In order to thoroughly analyze the current status and challenges faced by the water and water conservation in Hotan County of Xinjiang,the use situation of water resources,the effectiveness and shortcomings of water a...In order to thoroughly analyze the current status and challenges faced by the water and water conservation in Hotan County of Xinjiang,the use situation of water resources,the effectiveness and shortcomings of water and soil conservation work in the region are reviewed.Hotan County has achieved several remarkable achievements in the soil and water conservation project,daily management and maintenance,and ecological restoration projects.Some measures,such as terrace construction,slope protection engineering,and the construction of windproof and sandwood belts,have also had a positive impact on improving the quality of surface water resources while effectively curbing soil erosion.But there are also lack of operating policy detailed rules and implementation plans,and planning and design of some water and soil conservation projects lack of integrity and systematicness,application and promotion of new technologies,and soil loss management and ecological recovery effect assessment lack of comprehensive assessment indicators and methods.It has caused some water and soil conservation works to fail to be effectively implemented.In this regard,countermeasures and suggestions are put forward,such as strengthening the planning and management of water and soil conservation,promoting the technology and measures of water and soil conservation,increasing investment and funding support,and strengthening publicity education and personnel training.展开更多
To comprehensively evaluate the alterations in water ecosystem service functions within arid watersheds,this study focused on the Bosten Lake Basin,which is situated in the arid region of Northwest China.The research ...To comprehensively evaluate the alterations in water ecosystem service functions within arid watersheds,this study focused on the Bosten Lake Basin,which is situated in the arid region of Northwest China.The research was based on land use/land cover(LULC),natural,socioeconomic,and accessibility data,utilizing the Patch-level Land Use Simulation(PLUS)and Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)models to dynamically assess LULC change and associated variations in water yield and water conservation.The analyses included the evaluation of contribution indices of various land use types and the investigation of driving factors that influence water yield and water conservation.The results showed that the change of LULC in the Bosten Lake Basin from 2000 to 2020 showed a trend of increasing in cultivated land and construction land,and decreasing in grassland,forest,and unused land.The unused land of all the three predicted scenarios of 2030(S1,a natural development scenario;S2,an ecological protection scenario;and S3,a cultivated land protection scenario)showed a decreasing trend.The scenarios S1 and S3 showed a trend of decreasing in grassland and increasing in cultivated land;while the scenario S2 showed a trend of decreasing in cultivated land and increasing in grassland.The water yield of the Bosten Lake Basin exhibited an initial decline followed by a slight increase from 2000 to 2020.The areas with higher water yield values were primarily located in the northern section of the basin,which is characterized by higher altitude.Water conservation demonstrated a pattern of initial decrease followed by stabilization,with the northeastern region demonstrating higher water conservation values.In the projected LULC scenarios of 2030,the estimated water yield under scenarios S1 and S3 was marginally greater than that under scenario S2;while the level of water conservation across all three scenarios remained rather consistent.The results showed that Hejing County is an important water conservation function zone,and the eastern part of the Xiaoyouledusi Basin is particularly important and should be protected.The findings of this study offer a scientific foundation for advancing sustainable development in arid watersheds and facilitating efficient water resource management.展开更多
The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the soil.This study focused on the effects of different...The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the soil.This study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony soil.The stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption experiment.Six experimental groups with gravel contents of 0%,10%,20%,30%,40%,and 50%were established to determine the saturated hydraulic conductivity(K_(s)),saturated water content(θ_(s)),initial water content(θ_(i)),and retention water content(θ_(r)),and explore the changes in the wetting front depth and cumulative absorption volume during the absorption experiment.The Philip model was used to fit the soil absorption process and determine the soil water absorption rate.Then the length of the characteristic wetting front depth,shape coefficient,empirical parameter,inverse intake suction and soil water suction were derived from the van Genuchten model.Finally,the hydraulic parameters mentioned above were used to fit the soil water characteristic curves,unsaturated hydraulic conductivity(K_(θ))and specific water capacity(C(h)).The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel content.Compared with control check treatment with gravel content of 0%,soil water absorption rates in the treatments with gravel contents of 10%,20%,30%,40%,and 50%decreased by 11.47%,17.97%,25.24%,29.83%,and 42.45%,respectively.As the gravel content increased,inverse intake suction gradually increased,and shape coefficient,K_(s),θ_(s),andθ_(r)gradually decreased.For the same soil water content,soil water suction and K_(θ)gradually decreased with increasing gravel content.At the same soil water suction,C(h)decreased with increasing gravel content,and the water use efficiency worsened.Overall,the water holding capacity,hydraulic conductivity,and water use efficiency of stony soil in the eastern foothills of the Helan Mountains decreased with increasing gravel content.This study could provide data support for improving soil water use efficiency in the eastern foothills of the Helan Mountains and other similar rocky mountainous areas.展开更多
Soil erosion control based on county scale Soil and Water Conservation Regionalization(SWCR)is an essential component of China's ecological civilization construction.In SWCR,the quantitative analysis of the spatia...Soil erosion control based on county scale Soil and Water Conservation Regionalization(SWCR)is an essential component of China's ecological civilization construction.In SWCR,the quantitative analysis of the spatial heterogeneity and driving factors of soil erosion among different regions is still lacking.It is of great significance for soil erosion control to deeply examine the factors contributing to soil erosion(natural,land use,and socioeconomic factors)and their interaction at the county and regional levels.This study focused on a highly cultivated area,Hechuan District of Chongqing in the Sichuan Basin.The district(with 30 townships)was divided into four soil and water conservation regions(Ⅰ-Ⅳ)using principal component and hierarchical cluster analysis.The driving factors of soil erosion were identified using the geographical detector model.The results showed thatⅰ)the high cultivation rate was a prominent factor of soil erosion,and the sloping farmland accounted for 78.4%of the soil erosion in the study area;ⅱ)land use factors demonstrated the highest explanatory power in soil erosion,and the average interaction of land use factors explained 60.1%of soil erosion in the study area;ⅲ)the interaction between natural factors,socioeconomic factors,and land use factors greatly contributes to regional soil erosion through nonlinear-enhancement of double-factor enhancement.This study highlights the importance of giving special attention to the effects of land use factors on soil erosion at the county scale,particularly in mountainous and hilly areas with extensive sloping farmland and a high cultivation rate.展开更多
Since water and soil conservation monitoring in the Yellow River Basin entered a new stage at the end of the 20th century,the monitoring scope has been expanding,the monitoring accuracy has been improving,the monitori...Since water and soil conservation monitoring in the Yellow River Basin entered a new stage at the end of the 20th century,the monitoring scope has been expanding,the monitoring accuracy has been improving,the monitoring content and indicators have been increasing,and the monitoring technology and methods have been improving.This paper mainly analyzes the status of soil and water conservation monitoring in the Yellow River Basin,as well as the construction of the monitoring system and related research,in order to provide a reference for watershed management and development and the scientific research of water and soil conservation.展开更多
Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)an...Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.展开更多
Water management is an important practice that affects fruit size and quality.Effective implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established man...Water management is an important practice that affects fruit size and quality.Effective implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established manly based on the effects of water deficits on final fruit quality.Few studies have focused on the real-time effects of water status on fruit and shoot growth.To establish soil water potential (ψ_(soil)) thresholds to trigger irrigation of peach at pivotal fruit developmental stages,photogrammetry,^(13)C labelling,and other techniques were used in this study to investigate real-time changes in stem diameter,fruit projected area,net leaf photosynthetic rate (P_(n)),and allocation of photoassimilates to fruit under soil water potential conditions ranging from saturation to stress in 6-year-old Shimizu hakuto’peach.Stem growth,fruit growth,and P_n exhibited gradually decreasing sensitivity to water deficits during fruit developmental stages I,II,and III.Stem diameter growth was significantly inhibited whenψ_(soil)dropped to-8.5,-7.6,and-5.4 k Pa,respectively.Fruit growth rate was low,reaching zero when theψ_(soil)was-9.0 to-23.1,-14.9 to-21.4,and-16.5 to-23.3 k Pa,respectively,and P_ndecreased significantly when theψ_(soil)reached-24.2,-22.7,and-20.4 kPa,respectively.In addition,more photoassimilates were allocated to fruit under moderateψ_(soil)conditions (-10.1 to-17.0 k Pa) than under otherψ_(soil)values.Our results revealed threeψ_(soil)thresholds,-10.0,-15.0,and-15.0 kPa,suitable for triggering irrigation during stages I,II,and III,respectively.These thresholds can be helpful for controlling excessive tree vigor,maintaining rapid fruit growth and leaf photosynthesis,and promoting the allocation of more photoassimilates to fruit.展开更多
The implementation of Ecological Function Protection Zone(EFPZ)policy is significant for the ecological restoration and conservation of soil and water in the territory space.This manuscript analyzed and quantified the...The implementation of Ecological Function Protection Zone(EFPZ)policy is significant for the ecological restoration and conservation of soil and water in the territory space.This manuscript analyzed and quantified the impact of EFPZ on the regional water conservation function,based on land use data from 2005,2008,2010,2015 and 2020,by conducting a counterfactual simulation along with the GeoSOS-FLUS model and the InVEST model.The results demonstrate that the delineation of EFPZ can significantly influence the water conservation.(1)From 2010 to 2020,as the EFPZ was implemented,the water conservation in the study area was increasing year by year,with a growth rate of 0.03×10^(8) m^(3)∙a^(-1).On the other hand,the simulated water conservation capacity without the implementation of EFPZ decreased year by year,with a decrease rate of 0.01×10^(8) m^(3)∙a^(-1).(2)The EFPZ accounts for only 23%of the total area,but the contribution rate of water conservation reaches 80%.The actual values of water conservation and average water yield per unit pixel in the EFPZ show an increasing trend both internally and externally,while the counterfactual simulation values exhibit a decreasing trend.(3)The water conservation is much higher within the EFPZ than without EFPZ.The implementation of EFPZ has a significant effect on the improvement of the water conservation capacity in Maqu EFPZ and Yellow River Source EFPZ.The protection effectiveness should be enhanced in Qilian Mountain EFPZ and afforestation activities need to be carefully considered in Loess Plateau EFPZ.展开更多
Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regio...Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regional environmental protection and sustainable development.However,there is little research on the coupling relationship between them.In this study,focusing on the Jinghe River Basin,China as a case study,we conducted a quantitative evaluation on meteorological,hydrological,and agricultural droughts(represented by the Standardized Precipitation Index(SPI),Standardized Runoff Index(SRI),and Standardized Soil Moisture Index(SSMI),respectively)using the Variable Infiltration Capacity(VIC)model,and quantified the soil conservation service using the Revised Universal Soil Loss Equation(RUSLE)in the historical period(2000-2019)and future period(2026-2060)under two Representative Concentration Pathways(RCPs)(RCP4.5 and RCP8.5).We further examined the influence of the three types of drought on soil conservation service at annual and seasonal scales.The NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)dataset was used to predict and model the hydrometeorological elements in the future period under the RCP4.5 and RCP8.5 scenarios.The results showed that in the historical period,annual-scale meteorological drought exhibited the highest intensity,while seasonal-scale drought was generally weakest in autumn and most severe in summer.Drought intensity of all three types of drought will increase over the next 40 years,with a greater increase under the RCP4.5 scenario than under the RCP8.5 scenario.Furthermore,the intra-annual variation in the drought intensity of the three types of drought becomes smaller under the two future scenarios relative to the historical period(2000-2019).Soil conservation service exhibits a distribution pattern characterized by high levels in the southwest and southeast and lower levels in the north,and this pattern has remained consistent both in the historical and future periods.Over the past 20 years,the intra-annual variation indicated peak soil conservation service in summer and lowest level in winter;the total soil conservation of the Jinghe River Basin displayed an upward trend,with the total soil conservation in 2019 being 1.14 times higher than that in 2000.The most substantial impact on soil conservation service arises from annual-scale meteorological drought,which remains consistent both in the historical and future periods.Additionally,at the seasonal scale,meteorological drought exerts the highest influence on soil conservation service in winter and autumn,particularly under the RCP4.5 and RCP8.5 scenarios.Compared to the historical period,the soil conservation service in the Jinghe River Basin will be significantly more affected by drought in the future period in terms of both the affected area and the magnitude of impact.This study conducted beneficial attempts to evaluate and predict the dynamic characteristics of watershed drought and soil conservation service,as well as the response of soil conservation service to different types of drought.Clarifying the interrelationship between the two is the foundation for achieving sustainable development in a relatively arid and severely eroded area such as the Jinghe River Basin.展开更多
The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific consideration...The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K<sup>+</sup>), Magnesium (Mg2<sup>+</sup>), Sulphur (S), CN ratio and Sodium (Na<sup>+</sup>) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels.展开更多
In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts f...In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.展开更多
Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbaniz...Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. Soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. Soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation Service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, São Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with API and soil moisture, it will be possible to determine thresholds, thus enabling anticipation of landslide occurrences.展开更多
In order to compare the influence of different soil types and stratification on water infiltration capacity,two main types of soil in the desert steppe,sierozem(S)and aeolian sandy soil(A),were selected,and infiltrati...In order to compare the influence of different soil types and stratification on water infiltration capacity,two main types of soil in the desert steppe,sierozem(S)and aeolian sandy soil(A),were selected,and infiltration simulation tests were conducted on homogeneous soil and layered soil(layer thickness 5,10,and 20 cm),respectively.The results show that during the whole experiment,there was a small difference between S5A95(aeolian sandy soil 95 cm thick was covered with sierozem 5 cm thick)and S10A90(aeolian sandy soil 90 cm thick was covered with sierozem 10 cm thick)in the wetting front process,infiltration rate and cumulative infiltration,but there was a significant difference between S5A95 and S20A80(aeolian sandy soil 80 cm thick was covered with sierozem 20 cm thick).In the initial infiltration stage,there was no significant difference between A5S95(sierozem 95 cm thick was covered with aeolian sandy soil 5 cm thick)and A10S90(sierozem 90 cm thick was covered with aeolian sandy soil 10 cm thick).However,with the increase of infiltration time,the wetting front process,A5S95,A10S90 and A20S80 had significant differences in terms of wetting front process,infiltration rate and cumulative infiltration.The infiltration capacity of A was significantly higher than that of S.Combined with linear R 2 value and model parameters,the three infiltration models were comprehensively compared,and the fitting process and results of the general empirical model for the infiltration process of homogeneous soil and layered soil showed good results.Three models were used to simulate the water infiltration process of layered soil with different textures,and the order of the effect is as follows:general empirical model>Kostiakov model>Philip model.Soil type and layer thickness had a great influence on water infiltration process.When sierozem was covered with aeolian sandy soil 20 cm thick,the infiltration capacity was the best.As aeolian sandy soil was covered with sierozem 10 cm thick,the infiltration effect was the worst.Therefore,once coarse graying occurs on the surface of sierozem(the thickness of sand is more than 20 cm)or when the content of fine particles overlying aeolian sandy soil(the thickness of silt and clay soil is more than 10 cm)during ecological restoration is high,the soil hydrological characteristics will change significantly,which may lead to changes in vegetation types and even ecosystem structure.展开更多
This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technol...This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technological advances since the 19th century. From 1900 to 2010, temperatures in the Midwest rose by an average of 1.5 degrees Fahrenheit, which would also lead to an increase in greenhouse gas emissions. Precipitation is also expected to increase due to increased storm activity and changes in regional weather patterns. This paper explores the impact of these changes on urban and agricultural areas. In urban areas such as the city of Chicago, runoff from the increasing impervious surface areas poses challenges to the drainage system, and agriculture areas are challenged by soil erosion, nutrient loss, and fewer planting days due to excessive rainfall. Sustainable solutions such as no-till agriculture and the creation of grassland zones are discussed. Using historical data, recent climate studies and projections, the paper Outlines ways to enhance the Midwest’s ecology and resilience to climate change.展开更多
Grazing exclusion is one of the primary management practices used to restore degraded grasslands on the Tibetan Plateau.However,to date,the effects of long-term grazing exclusion measures on the process of restoring d...Grazing exclusion is one of the primary management practices used to restore degraded grasslands on the Tibetan Plateau.However,to date,the effects of long-term grazing exclusion measures on the process of restoring degraded alpine meadows have not been evaluated.In this study,moderately degraded plots,in which the vegetation coverage was approximately 65%and the dominant plant species was Potentilla anserina L,with grazing exclusion for 2 to 23 years,were selected in alpine meadows of Haibei in Qinghai-Tibet Plateau.Plant coverage,plant height,biomass,soil bulk density,saturated water content,soil organic carbon(SOC)and total nitrogen(TN)were evaluated.The results were as follows:(1)With aboveground biomass and total saturated water content at 0-40 cm depth,the average SOC and TN contents in moderately degraded alpine meadows increased as a power function,and the plant height increased as a log function.(2)The average soil bulk density at 0-40 cm depth first decreased and then increased with increasing grazing exclusion duration,and the minimum value of 0.90 g·cm^(-3) was reached at 15.23 years.The plant coverage,total belowground biomass at 0-40 cm depth,total aboveground and belowground biomass first increased and then decreased,their maximum values(80.49%,2452.92g·m^(-2),2891.06 g·m^(-2))were reached at 9.41,9.46 and 10.25 years,respectively.Long-term grazing exclusion is apparently harmful for the sustainable restoration of degraded alpine meadows.The optimal duration of grazing exclusion for the restoration of moderately degraded alpine meadows was 10 years.This research suggests that moderate disturbance should be allowed in moderately degraded alpine meadows after 10years of grazing exclusion.展开更多
The ecology of Qilian Mountains has been seriously threatened by uncontrolled grazing and wasteland reclamation. This study examined the ecological changes on the southern slope of Qilian Mountains in China from the p...The ecology of Qilian Mountains has been seriously threatened by uncontrolled grazing and wasteland reclamation. This study examined the ecological changes on the southern slope of Qilian Mountains in China from the perspective of water conservation by classifying different clusters of water conservation functional areas to efficiently use limited human resources to tackle the water conservation protection problem. In this study, we used Integrate Valuation of Ecosystem Services and Tradeoffs(InVEST) model to estimate water conservation and analyzed the factors that influence the function. The results of this study include:(1) from 2000 to 2015, the water conservation of the southern slope of Qilian Mountains generally showed an increasing trend, and the total water conservation in 2015 increased by 42.18% compared with that in 2000.(2) Rainfall, fractional vegetation cover(FVC), and evapotranspiration have the most significant influence on the water conservation of the study area. Among them, water conservation is positively correlated with rainfall and FVC(P<0.05) and negatively correlated with evapotranspiration(P<0.05).(3) The importance level of water conservation functional areas gradually increases from northwest to southeast, and the region surrounding Menyuan Hui Autonomous County in the southeast of the southern slope of Qilian Mountains is the core water conservation functional area. And(4) the study area was divided into five clusters(Cluster Ⅰ–Cluster Ⅴ) of water conservation, with the areas of Clusters Ⅰ through Ⅴ accounting for 0.58%, 13.74%, 41.23%, 32.43%, and 12.01% of the whole study area, respectively.展开更多
The rapidly growing world population,water shortage,and food security are promising problems for sustainable agriculture.Farmers adopt higher irrigation and fertilizer applications to increase crop production resultin...The rapidly growing world population,water shortage,and food security are promising problems for sustainable agriculture.Farmers adopt higher irrigation and fertilizer applications to increase crop production resulting in environmental pollution.This study aimed to identify the long-term effects of intelligent water and fertilizers used in corn yield and soil nutrient status.A series of field experiments were conducted for six years with treatments as:farmer accustomed to fertilization used as control(CON),fertilizer decrement(KF),fertilizer decrement+watersaving irrigation(BMP1);combined application of organic and inorganic fertilizer+water-saving irrigation(BMP2),and combined application of controlled-release fertilizer(BMP3).A significant improvement was observed in soil organic matter(14.9%),nitrate nitrogen(106.7%),total phosphorus(23.9%),available phosphorus(26.2%),straw yield(44.8%),and grain yield(54.7%)with BMP2 treatment as compared to CON.The study concludes that integrating chemical and organic fertilizers with water-saving irrigation(BMP2)is a good approach to increasing corn productivity,ensuring water safety and improving soil health.The limitations of the current study include the identification of fertilizer type and its optimum dose,irrigation water type,and geographical position.展开更多
To improve the soil and water stability of expansive soil slopes and reduce the probability of slope failure,novel protection systems based on polymer waterproof coatings(PWC)were used in this study.Herein,three group...To improve the soil and water stability of expansive soil slopes and reduce the probability of slope failure,novel protection systems based on polymer waterproof coatings(PWC)were used in this study.Herein,three groups of expansive soil slope model tests were designed to investigate the effects of polyester nonwovens and PWC(P-PWC)composite protection system,three-dimensional vegetation network and PWC(T-PWC)composite protection system,and nonprotection on the soil and water behavior in the slopes under precipitation–evaporation cycles.The results showed that the moisture change of P-PWC and T-PWC composite protected slopes was significantly smaller than that of bare slope,which reduced the sensitivity of slope moisture to environmental changes and improved its stability.The soil temperature of the slope protected by the P-PWC and T-PWC systems at a depth of 70 cm increased by 5.6℃ and 2.7℃,respectively.Using PWC composite protection systems exhibited better thermal storage performance,which could increase the utilization of shallow geothermal resources.Moreover,the maximum average crack widths of the bare slopes were 7.89 and 3.17 times those of the P-PWC and TPWC protected slopes,respectively,and the maximum average crack depths were 6.87 and 3 times those of the P-PWC and T-PWC protected slopes,separately.The PPWC protection system weakened the influence of hydro–thermal coupling on the slopes,inhibited the development of cracks on the slopes,and reduced the soil erosion.The maximum soil erosion of slopes protected by P-PWC and T-PWC systems was 332 and 164 times lower than that of bare slope,respectively.The P-PWC and T-PWC protection systems achieved excellent"anti-seepage and moisture retention"and anti-erosion effects,thus improving the soil and water stability of slopes.These findings can provide important guiding reference for controlling rainwater infiltration and soil erosion in expansive soil slope projects.展开更多
To test the patterns of the root morphology and architecture indexes of Tamarix chinensis in response to water and salt changes in the two media of the groundwater and soil,three-year-old T.chinensis seedlings were ch...To test the patterns of the root morphology and architecture indexes of Tamarix chinensis in response to water and salt changes in the two media of the groundwater and soil,three-year-old T.chinensis seedlings were chosen as the research object.Groundwater with four salinity levels was created,and three groundwater level(GL)were applied for each salinity treatment to measure the root growth and architecture indexes.In the fresh water and brackish water treatments,the topological index(TI)of the T.chinensis roots was close to 0.5,and the root architecture was close to a dichotomous branching pattern.In the saline water and saltwater treatments,the TI of the T.chinensis roots was large and close to 1.0,and the root architecture was close to a herringbone-like branching pattern.Under different GLs and salinities,the total root length was significantly greater than the internal link length,the external link length was greater than the internal link length,and the root system showed an outward expansion strategy.The treatment with fresh water and a GL of 1.5 m was the most suitable for T.chinensis root growth,while the root growth of T.chinensis was the worst in the treatment with saline water and a GL of 0.3 m.T.chinensis can adapt to the changes in soil water and salt by regulating the growth and morphological characteristics of the root system.T.chinensis can adapt to high-salt environments by reducing its root branching and to water deficiencies by expanding the distribution and absorption area of the root system.展开更多
Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core prio...Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core priority in Saudi Arabia.The present study aimed to recognize the influence of different types of water irrigation(tap water as a control,salinized well water,and magnetized salinized well water)with or without soil amendments(soil without any amendment as a control,peat-moss,ferrous sulfate,and peat-moss plus ferrous sulfate)on petunia plant growth and flowering as well as ion content.Irrigating Petunia plants with saline well water adversely affected growth and flowering as compared to tap water and magnetized saline well water.Additionally,plants irrigated with magnetized water showed a significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with salinized well water.Furthermore,mineral contents and survival of Petunia plants irrigated with magnetized well water were higher than those irrigated with tap water.Irrigation with magnetized well water significantly reduced levels of Na+and Cl−ions in leaves of Petunia plants indicating the role of magnetization in alleviating harmful effects of salinity.In conclusion,we recommend the utilization of magnetized saline well water for irrigating Petunia plants either alone or in combination with soil amendments(peat moss plus ferrous sulfate).展开更多
基金Supported by Annual Regional Science and Technology Plan Project of Hotan Science and Technology Bureau(202439).
文摘In order to thoroughly analyze the current status and challenges faced by the water and water conservation in Hotan County of Xinjiang,the use situation of water resources,the effectiveness and shortcomings of water and soil conservation work in the region are reviewed.Hotan County has achieved several remarkable achievements in the soil and water conservation project,daily management and maintenance,and ecological restoration projects.Some measures,such as terrace construction,slope protection engineering,and the construction of windproof and sandwood belts,have also had a positive impact on improving the quality of surface water resources while effectively curbing soil erosion.But there are also lack of operating policy detailed rules and implementation plans,and planning and design of some water and soil conservation projects lack of integrity and systematicness,application and promotion of new technologies,and soil loss management and ecological recovery effect assessment lack of comprehensive assessment indicators and methods.It has caused some water and soil conservation works to fail to be effectively implemented.In this regard,countermeasures and suggestions are put forward,such as strengthening the planning and management of water and soil conservation,promoting the technology and measures of water and soil conservation,increasing investment and funding support,and strengthening publicity education and personnel training.
基金This research was supported by the Special Project for the Construction of Innovation Environment in the Autonomous Region(2022D04007)the National Natural Science Foundation of China(42361030).
文摘To comprehensively evaluate the alterations in water ecosystem service functions within arid watersheds,this study focused on the Bosten Lake Basin,which is situated in the arid region of Northwest China.The research was based on land use/land cover(LULC),natural,socioeconomic,and accessibility data,utilizing the Patch-level Land Use Simulation(PLUS)and Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)models to dynamically assess LULC change and associated variations in water yield and water conservation.The analyses included the evaluation of contribution indices of various land use types and the investigation of driving factors that influence water yield and water conservation.The results showed that the change of LULC in the Bosten Lake Basin from 2000 to 2020 showed a trend of increasing in cultivated land and construction land,and decreasing in grassland,forest,and unused land.The unused land of all the three predicted scenarios of 2030(S1,a natural development scenario;S2,an ecological protection scenario;and S3,a cultivated land protection scenario)showed a decreasing trend.The scenarios S1 and S3 showed a trend of decreasing in grassland and increasing in cultivated land;while the scenario S2 showed a trend of decreasing in cultivated land and increasing in grassland.The water yield of the Bosten Lake Basin exhibited an initial decline followed by a slight increase from 2000 to 2020.The areas with higher water yield values were primarily located in the northern section of the basin,which is characterized by higher altitude.Water conservation demonstrated a pattern of initial decrease followed by stabilization,with the northeastern region demonstrating higher water conservation values.In the projected LULC scenarios of 2030,the estimated water yield under scenarios S1 and S3 was marginally greater than that under scenario S2;while the level of water conservation across all three scenarios remained rather consistent.The results showed that Hejing County is an important water conservation function zone,and the eastern part of the Xiaoyouledusi Basin is particularly important and should be protected.The findings of this study offer a scientific foundation for advancing sustainable development in arid watersheds and facilitating efficient water resource management.
基金funded by the National Natural Science Foundation of China(32360321)the Natural Science Foundation of Ningxia Hui Autonomous Region,China(2023AAC03046,2023AAC02018)the Ningxia Key Research and Development Project(2021BEG02011).
文摘The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the soil.This study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony soil.The stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption experiment.Six experimental groups with gravel contents of 0%,10%,20%,30%,40%,and 50%were established to determine the saturated hydraulic conductivity(K_(s)),saturated water content(θ_(s)),initial water content(θ_(i)),and retention water content(θ_(r)),and explore the changes in the wetting front depth and cumulative absorption volume during the absorption experiment.The Philip model was used to fit the soil absorption process and determine the soil water absorption rate.Then the length of the characteristic wetting front depth,shape coefficient,empirical parameter,inverse intake suction and soil water suction were derived from the van Genuchten model.Finally,the hydraulic parameters mentioned above were used to fit the soil water characteristic curves,unsaturated hydraulic conductivity(K_(θ))and specific water capacity(C(h)).The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel content.Compared with control check treatment with gravel content of 0%,soil water absorption rates in the treatments with gravel contents of 10%,20%,30%,40%,and 50%decreased by 11.47%,17.97%,25.24%,29.83%,and 42.45%,respectively.As the gravel content increased,inverse intake suction gradually increased,and shape coefficient,K_(s),θ_(s),andθ_(r)gradually decreased.For the same soil water content,soil water suction and K_(θ)gradually decreased with increasing gravel content.At the same soil water suction,C(h)decreased with increasing gravel content,and the water use efficiency worsened.Overall,the water holding capacity,hydraulic conductivity,and water use efficiency of stony soil in the eastern foothills of the Helan Mountains decreased with increasing gravel content.This study could provide data support for improving soil water use efficiency in the eastern foothills of the Helan Mountains and other similar rocky mountainous areas.
基金supported by the Fundamental Research Funds for the National Natural Science Foundation of China(No:42077007)the General Project of Chongqing Natural Science Foundation(No:CSTB2022NSCQ-MSX0446)。
文摘Soil erosion control based on county scale Soil and Water Conservation Regionalization(SWCR)is an essential component of China's ecological civilization construction.In SWCR,the quantitative analysis of the spatial heterogeneity and driving factors of soil erosion among different regions is still lacking.It is of great significance for soil erosion control to deeply examine the factors contributing to soil erosion(natural,land use,and socioeconomic factors)and their interaction at the county and regional levels.This study focused on a highly cultivated area,Hechuan District of Chongqing in the Sichuan Basin.The district(with 30 townships)was divided into four soil and water conservation regions(Ⅰ-Ⅳ)using principal component and hierarchical cluster analysis.The driving factors of soil erosion were identified using the geographical detector model.The results showed thatⅰ)the high cultivation rate was a prominent factor of soil erosion,and the sloping farmland accounted for 78.4%of the soil erosion in the study area;ⅱ)land use factors demonstrated the highest explanatory power in soil erosion,and the average interaction of land use factors explained 60.1%of soil erosion in the study area;ⅲ)the interaction between natural factors,socioeconomic factors,and land use factors greatly contributes to regional soil erosion through nonlinear-enhancement of double-factor enhancement.This study highlights the importance of giving special attention to the effects of land use factors on soil erosion at the county scale,particularly in mountainous and hilly areas with extensive sloping farmland and a high cultivation rate.
文摘Since water and soil conservation monitoring in the Yellow River Basin entered a new stage at the end of the 20th century,the monitoring scope has been expanding,the monitoring accuracy has been improving,the monitoring content and indicators have been increasing,and the monitoring technology and methods have been improving.This paper mainly analyzes the status of soil and water conservation monitoring in the Yellow River Basin,as well as the construction of the monitoring system and related research,in order to provide a reference for watershed management and development and the scientific research of water and soil conservation.
基金the National Natural Science Foundation of China(Grant No.U20A2081)West Light Foundation of the Chinese Academy of Sciences(Grant No.xbzg-zdsys-202102)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Project(Grant No.2019QZKK0105).
文摘Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.
基金supported by the projects of China Agriculture Research System of MOF and MARA (Grant No.CARS-29-ZP-7)Outstanding Youth Science and Technology Fund of Henan Academy of Agricultural Sciences (Grant No.2022YQ08)。
文摘Water management is an important practice that affects fruit size and quality.Effective implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established manly based on the effects of water deficits on final fruit quality.Few studies have focused on the real-time effects of water status on fruit and shoot growth.To establish soil water potential (ψ_(soil)) thresholds to trigger irrigation of peach at pivotal fruit developmental stages,photogrammetry,^(13)C labelling,and other techniques were used in this study to investigate real-time changes in stem diameter,fruit projected area,net leaf photosynthetic rate (P_(n)),and allocation of photoassimilates to fruit under soil water potential conditions ranging from saturation to stress in 6-year-old Shimizu hakuto’peach.Stem growth,fruit growth,and P_n exhibited gradually decreasing sensitivity to water deficits during fruit developmental stages I,II,and III.Stem diameter growth was significantly inhibited whenψ_(soil)dropped to-8.5,-7.6,and-5.4 k Pa,respectively.Fruit growth rate was low,reaching zero when theψ_(soil)was-9.0 to-23.1,-14.9 to-21.4,and-16.5 to-23.3 k Pa,respectively,and P_ndecreased significantly when theψ_(soil)reached-24.2,-22.7,and-20.4 kPa,respectively.In addition,more photoassimilates were allocated to fruit under moderateψ_(soil)conditions (-10.1 to-17.0 k Pa) than under otherψ_(soil)values.Our results revealed threeψ_(soil)thresholds,-10.0,-15.0,and-15.0 kPa,suitable for triggering irrigation during stages I,II,and III,respectively.These thresholds can be helpful for controlling excessive tree vigor,maintaining rapid fruit growth and leaf photosynthesis,and promoting the allocation of more photoassimilates to fruit.
基金funded by the National Science Foundation of China(Grant No.42161043)the improvement plan of scientific research ability in Northwest Normal University(NWNU-LKQN2020-16).
文摘The implementation of Ecological Function Protection Zone(EFPZ)policy is significant for the ecological restoration and conservation of soil and water in the territory space.This manuscript analyzed and quantified the impact of EFPZ on the regional water conservation function,based on land use data from 2005,2008,2010,2015 and 2020,by conducting a counterfactual simulation along with the GeoSOS-FLUS model and the InVEST model.The results demonstrate that the delineation of EFPZ can significantly influence the water conservation.(1)From 2010 to 2020,as the EFPZ was implemented,the water conservation in the study area was increasing year by year,with a growth rate of 0.03×10^(8) m^(3)∙a^(-1).On the other hand,the simulated water conservation capacity without the implementation of EFPZ decreased year by year,with a decrease rate of 0.01×10^(8) m^(3)∙a^(-1).(2)The EFPZ accounts for only 23%of the total area,but the contribution rate of water conservation reaches 80%.The actual values of water conservation and average water yield per unit pixel in the EFPZ show an increasing trend both internally and externally,while the counterfactual simulation values exhibit a decreasing trend.(3)The water conservation is much higher within the EFPZ than without EFPZ.The implementation of EFPZ has a significant effect on the improvement of the water conservation capacity in Maqu EFPZ and Yellow River Source EFPZ.The protection effectiveness should be enhanced in Qilian Mountain EFPZ and afforestation activities need to be carefully considered in Loess Plateau EFPZ.
基金supported by the National Natural Science Foundation of China(42071285,42371297)the Key R&D Program Projects in Shaanxi Province of China(2022SF-382)the Fundamental Research Funds for the Central Universities(GK202302002).
文摘Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regional environmental protection and sustainable development.However,there is little research on the coupling relationship between them.In this study,focusing on the Jinghe River Basin,China as a case study,we conducted a quantitative evaluation on meteorological,hydrological,and agricultural droughts(represented by the Standardized Precipitation Index(SPI),Standardized Runoff Index(SRI),and Standardized Soil Moisture Index(SSMI),respectively)using the Variable Infiltration Capacity(VIC)model,and quantified the soil conservation service using the Revised Universal Soil Loss Equation(RUSLE)in the historical period(2000-2019)and future period(2026-2060)under two Representative Concentration Pathways(RCPs)(RCP4.5 and RCP8.5).We further examined the influence of the three types of drought on soil conservation service at annual and seasonal scales.The NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)dataset was used to predict and model the hydrometeorological elements in the future period under the RCP4.5 and RCP8.5 scenarios.The results showed that in the historical period,annual-scale meteorological drought exhibited the highest intensity,while seasonal-scale drought was generally weakest in autumn and most severe in summer.Drought intensity of all three types of drought will increase over the next 40 years,with a greater increase under the RCP4.5 scenario than under the RCP8.5 scenario.Furthermore,the intra-annual variation in the drought intensity of the three types of drought becomes smaller under the two future scenarios relative to the historical period(2000-2019).Soil conservation service exhibits a distribution pattern characterized by high levels in the southwest and southeast and lower levels in the north,and this pattern has remained consistent both in the historical and future periods.Over the past 20 years,the intra-annual variation indicated peak soil conservation service in summer and lowest level in winter;the total soil conservation of the Jinghe River Basin displayed an upward trend,with the total soil conservation in 2019 being 1.14 times higher than that in 2000.The most substantial impact on soil conservation service arises from annual-scale meteorological drought,which remains consistent both in the historical and future periods.Additionally,at the seasonal scale,meteorological drought exerts the highest influence on soil conservation service in winter and autumn,particularly under the RCP4.5 and RCP8.5 scenarios.Compared to the historical period,the soil conservation service in the Jinghe River Basin will be significantly more affected by drought in the future period in terms of both the affected area and the magnitude of impact.This study conducted beneficial attempts to evaluate and predict the dynamic characteristics of watershed drought and soil conservation service,as well as the response of soil conservation service to different types of drought.Clarifying the interrelationship between the two is the foundation for achieving sustainable development in a relatively arid and severely eroded area such as the Jinghe River Basin.
文摘The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K<sup>+</sup>), Magnesium (Mg2<sup>+</sup>), Sulphur (S), CN ratio and Sodium (Na<sup>+</sup>) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels.
基金This work was supported by the Budgetary Project the Chinese Academy of Sciences Leads the Sub-Project of Class A Project(XDA26020202)the National“973”Program Project Topics(2014CB138702)+2 种基金the Basic Scientific Research Business Expenses of Central Universities(Lzujbky-2022-kb10)the 111 Wisdom Base(B12002)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Chinese Academy of Forestry)(CAFYBB2021ZD001).
文摘In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.
文摘Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. Soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. Soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation Service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, São Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with API and soil moisture, it will be possible to determine thresholds, thus enabling anticipation of landslide occurrences.
基金Supported by the Natural Science Foundation of Ningxia Hui Autonomous Region(2022AAC03661)Financial Project of Geological Bureau of Ningxia Hui Autonomous Region(NXCZ20220201).
文摘In order to compare the influence of different soil types and stratification on water infiltration capacity,two main types of soil in the desert steppe,sierozem(S)and aeolian sandy soil(A),were selected,and infiltration simulation tests were conducted on homogeneous soil and layered soil(layer thickness 5,10,and 20 cm),respectively.The results show that during the whole experiment,there was a small difference between S5A95(aeolian sandy soil 95 cm thick was covered with sierozem 5 cm thick)and S10A90(aeolian sandy soil 90 cm thick was covered with sierozem 10 cm thick)in the wetting front process,infiltration rate and cumulative infiltration,but there was a significant difference between S5A95 and S20A80(aeolian sandy soil 80 cm thick was covered with sierozem 20 cm thick).In the initial infiltration stage,there was no significant difference between A5S95(sierozem 95 cm thick was covered with aeolian sandy soil 5 cm thick)and A10S90(sierozem 90 cm thick was covered with aeolian sandy soil 10 cm thick).However,with the increase of infiltration time,the wetting front process,A5S95,A10S90 and A20S80 had significant differences in terms of wetting front process,infiltration rate and cumulative infiltration.The infiltration capacity of A was significantly higher than that of S.Combined with linear R 2 value and model parameters,the three infiltration models were comprehensively compared,and the fitting process and results of the general empirical model for the infiltration process of homogeneous soil and layered soil showed good results.Three models were used to simulate the water infiltration process of layered soil with different textures,and the order of the effect is as follows:general empirical model>Kostiakov model>Philip model.Soil type and layer thickness had a great influence on water infiltration process.When sierozem was covered with aeolian sandy soil 20 cm thick,the infiltration capacity was the best.As aeolian sandy soil was covered with sierozem 10 cm thick,the infiltration effect was the worst.Therefore,once coarse graying occurs on the surface of sierozem(the thickness of sand is more than 20 cm)or when the content of fine particles overlying aeolian sandy soil(the thickness of silt and clay soil is more than 10 cm)during ecological restoration is high,the soil hydrological characteristics will change significantly,which may lead to changes in vegetation types and even ecosystem structure.
文摘This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technological advances since the 19th century. From 1900 to 2010, temperatures in the Midwest rose by an average of 1.5 degrees Fahrenheit, which would also lead to an increase in greenhouse gas emissions. Precipitation is also expected to increase due to increased storm activity and changes in regional weather patterns. This paper explores the impact of these changes on urban and agricultural areas. In urban areas such as the city of Chicago, runoff from the increasing impervious surface areas poses challenges to the drainage system, and agriculture areas are challenged by soil erosion, nutrient loss, and fewer planting days due to excessive rainfall. Sustainable solutions such as no-till agriculture and the creation of grassland zones are discussed. Using historical data, recent climate studies and projections, the paper Outlines ways to enhance the Midwest’s ecology and resilience to climate change.
基金funded by the National Natural Science Foundation of China(32001149,U20A2006,31971507)Applied Basic Research Project of Qinghai Province(2022-ZJ-716)+3 种基金Youth Innovation Promotion Association CAS(2022436)Joint Grant from Chinese Academy of Sciences-People’s Government of Qinghai Province on Sanjiangyuan National Park(LHZX-2020-07)Chinese Academy of Science(CAS)"Light of West China"Program(2018)"The effect of grazing on grassland productivity in the basin of Qinghai Lake"。
文摘Grazing exclusion is one of the primary management practices used to restore degraded grasslands on the Tibetan Plateau.However,to date,the effects of long-term grazing exclusion measures on the process of restoring degraded alpine meadows have not been evaluated.In this study,moderately degraded plots,in which the vegetation coverage was approximately 65%and the dominant plant species was Potentilla anserina L,with grazing exclusion for 2 to 23 years,were selected in alpine meadows of Haibei in Qinghai-Tibet Plateau.Plant coverage,plant height,biomass,soil bulk density,saturated water content,soil organic carbon(SOC)and total nitrogen(TN)were evaluated.The results were as follows:(1)With aboveground biomass and total saturated water content at 0-40 cm depth,the average SOC and TN contents in moderately degraded alpine meadows increased as a power function,and the plant height increased as a log function.(2)The average soil bulk density at 0-40 cm depth first decreased and then increased with increasing grazing exclusion duration,and the minimum value of 0.90 g·cm^(-3) was reached at 15.23 years.The plant coverage,total belowground biomass at 0-40 cm depth,total aboveground and belowground biomass first increased and then decreased,their maximum values(80.49%,2452.92g·m^(-2),2891.06 g·m^(-2))were reached at 9.41,9.46 and 10.25 years,respectively.Long-term grazing exclusion is apparently harmful for the sustainable restoration of degraded alpine meadows.The optimal duration of grazing exclusion for the restoration of moderately degraded alpine meadows was 10 years.This research suggests that moderate disturbance should be allowed in moderately degraded alpine meadows after 10years of grazing exclusion.
基金financially supported by the National Key Research and Development Program Project (2017YFC0404304)the National Natural Science Foundation of China (41361005)。
文摘The ecology of Qilian Mountains has been seriously threatened by uncontrolled grazing and wasteland reclamation. This study examined the ecological changes on the southern slope of Qilian Mountains in China from the perspective of water conservation by classifying different clusters of water conservation functional areas to efficiently use limited human resources to tackle the water conservation protection problem. In this study, we used Integrate Valuation of Ecosystem Services and Tradeoffs(InVEST) model to estimate water conservation and analyzed the factors that influence the function. The results of this study include:(1) from 2000 to 2015, the water conservation of the southern slope of Qilian Mountains generally showed an increasing trend, and the total water conservation in 2015 increased by 42.18% compared with that in 2000.(2) Rainfall, fractional vegetation cover(FVC), and evapotranspiration have the most significant influence on the water conservation of the study area. Among them, water conservation is positively correlated with rainfall and FVC(P<0.05) and negatively correlated with evapotranspiration(P<0.05).(3) The importance level of water conservation functional areas gradually increases from northwest to southeast, and the region surrounding Menyuan Hui Autonomous County in the southeast of the southern slope of Qilian Mountains is the core water conservation functional area. And(4) the study area was divided into five clusters(Cluster Ⅰ–Cluster Ⅴ) of water conservation, with the areas of Clusters Ⅰ through Ⅴ accounting for 0.58%, 13.74%, 41.23%, 32.43%, and 12.01% of the whole study area, respectively.
基金This study was supported by the National Natural Science Foundation of China[Grant No.U20A20114]the soil N losses in the greenhouse field in the Yellow River Irrigation as affected by the annual changes of groundwater depth[Grant No.41361062].
文摘The rapidly growing world population,water shortage,and food security are promising problems for sustainable agriculture.Farmers adopt higher irrigation and fertilizer applications to increase crop production resulting in environmental pollution.This study aimed to identify the long-term effects of intelligent water and fertilizers used in corn yield and soil nutrient status.A series of field experiments were conducted for six years with treatments as:farmer accustomed to fertilization used as control(CON),fertilizer decrement(KF),fertilizer decrement+watersaving irrigation(BMP1);combined application of organic and inorganic fertilizer+water-saving irrigation(BMP2),and combined application of controlled-release fertilizer(BMP3).A significant improvement was observed in soil organic matter(14.9%),nitrate nitrogen(106.7%),total phosphorus(23.9%),available phosphorus(26.2%),straw yield(44.8%),and grain yield(54.7%)with BMP2 treatment as compared to CON.The study concludes that integrating chemical and organic fertilizers with water-saving irrigation(BMP2)is a good approach to increasing corn productivity,ensuring water safety and improving soil health.The limitations of the current study include the identification of fertilizer type and its optimum dose,irrigation water type,and geographical position.
基金the financial supports from the Key Research and Development Program of Guangxi(No.GUIKE AB22080061)the Guangxi Transportation Industry Key Science and Technology Projects(No.GXJT-2020-02-08)+2 种基金the National Natural Science Foundation of China(No.52268062)the Guangxi Key Project of Nature Science Foundation(No.2020GXNSFDA238024)。
文摘To improve the soil and water stability of expansive soil slopes and reduce the probability of slope failure,novel protection systems based on polymer waterproof coatings(PWC)were used in this study.Herein,three groups of expansive soil slope model tests were designed to investigate the effects of polyester nonwovens and PWC(P-PWC)composite protection system,three-dimensional vegetation network and PWC(T-PWC)composite protection system,and nonprotection on the soil and water behavior in the slopes under precipitation–evaporation cycles.The results showed that the moisture change of P-PWC and T-PWC composite protected slopes was significantly smaller than that of bare slope,which reduced the sensitivity of slope moisture to environmental changes and improved its stability.The soil temperature of the slope protected by the P-PWC and T-PWC systems at a depth of 70 cm increased by 5.6℃ and 2.7℃,respectively.Using PWC composite protection systems exhibited better thermal storage performance,which could increase the utilization of shallow geothermal resources.Moreover,the maximum average crack widths of the bare slopes were 7.89 and 3.17 times those of the P-PWC and TPWC protected slopes,respectively,and the maximum average crack depths were 6.87 and 3 times those of the P-PWC and T-PWC protected slopes,separately.The PPWC protection system weakened the influence of hydro–thermal coupling on the slopes,inhibited the development of cracks on the slopes,and reduced the soil erosion.The maximum soil erosion of slopes protected by P-PWC and T-PWC systems was 332 and 164 times lower than that of bare slope,respectively.The P-PWC and T-PWC protection systems achieved excellent"anti-seepage and moisture retention"and anti-erosion effects,thus improving the soil and water stability of slopes.These findings can provide important guiding reference for controlling rainwater infiltration and soil erosion in expansive soil slope projects.
基金financially supported by the Joint Funds of the National Natural Science Foundation of China(U2006215)the National Natural Science Foundation of China(31770761)+2 种基金the Shandong Key Laboratory of Coastal Environmental Processes,YICCAS(2019SDHADKFJJ16)the Natural Science Foundation of Shangdong Province(ZR2020QD003)Taishan Scholars Program of Shandong Province,China(TSQN201909152)。
文摘To test the patterns of the root morphology and architecture indexes of Tamarix chinensis in response to water and salt changes in the two media of the groundwater and soil,three-year-old T.chinensis seedlings were chosen as the research object.Groundwater with four salinity levels was created,and three groundwater level(GL)were applied for each salinity treatment to measure the root growth and architecture indexes.In the fresh water and brackish water treatments,the topological index(TI)of the T.chinensis roots was close to 0.5,and the root architecture was close to a dichotomous branching pattern.In the saline water and saltwater treatments,the TI of the T.chinensis roots was large and close to 1.0,and the root architecture was close to a herringbone-like branching pattern.Under different GLs and salinities,the total root length was significantly greater than the internal link length,the external link length was greater than the internal link length,and the root system showed an outward expansion strategy.The treatment with fresh water and a GL of 1.5 m was the most suitable for T.chinensis root growth,while the root growth of T.chinensis was the worst in the treatment with saline water and a GL of 0.3 m.T.chinensis can adapt to the changes in soil water and salt by regulating the growth and morphological characteristics of the root system.T.chinensis can adapt to high-salt environments by reducing its root branching and to water deficiencies by expanding the distribution and absorption area of the root system.
基金funded by Abdulaziz City for Science and Technology,Saudi Arabia(Grant Research No.1-17-04-001-0021).
文摘Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core priority in Saudi Arabia.The present study aimed to recognize the influence of different types of water irrigation(tap water as a control,salinized well water,and magnetized salinized well water)with or without soil amendments(soil without any amendment as a control,peat-moss,ferrous sulfate,and peat-moss plus ferrous sulfate)on petunia plant growth and flowering as well as ion content.Irrigating Petunia plants with saline well water adversely affected growth and flowering as compared to tap water and magnetized saline well water.Additionally,plants irrigated with magnetized water showed a significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with salinized well water.Furthermore,mineral contents and survival of Petunia plants irrigated with magnetized well water were higher than those irrigated with tap water.Irrigation with magnetized well water significantly reduced levels of Na+and Cl−ions in leaves of Petunia plants indicating the role of magnetization in alleviating harmful effects of salinity.In conclusion,we recommend the utilization of magnetized saline well water for irrigating Petunia plants either alone or in combination with soil amendments(peat moss plus ferrous sulfate).