On the nature of fresh volcanic ashes as parent material ejected from the Sakurajima and Aso volcanoes

There are few pedological studies in Japan of fresh volcanic ash. Fundamental information of the material from which Japanese volcanic-ash soils have developed, is of importance to obtain a better understanding of pedogenesis of such soils. The present paper deals with the mechanical. mmeralogical, and chemical characteristics of fresh ash ejected from the Sakurajima and Aso volcanoes which are among the most active in Japan.     

Bacterial 16S rDNA sequences in immature volcanic ash soil on volcanoes Mt. Sakurajima and Mt. Fugen in Japan determined by PCR amplification

Volcanogenous soils are widely distributed in Japan. Andosols, a group of volcanogenous soil, are known to show several physicochemical characteristics such as high porosity, presence of allophane, and high content of organic carbon (FitzPatrick 1980). The formation of Andosols is a very rapid process resulting from the large surface area of the volcanic ash-derived parent materials.     

Nitrous and Nitric Acid Measurements Inside and Outside of Clouds at Mt. Brocken

A measurement method for the continuous and in situ analysis of atmospheric concentration of HNO₂ and HNO₃ inside and outside of clouds has successfully been established. The approach for a wet effluent diffusion denuder (parallel plate design) was adopted and performed quasi on-line with an ion chromatography unit. The air flow through the denuder was 10 1/min and at 15 minutes of preconcentration we are able to record atmospheric concentrations of 15 ng/m³ of HNO₂ and HNO₃, respectively. Field measurements using the denuder system were done at the Mt. Brocken summit (1142 m a.s.l., Harz Mountains, Germany) in 1998 and 1999. During day-time and under clear conditions maximum values of HNO₃ up to 7000 ng/m³ were observed. Measurements performed during cloud events assess first time our expectation that the comparatively very great specific droplet surface in clouds is a place for a heterogeneous HNO₂ formation, after nocturnal accumulation up to 320 ng/m³ were found. Strong positive correlation between HNO₂ concentrations and those of NO₂ were obtained during and after cloud events to assess the origin of the observed nitrous acid. The HNO₂/NO₂ ratio reached 10% under humid conditions. The observed surface to volume ratios in investigated clouds were between 0.4 and 0.7. In dependence on the cloud water pH nitrite concentrations between 5–300 µg/l (1–30 ng/m³ air) were observed.     

Acidic Precipitation and Large-Scale Transport of Air Pollutants Observed in Korea

Acid rain at a rural site in Chongwon (KHN), central Korea has been under observation since 1990. To substantiate the 10-year observations, rain samples from six other sites were also collected and analyzed. Results show that acid rain occurred frequently at all sites. At KHN, seasonal and annual variability of pH values had a 10-year VWM value of 4.67 and an arithmetic mean value of 5.09. In general, a high value of pH occurred during springtime when the occurrence of yellow sand (dust) was prevalent in East Asia; during summer, heavy rain usually contained neutral pH values. During other seasons, the degree of acidic precipitation usually coincided with certain air flows. Most frequently, air flows and cyclones coming from south and central China often resulted in precipitation with low pH values observed in Korea. Using daily satellite observations from 1996, we have also been monitoring the long-range and large-scale transport of air pollutants (LSTAP) over East Asia. Many samples of LSTAP were obtained when they were crossing the Yellow Sea and moving over the Korean Peninsula and to SW Japan. The width of the Yellow Sea is ca. 350～700 km and air pollutants take 1～2 days to cross it. Cases of acid rain in Korea clearly correlate wth the LSTAP from source regions in China.     

Changes in the Chemical and Mineralogical Properties of Mt. Talang Volcanic Ash in West Sumatra during the Initial Weathering Phase

Eruptions from Talang volcano on 12 April 2005 distributed volcanic ash over portions of the Solok District of West Sumatra, Indonesia. Unleached and leached pristine volcanic ash were collected immediately after the eruption, and the third sample was collected after 2 years. The mineralogy and chemical properties of pristine volcanic ash and volcanic ash deposits that were weathered for 2 years from the 2005 eruption of Mt. Talang, Sumatra, were studied to characterize the volcanic ash, identify the primary minerals present, and determine its chemical properties. Results showed that the volcanic ash contained 30% noncrystalline minerals (or volcanic glass); the remaining ash is composed of crystalline minerals such as labradorite, hypersthene, augite, hornblende, olivine, opaque ferromagnetic minerals, and rock fragments. Notable differences in pH values were observed as the pH tended to become more acidic from the unleached, leached, and weathered volcanic ash, but the ash did not give much response to the sodium fluoride (NaF) test. Total sulfur gradually decreased from 3.28% in unleached ash to 1.93% after 2 years. Available phosphorus (P) in the unleached volcanic ash was 68 mg kg^?1, and this value was decreased by 15 % after 2 years of being exposed to the atmosphere, while phosphate retention ranged between 52.8% and 66.8%. Cation exchange capacity (CEC) was low with the value of 10 cmol_c kg^?1 although base saturation was high, exceeding 75%. The low acid oxalate–extractable silicon (Si), aluminum (Al), and iron (Fe) values of 0.07%, 0.25% and 1.17%, respectively, show the scarcity of secondary amorphous compounds in the ash. Total elemental analysis indicated that no differences were found in total silica oxide (SiO₂) content of all samples, with a value about 56%, and this volcanic ash can be classified as basaltic andesite. We observed that removal of chemical elements by leaching was large for calcium oxide (CaO), magnesium oxide (MgO), and sodium oxide (Na₂O) as the values decreased in time. Solid-state ²⁹Si and ²⁷Al magic angle spinning (MAS) nuclear magnetic resonance (NMR) studies indicated that Al occurred in both tetrahedral and octahedral forms. Silicon was not present in the tetrahedral layer. An intense peak at ?92 ppm was indicative of the presence of aluminosilicates.     

Soil formation of new lahar materials derived from Mt. Pinatubo

The early stage of weathering / soil formation processes from new volcanic mudflow (new lahar materials) brought from Mt. Pinatubo was examined. For this purpose, comparative studies on the physical / chemical characteristics of the new lahar materials and soils formed by the deposition of old lahar materials were conducted. Original soils contained less coarse sand, more silt, and clay than the new lahar materials. Increase in the clay content of the original soils reflected the progression of weathering. The occurrence of a higher leaching process of Fe, Ca, and Mg and of a moderate accumulation of organic matter in the original soils was suggested, based on the differences in the soil elemental composition and chemical properties. Values of base saturation and phosphate absorption coefficient (PAC) of the new lahar materials were 388% and 44, while those of all the original soils ranged 15–160% and 55–894, respectively. With the progression of weathering, the PAC value tended to increase gradually while the base saturation value decreased abruptly under the environmental conditions prevailing in the Philippines.     

超声波技术在火山碎屑物发育土壤粒度分析中的应用

利用40kHz超声波清洗机,设计不同的超声功率和超声时间,对火山碎屑物发育土壤进行分散处理;再用湿筛-吸管法测定土壤颗粒含量,对测定结果进行分析。研究表明:增大超声功率能促进土壤颗粒的分散,但80w和140w超声功率引起的土壤各粒级含量变化不大,均小于3.00%;延长超声时间对火山碎屑物土壤分散效果影响显著,对于粗颗粒为主的样品各粒级含量变化均很小,对于细颗粒为主的火山碎屑物土壤样品,以粉粒和黏粒含量变化更大;建议火山碎屑物发育土壤的颗粒分散采用(NaPO_3)_6-超声波联合分散法,超声条件设定为:频率40kHz,功率140w,震荡时间25min。     

The contribution of mercury from thermal springs to the environmental contamination of Mt. Amiata

Historically Mt. Amiata has served as an important source of Hg in the Mediterranean basin. In spite of more than a decade without mining or smelting operations, the area remains heavily contaminated. Many old mine sites as well as geothermal plumes still exist. A common belief is, however, that the many thermal springs which carry their contents over the mountainous area, constitute a significant source of Hg. A 1987–88 study of the Hg distribution in air, soil and vegetation at the Bagno Vignoni and Bagni S. Filippo thermal springs, and at the mining town of Abbadia S. Salvatore has demonstrated that Hg content around the springs was comparable to reported values in areas of little or no contamination, whereas those values found at Abbadia S. Salvatore compare well with high levels reported in the mining community of Fort St. James, British Columbia.     

Study on Water-Soluble Organic Reducing Substances: II. Organic Reducing Substances Produced from Anaerobic Decomposition of Milk Vetch (Astragalus sinicus L.)

The characteristics of electric charge and molecular weight distribution,oxidation-reduction regimes,e.g.Eh and amounts of organic reducing substances produced by milk vetch during anaerobic decomposition process,were studied by using electrochemical methods.Interaction between soils and organic reducing substances was also observed.The results indicate that the organic reducing substances were mainly the organic compounds with negative and amphoteric charges,which were distributed in two groups at anodic peak potentials of 0.25 and 0.69 volt in differential pulse voltammograms,respectively.Their apparent molecular weights are all less than 700 daltons,in which those active in oxidation-reducion reaction were distributed in the fraction with apparent molecular weight less than 200 daltons.The organic reduction substances can be oxidized by manganese oxides in their interaction with soils.     

Solubility and Leaching of Boron from Borax and Colemanite in Flooded Acidic Soils

Boron (B) is a micronutrient essential for adequate plant growth. Borax (Na₂B₄O₇·10H₂O) and colemanite (Ca₂B₆O₁₁·5H₂O) are common B fertilizer materials, the former being widely used worldwide. Boron is completely water soluble and subjected to leaching. In this study, the dissolution kinetics of both borax and colemanite in deionized water and at pH 3.8, 5.2, 6.5, and 8.2 were determined. Soils incubated with minerals for 40 days and 80 pore volumes of leachates from repacked soil column treated with either surface-applied borax or colemanite (powdered and granular) were collected and analyzed for B contents. Two different soils, Chempaka (Typic paleudult) and Tepus (Typic Kandiaquult) series, taken from paddy-growing areas were used in leaching and incubation studies. Dissolution rate of borax was greater than that of colemanite, and complete dissolution was observed after 100 min, whereas complete dissolution of colemanite was not reached even after 300 min. There was no effect of pH on dissolution rate of borax and colemanite. Boron released from borax was hasty, and after 5 weeks no more B was released. In the case of colemanite, B released was steadily increased until the end of the incubation study. At the end of the study, there was no significant difference in B levels of both borax- and colemanite-applied soils. Particle size had a significant effect on the solubility and dissolution rate of colemanite. Boron dissolution rate and solubility from colemanite powder were significantly greater than those from granular colemanite. Leaching losses from borax were much greater than from colemanite as indicated by the breakthrough curves, which were earlier for borax than colemanite. After 60 pore volumes, no more B was leached out from borax, and in the leachates of colemanite some concentration was detected even after 80 pore volumes. Boron content in soil of columns after the completion of the experiment was greater in case of colemanite. Borax and colemanite fertilizers showed the same trend of leaching and B releasing in both Tepus and Chempaka soil series.     

Utilization of Large-Sized Dolomite By-Product Particles and Losses of Cations from Acidic Soil

To investigate the possibilities of utilization of dolomite large size fractions (dropouts) and their effect on plants a five-year experiment was set in 2015. A fertilization value of large fractions (5–7 and 7–10 mm) of dolomite in two doses was studied. The biomass yield of crops in dolomite dropout treatment was around 90% from the treatment using dolomite flour (control). Losses of bases from the soil treated with high doses of dropouts did not exceed the migration losses of the treatment with dolomite flour. Dynamics of dolomite flour dissolution in the soil was empirically modeled. The data prove that high doses of the large-sized dolomite fractions act similarly to standard dolomite flour and have more persistent effects on soil and plants.     

火山喷出物发育土壤的比重及颗粒组成测定

利用比重瓶法对火山喷出物发育土壤的比重进行测定,结果表明:玄武岩质火山喷出物发育土壤的比重大于粗面岩质火山喷出物发育土壤的比重;基于粒径小于1 mm土粒测定的比重,玄武岩质火山喷出物和粗面岩质火山喷出物发育土壤的比重均小于一般土壤的平均比重2.65 g cm~(-3);基于粒径小于0.1 mm土粒测定的比重,除个别玄武岩质火山喷出物发育土壤外也小于2.65 g cm~(-3)。分别取比重值为2.65 g cm~(-3)、粒径小于1 mm土粒的实测比重和粒径小于0.1 mm土粒的实测比重,计算不同粒级土粒的沉降时间,并进行颗粒组成的实验研究表明:取不同比重值测定的土壤颗粒组成含量相差较大而且影响土壤质地定名。由于成土母质的矿物组成决定土壤的比重,且土壤颗粒组成的静水沉降实验是在粒径小于0.1 mm土粒的悬液中进行的,所以,准确测定土壤颗粒组成含量,需要区分成土母质的矿物组成,并测定其小于0.1 mm粒径的土粒比重,重新计算沉降时间。     

Acidic deposition in California: Findings from a program of monitoring and effects research

California's 14-year, $25 million acidic deposition program has studied the causes and effects of acidic air pollutants. In contrast to the eastern United States where sulfur-derived (S-derived) by-products from coal combustion dominate precipitation chemistry, nitrogen-derived (N-derived) acids predominate in wet and dry deposition in California. Adverse effects on the human lung have not been observed after short-term exposures to acidity, but extended exposures to ambient acidity may pose a chronic risk. No irreversible, adverse effects on surface waters in the Sierra Nevada mountain range or to the state's forests have been found due to extant acidic inputs. The longer-term outlook for forests is less certain because the impacts observed elsewhere occurred after decades of S and N deposition, but at lower ambient ozone levels. Ozone is the major air pollutant stressor for forests, but atmospheric N has the potential to cause adverse changes in soil nutrient cycling. Impacts on man-made materials in southern California (e.g., galvanized steel) were found to be minor. While California does not have an ambient air quality standard for acidic air pollutants, emissions of precursors have declined since the 1960's due to changes in industrial practices, improvements in technology, and adoption of control measures for ozone. Lowering emissions from motor vehicles will be emphasized to prevent future increases in N deposition.     

贡嘎山旅游景区泥石流灾害及减灾对策

采用文献资料法和理论分析法,探讨了矿区沉陷地复垦与生态重建的若干问题,目的在于提高矿区环境治理投资效果,促进矿区可持续发展.构建了矿区沉陷地复垦与生态重建的主要理论、关键技术和投资效果评价方法.最后指出,矿区沉陷地环境治理中,应将土地复垦与生态重建相结合.     

Aluminum concentrations in sclerotia from a buried humic horizon of volcanic ash soils in Mt. Myoko,Central Japan

The morphology and chemical composition of fungal sclerotium-like grains collected from the buried humic horizon of volcanic ash soil in Mt. Myoko were examined using a scanning electron microscope (SEM), energy dispersion xray micro-analyzer (EDX), and electron probe micro-analyzer (EPMA). A high C content, low level of Si and high concentration of Al characterized the grains considered to correspond to the sclerotia of Cenoccocum graniforme. The ²⁷Al MAS NMR spectrum of the sclerotia showed the existence of 6- and 4-coordinated Al. X-ray diffraction analyses supported the presence of amorphous Al (ex. Al-humus complex) in the sclerotia.     

概述酸沉降对加拿大鱼类和渔业资源的影响及评价方法

本文概述了淡水资源及其产业在加拿大经济中的重要性、酸沉降对加拿大渔业资源造成的损失。通过现场调查、生物测定和试验研究探索了酸沉降对湖泊等水域酸化的影响。〔H~+〕是危害鱼类的主要毒物。提出利用模型评价酸沉降对生物损害是今后的发展趋势。     

Determination of the geochemical weathering indices and trace elements content of new volcanic ash deposits from Mt. Talang (West Sumatra) Indonesia

Since the Indonesian archipelago is part of the very active and dynamic Pacific Ring of Fires, the volcanic eruptions occur from time to time. Immediately after the eruption of Mount Talang in West Sumatra (April 12, 2005), volcanic ashes, both unleached and leached were collected. The deposits from Mt. Talang were andesitic to basaltic in composition. The volcanic ash consisted of volcanic glass, plagioclase feldspar in various proportions, orthopyroxene, clinopyroxene, olivine, amphibole, titanomagnetite. We conducted the total elemental analysis of the bulk samples of the volcanic ash. The contents of major, trace and rare elements as well as heavy metals were determined by wet chemical methods and x-ray fluorescence (XRF) analyses. Although the volcanic ash of Mt. Talang are still very new, an evaluation of the geochemical weathering indices was performed with the objective of showing the volcanic ash condition at the early stage of weathering. Eight weathering indices were evaluated. The results showed that the unleached volcanic ash has higher Ruxton Ratio (R), Weathering Index of Parker (WIP), Product of Weathering Index (PWI) and Silica Titanium Index (STI) values compared to the leached ash, while the leached ash exhibited higher Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), Vogt’s Residual Index (VO), and Plagioclase Index of Alteration (PIA). These weathering indices can be used to quantify the condition of the volcanic ashes at the initial stage of weathering, to evaluate their fertility, to provide a better understanding of element mobility during weathering, and predict the source of soil nutrients as well as determine the products of primary minerals alteration.     

Carbon Stock, Afforestation and Acidic Deposition: An Analysis of Inter-Relation with Reference to Arid Areas

Recent advances in desert afforestation underlines its viability and importance in combating global warming and acidification. In this paper, the inter-relation between afforestation, global warming and acid rain has been analyzed. Numerical simulations indicate that afforestation of deserts has distinct advantage as carbon sink and as an important factor for changing microclimate of the region rather than a source of energy. Acidic deposition may well be utilised as fertiliser in nutrient deficit soil of tropical arid areas. However, past trends and projections of acidic deposition in arid areas adjacent to Thar deserts indicate an early efforts are required to cap the opportunity. Delays may contribute towards more incidences of failures.     

黄连木雌雄株叶水溶性酚类物质和两种氧化酶活性的比较

黄连木为雌雄异株植物。为探索鉴别黄连木幼苗性别的方法,应用比色法对其雌雄株不同发育阶段叶片中水溶性酚类物质的含量、过氧化物酶（POD）活性和多酚氧化酶（PPO）相对活性进行测定和比较分析,结果表明：不同性别的黄连木叶片水溶性酚类物质含量存在极显著的差异（P〈0．01）;POD、PPO相对活性在雌雄株问也存在显著差异,特别在老叶中则存在极显著差异,认为黄连木雌雄株老叶中的水溶性酚类物质含量差异,可以作为其性别鉴定的依据,为进一步研究黄连木植株早期性别鉴定提供参考。     

Quinone profiling of bacterial populations developed in the surface layer of volcanic mudflow deposits from Mt. Pinatubo (the Philippines)

The diversity of bacterial populations developed in the surface layer (0-0.25 m depth) of volcanic mudflow deposits from the Mt. Pinatubo volcano (the Philippines) was investigated using quinone profiling. Samples were collected from sites (named N and S1) that had been hit repeatedly by mudflows during successive rainy seasons after the violent eruption of 1991 and also from sites (F1 and F3) covered by mudflow in 1991 but with no deposition in following years. The total microscopic count ranged from 10⁸ g⁻¹ (N and S1 sites) to 3.9×10⁹ g⁻¹(site F3). In the N sample only three quinone species were detected, while the quinone profiles of samples from sites S3 and F3 showed higher diversity. Tetrahydrogenated menaquinone with eight isoprenoid units [MK-8 (H₄)] was the predominant quinone species in the sample from site N, while MK-8, MK-8 (H₂), MK-8 (H₄), MK-9 (H₄) and MK-9 (H₈) were found as major quinones in the sample from site F3. Because these MK species are known to be the major respiratory quinones of the Actinobacteria, this bacterial group is expected to predominate in the land with primary vegetation recovery following the impact of the volcanic mudflow.