Effects of vegetation restoration on the concentrations of multiple metal elements in post-mining soils.

Vegetation restoration is vital for soil ecological restoration in post-mining areas, but a global-scale quantitative assessment of its effects on soil metal elements is lacking. Here, we conducted a meta-analysis with 2308 paired observations collected from 137 publications to evaluate vegetation restoration effects on the concentrations of 17 metal elements, namely K, AK (available K), Ca, Na, Mg, Fe, Mn, Zn, Cu, Al, Cr, Co, Ni, Cd, Sb, Hg, and Pb in post-mining soils. We found that (1) vegetation restoration significantly increased the concentrations of K, AK, Ca, Mg and Co by 43.2, 42.5, 53.4, 53.7, and 137.2%, respectively, but did not affect the concentrations of Na, Fe, Mn, Zn, Cu, Al, Cr, Ni, Cd, Sb, Hg, and Pb; (2) the effects of vegetation restoration on soil metal concentration were seldom impacted by vegetation type, while soil depth only affected the responses of AK, Cd, and Pb concentrations to vegetation restoration, and leaf type only impacted the responses of Ca and Ni concentrations to vegetation restoration; (3) latitude, elevation, restoration year, climate, and initial soil properties were also important moderator variables of vegetation restoration effects, but their impacts varied among different metals. Overall, our results clearly showed that vegetation restoration in posting-mining areas generally have a positive effect on the concentrations of nutrient elements but did not influence that of toxic elements, which provides useful information for the restoration and reconstruction of soil ecosystem in post-mining areas.

Melatonin or vitamin C attenuates lead acetate-induced testicular oxidative and inflammatory damage in mice by inhibiting oxidative stress mediated NF-κB signaling.

Lead (Pb) acts as an environmental endocrine disruptor and has negative effects in animals; excessive accumulation of lead causes reproductive dysfunction in male animals. Oxidative stress plays a vital role in Pb-induced injury. However, the mechanisms underlying chronic testicular toxicity of Pb remain unclear. In this study, we aimed to determine the effects of lead acetate on reproductive function in male mice, identify the underlying mechanisms, and test counter measures to alleviate the toxic effects. Male mice were dosed with lead acetate (500 mg/L) in free drinking water for 12 weeks, and administered melatonin (5 mg/kg) or vitamin C (500 mg/kg) by intraperitoneal injection. Blood from the eyeball, testicles, and sperm from the caudal epididymis were collected after 12 weeks and analyzed. Pb exposure reduced sperm count and motility, increased sperm malformation (P < 0.01), disrupted testicular morphology and structure, and decreased the expression of steroid hormone synthesis-related enzymes and serum testosterone concentration (P < 0.01). Pb also increased the number of inflammatory cells and the levels of the pro-inflammatory cytokines TNF-α and IL-6 (P < 0.01), and activated NF-κB signaling. Furthermore, the ROS yield and oxidation indicators LPO and MDA were significantly increased (P < 0.01), and the antioxidant indicators T-AOC, SOD, and GSH were significantly reduced (P < 0.01). Treatment with melatonin or vitamin C reversed the effects of lead acetate; vitamin C was more effective in restoring SOD activity (P < 0.01) and enhancing ZO-1 protein levels (P < 0.01). Thus, long-term exposure to lead acetate at low concentrations could adversely affect sperm quality and induce inflammatory damage by oxidative stress mediated NF-κB signaling. Vitamin C could act as a protective agent and improve reproductive dysfunction in male animals after lead accumulation.

Global patterns and drivers of lead concentration in inland waters.

Water bodies are important carriers for lead (Pb) biogeochemical cycling, which is a key pathway of Pb transport. Although existing studies on Pb loading in inland waters have developed rapidly, a quantitative assessment of the distribution patterns and drivers of Pb concentration in inland waters at the global scale remains unclear. Here, by analyzing 1790 observations collected from 386 independent publications, we assessed the spatial distribution and drivers of Pb concentration in inland waters worldwide. We found that (1) globally, the median of Pb concentration in inland waters was 5.81 µg L-1; (2) among different inland water types, Pb concentration was higher in rivers, and the highest Pb concentration was in industrial land in terms of land use type; (3) Pb concentration in inland waters were positively driven by potential evapotranspiration, elevation and road density; and (4) Pb concentration showed a negative relationship with absolute latitude, decreasing from tropic to boreal regions. Overall, our global assessment of the patterns and drivers of Pb concentration in inland waters contributed to a better understanding of the natural and anthropogenic attributions of Pb in the inland hydrological cycling.

Vegetation restoration effects on soil carbon and nutrient concentrations and enzymatic activities in post-mining lands are mediated by mine type, climate, and former soil properties.

Vegetation restoration is a widely used, effective, and sustainable method to improve soil quality in post-mining lands. Here we aimed to assess global patterns and driving factors of potential vegetation restoration effects on soil carbon, nutrients, and enzymatic activities. We synthesized 4838 paired observations extracted from 175 publications to evaluate the effects that vegetation restoration might have on the concentrations of soil carbon, nitrogen, and phosphorus, as well as enzymatic activities. We found that (1) vegetation restoration had consistent positive effects on the concentrations of soil organic carbon, total nitrogen, available nitrogen, ammonia, nitrate, total phosphorus, and available phosphorus on average by 85.4, 70.3, 75.7, 54.6, 58.6, 34.7, and 60.4 %, respectively. Restoration also increased the activities of catalase, alkaline phosphatase, sucrase, and urease by 63.3, 104.8, 125.5, and 124.6 %, respectively; (2) restoration effects did not vary among different vegetation types (i.e., grass, tree, shrub and their combinations) or leaf type (broadleaved, coniferous, and mixed), but were affected by mine type; and (3) latitude, climate, vegetation species richness, restoration year, and initial soil properties are important moderator variables, but their effects varied among different soil variables. Our global scale study shows how vegetation restoration can improve soil quality in post-mining lands by increasing soil carbon, nutrients, and enzymatic activities. This information is crucial to better understand the role of vegetation cover in promoting the ecological restoration of degraded mining lands.

[Dynamics of Ca and Mg storage of non-woody debris in a subtropical forest headwater stream during the rainy season.] / 亚热带森林降雨季节源头溪流非木质残体钙和镁储量动态特征.

Forest headwater streams are the monumental cement for relating habitats of the terrene and water. Nutri-ent dynamics of non-woody debris in stream can directly and indirectly regulate the cycle and transport of forest nutrients, for example, Ca and Mg. In the rainy season (from March to August) of 2021, we monitored the dyna-mics of Ca and Mg storage of non-woody debris in a typical headwater stream in a subtropical forest. The results showed that total Ca and Mg storage of non-woody debris per unit area of stream ranged from 178.1 to 890.5 mg·m-2 and 13.8 to 61.6 mg·m-2 during the rainy season, respectively. The Ca and Mg storages of non-woody debris per unit area of stream during the rainy season displayed a pattern of first increase and then decrease, and overall a decrease pattern. The storage varied significantly among different sites, with higher values in stream source than others. The total Ca and Mg storage of non-woody debris positively correlated with precipitation, but negatively with stream water alkalinity, temperature, and dissolved oxygen. The variation of riparian forest type (e.g., Castano-psis carlesii forests or mixed coniferous forests) and with or without tributaries did not affect the storage of Ca and Mg in stream non-woody debris. During the rainy season, total Ca and Mg storage of non-woody debris in the headwater stream from forest generally decreased over time, which was mainly controlled by the characteristics of rainfall and stream.

Sarcoptic mange is an emerging threat to biodiversity in the Qinling Mountains in China.

Sarcoptic mange, a disease caused by the burrowing mite Sarcoptes scabiei, is globally endemic and an emerging threat to wildlife. Although many studies have shown that wildlife diseases play key roles in biodiversity conservation, knowledge about sarcoptic mange is still insufficient. In this study, we aim to improve the understanding of the impacts of sarcoptic mange on wildlife populations, the mechanisms involved in its eco-epidemiology and the associated risks to public and ecosystem health by investigating mass death events in gorals and serows in the Qinling Mountains. We conducted interviews with practitioners and local people in the central Qinling Mountains. From the same locations, we collected 24 cutaneous samples from various animals and surveillance data from infrared cameras. Pathological, parasitological and microbiological examinations of the samples were performed. Mite-induced cutaneous lesions, mites and eggs were observed in samples from dead gorals and one dead serow but not in other species. Molecular analysis confirmed the mites to be S. scabiei and shared the same cox 1 genotype. The data obtained from the interviews and infrared cameras indicated that the death of wildlife was related to sarcoptic mange infection and that there had been a decrease in the goral population since the outbreak of the disease. We confirmed that sarcoptic mange was the major cause of the mass death events and may have spread from the western to eastern Qinling Mountains. Based on our findings, we propose several protection strategies to help preserve biodiversity in the Qinling Mountains.

Base-Promoted Stereoselective Hydrogenation of Ynamides with Sulfonyl Hydrazide to Give Z-Enamides.

A base-mediated semihydrogenation of ynamides using p-toluenesulfonyl hydrazide as an inexpensive and easy-to-handle hydrogen donor is reported. This transition-metal-free protocol avoids overhydrogenation and reduction of other functional groups, generating the thermodynamically unfavorable Z-enamides exclusively.

Ruthenium(II)-Catalyzed Construction of Isocoumarins via Dual C-H/C-C Activation of Sulfoxonium Ylides.

A ruthenium(II)-catalyzed annulation between two molecules of sulfoxonium ylides is achieved, generating a variety of substituted isocoumarins in reasonable yields. This strategy features dual C-H/C-C activation in one pot and has a wide substrate scope and good functional group tolerance.

Palladium-Catalyzed Regioselective Heck Coupling of Alkynes with Aryl Iodides for the Synthesis of Trisubstituted Allenes.

A utility approach toward trisubstituted allenes through Pd-catalyzed alkynyl Heck coupling reaction of alkynes and aryl iodides is reported. This process proceeded via regioselective carbopalladation of 1-aryl-1-alkynes to give alkenyl palladium species, which undergo ß-hydride elimination to provide 1,1-diarylallenes in 25-71% yields. This method features unique regioselectivity and high functional group compatibility.