of soil physical and chemical characteristics were measured and used to establish a total data set (TDS), while a minimum data set (MDS) was obtained by using the principal component analysis (PCA) and Pearson correlation analysis methods. Two scoring methods, linear (L) and non-linear (NL), were used to calculate the soil quality index (SQI), and the key factors influencing soil quality by vegetation were identified by a general linear model (GLM), PCA, and correlation analysis. The results showed that: (1) The screened MDS indicators which showed good relationships with the SQIs in the study areas were total nitrogen (TN), sand content, total potassium (TK), pH, and available water capacity (AWC). The SQI–NLM method has better applicability. (2) The contribution rates of vegetation to different soil factors accounted for 28.644% (TN), 21.398% (sand content), 24.551% (TK), 16.075% (pH), and 9.332% (AWC). (3) TN showed a positive relationship with all vegetation types; the content of TN in PTCB and DBMF was obviously larger than in the other types in the 0–10 cm layer; PPM, PTCB, and POCB affected the sand content, which showed negative correlativity; and DBMF showed positive correlativity with AWC. The mechanism of how different species affect TN, sand content, and AWC should be focused on and taken into consideration in further studies. [ABSTRACT FROM AUTHOR]

Smoke is one of the fire-related cues that can alter vegetation communities' compositions, by promoting or excluding different plant species. For over 30 years, smoke-derived compounds have been a hot topic in plant and crop physiology. Research in this field was initiated in fire-prone areas in Australia, South Africa and some countries of both Americas, mostly with Mediterranean-type climates. Then, research extended to regions with moderate climates, like Central European countries; this was sometimes determined by the fact that in those regions, extensive prescribed or illegal burning (swailing) occurs. Hence, this review updates information about the effects of smoke compounds on plant kingdoms in different regions. It also focuses on research advances in the field of the physiological effects of smoke chemicals, mostly karrikins, and attempts to gather and summarize the current state of research and opinions on the roles of such compounds in plants' lives. We finish our review by discussing major research gaps, which include issues such as why plants that occur in non-fire-prone areas respond to smoke chemicals. Have recent climate change and human activities increased the risk of wildfires, and how may these affect local plant communities through physiologically active smoke compounds? Is the response of seeds to smoke and smoke compounds an evolutionarily driven trait that allows plants to adapt to the environment? What can we learn by examining post-fire smoke on a large scale? [ABSTRACT FROM AUTHOR]

Fire is a common natural disturbance in forest ecosystems and plays an important role in subsequent vegetation patterns. Based on the spatial sequence method, adopted as an alternative to the time successional sequence method, we selected burned areas in different locations in the Anning River Basin, which encompasses typical dry valleys. Quadrat surveys and quantitative classification were used to identify and classify the vegetation and distribution pattern and to carry out environmental interpretation during the natural restoration process after a forest fire. The results showed the following: (1) in the early stage of natural recovery after a forest fire disturbance, the vegetation community could be divided into seven community types, and Quercus guyavaefolia H. Leveille (Qg) was the dominant species in the community; (2) the vegetation samples could be divided into five ecological types, and the classification and distribution pattern of community types in this region changed most notably with altitude; and (3) a detrended correspondence analysis could be used to accurately classify vegetation community types, while a detrended canonical correspondence analysis could reveal the relationships between species and environmental factors. This study provides a scientific basis for guiding the restoration of ecosystem structural stability and biodiversity in burned areas. [ABSTRACT FROM AUTHOR]

Soil nematode communities can offer valuable indicators for monitoring the status of soil ecosystems. However, their potential for assessing soil restoration under revegetation has been neglected in temperate arid and semiarid areas. This study examined the characteristics of soil nematode communities and their relationships with soil physicochemical properties under five typical revegetation approaches in the semiarid Loess Plateau of China. The results showed that planting an artificial Caragana korshinskii forest led to the recovery of the soil food web, which significantly increased soil nematode abundance (138.10 ± 11.60 inds./100 g dry soil) and community diversity (Shannon-Wiener diversity: 2.48 ± 0.13; trophic diversity: 3.08 ± 0.02), associated with the high contents of SOC and NH4+-N. However, establishing an artificial Prunus sibirica forest improved neither soil properties nor nematode community characteristics, reflecting poor soil ecosystem restoration. After establishing an artificial Prunus davidiana forest (PD) and an artificial Medicago sativa grassland (MS), substantial increases in herbivorous and fungivorous nematodes were observed, respectively, likely due to the accumulation of particular genera that fed on roots (e.g., Pratylenchus) or their symbiotic fungi (e.g., Tylencholaimus), which might result in the deterioration (in MS) or restoration (in PD) of the soil food webs. Natural grassland restoration greatly improved soil properties (i.e., SOC, NH4+-N, microbial biomass carbon) but did not change the nematode community obviously, probably due to top-down predation in natural habitats. In conclusion, the characteristics of nematode communities can effectively indicate the restoration of soil food webs and identify their possible driving forces under revegetation, which have important implications for vegetation restoration in arid and semiarid regions. [ABSTRACT FROM AUTHOR]

Inappropriate vegetation reconstruction in the Loess Plateau region has led to a significant increase in regional evapotranspiration and water consumption, further aggravating the shortage of soil water resources in the Loess Plateau region. The Jing River basin is a typical area for vegetation reconstruction in the Loess Plateau region. A thorough understanding of changes in hydrological processes in the Jing River basin is of significant scientific importance for efficient utilization of soil water resources and sustainable vegetation restoration in the region. In this study, the physically based Water and Energy Transfer Processes (WEP) distributed hydrological model was used to simulate key hydrological processes in the Jing River Basin during different periods before and after the implementation of cropland conversion to forest and grassland from 1980 to 2019. The results showed that after the implementation of cropland conversion to forest and grassland from 2000 to 2019, the average runoff volume in the Jing River Basin decreased by 20.91%. The most significant decrease in average runoff occurred in the central and northern parts of the basin, with a maximum reduction of 48.6%. The decrease in runoff in flood season is more obvious. The peak discharge decreased by 24.91%, and the most significant decrease occurred in the northern and central parts of the basin, ranging from 10.3% to 50.2%. The spatial distribution pattern of average soil moisture in the 0–0.8 m soil layer showed more moisture in the south and less in the north, with the minimum value occurring in certain areas in the eastern part of the basin. Overall, the implementation of cropland conversion to forest and grassland led to a certain degree of decrease in soil moisture in the basin. After the implementation of cropland conversion to forest and grassland, reference evapotranspiration fluctuated only in specific areas of the basin with no significant overall change. [ABSTRACT FROM AUTHOR]

In the process of vegetation restoration for karst desertification management, the lack of scientific and rational intercropping technology and the blind application of large amounts of nitrogen fertilizer have made the soil the main source of atmospheric N2O in this region. How soil N2O emissions vary under different intercropping modes is a scientific question worthy of study. This study took a three-year-old loquat (Eribotrya japonica L.) artificial forest in the karst plateau canyon as the experimental site and designed loquat intercropping with peanut, corn, and sweet potato (Ipomoeabatatas (L.) Lam.) as well as non-intercropping to analyze the differences in soil physicochemical properties and greenhouse gas emissions under different intercropping patterns. The results showed that intercropping with peanut significantly increased loquat yield, soil moisture, temperature, SOC, MBC, TN, and MBN content. The emissions of N2O and CO2were mainly positively correlated with soil moisture and temperature, while CH4 showed a negative correlation with soil moisture and soil temperature. The soil absorbed CH4 in the control of karst desertification. Karst area soils exhibited higher N2O emissions. Intercropping patterns significantly influenced soil N2O emissions, with N2O-N cumulative emissions ranging from 5.28 to 8.13 kg·hm−2 under different intercropping conditions. The lowest N2O-N cumulative emissions were observed for peanut intercropped under the forest. The peak N2O emission occurred in April 2022, which may be attributed to the higher rainfall and soil moisture during that month. Intercropping peanut with loquat significantly reduced the global warming potential. Therefore, intercropping peanut in young forests can improve soil water and fertilizer conditions, reduce soil N2O emissions and global warming potential, and serve as a nitrogen fixation and emission reduction technique suitable for karst desertification areas. [ABSTRACT FROM AUTHOR]

Surface vegetation has a substantial impact on soil aggregate stability, which is an important indicator of soil quality. However, there is still limited research on the response of soil aggregate stability indicators and the organic carbon, total nitrogen, and total phosphorus content in soil aggregates for different vegetation patterns in rocky desertification fragile ecological areas. Therefore, in order to study the effects of different vegetation restoration models on soil aggregate stability and aggregate related nutrient content and their promoting relationships in the karst rocky desertification areas in southwest China, soil samples under three artificial restoration vegetation measures (Juglans regia L.-Rosa roxburghii Tratt., Rosa roxburghii Tratt.-Lolium perenne L., Juglans regia L.-Lolium perenne L.) were collected in 0–10 cm and 10–20 cm soil, and the traditional farmland (Zea mays L.) was used as the control, combined with dry and wet sieving experiments for the research and analysis. The results showed that there were significant differences in the distribution of aggregates and soil nutrients among the four types of plots. Compared with traditional agricultural land, artificial afforestation increased the content of soil large macroaggregates (LMAs) and decreased the proportion of microaggregates (MIAs) and silt+clay (SCA), which enhanced the soil aggregate stability and reduced the soil fragmentation and erodibility. The afforestation restoration increased the content of soil aggregate-related SOC, TN, and TP, and increased with the decrease in the aggregate particle size. Research has found that soil aggregate stability indicators are significantly influenced by the particle size distribution of soil aggregates. In the positive succession process of vegetation types, soil nutrient accumulation is controlled by changes in the soil aggregate particle size, which affects the soil aggregate stability and reduces soil erodibility, thereby protecting the soil nutrient loss. The composite management of forest and irrigation in degraded ecological areas has certain reference and indicative significance for ecological restoration in rocky desertification areas. [ABSTRACT FROM AUTHOR]

The Three Rivers Headwaters Region (TRHR), situated in the high-altitude region of the Tibetan Plateau, represents a critical ecological security barrier for both China and Southeast Asia. In addition to providing a vital freshwater supply for China, it is also one of the most biodiverse areas in the world. However, the region is characterized by a fragile and sensitive ecosystem, which makes it particularly vulnerable to environmental disturbances. Given the role of vegetation as a reliable indicator of ecosystem changes, investigating the patterns and drivers of vegetation change in the TRHR can provide valuable insights into the state and trajectory of its ecological system. To assess the spatiotemporal dynamics of vegetation changes in TRHR, this study constructed a comprehensive vegetation index (CVI) based on leaf area index (LAI), fractional vegetation cover (FVC), and net primary productivity (NPP). Trend analysis and significance testing were employed to detect and quantify the magnitude and direction of vegetation changes over the past two decades. Moreover, correlation analysis, spatial overlay, and statistical modeling techniques were applied to examine the relative contributions of climate, land use/cover changes, and slope altitude to CVI changes. The results showed the following: (1) the CVI in the TRHR showed an overall increasing trend from 2000 to 2019, with an average annual increase of 0.6%, indicating a positive development trend of vegetation, but with obvious spatial differences. (2) The vegetation in the TRHR has shown a marked increase over the past two decades, with significant increase accounting for 19% of the total area, mainly concentrated in the Yellow River Basin. Conversely, a significant decline in vegetation was observed in 3% of the total area, predominantly in the Yangtze River Basin. (3) Both temperature and precipitation had a positive impact on vegetation restoration in the TRHR, but the area affected by temperature was larger than that affected by precipitation. (4) The land-use regime had a discernible impact on vegetation increase, with the conversion of land use to ecological land promoting vegetation restoration. However, the efficacy of restoration efforts might have varied depending on natural resource endowments in certain regions. (5) With increasing altitude, vegetation conditions initially improved before eventually deteriorating. Conversely, as the slope increased, vegetation experienced an initial improvement before ultimately stabilizing. This study helps to understand the overall changes and driving mechanisms of vegetation in the TRHR and provides a scientific basis and decision-making reference for the dynamic adjustment of vegetation restoration and ecological engineering in the region in the future. [ABSTRACT FROM AUTHOR]

Large-scale vegetation restoration can significantly affect catchment hydrology. Assessing the impact of vegetation restoration on hydrological regimes is important for water resource management. We chose three less-forested catchments (LFCs, forested area <30%) undergoing major vegetation restoration, i.e., Wuqi, Zhidan, and Liujiahe, and two forested reference catchments (FCs, forested area >77%) that have had secondary forests for more than 150 years, i.e., Zhangcunyi and Huangling, of the Beiluo River basin located in the Loess Plateau (LP) to compare and analyze the stationary and variation characteristics of streamflow and its components from 1958 to 2019. Results show that the mean annual streamflows were 25.07~34.21 and 21.62~48.02 mm in the LFCs and FCs, respectively. The mean streamflow in the LFCs decreased by 50% on average from before the year 2000 to after. The decreasing trend of high flows and increasing trend of low flows is represented in the daily flow duration curves of the LFCs. The result of baseflow separation shows that the average percentages of baseflow in the streamflow were 31.89~43.36% in the LFCs and 58.23~60.14% in the FCs. The Mann–Kendall tests showed significant decreasing trends in annual streamflow (−0.27~−0.70 mm/a) and stormflow (−0.29~−0.64 mm/a) in the LFCs from 1958 to 2019, while the baseflow exhibited increasing trends except for in the Zhidan catchment. The seasonal streamflow and stormflow showed significant decreasing trends in the summer and non-flood season, while the winter and non-flood season's baseflow increased in LFCs. In FCs, however, the streamflow and its components showed only slight fluctuations over the study period in annual trends, decadal variability, and seasonal trends over the study period, suggesting that FCs have stable hydrological regimes. These results indicate that 20 years of large-scale vegetation restoration greatly influenced hydrological regimes by reducing stormflow and increasing baseflow, and played an important role in streamflow regulation. Conversely, areas with well-preserved vegetation can effectively mitigate the effects of weather and other factors on runoff with stable hydrological regimes. This study can help vegetation restoration and water resource management on the LP. [ABSTRACT FROM AUTHOR]

Although an increasing amount of attention is being paid to how human activities alter plant communities, little is known about the consequences of these changes on species' assemblages and biodiversity patterns. Using three forest types (a Pinus yunnanensis man-made forest; Eucalyptus smithii man-made forest; and natural secondary forest) in mid-Yunnan, China, we investigated the distribution patterns of species and traits and analyzed diversity patterns and relationships, including those between species diversity, functional diversity, and soil microbial diversity. We found that species co-occurrence patterns in the Pinus yunnanensis man-made forest and natural secondary forest were non-random. The specific leaf area in the Eucalyptus smithii man-made forest and leaf nitrogen concentration in the Pinus yunnanensis man-made forest were both over-dispersed according to the mean Euclidean neighbor distance in the trait space. The natural secondary forest had higher values of species diversity, functional diversity, community-weighted means, and soil microbial diversity than the man-made forest types did. An overall low covariation between species diversity and community-weighted means suggested that the coexistence of many species does not necessarily support functional differentiation among these species. Variance partitioning revealed that soil microbial diversity was mainly regulated by community-weighted means. In conclusion, our results suggest that the naturally recovering forest was better than man-made plantations based on biodiversity patterns. [ABSTRACT FROM AUTHOR]

Soil erosion and water loss are serious problems on the rocky desertification slopes in the karst dynamic system of southwest China. The lack of soil and shortage of water restrict the ecological restoration of the regional slopes and utility of water resources. Therefore, a new slab trench capable of storing soil and water in layers on rocky desertification slopes is introduced in this paper to promote vegetation restoration. To explore the water-storing and -holding capacity of the new type of vegetated slab trench, five groups of model experiments were carried out on the vegetated slab trench under different rainfall intensities and different numbers of plants. Under rainfall and then following dry conditions, the effects of rainfall intensity and the number of plants on the water-storing and -holding capacity of vegetated slab trench models were compared and analyzed. Water-storing and -holding capacity was further explored in three groups of models with single planting or combinations of plants including water stored only in succulent root plant, only in succulent stem plant, or in mixed plants. The test results show that the new type of vegetated slab trench can effectively help to store and hold water. In the rainfall period, due to the runoff of the rainfall not being considered, the greater the rainfall intensity, the higher the water storage efficiency; the more vegetation implanted, the greater the blocking effect of the plant canopy during falling rainwater, and the more reduction is induced on the water storage efficiency of the vegetated slab trench. In the following dry period, both the succulent root plant and succulent stem plant have strong water storage capacity, but the succulent root plant has a stronger capacity for water storage. The growth status of the mixed plants was better than that of single planting, which may be due to the water complementarities between the succulent root plant and succulent stem plant in a mixed planting manner. This study is important for solving the problem of soil erosion and water loss in rocky desertification slopes, and it helps to restore the ecological environment of the area. [ABSTRACT FROM AUTHOR]

Erosion-induced soil organic carbon (SOC) loss substantially affects the redistribution of global organic carbon. The Chinese Loess Plateau, the most severely eroded region on Earth, has experienced notable soil erosion mitigation over the last few decades, making it a hotspot for soil erosion studies. However, the overall rate of SOC loss and spatiotemporal evolution under changing environments remain unclear. In this study, we investigated SOC loss from 1982 to 2015 in the severely eroded Hetong region of the Chinese Loess Plateau by combining the Revised Universal Soil Loss Equation (RUSLE) model and the localized enrichment ratio function derived from field observations and attributed the changes in SOC loss to climate- and human-induced vegetation changes. The results showed that SOC loss in the Hetong region was 64.73 t·km−2·yr−1, 16.79 times higher than the global average. Over the past 34 years, SOC loss decreased by 23.84%, with a total reduction of more than 105.64 Tg C since the change-point year. Moreover, our study found that vegetation changes dominated the changes in SOC loss in the Hetong region, contributing 89.67% of the total reduction in SOC loss in the Hetong region. This study can inform carbon accounting and sustainable catchment management in regions that have experienced large-scale ecological restoration. [ABSTRACT FROM AUTHOR]

Litter and soil play an important role in influencing hydrological processes and the global water cycle. Artificial afforestation, as a part of vegetation restoration, was constructed in the gully erosion areas of latosol with the objective to prevent erosion. Variations in the hydrological properties in soils that have undergone vegetation restoration from gully erosion are not well understood. In this study, we examine the variations in the litter thickness and mass, soil structure and porosity, and hydrological properties of four forest types (eucalyptus–grass forest, bamboo–grass forest, acacia–grass forest, and shrub–grass forest). The results show that the total litter thickness varied from 1.71 to 3.74 cm and was highest in the acacia–grass forest. The total litter mass for the acacia–grass forest, 3.49 ± 0.06 t·ha−1, was significantly higher than that for the other forest types. The mass of the undecomposed litter (UL) layer was significantly lower than that of the semi-decomposed litter (SL). (2) The maximum water-retention capacity (Wmax) and effective water-retention capacity (Weff) of the SL layer were greater than those of the UL layer. The Wmax and Weff for the acacia–grass forest were markedly larger than those of the eucalyptus–grass, bamboo–grass, and shrub–grass forests. The water absorption rates of the SL and UL layers were highest during the onset of the immersion experiment, declined exponentially with time, and declined rapidly in the first 2 h. (4) The soil bulk density ranged from 1.46 g·cm−3 to 1.54 g·cm−3, and the total porosity ranged from 32.06% to 37.13%. The soil bulk density increased with the increasing soil depth, while the total porosity decreased gradually. The soil water-holding capacity of the soil layer of 0–60 cm in the acacia–grass forest (301.76 t·ha−1) was greater than that of the other forest types. A comprehensive evaluation of the water conservation capacity by the entropy weight method showed that the water conservation capacity was greatest in the acacia–grass forest. The higher water-holding capacity of the acacia–grass forest may be more effective in enhancing rainfall interception, minimizing splash erosion, and decreasing surface runoff. Here, the results indicate that acacia–grass forest restoration can mitigate soil erosion by favoring soil and water conservation, improving the environment in the gully erosion area of latosol. [ABSTRACT FROM AUTHOR]

Studying the changes and linkages between dissolved organic matter (DOM) and microorganisms in soils during vegetation restoration will help to understand the role of vegetation restoration in soil carbon sequestration and thus improve the understanding of the global soil carbon cycle. Soil DOM molecules were characterized by Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and the results showed that the soil DOM consisted mainly of lignin/carboxylic rich alicyclic molecule (CRAM)-like structures, while the ratios of lipids and aliphatic/protein decreased in sequence with recovery time. Lipids and aliphatic/proteins with high H/C DOM (labile DOM) degrade preferentially, while lignin/CRAM-like structures and tannins with low H/C DOM (recalcitrant DOM) are recalcitrant during vegetation restoration. With the restoration of vegetation, DOM molecules tend to be diversified and complicated, and DOM compounds with low double bond equivalent (DBE), low aromatic, and low alkyl structures will be converted into persistent organic matter with high carbon numbers and high DBE. The diversity of soil microorganisms was determined by high-throughput sequencing. The results showed that the abundance and diversity of soil bacteria increased significantly after revegetation, while the abundance and diversity of soil fungi began to increase when the ecosystem became a more mature coniferous forest. The soil microbial community exhibited complex connectivity and strong interaction with DOM molecules during vegetation restoration. As most of the DOM molecules are recalcitrant, vegetation restoration facilitates C sequestration in the soil, thereby contributing to climate change mitigation. [ABSTRACT FROM AUTHOR]

The status and drivers of soil-available nutrients in plant-recovered soils are not fully understood, limiting our ability to explore the role of soil-available nutrients in soil geochemical cycling and ecosystem sustainability. Here, we combined the spatial distribution of soil-available nutrients and chemical and aggregate properties from six soil types (subalpine meadow soil, meadow soil, dark brown soil, brown soil, yellow-brown soil, and cinnamon soil) and three horizons (a leaching horizon, sediment horizon, and parent material horizon) to study the status and drivers of soil-available nutrients. Our findings reveal that the soil-available nitrogen (AN) ranged from 72.33 to 169.67 mg/kg, the soil-available phosphorus (AP) ranged from 1.77 to 75.90 mg/kg, and the soil-available potassium (AK) ranged from 46.43 to 88.55 mg/kg in the six soil types. The subalpine meadow soil and the dark brown soil had the highest soil AN, with means of 169.67 and 139.35 mg/kg, respectively. The brown soil had the highest soil AP, with a mean of 75.9 mg/kg, and the dark brown soil and the brown soil had the highest soil AK, with means of 83.49 and 88.55 mg/kg, respectively. The results show that the soil types and soil depths had a significant impact on the status of AN, AP, and AK (p < 0.05). Moreover, a higher cation exchange capacity (CEC), the macro-aggregate contents (with 2–1 mm and 1–0.5 mm particle sizes) of the non-water-stable aggregates, and the macro-aggregate content and stability (2–1 mm particle size and geometric mean diameter (GMD) of the water-stable aggregates were deemed to facilitate soil-available nitrogen because of the positive correlations (p < 0.05). Lower exchangeable cations (ECs) and the micro-aggregate content (≤0.1 mm particle size) of the water-stable aggregates and higher soil cations helped in the accumulation of soil-available phosphorus and soil-available potassium, respectively. Moreover, the regulation of the soil chemical and aggregate properties was found to vary with soil type and horizon in a correlation analysis. Together, our results provide insights into the importance of chemical and aggregate properties in regulating soil nutrient availability across soil types, as well as providing strong support for the inclusion of soil resource utilization in regional forest restoration and management. [ABSTRACT FROM AUTHOR]

Open-pit mining has caused extensive land destruction, including land abandonment and reduction in agricultural land, resulting in serious environmental problems. Ecological restoration and mine reclamation have become important components of the sustainable development strategies in Inner Mongolia, China. Therefore, the rehabilitation of mines and agricultural land is vital and has attracted widespread attention from the Chinese government. In this light, we reviewed the progress of mine restoration technologies in China in recent years and summarized the integrated technology of open-pit mine reclamation with microbial restoration technology as the core, ecological vegetation restoration as the essential, and soil restoration and improvement as the promotion. As a cost-effective and environmentally beneficial technique, combining the microbial recovery technology with vegetation and the recovery of vegetation and the improvement of the soil is widely recommended in the mining reclamation area. At the same time, we comprehensively analyzed the current status and progress of ecological restoration technology and put forward the development direction of green mining in the future. In conclusion, this review can provides guiding the sustainable development of green, ecological mines, as well as provide reference for mining reclamation and agricultural land restoration and other related fields. [ABSTRACT FROM AUTHOR]

In semi-arid and arid terrestrial ecosystems, terracing and vegetation may improve soil conditions and enhance habitats. Considerable recent works have focused on evaluating how terracing and vegetation affect individual ecosystem function, but none of these evaluations included soil ecosystem multifunctionality (SEMF), which has a positive significance for optimizing soil ecosystem management. Based on the survey data of six different combinations of terracing and vegetation in the Chinese Loess Plateau, 15 functional indicators related to soil fertility, nutrient transformation/cycling, and water conservation were selected. The maximum conversion of the mean value method was employed to quantify SEMF. Concerning individual ecosystem services, the capacities of half-moon terraces-Pinus tabulaeformis (Ht-P. tabulaeformis) and level benches-Caragana korshinskii (Lb-C. korshinskii) to maintain soil fertility were 43.25% and 42.01% higher than those of counter-slope terraces-Platycladus orientalis (Ct-P. orientalis). On the contrary, Ct-P. orientalis showed better nutrient transformation and cycling services, which was 9.23% higher than those of Ht-P. tabulaeformis, therefore, we observed the highest SEMF in the Ht-P. tabulaeformis. Terracing, with a 29.2% explained variation, had a greater influence than that of vegetation (12.6%), while the coupling effect of terracing and vegetation (37.9%) was the most important factor that determined the SEMF. Thus, Ht-P. tabulaeformis and Lb-C. korshinskii should be promoted in the Loess Plateau area. The results of this study have significance in terms of understanding the interactions between terracing, vegetation, and soil ecosystems. [ABSTRACT FROM AUTHOR]

As the oldest species of Betulaceae, Nepalese alder (Alnus nepalensis) shows a high capacity for nitrogen fixation, rapid growth rate, and strong adaptability to stress environments, and it plays an important role in maintaining the structure and function of forest and agroforestry ecosystems. We explored its geographic distribution and the corresponding environmental drivers through collecting specimen records and published literature for Nepalese alder over the world during the past 40 years. The research trends, the growth limiting factors, the physiological characteristics, and ecological functions were all summarized as well. In terms of geographical distribution and limiting factors, Nepalese alder is mainly distributed in southern mountainous areas of the Himalayas and southwest China. Since it presented a clear northern limit of distribution and an upper limit of elevation, temperature is assumed to be the main environmental limiting factor. According to historical development, the research history of Nepalese alder could be divided into three main periods: the initial development (before 2001), the fast development (2002–2015), and the high-quality development (2016–2022), with the two key points in 2002 and 2015 relating to the conversion of cropland to a forest project that the government conducted and the application from theory to practice, respectively. As can be seen from the ecological functions, Nepalese alder could form symbiotic nodules with Frankia, which plays an important role in improving soil physical and chemical properties and facilitating vegetation secondary succession. Overall, the present review provides a reference for further studies on ecological adaptability and sustainable utilization of Nepalese alder under climate change, and also for regional ecosystem service, forestry production practice, and vegetation restoration. [ABSTRACT FROM AUTHOR]

The Loess Plateau (LP) is a heavily soil-eroded area. Since the year 1999, the Chinese government has carried out the "Grain for Green Project (GGP)" that has focused on increasing the regional vegetation coverage. Understanding the temporal and spatial variation of ecosystem services and the synergy in the LP is important for prospective regional re-vegetation and watershed administration. Therefore, three typical watersheds in the LP were selected: Huangfuchuan, Dalihe, and Yanhe. The spatial and temporal changes in carbon storage (CS), soil conservation (SC), and water yield (WY) in the watersheds were analyzed by the InVEST model from 2000 to 2020. Correlation analysis and root mean square deviation (RMSD) were used to investigate and compare the trade-offs in different ecosystem services (ESs). The results showed that the ES in the Huangfuchuan, Dalihe, and Yanhe watersheds overall developed in a positive direction, and increased from north to south. CS and SC showed a positive correlation in the three watersheds; however, there were negative correlations between CS and WY and between SC and WY. From 2000 to 2020, the trade-offs among CS, SC, and WY in the study area were in the descending order of the Yanhe, Dalihe, and Huangfuchuan watersheds, while the comprehensive benefits were in the opposite order. The results provided an essential basis for the high-quality development and ecological environment preservation of the Yellow River basin. [ABSTRACT FROM AUTHOR]