OBJECTIVE: Baby skin differs significantly from adult skin and requires special care. The Cussons Baby Sensicare Range (Sensicare) of products has been specifically formulated for baby skin and a range of standard cos...OBJECTIVE: Baby skin differs significantly from adult skin and requires special care. The Cussons Baby Sensicare Range (Sensicare) of products has been specifically formulated for baby skin and a range of standard cosmetic clinical tests were conducted in adult females with dry skin to evaluate the effectiveness of the range on skin moisturization and barrier function. METHODS: The studies were within subject, controlled, single blind studies. For the Sensicare Body Wash skin moisturization (Corneometer) was measured before application and after 7 and 14 days of twice daily use. For the Sensicare Moisturizing Lotion and Sensicare Soothing Cream skin moisturization was measured before application and at 2, 4, 6, 8 and 24 hours after a single application;skin elasticity (Cutometer) and transepidermal water loss (TEWL, Tewameter) were assessed before and after 14 days of twice daily use;and skin erythema (Mexameter) before induction with sodium lauryl sulphate (SLS), and at 30 mins, 24 and 48 hours after patch removal. Changes from baseline and changes versus control were evaluated. RESULTS: Thirty to thirty-five subjects completed each study. Skin moisture content was significantly increased from baseline for all Cussons Baby Sensicare Products (p < 0.05 for Hair & Body Wash;and p < 0.001 for Cream & Lotion). Changes from baseline in skin elasticity were significantly superior to control (unperfumed liquid soap) after 14 days twice daily use of the Lotion, and Cream (p < 0.05). There were no significant changes from baseline or significant differences from control in TEWL for the Lotion, or Cream. The increases in the average skin erythema index were significantly smaller for the Lotion, and Cream 30 minutes following SLS patch removal (p < 0.05 v sterile water, p < 0.001 v no treatment for both products). All the Sensicare products were well tolerated. CONCLUSION: These studies support the use of the Cussons Baby Sensicare range of products for new born, sensitive and eczema prone skin.展开更多
Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These su...Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These surge events typically occur for days in the early-summer season(from April to June)and can lead to heavy rains in South China.This study categorizes surge events into three types of flow patterns and examines their multiscale variations and impacts on rainfall.The first type occurs mainly in April,with the southeasterlies enhanced by a deepening trough in South China and the western Pacific subtropical high established over the SCS.The second type of surge events mostly appears in June,featuring the prevailing southwesterlies of summer monsoon from the Indian Ocean during the active phases of intraseasonal oscillations.Most surge events exhibit semi-diurnal variations with morning and afternoon peaks of northward moisture fluxes.Specifically,the first type features a dominant afternoon peak,while the second type shows a dominant early-morning peak,which is induced by thermal contrast between the Indochina Peninsula and the SCS.In general,the surge events enhance moisture convergence and increase rainfall downstream in South China,but they show some regional differences.The second type strengthens moisture convergence and rainfall in coastal regions with a morning peak.In contrast,the first type enhances inland rainfall with a morning peak,while moisture divergence dominates coastal regions.The third type of surge events denotes transitional conditions between the first two types,in terms of atmospheric circulations,diurnal cycles,and rainfall patterns.These results highlight a diversity of regional moisture surges and related rainfall ranging from diurnal to sub-seasonal scales.展开更多
Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution...Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions.展开更多
Soil moisture(SM)is a critical variable in terrestrial ecosystems,especially in arid and semi-arid areas where water sources are limited.Despite its importance,understanding the spatiotemporal variations and influenci...Soil moisture(SM)is a critical variable in terrestrial ecosystems,especially in arid and semi-arid areas where water sources are limited.Despite its importance,understanding the spatiotemporal variations and influencing factors of SM in these areas remains insufficient.This study investigated the spatiotemporal variations and influencing factors of SM in arid and semi-arid areas of China by utilizing the extended triple collation(ETC),Mann-Kendall test,Theil-Sen estimator,ridge regression analysis,and other relevant methods.The following findings were obtained:(1)at the pixel scale,the long-term monthly SM data from the European Space Agency Climate Change Initiative(ESA CCI)exhibited the highest correlation coefficient of 0.794 and the lowest root mean square error(RMSE)of 0.014 m^(3)/m^(3);(2)from 2000 to 2022,the study area experienced significant increase in annual average SM,with a rate of 0.408×10^(-3)m^(3)/(m^(3)•a).Moreover,higher altitudes showed a notable upward trend,with SM increasing rates at 0.210×10^(-3)m^(3)/(m^(3)•a)between 1000 and 2000 m,0.530×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m,and 0.760×10^(-3)m^(3)/(m^(3)•a)at altitudes above 4000 m;(3)land surface temperature(LST),root zone soil moisture(RSM)(10-40 cm depth),and normalized difference vegetation index(NDVI)were identified as the primary factors influencing annual average SM,which accounted for 34.37%,24.16%,and 22.64%relative contributions,respectively;and(4)absolute contribution of LST was more significant in subareas at higher altitudes,with average absolute contributions of 0.800×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m and 0.500×10^(-2) m^(3)/(m^(3)•a)above 4000 m.This study reveals the spatiotemporal variations and main influencing factors of SM in Chinese arid and semi-arid areas,highlighting the more pronounced absolute contribution of LST to SM in high-altitude areas,providing valuable insights for ecological research and water resource management in these areas.展开更多
Soil desiccation cracking is a common phenomenon on the earth surface.Numerical modeling is an effective approach to study the desiccation cracking mechanism of soil.This work develops a novel 3D moisture diffusion di...Soil desiccation cracking is a common phenomenon on the earth surface.Numerical modeling is an effective approach to study the desiccation cracking mechanism of soil.This work develops a novel 3D moisture diffusion discrete model that is capable of dynamically assessing the effect of cracking on moisture diffusion and allowing moisture to be discontinuous on both sides of the cracks.Then,the parametric analysis of the moisture exchange coefficient in the 3D moisture diffusion discrete model is carried out for moisture diffusion in continuous media,and the selection criterion of the moisture exchange coefficient for the unbroken cohesive element is given.Subsequently,an example of moisture migration in a medium with one crack is provided to illustrate the crack hindering effect on moisture migration.Finally,combining the 3D moisture diffusion discrete model with the finite-discrete element method(FDEM),the moisture diffusion-fracture coupling model is built to study the desiccation cracking in a strip soil and the crack pattern of a rectangular soil.The evolution of crack area and volume with moisture content is quantitatively analyzed.The modeling number and average width of cracks in the strip soil show a good consistency with the experimental results,and the crack pattern of the rectangular soil matches well with the existing numerical results,validating the coupled moisture diffusion-fracture model.Additionally,the parametric study of soil desiccation cracking is performed.The developed model offers a powerful tool for exploring soil desiccation cracking.展开更多
This study investigates the mechanism of action of representative molecules of basalt fibers on the healing of water-soaked asphalt.Thermodynamic parameters,morphological characteristics,interfacial healing energy,and...This study investigates the mechanism of action of representative molecules of basalt fibers on the healing of water-soaked asphalt.Thermodynamic parameters,morphological characteristics,interfacial healing energy,and interfacial healing strength were analyzed using molecular dynamics and macroscopic tests under different time,temperature,and water conditions to evaluate the specific states and critical conditions involved in self-healing.The results indicate that basalt-fiber molecules can induce rearrangement and a combination of water-soaked asphalt at the healing interface.Hydroxyl groups with different bonding states increase the interfacial adsorption capacity of water-soaked asphalt.The interaction between basalt fiber molecules and water molecules leads to a"hoop"phenomenon,while aromatics-2 molecules exhibit a"ring band aggregation"phenomenon.The former reduces the miscibility of water and asphalt molecules,while the latter causes slow diffusion of the components.Furthermore,a micro-macro dual-scale comparison of interfacial healing strength was conducted at temperatures of 297.15 and 312.15 K to identify the strength transition point and critical temperature of 299.4 K during the self-healing process of basalt-fiber modified water-soaked asphalt.展开更多
During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the s...During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the subtropical Northwestern Pacific(10°-20°N,130°E-175°W).The former is well-documented and considered to be influenced by the ENSO,while the latter has received comparatively less attention and is likely influenced by the Pacific Meridional Mode(PMM),as suggested by partial correlation analysis results.To elucidate the physical processes responsible for the enhanced(weakened)intraseasonal convection over the subtropical northwestern Pacific during warm(cold)PMM years,the authors employed a moisture budget analysis.The findings reveal that during warm PMM years,there is an increase in summer-mean moisture over the subtropical northwestern Pacific.This increase interacts with intensified vertical motion perturbations in the region,leading to greater vertical moisture advection in the lower troposphere and consequently resulting in convective instability.Such a process is pivotal in amplifying intraseasonal convection anomalies.The observational findings were further verified by model experiments forced by PMM-like sea surface temperature patterns.展开更多
A cytotoxicity study based on keratinocytes was carried out to determine the safe dosing concentration of plant extract formulation(hereinafter referred to as the MOSOGY).On this basis,the 3D epidermal skin model(Epik...A cytotoxicity study based on keratinocytes was carried out to determine the safe dosing concentration of plant extract formulation(hereinafter referred to as the MOSOGY).On this basis,the 3D epidermal skin model(Epikutis^(®),which is abbreviated as Epikutis later)was stimulated with anionic surfactant sodium lauryl sulfate(SLS)was used to construct an in vitro 3D epidermal skin injury model and detect the proinflammatory factor(IL-1α)after MOSOGY acted on the 3D epidermal skin model.Additionally,capsaicin(CAP)was used to stimulate the 3D epidermal skin model(EpiKutis)to detect changes in the content of transient receptor potential vanilloid 1(TRPV1)after MOSOGY treatment.The hydration levels of the stratum corneum were tested using the 3D epidermal skin model.A hyaluronidase(HAase)inhibition experiment was conducted to assess the soothing effect of BSBE.The experimental results showed that MOSOGY exhibited no significant cytotoxicity within the concentration range of 0~2.50%At a concentration of 2.00%,the inhibition rates of IL-1αand PGE2 were 15.71%and 19.00%respectively.At a concentration of 5.00%,MOSOGY exhibited inhibition rates of 43.76%for TRPV1 and 11.11%for IL-1α.MOSOGY at concentrations of 1.00%and 5.00%showed inhibition rates of 76.50%and 86.50%for HAase,respectively.The moisturizing efficacy test showed that at the concentration of 5.00%,the water content of the stratum corneum of the 3D epidermal skin model increased by 31.91%.In addition,the 3D epidermal skin model used in this experiment has the characteristics of layered structure,physiological and metabolic functions that are highly similar to natural human skin.The above research shows that MOSOGY at a certain concentration effectively inhibits IL-1α,PGE2,TRPV1 and HAase in human skin,especially the inhibition rate of HAase is more than 70.00%,indicating that BSBE have strong anti-allergic effect,and skin hydration of the 3D epidermal skin model also has a significant increase.The results indicate that MOSOGY exhibits inhibitory effects on IL-1α,PGE2,TRPV1,and HAase,achieving significant soothing and reparative effects through the inhibition of multiple targets.Additionally,it demonstrates good moisturizing efficacy and safety,making it suitable for use in cosmetics with corresponding efficacy claims.展开更多
Moisture-enabled electricity generation(MEG)has emerged as a promising sustainable energy harvesting technology,comparable to photovoltaics,thermoelectrics,and triboelectrics[1].MEGs generate electricity by converting...Moisture-enabled electricity generation(MEG)has emerged as a promising sustainable energy harvesting technology,comparable to photovoltaics,thermoelectrics,and triboelectrics[1].MEGs generate electricity by converting the chemical potential of moisture into electric energy through interactions with hygroscopic materials and nanostructured interfaces.Unlike solar or thermal harvesters,MEGs operate continuously by utilizing ubiquitous atmospheric moisture,granting them unique spatial and temporal adaptability.Despite nearly a decade of progress and the exploration of diverse material systems for MEG,the overall output power remains significantly limited due to inherently low charge carrier concentrations and restricted ion diffusion fluxes[2].As a result,standalone MEG devices often deliver low and unstable output,limiting practical applications.To enhance performance and versatility,recent efforts have explored hybridization of MEG with other ambient energy sources such as triboelectric or thermoelectric effects.展开更多
Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some common factors that usually cause damage to trees when they are struck by lightning?2.How might the un...Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some common factors that usually cause damage to trees when they are struck by lightning?2.How might the unique characteristics of a tree contribute to its ability to survive a lightning strike?展开更多
A common concern to planting for reforestation is seedling failure that is directly measurable by seedling early field performance of growth and survival.Root growth potential(RGP)is a commonly used metric of seedling...A common concern to planting for reforestation is seedling failure that is directly measurable by seedling early field performance of growth and survival.Root growth potential(RGP)is a commonly used metric of seedling quality and has been considered indicative of seedling field performance.The effect of RGP is thought to be dependent on planting site and underlining environmental conditions.Moisture stress often is considered the primary cause of seedling failure in addition to other environmental factors such as soil physicochemical properties in regions such as the Inland Northwest of the United States that is prone to growing season drought.In addition,it is interesting to test whether seedling early field performance is related to their morphological attributes and whether the morphological attributes are related to RGP.A comprehensive evaluation on early field performance of three planted conifer species of interior Douglas-fir(Pseudotsuga menziesii(Mirb.)Franco var.glauca(Beissn.)Franco),grand fir(Abies grandis(Douglas ex D.Don)Lindl.),and western larch(Larix occidentalis Nutt.)was conducted in this study.It was found that RGP did not show clear correlation with early field performance across species.RGP also was not significantly correlated with seedling morphological measures such as below-and above-ground biomass and root-to-shoot ratio(R:S,by mass).Early field performance of growth and survival varied greatly across individuals of seedlings.The most influential predictors of early seedling growth and survival were their initial size(indicative of energy reserve)and soil temperature that likely interacted with soil moisture.Our findings suggest that seed stock selection for reforestation probably should favor species and genotypes with greatest heat tolerance that may be better adapted to future conditions in the region.展开更多
In this study,we investigate the complex relationship between western disturbances(WDs),the El Ni?o–Southern Oscillation(ENSO),and extreme precipitation events(EPEs) in the western Himalaya(WH) during the extended wi...In this study,we investigate the complex relationship between western disturbances(WDs),the El Ni?o–Southern Oscillation(ENSO),and extreme precipitation events(EPEs) in the western Himalaya(WH) during the extended winter season(November–March).WDs west of WH coincide with 97% of recorded EPEs,contributing substantially(32% in winter,11% annually) to total precipitation within WH.WDs are 6% less frequent and 4% more intense during El Ni?o than La Ni?a to the west of WH.During El Ni?o(compared to La Ni?a) years,WDs co-occurring with EPEs are significantly more intense and associated with 17% higher moisture transport over “WH box”(the selected region where most of the winter precipitation over WH occurs).This results in twice the EPE frequency during El Ni?o periods than La Ni?a periods.A substantial southward shift(~180 km) of the subtropical jet(STJ) axis during El Ni?o brings WD tracks further south towards their primary moisture sources,especially the Arabian Sea.We have shown that WDs that are both more intense and pass to the south of their typical latitudes have higher levels of vertically integrated moisture flux(VIMF)within them.VIMF convergence in the most intense pentile of WDs is 5.7 times higher than in the weakest,and is 3.4 times higher in the second lowest latitude pentile than in the highest.Overall,this study demonstrates a direct link between changes in the latitudinal position and intensity of WDs associated with the winter STJ,and moisture convergence,which leads to the occurrence of EPEs over WH during ENSO phases.展开更多
The article examines the impact of increased aridization of the territory due to an increase in air temperature,reduced precipitation,and the formation of moisture deficiency on grain yields in Northern Kazakhstan.The...The article examines the impact of increased aridization of the territory due to an increase in air temperature,reduced precipitation,and the formation of moisture deficiency on grain yields in Northern Kazakhstan.The most important result of the work is the revealed inverse relationship between grain yields and the temperature of the growing season:low-yielding years are associated with high temperatures and droughts,and high-yielding years are associated with lower temperatures and an optimal ratio of heat and moisture.The novelty of this study is the use of the method of hydrological and climatic calculations in identifying the nature of temperature variability and precipitation in the territory of Northern Kazakhstan for the modern period(1991–2020)compared with the base period(1961–1990).At all the studied meteorological stations,there is a tendency for the average annual temperature and the temperature of the growing season to increase:in the forest-steppe zone with an average warming intensity of 0.3–0.33℃ per decade;in the steppe zone by 0.2–0.43℃ per decade;and in the growing season by 0.2–0.7℃ per decade.The air temperature in the steppe zone is rising more intensively than in the forest-steppe zone,and precipitation in the forest-steppe zone has changed more than in the steppe zone.An increase in the average annual air temperature during the growing season(May–August),combined with a shortage of atmospheric moisture or a constant amount of it,led to an increase in the degree of aridization of the territory,an increase in the frequency of droughts in the steppe zone of Northern Kazakhstan.展开更多
Extensive flooding swept across large areas of Central Asia,mainly over Kazakhstan and southwestern Russia,from late March to April 2024.It was reported to be the worst flooding in the area in the past 70 years and ca...Extensive flooding swept across large areas of Central Asia,mainly over Kazakhstan and southwestern Russia,from late March to April 2024.It was reported to be the worst flooding in the area in the past 70 years and caused widespread devastation to society and infrastructure.However,the drivers of this record-breaking flood remain unexplored.Here,we show that the record-breaking floods were contributed by both long-term climate warming and interannual variability,with multiple climatic drivers at play across the synoptic to seasonal timescales.First,the heavy snowmelt in March 2024 was associated with above-normal preceding winter snow accumulation.Second,extreme rainfall was at a record-high during March 2024,in line with its increasing trend under climate warming.Third,the snowmelt and extreme rainfall in March were compounded by record-high soil moisture conditions in the preceding winter,which was a result of interannual variability and related to excessive winter rainfall over Central Asia.As climate warming continues,the interplay between the increasing trend of extreme rainfall,interannual variations in soil moisture pre-conditions,as well as shifting timing and magnitudes of spring snowmelt,will further increase and complicate spring flooding risks.This is a growing and widespread challenge for the mid-to high-latitude regions.展开更多
Heatwaves are becoming increasingly frequent and severe,posing escalating risks to ecosystems and human well-being.While soil moisture(SM)deficits are recognized as important contributors to heatwave amplification,the...Heatwaves are becoming increasingly frequent and severe,posing escalating risks to ecosystems and human well-being.While soil moisture(SM)deficits are recognized as important contributors to heatwave amplification,their spatially heterogeneous impacts across the Northern Hemisphere remain insufficiently understood.In this study,we analyze ERA5 reanalysis data(1980-2022)to investigate trends in heatwave frequency,intensity,and duration,as well as their sensitivity to SM variability.Our results show robust increases in heatwave occurrence(0.76 events per decade),intensity(0.81℃per decade),and average duration(0.40 days per decade),with extreme events,as represented by maximum intensity and duration,rising at even faster rates(2.18℃per decade and 0.83 days per decade,respectively).Strong negative correlations are observed between SM deficits and heatwave metrics,with the magnitude of this relationship varying across land cover types and heatwave severity levels.Quantile regression reveals that SM reductions have a greater impact at higher quantiles for most indicators.Cropland exhibits the highest sensitivity to SM anomalies,whereas forests show more resilience due to their superior water retention capacities.These findings underscore the crucial role of land-atmosphere interactions in shaping heatwave extremes,providing a scientific basis for enhancing early warning and adaptation strategies in the context of ongoing climate change.展开更多
Understanding the ecological processes shaping competitive interactions among forest trees is crucial for predicting ecosystem productivity and climate change resilience.However,few studies have investigated how the b...Understanding the ecological processes shaping competitive interactions among forest trees is crucial for predicting ecosystem productivity and climate change resilience.However,few studies have investigated how the biological attributes of tropical species may affect competitive outcomes under varying resource conditions.We collected and analysed a 10-year dataset of radial growth rates in canopy trees from a network of forest inventory plots located in divergent forest types over an extensive meteorological gradient in Ghana,West Africa.We used nonlinear models to estimate the relative reduction in potential growth(basal area increment)of individual target trees of a given species as a consequence of the combined effects of(1)target tree size,(2)variation in crowding levels by neighbouring trees,(3)the functional attributes of those neighbours(wood density and shade tolerance),and(4)local soil moisture levels.Analyses were conducted separately for the 15 most common species in the inventory network.In opposition to neutral theory,our findings indicate that the strength of interactions among competing species was distinctly asymmetric and dynamic.Wood density was an important characteristic that modified competitive outcomes for most species,particularly under varying levels of resource availability.Specifically,dense wood was an attribute that conferred comparatively stronger competitive ability in moisture-limited conditions.Larger individuals were notably less sensitive to the effects of moisture-dependent competition.Our results suggest that attributes such as wood density may reflect divergent life history strategies that differentiate species’fitness and competitive ability in varying environments.The dynamic nature of competition,influenced by a complex interplay of biological and abiotic factors,implies that more prevalent dry periods,which have been forecast for tropical Africa,may impact the physiognomy and function of future forest communities in the region.展开更多
The primary mechanism driving plant species loss after nitrogen(N)addition has been often hypothesized to be asymmetric competition for light,resulting from increased aboveground biomass.However,it is largely unknown ...The primary mechanism driving plant species loss after nitrogen(N)addition has been often hypothesized to be asymmetric competition for light,resulting from increased aboveground biomass.However,it is largely unknown whether plants’access to soil water at different depths would affect their responses,fate,and community composition under nitrogen addition.In a semiarid grassland exposed to 8-years of N addition,we measured plant aboveground biomass and diversity under four nitrogen addition rates(0,4,10,and 16 g m2 year1),and evaluated plant use of water across the soil profile using oxygen isotope.Aboveground biomass increased significantly,but diversity and shallow soil-water content decreased,with increasing rate of nitrogen addition.The water isotopic signature for both plant and soil water at the high N rate indicated that Leymus secalinus(a perennial grass)absorbed 7%more water from the subsurface soil layer(20e100 cm)compared to Elymus dahuricus(a perennial grass)and Artemisia annua(an annual forb).L.secalinus thus had a significantly larger biomass and was more abundant than the other two species at the high N rate but did not differ significantly from the other two species under ambient and the low N rate.Species that could use water from deeper soil layers became dominant when water in the shallow layers was insufficient to meet the demands of increased aboveground plant biomass.Our study highlights the importance of water across soil depths as key driver of plant growth and dominance in grasslands under N addition.展开更多
Moistube irrigation is a newly-developed irrigation technique that utilizes a semipermeable membrane to release water slowly and continuously into the plant root zone.Alternate Moistube Irrigation(AMI)is a combination...Moistube irrigation is a newly-developed irrigation technique that utilizes a semipermeable membrane to release water slowly and continuously into the plant root zone.Alternate Moistube Irrigation(AMI)is a combination of alternative irrigation and moistube irrigation.In order to investigate the effects of AMI on plant growth,greenhouse experiments were conducted on spinach(Spinacia oleracea)and water spinach(Ipomoea aquatica)plants at different time.We measured soil water content at a depth of 20 cm in the planting boxes,and also determined seed emergence rate,plant height,largest leaf area,fresh weight per plant,yield,and irrigation water productivity(IWP)for both spinach and water spinach.The results showed that the AMI treatments had significantly higher soil water content than the conventional surface irrigation control(CK).The emergence rates of spinach and water spinach were significantly higher in the AMI treatments than in the CK,and the plant height,largest leaf area,and fresh weight during the middle and late stages of spinach and water spinach growth were also significantly higher than those of the CK.Both spinach and water spinach grew well and produced high yield with high IWP under AMI with a high water head pressure of 1.5 m at tube spacing of 20 or 30 cm.We found that AMI with a suitable combination of head pressure and tube spacing can promote plant growth and increase yield and IWP under controlled conditions.展开更多
Tafoni are globally developed on cliffy slopes,and many of them are favorable places for the preservation of stone historical relics.However,the characteristics and formation processes of tafoni in the Loess Plateau a...Tafoni are globally developed on cliffy slopes,and many of them are favorable places for the preservation of stone historical relics.However,the characteristics and formation processes of tafoni in the Loess Plateau are yet to be understood.This paper studied the features of the tafoni on conglomerate slopes in Huoshizhai National Geopark of Ningxia Hui Autonomous Region and discussed its formation processes by field investigation and morphometry,insitu relative humidity(RH)measurement,salt chemistry and X-ray fluorescence spectrometer(XRF)experiments of 24 samples.The bedrock of the tafoni is dominated by reddish fluvial conglomerates of the Lower Cretaceous Heshangpu Formation with abundant chemically unstable components including feldspars,lithic fragments,and calcite cements.The RH values vary from 5%to 100%,but the backwalls of the tafoni have higher RH values than outer surfaces.The more moisture on the backwalls is possibly generated by water influx from the rock interior,resulting in more salt precipitation on the backwalls.As a result,the backwalls have been subject to predominant salt weathering.The dominant salts involved in salt weathering are probably derived from the dissolution of the salt interbeds in the basin,although the chemical dissolution of the unstable components such as feldspars,lithic fragments,and calcite cements might have produced small amounts of salts.The salt types dominantly include nitrates,sulfates,and halite.In the progression of tafoni,the moisture maintenance on the backwalls gives rise to the accretion of salts,which in turn enhance the weathering rates of the backwalls.As a result,the volumes of the tafoni have become enlarged owing to inward growth and coalescence of adjacent smaller ones.展开更多
The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments o...The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments on homogeneous fuels but has not been validated for conifer-deciduous mixed fuel.In this study,Pinus koraiensis and Quercus mongolica litter was used in a laboratory burning experiment to simulate surface fire spread in the field.The effects of fuel moisture content,mixed fuel ratio and slope on spread rate were analyzed.The optimum packing ratio,moisture-damping coefficient and slope parameters in the Rothermel model were modified using the measured spread rate which was positively correlated with slope and negatively with fuel moisture content.As the Q.mongolica load increased,the spread rate increased and was highest at a fuel ratio of 4:6.The model with modified optimal packing ratio and slope parameters has a significantly lower spread rate prediction error than the unmodified model.The spread rate prediction accuracy was significantly improved after modifying the model parameters based on spread rates from laboratory burning simulations.展开更多
文摘OBJECTIVE: Baby skin differs significantly from adult skin and requires special care. The Cussons Baby Sensicare Range (Sensicare) of products has been specifically formulated for baby skin and a range of standard cosmetic clinical tests were conducted in adult females with dry skin to evaluate the effectiveness of the range on skin moisturization and barrier function. METHODS: The studies were within subject, controlled, single blind studies. For the Sensicare Body Wash skin moisturization (Corneometer) was measured before application and after 7 and 14 days of twice daily use. For the Sensicare Moisturizing Lotion and Sensicare Soothing Cream skin moisturization was measured before application and at 2, 4, 6, 8 and 24 hours after a single application;skin elasticity (Cutometer) and transepidermal water loss (TEWL, Tewameter) were assessed before and after 14 days of twice daily use;and skin erythema (Mexameter) before induction with sodium lauryl sulphate (SLS), and at 30 mins, 24 and 48 hours after patch removal. Changes from baseline and changes versus control were evaluated. RESULTS: Thirty to thirty-five subjects completed each study. Skin moisture content was significantly increased from baseline for all Cussons Baby Sensicare Products (p < 0.05 for Hair & Body Wash;and p < 0.001 for Cream & Lotion). Changes from baseline in skin elasticity were significantly superior to control (unperfumed liquid soap) after 14 days twice daily use of the Lotion, and Cream (p < 0.05). There were no significant changes from baseline or significant differences from control in TEWL for the Lotion, or Cream. The increases in the average skin erythema index were significantly smaller for the Lotion, and Cream 30 minutes following SLS patch removal (p < 0.05 v sterile water, p < 0.001 v no treatment for both products). All the Sensicare products were well tolerated. CONCLUSION: These studies support the use of the Cussons Baby Sensicare range of products for new born, sensitive and eczema prone skin.
基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)National Natural Science Foundation of China(42475003)Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP209)。
文摘Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These surge events typically occur for days in the early-summer season(from April to June)and can lead to heavy rains in South China.This study categorizes surge events into three types of flow patterns and examines their multiscale variations and impacts on rainfall.The first type occurs mainly in April,with the southeasterlies enhanced by a deepening trough in South China and the western Pacific subtropical high established over the SCS.The second type of surge events mostly appears in June,featuring the prevailing southwesterlies of summer monsoon from the Indian Ocean during the active phases of intraseasonal oscillations.Most surge events exhibit semi-diurnal variations with morning and afternoon peaks of northward moisture fluxes.Specifically,the first type features a dominant afternoon peak,while the second type shows a dominant early-morning peak,which is induced by thermal contrast between the Indochina Peninsula and the SCS.In general,the surge events enhance moisture convergence and increase rainfall downstream in South China,but they show some regional differences.The second type strengthens moisture convergence and rainfall in coastal regions with a morning peak.In contrast,the first type enhances inland rainfall with a morning peak,while moisture divergence dominates coastal regions.The third type of surge events denotes transitional conditions between the first two types,in terms of atmospheric circulations,diurnal cycles,and rainfall patterns.These results highlight a diversity of regional moisture surges and related rainfall ranging from diurnal to sub-seasonal scales.
基金financially supported by the Central Public-Interest Scientific Institution Basal Research Fund of Chinese Academy of Forestry(CAFYBB2021ZW002)the National Key Research and Development Program of China(2022YFF1300404)the National Natural Science Foundation of China(U21A2005)。
文摘Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions.
基金supported by the Natural Science Foundation of Henan Province(252300421290)the National Natural Science Foundation of China(41771438)+1 种基金the Program for Innovative Research Team(in Science and Technology)of Henan University(22IRTSTHN010)the Postgraduate Education Reform and Quality Improvement Project of Henan Province(HNYJS2020JD14).
文摘Soil moisture(SM)is a critical variable in terrestrial ecosystems,especially in arid and semi-arid areas where water sources are limited.Despite its importance,understanding the spatiotemporal variations and influencing factors of SM in these areas remains insufficient.This study investigated the spatiotemporal variations and influencing factors of SM in arid and semi-arid areas of China by utilizing the extended triple collation(ETC),Mann-Kendall test,Theil-Sen estimator,ridge regression analysis,and other relevant methods.The following findings were obtained:(1)at the pixel scale,the long-term monthly SM data from the European Space Agency Climate Change Initiative(ESA CCI)exhibited the highest correlation coefficient of 0.794 and the lowest root mean square error(RMSE)of 0.014 m^(3)/m^(3);(2)from 2000 to 2022,the study area experienced significant increase in annual average SM,with a rate of 0.408×10^(-3)m^(3)/(m^(3)•a).Moreover,higher altitudes showed a notable upward trend,with SM increasing rates at 0.210×10^(-3)m^(3)/(m^(3)•a)between 1000 and 2000 m,0.530×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m,and 0.760×10^(-3)m^(3)/(m^(3)•a)at altitudes above 4000 m;(3)land surface temperature(LST),root zone soil moisture(RSM)(10-40 cm depth),and normalized difference vegetation index(NDVI)were identified as the primary factors influencing annual average SM,which accounted for 34.37%,24.16%,and 22.64%relative contributions,respectively;and(4)absolute contribution of LST was more significant in subareas at higher altitudes,with average absolute contributions of 0.800×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m and 0.500×10^(-2) m^(3)/(m^(3)•a)above 4000 m.This study reveals the spatiotemporal variations and main influencing factors of SM in Chinese arid and semi-arid areas,highlighting the more pronounced absolute contribution of LST to SM in high-altitude areas,providing valuable insights for ecological research and water resource management in these areas.
基金supported by the State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering(Grant No.SKLGDUEK2206)National Natural Science Foundation of China(Grant No.11872340).
文摘Soil desiccation cracking is a common phenomenon on the earth surface.Numerical modeling is an effective approach to study the desiccation cracking mechanism of soil.This work develops a novel 3D moisture diffusion discrete model that is capable of dynamically assessing the effect of cracking on moisture diffusion and allowing moisture to be discontinuous on both sides of the cracks.Then,the parametric analysis of the moisture exchange coefficient in the 3D moisture diffusion discrete model is carried out for moisture diffusion in continuous media,and the selection criterion of the moisture exchange coefficient for the unbroken cohesive element is given.Subsequently,an example of moisture migration in a medium with one crack is provided to illustrate the crack hindering effect on moisture migration.Finally,combining the 3D moisture diffusion discrete model with the finite-discrete element method(FDEM),the moisture diffusion-fracture coupling model is built to study the desiccation cracking in a strip soil and the crack pattern of a rectangular soil.The evolution of crack area and volume with moisture content is quantitatively analyzed.The modeling number and average width of cracks in the strip soil show a good consistency with the experimental results,and the crack pattern of the rectangular soil matches well with the existing numerical results,validating the coupled moisture diffusion-fracture model.Additionally,the parametric study of soil desiccation cracking is performed.The developed model offers a powerful tool for exploring soil desiccation cracking.
文摘This study investigates the mechanism of action of representative molecules of basalt fibers on the healing of water-soaked asphalt.Thermodynamic parameters,morphological characteristics,interfacial healing energy,and interfacial healing strength were analyzed using molecular dynamics and macroscopic tests under different time,temperature,and water conditions to evaluate the specific states and critical conditions involved in self-healing.The results indicate that basalt-fiber molecules can induce rearrangement and a combination of water-soaked asphalt at the healing interface.Hydroxyl groups with different bonding states increase the interfacial adsorption capacity of water-soaked asphalt.The interaction between basalt fiber molecules and water molecules leads to a"hoop"phenomenon,while aromatics-2 molecules exhibit a"ring band aggregation"phenomenon.The former reduces the miscibility of water and asphalt molecules,while the latter causes slow diffusion of the components.Furthermore,a micro-macro dual-scale comparison of interfacial healing strength was conducted at temperatures of 297.15 and 312.15 K to identify the strength transition point and critical temperature of 299.4 K during the self-healing process of basalt-fiber modified water-soaked asphalt.
基金supported by the National Natural Science Foundation of China [grant number 42088101]。
文摘During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the subtropical Northwestern Pacific(10°-20°N,130°E-175°W).The former is well-documented and considered to be influenced by the ENSO,while the latter has received comparatively less attention and is likely influenced by the Pacific Meridional Mode(PMM),as suggested by partial correlation analysis results.To elucidate the physical processes responsible for the enhanced(weakened)intraseasonal convection over the subtropical northwestern Pacific during warm(cold)PMM years,the authors employed a moisture budget analysis.The findings reveal that during warm PMM years,there is an increase in summer-mean moisture over the subtropical northwestern Pacific.This increase interacts with intensified vertical motion perturbations in the region,leading to greater vertical moisture advection in the lower troposphere and consequently resulting in convective instability.Such a process is pivotal in amplifying intraseasonal convection anomalies.The observational findings were further verified by model experiments forced by PMM-like sea surface temperature patterns.
文摘A cytotoxicity study based on keratinocytes was carried out to determine the safe dosing concentration of plant extract formulation(hereinafter referred to as the MOSOGY).On this basis,the 3D epidermal skin model(Epikutis^(®),which is abbreviated as Epikutis later)was stimulated with anionic surfactant sodium lauryl sulfate(SLS)was used to construct an in vitro 3D epidermal skin injury model and detect the proinflammatory factor(IL-1α)after MOSOGY acted on the 3D epidermal skin model.Additionally,capsaicin(CAP)was used to stimulate the 3D epidermal skin model(EpiKutis)to detect changes in the content of transient receptor potential vanilloid 1(TRPV1)after MOSOGY treatment.The hydration levels of the stratum corneum were tested using the 3D epidermal skin model.A hyaluronidase(HAase)inhibition experiment was conducted to assess the soothing effect of BSBE.The experimental results showed that MOSOGY exhibited no significant cytotoxicity within the concentration range of 0~2.50%At a concentration of 2.00%,the inhibition rates of IL-1αand PGE2 were 15.71%and 19.00%respectively.At a concentration of 5.00%,MOSOGY exhibited inhibition rates of 43.76%for TRPV1 and 11.11%for IL-1α.MOSOGY at concentrations of 1.00%and 5.00%showed inhibition rates of 76.50%and 86.50%for HAase,respectively.The moisturizing efficacy test showed that at the concentration of 5.00%,the water content of the stratum corneum of the 3D epidermal skin model increased by 31.91%.In addition,the 3D epidermal skin model used in this experiment has the characteristics of layered structure,physiological and metabolic functions that are highly similar to natural human skin.The above research shows that MOSOGY at a certain concentration effectively inhibits IL-1α,PGE2,TRPV1 and HAase in human skin,especially the inhibition rate of HAase is more than 70.00%,indicating that BSBE have strong anti-allergic effect,and skin hydration of the 3D epidermal skin model also has a significant increase.The results indicate that MOSOGY exhibits inhibitory effects on IL-1α,PGE2,TRPV1,and HAase,achieving significant soothing and reparative effects through the inhibition of multiple targets.Additionally,it demonstrates good moisturizing efficacy and safety,making it suitable for use in cosmetics with corresponding efficacy claims.
基金the financial support of the National Natural Science Foundation of China(No.22205165).
文摘Moisture-enabled electricity generation(MEG)has emerged as a promising sustainable energy harvesting technology,comparable to photovoltaics,thermoelectrics,and triboelectrics[1].MEGs generate electricity by converting the chemical potential of moisture into electric energy through interactions with hygroscopic materials and nanostructured interfaces.Unlike solar or thermal harvesters,MEGs operate continuously by utilizing ubiquitous atmospheric moisture,granting them unique spatial and temporal adaptability.Despite nearly a decade of progress and the exploration of diverse material systems for MEG,the overall output power remains significantly limited due to inherently low charge carrier concentrations and restricted ion diffusion fluxes[2].As a result,standalone MEG devices often deliver low and unstable output,limiting practical applications.To enhance performance and versatility,recent efforts have explored hybridization of MEG with other ambient energy sources such as triboelectric or thermoelectric effects.
文摘Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some common factors that usually cause damage to trees when they are struck by lightning?2.How might the unique characteristics of a tree contribute to its ability to survive a lightning strike?
基金Funded by PotlatchDeltic Corporation,grant number RGPSQ17。
文摘A common concern to planting for reforestation is seedling failure that is directly measurable by seedling early field performance of growth and survival.Root growth potential(RGP)is a commonly used metric of seedling quality and has been considered indicative of seedling field performance.The effect of RGP is thought to be dependent on planting site and underlining environmental conditions.Moisture stress often is considered the primary cause of seedling failure in addition to other environmental factors such as soil physicochemical properties in regions such as the Inland Northwest of the United States that is prone to growing season drought.In addition,it is interesting to test whether seedling early field performance is related to their morphological attributes and whether the morphological attributes are related to RGP.A comprehensive evaluation on early field performance of three planted conifer species of interior Douglas-fir(Pseudotsuga menziesii(Mirb.)Franco var.glauca(Beissn.)Franco),grand fir(Abies grandis(Douglas ex D.Don)Lindl.),and western larch(Larix occidentalis Nutt.)was conducted in this study.It was found that RGP did not show clear correlation with early field performance across species.RGP also was not significantly correlated with seedling morphological measures such as below-and above-ground biomass and root-to-shoot ratio(R:S,by mass).Early field performance of growth and survival varied greatly across individuals of seedlings.The most influential predictors of early seedling growth and survival were their initial size(indicative of energy reserve)and soil temperature that likely interacted with soil moisture.Our findings suggest that seed stock selection for reforestation probably should favor species and genotypes with greatest heat tolerance that may be better adapted to future conditions in the region.
基金the Ministry of Science and Technology,Government of India,and Council of Scientific and Industrial Research(CSIR)(09/081(1371)/2019-EMRI)for its funding,supported by a NERC Independent Research Fellowship(MITRE,NE/W007924/1)。
文摘In this study,we investigate the complex relationship between western disturbances(WDs),the El Ni?o–Southern Oscillation(ENSO),and extreme precipitation events(EPEs) in the western Himalaya(WH) during the extended winter season(November–March).WDs west of WH coincide with 97% of recorded EPEs,contributing substantially(32% in winter,11% annually) to total precipitation within WH.WDs are 6% less frequent and 4% more intense during El Ni?o than La Ni?a to the west of WH.During El Ni?o(compared to La Ni?a) years,WDs co-occurring with EPEs are significantly more intense and associated with 17% higher moisture transport over “WH box”(the selected region where most of the winter precipitation over WH occurs).This results in twice the EPE frequency during El Ni?o periods than La Ni?a periods.A substantial southward shift(~180 km) of the subtropical jet(STJ) axis during El Ni?o brings WD tracks further south towards their primary moisture sources,especially the Arabian Sea.We have shown that WDs that are both more intense and pass to the south of their typical latitudes have higher levels of vertically integrated moisture flux(VIMF)within them.VIMF convergence in the most intense pentile of WDs is 5.7 times higher than in the weakest,and is 3.4 times higher in the second lowest latitude pentile than in the highest.Overall,this study demonstrates a direct link between changes in the latitudinal position and intensity of WDs associated with the winter STJ,and moisture convergence,which leads to the occurrence of EPEs over WH during ENSO phases.
文摘The article examines the impact of increased aridization of the territory due to an increase in air temperature,reduced precipitation,and the formation of moisture deficiency on grain yields in Northern Kazakhstan.The most important result of the work is the revealed inverse relationship between grain yields and the temperature of the growing season:low-yielding years are associated with high temperatures and droughts,and high-yielding years are associated with lower temperatures and an optimal ratio of heat and moisture.The novelty of this study is the use of the method of hydrological and climatic calculations in identifying the nature of temperature variability and precipitation in the territory of Northern Kazakhstan for the modern period(1991–2020)compared with the base period(1961–1990).At all the studied meteorological stations,there is a tendency for the average annual temperature and the temperature of the growing season to increase:in the forest-steppe zone with an average warming intensity of 0.3–0.33℃ per decade;in the steppe zone by 0.2–0.43℃ per decade;and in the growing season by 0.2–0.7℃ per decade.The air temperature in the steppe zone is rising more intensively than in the forest-steppe zone,and precipitation in the forest-steppe zone has changed more than in the steppe zone.An increase in the average annual air temperature during the growing season(May–August),combined with a shortage of atmospheric moisture or a constant amount of it,led to an increase in the degree of aridization of the territory,an increase in the frequency of droughts in the steppe zone of Northern Kazakhstan.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.42422502,42275038)the China Meteorological Administration Climate Change Special Program(Grant No.QBZ202306)。
文摘Extensive flooding swept across large areas of Central Asia,mainly over Kazakhstan and southwestern Russia,from late March to April 2024.It was reported to be the worst flooding in the area in the past 70 years and caused widespread devastation to society and infrastructure.However,the drivers of this record-breaking flood remain unexplored.Here,we show that the record-breaking floods were contributed by both long-term climate warming and interannual variability,with multiple climatic drivers at play across the synoptic to seasonal timescales.First,the heavy snowmelt in March 2024 was associated with above-normal preceding winter snow accumulation.Second,extreme rainfall was at a record-high during March 2024,in line with its increasing trend under climate warming.Third,the snowmelt and extreme rainfall in March were compounded by record-high soil moisture conditions in the preceding winter,which was a result of interannual variability and related to excessive winter rainfall over Central Asia.As climate warming continues,the interplay between the increasing trend of extreme rainfall,interannual variations in soil moisture pre-conditions,as well as shifting timing and magnitudes of spring snowmelt,will further increase and complicate spring flooding risks.This is a growing and widespread challenge for the mid-to high-latitude regions.
基金National Key Research and Development Plan of China,No.2023YFF0805703National Natural Science Foundation of China,No.42271268。
文摘Heatwaves are becoming increasingly frequent and severe,posing escalating risks to ecosystems and human well-being.While soil moisture(SM)deficits are recognized as important contributors to heatwave amplification,their spatially heterogeneous impacts across the Northern Hemisphere remain insufficiently understood.In this study,we analyze ERA5 reanalysis data(1980-2022)to investigate trends in heatwave frequency,intensity,and duration,as well as their sensitivity to SM variability.Our results show robust increases in heatwave occurrence(0.76 events per decade),intensity(0.81℃per decade),and average duration(0.40 days per decade),with extreme events,as represented by maximum intensity and duration,rising at even faster rates(2.18℃per decade and 0.83 days per decade,respectively).Strong negative correlations are observed between SM deficits and heatwave metrics,with the magnitude of this relationship varying across land cover types and heatwave severity levels.Quantile regression reveals that SM reductions have a greater impact at higher quantiles for most indicators.Cropland exhibits the highest sensitivity to SM anomalies,whereas forests show more resilience due to their superior water retention capacities.These findings underscore the crucial role of land-atmosphere interactions in shaping heatwave extremes,providing a scientific basis for enhancing early warning and adaptation strategies in the context of ongoing climate change.
基金We express our gratitude to the Internal Grant Agency of the Faculty of Forestry and Wood Sciences,Czech University of Life Sciences,Prague(Grant No.IGA A_24_24)the Ministry of Education,Youth and Sports of the Czech Republic(Grant INTER-TRANSFER No.LTT20017)for funding this study.
文摘Understanding the ecological processes shaping competitive interactions among forest trees is crucial for predicting ecosystem productivity and climate change resilience.However,few studies have investigated how the biological attributes of tropical species may affect competitive outcomes under varying resource conditions.We collected and analysed a 10-year dataset of radial growth rates in canopy trees from a network of forest inventory plots located in divergent forest types over an extensive meteorological gradient in Ghana,West Africa.We used nonlinear models to estimate the relative reduction in potential growth(basal area increment)of individual target trees of a given species as a consequence of the combined effects of(1)target tree size,(2)variation in crowding levels by neighbouring trees,(3)the functional attributes of those neighbours(wood density and shade tolerance),and(4)local soil moisture levels.Analyses were conducted separately for the 15 most common species in the inventory network.In opposition to neutral theory,our findings indicate that the strength of interactions among competing species was distinctly asymmetric and dynamic.Wood density was an important characteristic that modified competitive outcomes for most species,particularly under varying levels of resource availability.Specifically,dense wood was an attribute that conferred comparatively stronger competitive ability in moisture-limited conditions.Larger individuals were notably less sensitive to the effects of moisture-dependent competition.Our results suggest that attributes such as wood density may reflect divergent life history strategies that differentiate species’fitness and competitive ability in varying environments.The dynamic nature of competition,influenced by a complex interplay of biological and abiotic factors,implies that more prevalent dry periods,which have been forecast for tropical Africa,may impact the physiognomy and function of future forest communities in the region.
基金supported by the Natural Science Foundation of Gansu Province(Grant Number:25JRRA749,24JRRA515,24JRRA527)the Fundamental Research Funds for the Central Universities(Grant Number:lzujbky-2022-ct01)+1 种基金JP and JS were supported by Spanish Government grants PID2020115770RB-I,PID2022-140808NB-I00,and TED2021-132627 BeI00funded by MCIN.SLC was supported by NSF award DEB-2423861.
文摘The primary mechanism driving plant species loss after nitrogen(N)addition has been often hypothesized to be asymmetric competition for light,resulting from increased aboveground biomass.However,it is largely unknown whether plants’access to soil water at different depths would affect their responses,fate,and community composition under nitrogen addition.In a semiarid grassland exposed to 8-years of N addition,we measured plant aboveground biomass and diversity under four nitrogen addition rates(0,4,10,and 16 g m2 year1),and evaluated plant use of water across the soil profile using oxygen isotope.Aboveground biomass increased significantly,but diversity and shallow soil-water content decreased,with increasing rate of nitrogen addition.The water isotopic signature for both plant and soil water at the high N rate indicated that Leymus secalinus(a perennial grass)absorbed 7%more water from the subsurface soil layer(20e100 cm)compared to Elymus dahuricus(a perennial grass)and Artemisia annua(an annual forb).L.secalinus thus had a significantly larger biomass and was more abundant than the other two species at the high N rate but did not differ significantly from the other two species under ambient and the low N rate.Species that could use water from deeper soil layers became dominant when water in the shallow layers was insufficient to meet the demands of increased aboveground plant biomass.Our study highlights the importance of water across soil depths as key driver of plant growth and dominance in grasslands under N addition.
基金Supported by Key Research and Development Program of Shanxi Province(202302140601009).
文摘Moistube irrigation is a newly-developed irrigation technique that utilizes a semipermeable membrane to release water slowly and continuously into the plant root zone.Alternate Moistube Irrigation(AMI)is a combination of alternative irrigation and moistube irrigation.In order to investigate the effects of AMI on plant growth,greenhouse experiments were conducted on spinach(Spinacia oleracea)and water spinach(Ipomoea aquatica)plants at different time.We measured soil water content at a depth of 20 cm in the planting boxes,and also determined seed emergence rate,plant height,largest leaf area,fresh weight per plant,yield,and irrigation water productivity(IWP)for both spinach and water spinach.The results showed that the AMI treatments had significantly higher soil water content than the conventional surface irrigation control(CK).The emergence rates of spinach and water spinach were significantly higher in the AMI treatments than in the CK,and the plant height,largest leaf area,and fresh weight during the middle and late stages of spinach and water spinach growth were also significantly higher than those of the CK.Both spinach and water spinach grew well and produced high yield with high IWP under AMI with a high water head pressure of 1.5 m at tube spacing of 20 or 30 cm.We found that AMI with a suitable combination of head pressure and tube spacing can promote plant growth and increase yield and IWP under controlled conditions.
基金financially supported by the National Natural Science Foundation of China(Grant No.42361002)the Fund of Ningxia Hui Autonomous Region(Grant No.2022AAC03665).
文摘Tafoni are globally developed on cliffy slopes,and many of them are favorable places for the preservation of stone historical relics.However,the characteristics and formation processes of tafoni in the Loess Plateau are yet to be understood.This paper studied the features of the tafoni on conglomerate slopes in Huoshizhai National Geopark of Ningxia Hui Autonomous Region and discussed its formation processes by field investigation and morphometry,insitu relative humidity(RH)measurement,salt chemistry and X-ray fluorescence spectrometer(XRF)experiments of 24 samples.The bedrock of the tafoni is dominated by reddish fluvial conglomerates of the Lower Cretaceous Heshangpu Formation with abundant chemically unstable components including feldspars,lithic fragments,and calcite cements.The RH values vary from 5%to 100%,but the backwalls of the tafoni have higher RH values than outer surfaces.The more moisture on the backwalls is possibly generated by water influx from the rock interior,resulting in more salt precipitation on the backwalls.As a result,the backwalls have been subject to predominant salt weathering.The dominant salts involved in salt weathering are probably derived from the dissolution of the salt interbeds in the basin,although the chemical dissolution of the unstable components such as feldspars,lithic fragments,and calcite cements might have produced small amounts of salts.The salt types dominantly include nitrates,sulfates,and halite.In the progression of tafoni,the moisture maintenance on the backwalls gives rise to the accretion of salts,which in turn enhance the weathering rates of the backwalls.As a result,the volumes of the tafoni have become enlarged owing to inward growth and coalescence of adjacent smaller ones.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC1511603)the Fundamental Research Funds for the Central Universities(2572021BA04).
文摘The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments on homogeneous fuels but has not been validated for conifer-deciduous mixed fuel.In this study,Pinus koraiensis and Quercus mongolica litter was used in a laboratory burning experiment to simulate surface fire spread in the field.The effects of fuel moisture content,mixed fuel ratio and slope on spread rate were analyzed.The optimum packing ratio,moisture-damping coefficient and slope parameters in the Rothermel model were modified using the measured spread rate which was positively correlated with slope and negatively with fuel moisture content.As the Q.mongolica load increased,the spread rate increased and was highest at a fuel ratio of 4:6.The model with modified optimal packing ratio and slope parameters has a significantly lower spread rate prediction error than the unmodified model.The spread rate prediction accuracy was significantly improved after modifying the model parameters based on spread rates from laboratory burning simulations.
