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[Objective] To understand the variations in soil erodibility and nutrient content caused by different slope positions and land uses, and to discuss the influence of various factors on soil erodibility and nutrient status. [Methods] Soil and root samples were collected, and the Comprehensive Soil Erodibility Index (CSEI) and Comprehensive Soil Nutrient Index (CSNI) were calculated using a weighted sum method under different slope positions and land uses. [Results] (1) There were differences in both CSEI and CSNI among different slope positions. The highest value of CSEI was recorded on the slope crest (0.653) and the lowest value was at the bottom of the slope (0.275), while the highest value of CSNI was found on the slope crest (0.715) and the lowest value was at the top of the slope (0.341). (2) Differences in both CSEI and CSNI were observed among different land uses. The highest value of CSEI was observed in fallow land (0.617) and the lowest value was in forests (0.252), while the highest value of CSNI was found in forests (0.793) and the lowest value was in fallow land (0.322). (3) CSEI was significantly negatively correlated with clay content, sand content, root length density and aboveground biomass. It was also significantly positively correlated with silt content and soil bulk density. Soil bulk density had the greatest direct impact (0.26). CSNI was significantly positively correlated with clay content, sand content, root length density and aboveground biomass. It was also significantly negatively correlated with silt content and soil bulk density. Clay content had the greatest direct impact (0.45). There was a significant negative correlation between CSEI and CSNI. [Conclusion] Slope position significantly influences both CSEI and CSNI, emphasizing the importance of focusing on slope crests and mid-slopes in vegetation restoration efforts. Vegetation restoration in various geomorphic positions effectively reduces CSEI and enhances CSNI, with trees being more effective in controlling soil erosion.

[Objective] To quantitatively study the relationship between land use change and ecosystem service value in Sichuan section of the upper reaches of the Yellow River in the past 20 years, and to evaluate the effect of comprehensive ecological management in this section, so as to provided a basis for improving ethnic regional spatial planning, ecological environmental protection and management, and promoted the high-quality development of the Yellow River Basin. [Methods] Using the land use data of the upper reaches of the Yellow River in Sichuan in 2000, 2010 and 2020, land use change was analyzed based on land use dynamic attitude and land use matrix, and the economic value of the ecosystem service value equivalent per unit area of the terrestrial ecosystem in China was revised. The effects of land use change on the ecosystem service value in the upper reaches of the Yellow River from 2000 to 2020 in Sichuan were quantitatively studied. [Results] (1) From 2000 to 2020, the land use area of forest, desert, wetland and water system in the upper reaches of the Yellow River in Sichuan showed an increasing trend, while the land use area of cultivated land, shrub, grassland and glacial and snow in the upper reaches of the Yellow River showed a decreasing trend, and the land use change in 2010—2020 was more significant than that in 2000—2010. (2) The ecosystem service value of the upper reaches of the Yellow River in Sichuan in 2000, 2010 and 2020, was 1.27×1010, 2.51×1010, 3.92×1010 yuan, respectively, showing an increasing trend. The sensitivity analysis showed that the analysis results were reliable. Amongall land use types, grassland made the most significant contribution to total ecosystem value, and the contribution rate of grassland ecological service was 93.90% and 72.90% in 2000—2010 and 2010—2020, respectively, followed by wetland and forest land. (3) In the study area, the value of each individual ecosystem service showed an increasing trend in the past 20 years, and the sub-value of regional ecological service function was regulatory service>support service>supply service>cultural service. Among the 11 individual functions, the significant service value was climate regulation, hydrology regulation, soil conservation and biodiversity. The sum of the four items accounted for more than 69.50% of the total value. Land use change in the upper reaches of the Yellow River in Sichuan affected the changes of regional ecosystem service value, and grassland was the most significant, followed by wetland and forest land. [Conclusion] The results showed that the results of ecological governance in the past 20 years have been gradually enhanced, and the ecological environment has continuously improved.

[Objective] The carbon and water cycles in terrestrial ecosystems are the core of the material and energy cycles in terrestrial ecosystems, and also the link connecting the geosphere, the biosphere and the atmosphere. Forest vegetation is an important component of terrestrial ecosystems, an important variable characterized the terrestrial carbon-water cycle, and plays an important role in maintaining the dynamic balance of the biosphere and the atmosphere. Currently, there is a lack of systematic analysis and summary of the coupling relationship and mechanism of carbon-water cycle in terrestrial ecosystems. [Methods] This paper summarizes the research and its progress on forest vegetation carbon and water cycle processes and their interactions, as well as the definition, methods, progress and outlook of carbon-water coupling at different spatial scales (leaf to regional/global scales) from the perspectives of forest vegetation carbon and water processes and their interactions, and vegetation water use and coupling mechanisms, respectively. [Results] Emerging technologies and methods have realized high-frequency observations of hydrocarbon processes at different scales, and coupled indicator systems such as WUE have promoted the research and development of hydrocarbon coupling mechanisms. [Conclusion] In conclusion, we have systematically elucidated the multi-scale integration of vegetation carbon-water coupling relationship and carbon-water coupling mechanism, which provides a theoretical basis for the systematic understanding of forest carbon-water coupling mechanism and water resource management, and is of great significance as a scientific support for the future decision-making of vegetation operation and management.

Elucidating the seasonal patterns of water sources for dominant species in the sub-tropical humid mountainous forest, analyzing the eco-hydrological complementarity and competition mechanisms among coexisting species, investigating the responses of plant water utilization to precipitation, could provide a theoretical basis for vegetation restoration and management. Based on the stable hydrogen and oxygen isotope technique, we analyzed the δ²H and δ18O characteristics of precipitation, xylem water from Pinus massoniana and Quercus variabilis, and soil water from 0-100 cm depth in Mount Lushan, China. The MixSIAR model, Levins index, and PS index were used to calculate the relative contribution rate of each water source, the hydrological niche breadth, and niche overlap of P. massoniana and Q. variabilis. The results showed that, in the wet season (March to July), P. massoniana primarily utilized soil water from the 0-20 cm and 20-40 cm depths, while Q. variabilis primarily utilized that from the 20-40 cm and 40-60 cm depths. During the dry season (August to September), P. massoniana and Q. variabilis utilized 40-60 cm and 60-80 cm of soil water, respectively, resulting in an increase in the depth of water absorption. In the early growing season ( March to April) and the late growing season ( September), there was a high hydrological niche overlap between P. massoniana and Q. variabilis, resulting in intensitive water competition. In the middle of the growing season ( May to August), the water source was adequately allocated, and the hydrological niche was segregated to meet the high transpiration demand. Q. variabilis primarily utilized soil water from a depth of 60-80 cm and 60-80 cm before a precipitation event, and from a depth of 0-20 cm and 20-40 cm after the event. In contrast, P. massoniana primarily utilized soil water from a depth of 0-20 cm and 20-40 cm both before and after a precipitation event. In conclusion, water utilization patterns of P. massoniana and Q. variabilis exhibited a seasonal trend, with shallow water uptake during the rainy season and deep water uptake during the dry season. These species are capable of efficiently allocating water resources during the peak growth season, and their root systems actively respond to change in soil moisture level. They have strong adaptability to extreme precipitation events and exhibit remarkable water conservation capabilities. [ABSTRACT FROM AUTHOR]

[Objective] To quantitatively study the relationship between land use change and ecosystem service value in Sichuan section of the upper reaches of the Yellow River in the past 20 years, and to evaluate the effect of comprehensive ecological management in this section, so as to provided a basis for improving ethnic regional spatial planning, ecological environmental protection and management, and promoted the high-quality development of the Yellow River Basin. [Methods] Using the land use data of the upper reaches of the Yellow River in Sichuan in 2000, 2010 and 2020, land use change was analyzed based on land use dynamic attitude and land use matrix, and the economic value of the ecosystem service value equivalent per unit area of the terrestrial ecosystem in China was revised. The effects of land use change on the ecosystem service value in the upper reaches of the Yellow River from 2000 to 2020 in Sichuan were quantitatively studied. [Results] (1) From 2000 to 2020, the land use area of forest, desert, wetland and water system in the upper reaches of the Yellow River in Sichuan showed an increasing trend, while the land use area of cultivated land, shrub, grassland and glacial and snow in the upper reaches of the Yellow River showed a decreasing trend, and the land use change in 2010-2020 was more significant than that in 2000-2010. (2) The ecosystem service value of the upper reaches of the Yellow River in Sichuan in 2000, 2010 and 2020, was 1.27X1010, 2.51 X1010, 3.92X1010 yuan, respectively, showing an increasing trend. The sensitivity analysis showed that he analysis results were reliable. Among all land use types, grassland made the most significant contribution o total ecosystem value, and the contribution rate of grassland ecological service was 93.90% and 72.90% in 2000-2010 and 2010-2020, respectively, followed by wetland and forest land. (3) In the study area, the value of each individual ecosystem service showed an increasing trend in the past 20 years, and the sub-value of regional ecological service function was regulatory service > support service > supply service > cultural service. Among the 11 individual functions, the significant service value was climate regulation, hydrology regulation, soil conservation and biodiversity. The sum of the four items accounted for more than 69.50% of he total value. Land use change in the upper reaches of the Yellow River in Sichuan affected the changes of regional ecosystem service value, and grassland was the most significant, followed by wetland and forest and. [Conclusion] The results showed that the results of ecological governance in the past 20 years have been gradually enhanced, and the ecological environment has continuously improved. [ABSTRACT FROM AUTHOR]

In order to recover Ni from acid leaching solution of waste oil refining catalyst, HBL110 was used as extractant to extract nickel directly and selectively. The saponification rate of extractant, extractant concentration and extraction equilibrium time were optimized, the extraction and de extraction stages were confirmed, and the multi-stage countercurrent series extraction simulation test and the continuous running of the on-line process were carried out. The results show that under the conditions of saponification rate of 40%, HBL110 concentration of 25% and extraction time of 10 min, the mass concentration of nickel in the raffinate is less than 30 mg/L, the extraction efficiency of nickel is more than 98%, and the extraction rate of Al and Fe is less than 3%. The three stage countercurrent extraction of nickel supported organic phase with 75 g/L sulfuric acid can achieve 100% back extraction of nickel supported organic phase. The on-line extraction process of the acid leaching solution of the waste catalyst is run continuously for 5 days, the nickel concentration in the raffinate is stable at 5 mg/L, and the extraction efficiency of nickel can reach 99%. The concentration of nickel in the back extraction solution is stable at 8 g/L, and the back extraction rate of nickel is 100%. The organic phase can be effectively recycled. [ABSTRACT FROM AUTHOR]