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Drunken horse grass [Achnatherum inebrians (Hance) Keng] is a perennial poisonous weed in western China. A comprehensive understanding of the ecological response of A. inebrians germination to environmental factors would facilitate the formulation of better management strategies for this weed. Experiments were conducted under laboratory conditions to assess the effects of various abiotic factors, including temperature, light, water, pH, and burial depth, on the germination and seedling emergence of A. inebrians. The seeds germinated at constant temperatures of 15, 20, 25, 30, and 35 C and in alternating-temperature regimes of 15/5, 20/10, 25/15, 30/20, 35/25, and 40/30 C, and the germination percentages under constant and alternating temperatures ranged from 51% to 94% and 15% to 93%, respectively. Maximum germination occurred at a constant temperature of 25 C, and germination was prevented at 45/35 C. Light did not appear to affect germination. The germination percentage of seeds was more than 75% in the pH range of 5 to 10, with the highest germination percentage at pH 6. The seeds germinated at osmotic potentials of 0 MPa to −1.0 MPa, but decreasing osmotic potential inhibited germination, with no germination at −1.2MPa. After 21 d of low osmotic stress, the seeds that did not germinate after rehydration had not lost their vitality. The seedling emergence percentage was highest (90%) when seeds were buried at 1 cm, but declined with increasing burial depth, with no emergence at 9 cm. Deep tillage may be effective in limiting the germination and emergence of this species. The results of this study provide useful information on the conditions necessary for A. inebrians germination and provide a theoretical basis for science-based prediction, prevention, and control of this species.

Navua sedge [Cyperus aromaticus (Ridley) Mattf. & Kük.] is an aggressive perennial sedge native to equatorial Africa that has become problematic in many Pacific islands and wet, tropical Queensland, Australia. It has had a significant impact on the livestock-grazing industry, sugarcane (Saccharum officinarum L.) and banana (Musa acuminata Colla) plantations, and various other ecosystems. A laboratory-based research investigation was conducted to understand germination and emergence requirements under various environmental conditions of three geographically varied populations sourced from South Johnstone (SJ), Mackay (M) and Nyleta Creek (NC) in Queensland. Germination was identified to be stimulated by light, with no germination recorded under darkness. Populations SJ and NC had optimal germination at alternating temperatures of 25/15, 30/20, and 35/25 C, whereas population M had optimal germination at 25/15 and 30/20 C. All populations recorded greater than 85% germination at all pH levels tested. Seeds of population SJ were more sensitive to salinity compared with populations M and NC, with SJ showing no germination at 100 mM, whereas populations M and NC had 23% and 9% germination, respectively. An inverse relationship was observed between osmotic potential and germination, with no germination recorded at osmotic potentials below –0.8 MPa in any population, indicating moisture availability is a critical requirement for germination. Exposing seeds to 120 C radiant heat completely inhibited germination in populations M and NC, whereas 3% of population SJ germinated following a 180-s exposure at 120 C. Seedling emergence decreased as planting depth increased. Emergence was greatest for seeds on the soil surface or at 0.5-cm burial depth, consistent with germination being stimulated by light. Knowledge of these biological characteristics of C. aromaticus seed germination will assist in investigation of suitable control actions for this species, particularly in the early stage of its invasion into new areas, and will contribute to significant reduction in the soil seedbank.

Spiny and slender amaranth are troublesome Amaranthaceae species of direct-seeded rice and other upland crops in many Asian countries. Seed germination and seedling emergence response of these species to various environmental factors was determined in laboratory and screenhouse experiments. Germination in both species was stimulated by 35/25 and 30/20 C fluctuating temperatures and light. Germination of slender amaranth was more sensitive to increasing salt and water stress than spiny amaranth. Spiny amaranth germinated at a NaCl concentration of 100 mM (19%), whereas slender amaranth seeds did not germinate at this concentration. In seed burial trials where the seeds were on the soil surface, emergence was 56 and 68% for spiny amaranth and slender amaranth, respectively. Only 7% of spiny amaranth seedling emerged from a soil depth of 0.5 cm, whereas no emergence was observed for 4 cm or deeper. For slender amaranth, 6 and 0% emergence was observed at 4 and 6 cm, respectively. Seedling emergence of spiny amaranth was affected more by high rates of rice residue than slender amaranth. Greater quantities of residue than those normally found in rice fields were required to significantly reduce weed densities.

Forensic entomology is a branch of science that uses insects as evidence in medicolegal investigations as they could provide valuable information regarding the cause and time since death specially in the case of buried bodies. The present study was the first attempt in India to compare the decomposition and associated insects on pig carcasses above the ground and those buried at two different depths (40 and 80 cm) during spring season over two consecutive years. Two pigs were buried at each depth and one pig carcass was placed above the ground. One of the buried carcasses was exhumed frequently and other one was kept undisturbed to investigate the decomposition rate and insect access to the carcass. The rate of decomposition was found to be faster above the ground as compared to the buried environment. Also, the carcass buried at 80 cm depth exhibited slower decomposition rates and had limited insect activity as compared to the one buried at 40 cm. Species within the Calliphoridae and Sarcophagidae families were dominant on the surface-exposed carcass, whereas Phoridae were more prevalent on the buried carcasses even at a depth of 80 cm. The findings of the study highlights the significant influence of burial depth and exhumation on decomposition rate and insect arrival and colonization.

【Objective】 The ascent of groundwater into the vadose zone and its ultimate evaporation into atmosphere is an important hydrological process. This paper investigates the impact of meteorological factors and soil texture on evaporation of shallow groundwater under different depths from winter wheat in a sandy ginger black soil and a yellow tide soil. 【Method】 The study was based on data measured from 2010 to 2022 from the Wudaogou experimental station. The relationship between groundwater evaporation and seven meteorological factors was analyzed using correlation analysis and function fitting technique. A multiple regression model, along with a nonlinear fitting function, was developed to calculate the change in evaporation of shallow groundwater with its depth ranging from 0.2 to 5.0 m. 【Result】 ① In the sandy ginger black soil, the significance of the impact of meteorological factors on groundwater evaporation was ranked in the order of surface temperature > average air temperature > surface evaporation > duration of sunshine > precipitation > wind speed; in the yellow tide soil, the ranking order was surface temperature > duration of sunshine > average air temperature > surface water evaporation > precipitation > wind speed. ② The multiple regression model is accurate for estimating evaporation of shallow groundwater at different depths, with R2>0.75 for the sandy ginger black soil and R2>0.70 for the yellow tide soil. ③ The relationship between groundwater evaporation and groundwater depth for the sandy ginger black soil followed an inverse function with R2>0.95 before the greening stage and a logarithmic function after the greening stage with R2>0.85. In contrast, in the yellow tide soil, it followed a logarithmic function with R2>0.75. ④ Depending on the growing season, the critical groundwater depth for evaporation ranged from 2.0 to 3.5 m for the sandy ginger black soil, and from 4.0 to 5.1 m for the yellow tide soil. 【Conclusion】 Groundwater evaporation depends not only on meteorological factors but also on soil texture and growing season of the winter wheat. The proposed models are accurate for estimating their relationships.

This study investigated the development and formation of ground fissures at panel 12,401 of the Shangwan Colliery in the Shendong mining area, characterized by the current largest mining height and an aeolian sand surface in China. An integrated monitoring method was employed to examine the ground subsidence, distribution and development pattern of ground fissures, and the relationship between fissure width and depth, including an unmanned aerial vehicle, ground penetrating radar, and real-time kinematic and manual measurements. Then, the development and formation mechanisms of ground fissures were elucidated through theoretical analysis and physical simulation. The results indicate that ultra large mining height longwall panel extraction causes a greater ground subsidence and horizontal deformation than those of the conventions, resulting in more severe damage in the permanent margin area. The ratio of burial depth to mining height ( H/M ) decreases to less than 30 due to the ultra large mining height, and deep-burial panel displays the characteristics of shallow coal seam mining, such as “step subsidence”. The sliding instability of the primary key stratum causes the simultaneous cutting-off of the aeolian sand layer to form step-like ground fissures. The cause of the tensile fissures is the horizontal surface deformation exceeding the deformation threshold of the aeolian sand layer, and the dynamic tensile fissures were self-restored in 2 weeks as the panel advanced. Step-like fissures connected the working face with the ground, but the depth of the tensile fissures was less than 5.0 m and increased linearly with the fissure width.

This paper uses shake table tests to study tunnel landslide failures in earthquake zones under four conditions: (GK1) the tunnel intersects the sliding mass, (GK2) the tunnel is perpendicular to the sliding surface, (GK3) the tunnel is positioned below the sliding surface, and (GK4) the tunnel is situated above the bedrock. The dynamic responses under the four conditions are analyzed using time-domain strain analysis methods. Additionally, from an energy perspective, the amplified Arias intensity (MIa) is employed to characterize the cumulative deformation damage of the tunnel lining. The results indicate that under four working conditions, the upper landslide region of the tunnel landslide system exhibits a “settlement-compression-shear” type of sliding failure. However, in conditions GK1 and GK2, where the lining structure is present, the tunnel lining provides additional support to the landslide, resulting in less severe damage to the slope compared to conditions GK3 and GK4. However, under conditions GK1 and GK2, the left sidewall of the tunnel lining experiences more severe damage due to landslide pressure. The maximum soil pressure and bending moment on the left sidewalls in GK3 and GK4 are only 40–60% of those observed in GK1 and GK2. In addition, based on the trend of MIa, the cumulative deformation evolution of the tunnel lining can be categorized into three stages: the initial stage (0.1–0.2 g), the progressive deformation stage (0.2–0.4 g), and the failure deformation stage (0.4–0.6 g). Further research confirms that under seismic action, the slope experiences a significant progressive catastrophic evolution. This process is characterized by typical seismic cumulative damage effects, with sustained seismic loading causing deformation and damage to gradually expand from localized areas to the entire slope. This continuous fatigue effect progressively weakens the stability of the lining structure, ultimately leading to its failure. Therefore, the deformation and damage of the slope under seismic loading pose a serious threat to the safety of tunnel linings, highlighting the need for close attention to their long-term stability. The research results provide a scientific basis for reinforcing tunnel linings in earthquake-prone mountainous areas.

The mechanical behavior of sandstones within coal-bearing strata exerts a critical influence on roof stability during coal mining, while their microstructure and porosity fundamentally determine the physical and mechanical properties. This study investigates the diagenetic and mechanical evolution of six medium-grained sandstones from the Bultai Coal Mine, Shendong Mining Area, spanning the Cretaceous (A) to Jurassic (B–F) periods with varying burial depths. Microstructural analysis reveals that the pore system, comprising intergranular and intragranular pores, cement-internal pores, and microfractures, becomes increasingly cemented with depth. The deeply buried Yan’an Formation (D–F) exhibits markedly superior mechanical properties compared to shallower units: porosity is reduced by 45.9–52.1%, while tensile strength, compressive strength, and elastic modulus are enhanced by 582–1134%, 552–656%, and 13.3–19.7 times, respectively, accompanied by a 60.6–69.2% lower peak strain. These results demonstrate that depositional period and burial depth jointly control microstructural and mechanical evolution. This study establishes a quantitative correlation between porosity, strength, and modulus. The results elucidate the coupled influence of diagenesis and burial depth on sandstone mechanics, thereby providing a more reliable framework for assessing geomechanical risks in the Shendong mining area.