To achieve the goal of carbon neutrality, China is projected to significantly reduce anthropogenic aerosols in addition to greenhouse gases. Here, the future changes in East Asian summer monsoon (EASM) and weather extremes responding to the idealized local emission reductions of anthropogenic aerosols (AA) in China are investigated based on time-slice simulations in an aerosol-climate model together with a localized carbon neutral emission scenario, while greenhouse gases and other anthropogenic climate forcers are kept at the present-day (2015) levels. The AA reduction in China leads to a positive change in June-July-August (JJA) mean effective radiative forcing over eastern China in 2030 and 2060s, along with a 0.2 degrees C-0.4 degrees C warming, respectively. It intensifies the temperature difference between land and ocean, and increases the precipitation over eastern China. Multiple EASM indices show that EASM intensity in JJA is estimated to be strengthened in the future, because of the AA decline in China. The AA emissions reduction toward carbon neutrality in China also presents a potential side effect of intensifying the summertime extreme temperatures and precipitation in China. This study reveals the important role of reductions of AA emissions in influencing EASM and weather extremes, which warrants careful assessment in the emission policymaking process prior to the implementation of mitigation strategies.

An anomalous warm weather event in the Antarctic McMurdo Dry Valleys on 18 March 2022 created an opportunity to characterize soil biota communities most sensitive to freeze-thaw stress. This event caused unseasonal melt within Taylor Valley, activating stream water and microbial mats around Canada Stream. Liquid water availability in this polar desert is a driver of soil biota distribution and activity. Because climate change impacts hydrological regimes, we aimed to determine the effect on soil communities. We sampled soils identified from this event that experienced thaw, nearby hyper-arid areas, and wetted areas that did not experience thaw to compare soil bacterial and invertebrate communities. Areas that exhibited evidence of freeze-thaw supported the highest live and dead nematode counts and were composed of soil taxa from hyper-arid landscapes and wetted areas. They received water inputs from snowpacks, hyporheic water, or glacial melt, contributing to community differences associated with organic matter and salinity gradients. Inundated soils had higher organic matter and lower conductivity (p < .02) and hosted the most diverse microbial and invertebrate communities on average. Our findings suggest that as liquid water becomes more available under predicted climate change, soil communities adapted to the hyper-arid landscape will shift toward diverse, wetted soil communities.

Human disturbance in the Arctic is increasing. Abrupt changes in vegetation may be expected, especially when spots without vegetation are made available; additionally, climate change alters competition between species. We studied whether 34- to 35-year-old seismic operations had left imprints on local vegetation and whether changes could be related to different soil characteristics. The study took place in Jameson Land in central east Greenland where winter seismic operations in search of oil took place from 1985 to 1989. This area is dominated by continuous dwarf shrub heath with Cassiope tetragona, Betula nana, and Vaccinium uliginosum as dominant species. Using point frame analyses, we registered vascular plants and other surface types in frames along 10-m transects in vehicle tracks (hereafter damages) and in undisturbed vegetation parallel to the track (hereafter references) at eleven study sites. We also measured temperature and pH and took soil samples for analysis. Damaged and reference vegetation types were compared with S & oslash;rensen similarity indices and detrended correspondence analyses. Although most vascular plant species were equally present in damaged vegetation and in references the detrended correspondence analyses showed that at ten out of eleven study sites the damages and references still differed from each other. Graminoids and the herb Polygonum viviparum had the highest occurrence in damages. Shrubs and the graminoid Kobresia myosuroides had the highest occurrence in references. Cassiope tetragona was negatively impacted where vehicles had compacted the snow. Moss, organic crust or biocrust, soil, and sand occurred more often in damages than in references, whereas lichens and litter had the highest occurrence in references. The richness of vascular plant species varied between the eleven study sites, but between damages and references the difference was only up to four species. Temperature was the soil parameter with the most significant differences between damages and references. Total recovery of the damaged vegetation will most likely not occur within several decades. The environmental regulations were important to avoid more serious impacts.

Taurine (TAU) has recently been found to have an impactful role in regulating plant responses under abiotic stresses. This study presented the comparative effects of TAU seed priming and foliar spray application on chickpea plants exposed to hexavalent chromium. Taurine priming and foliar applications (1.6 and 2.4 mM) notably modulated morpho-physiological and biochemical responses of plants under Cr(VI) stress. Plants subjected to 25 mg kg-1 soil Cr in the form of potassium dichromate (K2Cr2O7) displayed a significant reduction in growth, chlorophyll, and uptake of essential nutrients (N, K, P, and Ca). Cr(VI) toxicity also resulted in a notable increase in osmolyte accumulation, lipid peroxidation, relative membrane permeability, ROS generation, antioxidant enzyme activities, antioxidant compounds, endogenous Cr levels, and aerial Cr translocation. Taurine abridged lipoxygenase activity to diminish lipid peroxidation owing to the overproduction of ROS initiated by a higher Cr content. The acquisition and assimilation of essential nutrients were augmented by the TAU-related decrease in leaf and root Cr levels. Consequently, TAU enhanced growth by mitigating oxidative damage, reducing Cr content in the aerial parts, and reinforcing the activities of antioxidant enzymes. Compared to foliar spray, TAU seed priming has demonstrated superior efficacy in mitigating Cr phytotoxicity in plants.

Climate warming changes in heat fluxes within the atmosphere-surface cover-soil system and affects the thermal state of permafrost. A comparison of heat fluxes from the atmosphere to the soil during the period with positive air temperatures and from the soil to the atmosphere during the cold period makes it possible to assess the permafrost stability. Snow and moss cover are important factors influencing heat fluxes. The influence of surface fluxes on heat fluxes is estimated based on mathematical modeling and numerical experiments on the model. The processing of data from field measurements of soil temperature made it possible to determine the heat fluxes for the cold and partially warm periods of the year. A comparison of the data from model calculations and measurements of heat fluxes showed a satisfactory agreement. The difference between them from December to February did not exceed 4%; in November and March, 9 and 8%, respectively. In 2023/24, during the period with negative air temperatures lasting 255 days with an average air temperature of -7 degrees C, soil heat losses amounted to 76.5 and 92.3 MJ/m2 with snow thickness of 1.14 and 0.63 m, respectively; the average values of heat fluxes from October to March were 4.9 and 5.9 W/m2. According to model calculations, with an average daily positive air temperature of 6.8 degrees C, the loss by the soil in winter is 10 MJ/m2 less than the heat flux into the soil in summer, which leads to permafrost degradation. At snow cover depth of 0.5 m, the heat input into the soil in summer coincides with the heat loss in winter. With a higher snow cover depth, the heat flux from the soil to the atmosphere decreases, soil cooling decreases, and permafrost degradation will occur. The same processes will occur when the snow cover is 1-m-deep and the moss cover is less than 3-cm-thick. For a moss cover of greater thickness, the thermal stability of permafrost rocks is preserved. Numerical experiments on the model estimated the heat fluxes and the thickness of the active layer for different snow and moss cover thicknesses and atmospheric air temperatures.

The existence of rock weathering products has an important effect on the infiltration of water in the soil. Understanding the mechanism of water infiltration in a mixed soil and weathered rock debris medium is highly important for soil science and hydrology. The purpose of this study is to explore the effects of mudstone hydrolysis on water infiltration in the soil under different mixing ratios (0-70 %) of weathered mudstone contents. Soil column experiments and numerical modelling were used to study the processes of hydrolysis of weathered mudstone and water infiltration in the mixed medium. The results revealed that water immersion can cause the dense mudstone surface to fall off, thus forming pores, and that the amount of these pores first increase but then decrease over time. The disintegration of post-hydrolysis mudstone debris occurs mainly among particles ranging from 2-2000 mu m, predominantly transforming sand particles into finer fractions. Increasing the mudstone content in the soil from 0 % to 50 % enhances the infiltration rate and cumulative infiltration volume. However, when the mudstone content exceeds 50 %, these parameters decrease. The mudstone weathering products promote water infiltration in the soil within a certain range of mudstone contents, but as the ratio of weathered products increases, excessive amounts of mudstone hinder the movement of water in the soil. The identified transformation phenomenon suggests that the infiltration capacity of mixed soil will not scale linearly with mudstone content. The findings enable some mitigation strategies of geologic hazards based on the hydrological stability in heterogeneous environments.

Root-knot nematodes (RKN) are globally distributed and highly pathogenic. By determining the threshold at which damage occurs, we can create effective measures to protect plants from nematodes. In our study, we investigated the impact of ten initial population densities (Pi-log series) of M. javanica, i.e., 0, 2.38, 2.68, 2.98, 3.28, 3.58, 3.88, 4.18, 4.48 and 4.78 juveniles (J2) g(-1) soil on tomato cv. S22 plants in pots. The graphical estimation of yield losses caused by RKN was calculated using Seinhorst's yield loss model based on the relationship between the RKN population and damage to tomato plants. The relationship between initial nematode population density (Pi) and plant yield was analyzed using Seinhorst's model, where T is the tolerance limit, m is the minimum yield, and z is a constant describing yield decline. This allowed us to determine the threshold at which nematode infestation significantly reduces tomato growth. Seinhorst's model, y = m + (1-m) 0.95(Pi/T-1) for Pi > T; y = 1 for Pi <= T for RKN, was fitted to the data of shoot length and fresh weight of infected and uninoculated control plants to estimate the damage threshold level. The impact of M. javanica on plant physiological parameters, including chlorophyll content, carotenoid and nitrate reductase activity, root-gall formation, and disease incidence, was also determined in this study. The tolerance limits for relative tomato shoot length and fresh weight were 3.34 J2 of M. javanica g(-1) soil. The minimum relative values (y(m)) for shoot length and fresh weights were 0.39 and 0.42, respectively. We found that the damage threshold level was between 3.28 and 3.58. The root galls index, nematode population and reproduction factors were 3.75, 113 and 29.42, respectively, at an initial population density (Pi) of 3.58 J2 g(-1) soil. The chlorophyll (0.43 mg g(-1)), carotenoids (0.06 mg g(-1)) and nitrate reductase activity (0.21 mu mol min(-1) g(-1)). Our study highlights the importance of the accurate estimation of damage thresholds, which can guide timely and effective nematode management strategies.

Excessive fluorine accumulation poses a significant threat to soil ecology and even human health, yet its impact on soil fauna, especially earthworms, remains poorly understood. This study employed multi-omics and biomarkers to investigate high fluorine-induced biochemical changes that cause tissue damages in Eisenia fetida. The results demonstrated that earthworms exhibited obvious damage with fluorine addition exceeding 200 mg kg(-1), with stress levels escalating as fluorine contents increased. Further analysis of the underlying mechanisms revealed that fluorine could upregulate genes encoding mitochondrial respiratory chain complexes I-III and downregulate those for IV-V, leading to reactive oxygen species (ROS) accumulation despite antioxidant system activation. The resulting ROS interfered with deoxyribonucleoside triphosphate synthesis, prompting homologous recombination as the main DNA repair mechanism. Additionally, fluorine-induced ROS also attacked and disrupted protein and lipid related metabolisms ultimately causing oxidative damages. These cumulative oxidative damages from high fluorine contents subsequently triggered autophagy or apoptosis, resulting in tissue ulceration and epithelial exfoliation. Therefore, high fluorine could threaten earthworms by inducing ROS accumulation and subsequent biomolecule damages.

Rhizoctonia solani is a significant soil-borne pathogenic fungus that poses a significant threat to the economically important agricultural crops. 4-(Diethylamino)salicylaldehyde (DSA) is a secondary metabolite produced by Streptomyces sp. KN37, which has antifungal activity, meanwhile its inhibitory mechanism is still unclear. In this study, we explored the antifungal efficacy of DSA and its potential mechanism of inhibiting R. solani. It was found that DSA exhibited significant antifungal activity against six tested plant pathogenic fungi, with R. solani being the most sensitive (EC50 = 26.904 mu g/mL). Notably, DSA effectively reduced the mycelial mass and inhibited sclerotia germination, demonstrating a good control efficacy of cucumber damping-off disease. Morphological observation showed that DSA significantly disrupted the shape and ultrastructure of the mycelium. Transcriptomic and metabolomic analyses revealed that DSA impacted the integrity of the cell membrane, redox processes, and energy metabolism in R. solani. The results of fluorescence staining, relative conductivity, H2O2 content, and antioxidant enzyme activity showed that the accumulation of ROS in hypha cells after DSA treatment possibly resulted in damage to cell membrane integrity. Furthermore, the reduction in ATP content, along with decreased ATPase and citrate synthase activity, indicates that energy production may be inhibited. Molecular docking analysis further showed that DSA may competitively inhibit citrate synthase, thereby inhibiting cell energy production and ultimately inducing apoptosis. Our study provides new insights into the potential mechanism by which DSA inhibits the mycelial growth of R. solani.

Soil compaction caused by heavy agricultural machinery poses a significant challenge to sustainable farming by degrading soil health, reducing crop productivity, and disrupting environmental dynamics. Field traffic optimization can help abate compaction, yet conventional algorithms have mostly focused on minimizing route length while overlooking soil compaction dynamics in their cost function. This study introduces Soil2Cover, an approach that combines controlled traffic farming principles with the SoilFlex model to minimize soil compaction by optimizing machinery paths. Soil2Cover prioritizes the frequency of machinery passes over specific areas, while integrating soil mechanical properties to quantify compaction impacts. Results from tests on 1000 fields demonstrate that our approach achieves a reduction in route length of up to 4-6% while reducing the soil compaction on headlands by up to 30% in both single-crop and intercropping scenarios. The optimized routes improve crop yields whilst reducing operational costs, lowering fuel consumption and decreasing the overall environmental footprint of agricultural production. The implementation code will be released with the third version of Fields2Cover, an open-source library for the coverage path planning problem in agricultural settings.