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There is an urgent need to understand the coupled relationship between belowground microbes and aboveground plants in response to temperature under climate change. The metabolic theory of ecology (MTE) provides a way to predict the metabolic rate and species diversity, but the spatial scale dependence and connections between plants and microorganisms are still unclear. Here, we used two independent datasets to address this question. One is from comprehensive sampling of paddy fields targeting bacteria and microbial functional genes, and the other is a global metadata of spatial turnover for microorganisms (bacteria, fungi and archaea, n = 139) and plants (n = 206). Results showed that spatial turnover of bacterial communities and microbial functional genes increased with temperature and fitted MTE. Through meta-analysis, the temperature-dependent spatial scale pattern was further extended to the global scale, with the spatial turnover of microorganisms and plants being consistent with MTE. Belowground microorganisms and aboveground plants were closely linked with each other even when controlling for temperature, suggesting that factors other than shared relationships with temperature also contribute to their linkages. These results implied a broad application of MTE in biology and have important implications for predicting the ecological consequences of future climate warming.

Fertilizer management influences the accumulation of soil organic C and N in agricultural soils. The combined use of chemical and organic fertilizers is considered a good method to enhance soil fertility, but it is still unclear about the effects of substituting manure for fertilizer on aggregation and aggregate associated organic C and N. We selected a 4-yr-old soil fertility experiment to examine the aggregation and aggregate associated organic C and N in response to substituting manure for fertilizer. In comparison to control, no fertilizer added (CK); substituting manure for fertilizer significantly increased organic C and N by 11.61 to 47.97% and 21.05 to 32.63% in 0- to 20-cm bulk soil, respectively. It promoted organic C in the silt + clay fraction, microaggregates, small macroaggregates, and large macroaggregates by 3.17 to 17.15%, 12.94 to 34.09%, 10.99 to 50.20%, and 25.32 to 52.09%, respectively. Aggregate associated N also presented significant increases under substituting manure for fertilizer compared to CK. The mass distribution of small and large macroaggregates were 8.16 to 15.54% and 8.89 to 49.51% higher in the manure-substituted plots than CK, respectively. Organic C and labile C were generally greater in macro- than microaggregates in the manure-substituted plots; redundancy analysis confirmed that macroaggregates had positive effects on organic C and N sequestration in bulk soil and aggregates. Based on these results we suggested that substituting manure increases macroaggregate associated organic C and N, and the formation of small and large macroaggregates is accelerated by organic amendment in the test soil compared to CK.

Dielectric techniques are fundamental methods for measuring soil water content, and they commonly rely on the conventional laboratory calibration of the dielectric permittivity models between a dielectric constant and water content. As a non‐negligible factor, porosity has been constructed differently in some models as a calibration constant, but the systematic porosity variations during the laboratory model calibration and field applications are not yet well addressed. Based on time‐domain reflectometer laboratory calibration experiments, this study investigated this issue using three preestablished dielectric permittivity models: the Purdue calibration equation (American Society for Testing and Materials model [ASTM]), the complex refractive index model (CRIM), and a piecewise CRIM model (CRIMP). Results demonstrate that a generalized porosity constant used in the calibration would bring in additional structural bias compared with the calibration using variable porosities, and its magnitude varies with the model structure. The deviation of the generalized porosity constant can further amplify the structural bias of ASTM and CRIM for soils with low clay content, but it is insensitive for the soils with high clay content due to the overwhelming role of model structure error. Only the model CRIMP with a “perfect” model structure can effectively cope with the systematic porosity variation and keep a stable built‐in capability for estimating calibration constants from readily available soil data. These findings highlight ignoring porosity variation should not be taken for granted for calibrating and applying the preestablished models.

MoS2 is promising anode material in lithium-ion batteries (LIBs) because of its layered structure analogous to that of graphite and high lithium storage capacity of 670 mAh g-1. However, practical implementation in LIBs is hindered by the poor conductivity, large volume change, and possible polysulfide shuttling during cycling. In this work, oriented MoS2 nanoflakes grown on N-doped carbon nanosheets (MoS2/NC) are investigated as high-performance anodes in LIBs. The materials are prepared by annealing dodecylamine intercalated MoO3 nanosheets under Ar at 400 oC followed by a hydrothermal treatment in the thiourea (CH4N2S) solution at 220 oC for 30 h. In the MoS2/NC structure, the NC nanosheets constitute the long-range conductive network for fast electron transfer, whereas the oriented MoS2 nanoflakes provide sufficient active sites for Li+ storage and fast Li+ diffusion along a-b plane. Consequently, the MoS2/NC electrode shows a remarkable capacity of 803 mAh g-1 at a current density of 100 mA g-1, a high rate capability of 554 mAh g-1 at 2000 mA g-1 and excellent cycle stability. Our results reveal a facile and general method to produce high-performance heterostructured MoS2/NC anodes and the process can be extended to other metal dichalcogenides for future high-performance LIBs.

Spatial variability and influential factors are important to evaluate soil organic C (SOC) and the C pool in large areas. In the present study, sampling was conducted from May to November 2011 in Henan Province, a typical agricultural region of Central China, to study the effects of soil properties and anthropogenic factors on SOC variability in cropland. Physicochemical properties of soil samples collected at 280 sites from the surface layer (at a depth of 0–20 cm) were analyzed, and related data about the sampling sites were also collected from the Second State Soil Survey of China, conducted in 1981. Firstly, we found increasing trends in SOC density (SOCD) and SOC pool (SOCP) were obvious from 1981 to 2011, and we concluded that cropland presents great C sequestration potential for the future. Carbon pool ability varied with soil properties: the order of fixed Camount in different soil types was found to be Inceptisols > Luvisols > semihydromorphic soil > Anthrosols, and the average SOCP increased significantly from 1981 to 2011. Secondly, soil bulk density, pH, and returning straw were the key influential factors for SOCD in the past 30 yr. Thirdly, although random factors (returning straw) only explain 29.1% of SOCD variability, more attention should be paid to the factors, because application of returning straw was the most dominant anthropogenic factor, which can be used to improve cropland productivity and C sink capacity within a short period if they are properly managed in the future.

Freestanding film electrode comprising face-to-face alternately stacked 2D TiO2 nanosheets and reduced graphene oxide (rGO) is designed and fabricated as binder-free anode for lithium-ion batteries. The ultrathin TiO2 nanosheets with (001) facet exposed having the lowest Li+ diffusion barrier face-to-face hetero-assembled onto the conductive rGO, the Li+ can swiftly diffuse into the TiO2 nanosheets across the (001) facets with the lowest barrier and short transfer distance. The spectacular configuration of this planary-aligned electrode leads to superior performances than other composite electrodes previously reported, which delivers a large capacity of 132.3 mA h g-1 with capacity retention of 89 % over 1,000 cycles at a high rate of 20 C (1 C = 168 mA g-1). This work proved that controlling the arrangement orientation of electrode materials with anisotropy Li+ diffusion barrier could remarkably improve the electrochemical properties, boosting promising application in high-power energy storage devices.

Acanthopanax koreanum Nakai (Araliaceae) is one of the most widely cultivated medicinal plants in Jeju Island, Korea, and the roots and stem bark of A. koreanum have been traditionally used as a tonic agent for general weakness. However, the use of A. koreanum for general weakness observed in the elderly, including those with declined cognitive function, has not been intensively investigated. This study was performed to investigate the effect of the ethanol extract of A. koreanum (EEAK) on cholinergic blockade-induced memory impairment in mice. To evaluate the ameliorating effects of EEAK against scopolamine-induced memory impairment, mice were orally administered EEAK (25, 50, 100, or 200 mg/kg), and several behavioral tasks, including a passive avoidance task, the Y-maze, and a novel object recognition task, were employed. Besides, western blot analysis was conducted to examine whether EEAK affected memory-associated signaling molecules, such as protein kinase B (Akt), Ca2+/calmodulin-dependent protein kinase II (CaMKII), and cAMP response element-binding protein (CREB). The administration of EEAK (100 or 200 mg/kg, p.o.) significantly ameliorated the scopolamine-induced cognitive impairment in the passive avoidance task, the Y-maze, and the novel object recognition task. The phosphorylation levels of both Akt and CaMKII were significantly increased by approximately two-fold compared with the control group because of the administration of EEAK (100 or 200 mg/kg) (p

The Green–Ampt model (GAM) is a widely used water infiltration model. However, it lacks a reliable theoretical basis to independently and simultaneously determine the GAM parameters of effective hydraulic conductivity (Kₑ) and the average matric pressure head at the wetting front (Hf) from those commonly measured soil hydraulic properties. In this paper, we derived an approximate analytical solution similar to GAM for one-dimensional vertical infiltration into soils with initially uniform soil moisture distribution, with Kₑ and Hf being simultaneously related to the Brooks–Corey (BC) model parameters. The new relationships are not restricted to the piston-type moisture profile or delta-type water diffusivity like in the traditional GAM (TGAM). Infiltration experiments on three soils of various textures were conducted to validate the new approximate analytical solution and the corresponding GAM parameters. It was demonstrated that the predicted cumulative infiltrations and soil moisture profiles by the GAM with Kₑ and Hf calculated by the new expressions (new GAM, NGAM) generally agreed well with the numerical solutions, especially for initially dry soils. In contrast, cumulative infiltrations were considerably over-predicted by the TGAM using Kₑ = Kₛ and Hf calculated by Neuman’s equation. Our theoretical analysis further indicated that even without air entrapped during infiltration, the effective hydraulic conductivity can still be less than the saturated hydraulic conductivity Kₛ. The relative effective hydraulic conductivity ζ (Kₑ/Kₛ) and the relative average matric pressure head at the wetting front η (-Hf/hd where hd is absolute value of the air-entry suction) show a dependency only on soil pore structure index (n) and effective initial soil-water saturation (Sᵢ). The values of ζ increased but η decreased with Sᵢ and n. The theoretical ranges of ζ and η were from 0.5 and 2 for dry heavy-texture soils to 1 and 0 for saturated soils, respectively, which are consistent with the experimental values reported in literatures.

The impact of fertilization on maize (Zea mays L.) yield and soil properties was investigated in a long-term (> 18 y) experimental field in N China. A completely randomized block design with seven fertilizer treatments and four replications was used. The seven fertilizer treatments were (1) compost (COMP), (2) half compost plus half chemical fertilizer (COMP1/2), (3) balanced NPK fertilizer (NPK), (4–6) unbalanced chemical fertilizers without one of the major elements (NP, PK, and NK), and (7) an unamended control (CK). In addition to maize yield, soil chemical and biological properties were investigated. Compared to the balanced NPK treatment, maize yield from the COMP treatment was 7.9% higher, from the COMP1/2 was similar, but from the NP, PK, NK, and CK treatment were 12.4%, 59.9%, 78.6%, and 75.7% lower. Across the growing season, microbial biomass C and N contents, basal soil respiration, and fluorescein diacetate hydrolysis, dehydrogenase, urease, and invertase activities in the COMP and COMP1/2 treatments were 7%–203% higher than the NPK treatment. Values from all other treatments were up to 60% lower than the NPK treatment. Maize yield is closely related to the soil organic C (OC) and biological properties, and the OC is closely related to various biological properties, indicating that OC is a suitable indicator for soil quality. Our results suggest the most limiting nutrient for improving the yield or soil quality was P, followed by N and K, and balanced fertilization is important in maintaining high crop yield and soil quality. Additionally, increases in OC, N, and biological activities in COMP and COMP1/2 treatments imply that organic compost is superior to the chemical fertilizers tested.

The activities of carbon-cycle enzymes were measured in soil and aggregates to understand compost and inorganic fertilizer amendment effects on soil organic carbon accumulation in an intensively cultivated upland field. Soil samples were collected from a long-term field experiment with seven treatments: compost, half-compost N plus half-fertilizer N, fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK and no fertilizer control. The 18-yr continuous application of compost increased organic C content in soil and three aggregate sizes by 72–124 and 78–234%, respectively, compared with the control. Fertilization also significantly increased organic C contents in soil, macroaggregates and the silt + clay fraction, but not in microaggregates. Compost application significantly reduced the specific activities of polyphenol oxidase (activity per unit organic C) in soil and three aggregate sizes compared with control, whereas fertilization had a much weaker effect. Compost amendment also significantly lowered the specific activities of invertase in macroaggregates and the silt + clay fraction, and this effect was more pronounced than the addition of fertilizer NPK. In contrast, inorganic fertilizer and compost application significantly increased the specific activities of cellobiohydrolase in soil, macroaggregates and microaggregates (but not in the silt + clay fraction), and xylosidase in microaggregates. The application of fertilizer NPK had a more pronounced effect than compost. We considered that the increase in organic C in compost-amended soil was therefore probably associated with the accumulation of lignocellulose and sucrose in macroaggregates, lignocellulose and hemicellulose in microaggregates and lignin (its derivative) and nonstructural carbohydrates in the silt + clay fraction. However, the application of fertilizer NPK enhanced organic C probably due to an increase in the content of lignin (its derivative) and sucrose in macroaggregates and the silt + clay fraction. Therefore, the application of compost with high lignocellulose should be effective to increase soil organic C in the North China Plain.

The Green-Ampt equation is often used to estimate infiltration in hydrologic modeling. Only a few of the currently used simulation models, however, can simulate infiltration into a heterogeneous soil with nonuniform initial soil water content by the Green-Ampt equation during nonsteady rainfall. In this study, we derived an infiltration model for layered soils under nonsteady infiltration based on the Green-Ampt method (Green-Ampt for Layered Soils, or GALS). In the GALS model, a formula for estimating average suction (S) was derived to include initial soil water effect, and the soil profile was divided into several layers to consider both soil texture and initial soil moisture effects on infiltration. The new model can predict infiltration capacity, ponding time, and cumulative infiltration. Three infiltration experiments, steady-state infiltration into a layered soil with nonuniform initial soil water content, nonsteady infiltration into a layered soil with uniform soil water content; and nonsteady-state infiltration into a layered soil with nonuniform soil water content, were conducted for model testing. Comparison showed that the GALS model was in good agreement with another Green-Ampt-based model and the measured data.

Recently, a method based on the soil water flux ( F )–saturation (Θ) relationship, F (Θ), assumed to be independent of time and soil properties, has become an important technique to simplify solving Richards’ equation so as to develop a simple, rapid, and low-cost approach to estimate soil hydraulic properties. However, the actual F (Θ) is soil pore-structure dependent. So far, there exists no theory that can provide a specific functional form of soil pore-structure-dependent F (Θ). In this research, we derived a general soil moisture profile function and then a general expression of F (Θ): F = Θ[1 + a 2 (1 − )]. The only parameter in F (Θ), a 2 , is a function of the initial soil water saturation and the soil pore structure index that reflects the shape of the soil water retention curve. Infiltration experiments with three test soils and four actual soils were conducted to test the proposed relationships. The results verified the independence of F (Θ) on time at small time scales. The results also indicated that the derived formula predicted F (Θ) in good agreement with what was measured for all test soils under different initial soil moisture conditions. In addition, the upper and lower limit curves of F (Θ) calculated by the proposed formula were consistent with the theoretical curves. Compared with other empirical relationships, the new formula was the best for describing the theoretical upper limit curve of F (Θ). Furthermore, the new theoretical relationship was also found to be appropriate for horizontal absorption. Generally, the developed relationship is more accurate and helpful to solve Richards’ equation.