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Soil is inevitably affected by highway construction, resulting in a large volume of bare soil exposed to degradation. As an increasingly important and demanding area, identifying and assessing soil...

The construction of highways in the subalpine mountains generates many cut slopes. Currently, the restoration of cut slope mainly focuses on the aboveground landscapes and slope stability. Yet, it remains elusive about the belowground ecosystem functions at the early stage of restoration. In this study, we evaluated the belowground ecosystem functions of cut slopes that had been restored approximately 3 years using soil enzymatic activities, microbial biomass, and stoichiometry as the proxies. The results indicated that the phenol oxidase activity was higher in cut slopes, while the activities of β-1,4-glucosidase, β-1,4-N-acetylglucosaminidase, leucine aminopeptidase, and acid phosphatase were lower in cut slope soils compared with natural soils. Soil nitrogen availabilities (total and/or ammonium nitrogen) showed high negative correlations with the phenol oxidase activity and positive correlations with the activities of almost all other enzymes. These results suggested that soil nitrogen was the key factor in driving the shifts of enzymatic activities across two types of soils. Moreover, we found the imbalance of soil nutrients in cut slope soils, especially the carbon vs. nitrogen and the nitrogen vs. phosphorus. By applying the vector analysis, we found that the vector A values were more than 45° in all samples, suggesting that microbial phosphorus limitation occurred in both cut slope and natural soils. These findings suggested that maintaining the balance of soil nutrient supplies is important to the recovery of the below-ground ecosystem functions at the early restoration stage of cut slopes. This study provided new insights into designing the ecological restoration strategies for cut slopes by considering the belowground ecosystem functions.

Cement is a critical building material used in the restorations of bare cut slopes. Yet, how cement affects ecosystem's functions and their undertakers remains elusive. Here, we revealed the dosage and temporal effects of cement on plant and soil traits, extracellular enzymes, greenhouse gas fluxes and microbiome using simulation experiments. The results showed that soil pH increased with the cement content at 1st day but relatively constant values around 7 to 7.5 were detected in the flowing days. The β-1,4-glucosidase, phenol oxidase, leucine aminopeptidase and acid phosphatase showed high activities under high cement content, and they generally increased with the cultivations except for acid phosphatase. CH

Novel double perovskite Na1-xEu1+x/3MgWO6 phosphors are synthesized through sol-gel route, and the effects of x on the microstructures and luminescence properties of the obtained phosphors are systemically investigated. Under the determined sintering conditions, all of the Na1-xEu1+x/3MgWO6 (0 ≤ x ≤ 0.4) phosphors are pure monoclinic double perovskite structure, whereas there is an obvious impure phase in the sample Na1-xEu1+x/3MgWO6 with x = 0.5, suggesting that there is a phase transformation between x = 0.4 and x = 0.5. All of the as-synthesized Na1-xEu1+x/3MgWO6 phosphors exhibit a weak orange emission at 592 nm and a very strong red emission at 615 nm under the excitation of 395 nm near-ultraviolet and 464 nm blue light. Compared with NaEuMgWO6, all of the Na1-xEu1+x/3MgWO6 (0

The stability of soil aggregates is regarded as the key factor for soil erosion resistance on cut slopes of engineering works in serious debris flow disaster areas. Information on the stability of soil aggregates and related physicochemical properties on cut slopes is helpful to maintain the soil quality and slope stability. Therefore, in order to evaluate the stability of artificial soil aggregates for cut slope restoration, soil samples from three positions of a cut slope restored with artificial soil (upper slope, URS; middle slope, MRS; lower slope, LRS) and a nearby natural slope (NS) were analyzed. The results showed that the stability of soil aggregates (MWD, mean weight diameter; GMD, geometric mean diameter) of artificial soil on the cut slope (URS, MRS, LRS) was significantly lower than that of NS based upon fast wetting (FW) test and wet sieving. The values of MWD and GMD for slow wetting (SW) and mechanical breakdown (WS) tests in the four slopes had no significant difference. Among the three positions of cut slope, URS had the highest MWD and GMD, whereas MRS had the lowest corresponding value. Furthermore, >2 mm soil aggregates accounted for a major percentage of the total weight determined in all the tests for each slope. MWD for fast wetting increased with the increase in content of soil organic matter (SOM). Slaking was the main disruptive force leading to the breakdown of artificial soil aggregates, and FW was the best method to measure the stability of soil aggregates in these conditions. These results demonstrate that the SOM and the stability of soil aggregates on cut slope should be given more attention while conducting engineering works in serious debris flow disaster areas.

Roadway rock-cut slopes have a strong effect on soil organic carbon (SOC), its fractions and overall soil health. However, it is still unknown how SOC fraction properties are influenced under different aspect conditions. We quantified differences in artificial SOC fractions, soil nutrients, and enzyme activities across eight types of roadway rock-cut slopes in Songpan, China. On slopes in landslide areas, four aspects (S, W, N, E) were selected for study, and four equivalent aspects on slopes not affected by a landslide were selected as a reference. SOC, easily oxidizable organic carbon (EOC), particulate organic carbon (POC), urease, sucrase, total nitrogen (TN), and carbon pool management index (CPMI) significantly differed among non-landslide aspects, however, except for POC and urease, did not differ with aspect on landslide-affected slopes. In contrast, dissolved organic carbon (DOC), nitrate nitrogen (NO3–-N), and ammonia nitrogen (NH4+-N) significantly differed among aspects on landslide-affected slopes, while they did not significantly differ on aspects of non-landslide slopes. However, higher SOC, EOC, POC, TN, urease, sucrase, and CPMI occurred on non-landslide slopes than landslide-affected slopes of the same aspect, suggesting that landslide slopes may face serious degradation. Our findings indicate that slope aspect and the occurrence of landslides have an influence on SOC pools, and consequently on CPMI.

The research of soil bacterial community biodiversity in special habitats is important for ecological restoration. In this paper, distribution patterns and drivers of artificial soil bacterial community on cut-slopes at different altitudes (2950 m, 3300 m, 3650 m and 4000 m) in alpine region were studied. The results demonstrated that the artificial soil bacteria genera on cut-slopes showed single-peak patterns along with altitude. Soil bacteria communities conformed to abundance distributions for a large number of rare species and a small number of common species, and there was a long tail for very rare species. The distribution patterns of plant communities along with altitude was basically the same as that of bacteria, and plant communities were mainly influenced by soil types and light-temperature conditions. The distribution pattern of bacterial communities was influenced by individual number of plants, the contents of available potassium (AK), organic matter (OM), total nitrogen (TN), alkali-hydrolyzed nitrogen (AN), moisture content (MC) and available phosphorus (AP). Complicated relationships of soil bacteria community, plant communities and soil nutrients in alpine regions are conducive to the stability of the community structure, which is beneficial to ecological restoration of cut-slopes.

A series of Li0.1Na0.9Gd0.5Tb0.5-xEux(MoO4)2 phosphors were successfully prepared via a conventional solid-state reaction method. The influences of the doping concentration of Eu3+ on the microstructures and luminescence properties for the as-prepared Li0.1Na0.9Gd0.5Tb0.5-xEux(MoO4)2 phosphors were investigated systematically. Our results indicate that the doping of Eu3+ hardly affect the microstructures while markedly impact luminescence properties for the Li0.1Na0.9Gd0.5Tb0.5-xEux(MoO4)2 phosphors. Due to an effective energy transfer from Tb3+ to Eu3+ in the Li0.1Na0.9Gd0.5Tb0.5-xEux(MoO4)2 phosphors, the multicolor emissions have been realized via varying the doping concentration of Eu3+ from 0 to 0.5, which can be adjusted from green→yellow-green→yellow→orange→red and yellow-green→ yellow→orange→red upon excitation of two visible light wavelengths (486 and 464 nm), respectively. Moreover, the doping of Eu3+ also can significantly boost the thermal stability of Li0.1Na0.9Gd0.5Tb0.5(MoO4)2 phosphor, and the obtained Li0.1Na0.9Gd0.5Tb0.42Eu0.08(MoO4)2 phosphor possesses superior thermal stability, can be expected as a candidate phosphor for white light diodes.

In the subalpine mountainous region of southwest China, the artificial soil properties of restored cut slopes along the altitude gradient were studied, including available nitrogen (AN), available phosphorus (AP), available potassium (AK), urease (UR), sucrase (SC), protease (PR), catalase (CAT), texture, and aggregate stability of soil. Soil aggregatet stability by mean weight diameter (MWD), geometric mean diameter (GMD), structure failure rate (P), index of unstable aggregates (IUA) and area difference of dry and wet sieve cumulative distribution curve (ΔS) were measured and analyzed. It was found that available soil nutrients, UR, and CAT activities increased initially and then decreased, but the texture of soil was finer, and aggregate structure tended to be more stable along with an increase in the altitude gradient. The soil aggregate stability index that MWD, GMD, P, IUA, and ΔS indicated that the higher the altitude, the stability of soil aggregates was better. Principal component analysis (PCA) was used to determine the soil quality index (SQI). The obtained results from this study showed that the artificial soil quality of the cut slopes was better at a higher altitude compared to a lower altitude. These results provide a reference for the improvement of artificial soil properties of cut slopes and their quality in the future. It is necessary to pay attention to the soil quality management at a low-altitude area and reform the soil nutrients, enzyme activities, and soil structure for the restored cut slopes in the mountainous subalpine highway of southwest China.