Characterization of Atmospheric Aerosol in the Northern Foot of Mt. Fuji, Central Japan

The unique characteristics of atmospheric aerosol in the northern foot of Mt. Fuji, central Japan were first clarified. The Mt. Fuji (an altitute of 3776 m) is the largest basaltic stratovolcano in the quaternary period in Japan. The aerosol measurements were carried out at an altitute of 1100 m from June 2000 to April 2001. Ambient aerosol in the predominant area of a typical volcanic rock like basalt was referred to as a basaltic aerosol in this study. Fifteen elements (Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn, Ba, Pb) of major to trace in the aerosol samples were determined by X-ray fluorescence spectrometry. Total mass concentration (< 10 μm) of the basaltic aerosol showed the higher values in summer and spring rather than autumn to winter, and the seasonal variation pattern differed widely from that of general urban aerosol. The behavior of the basaltic aerosol was mainly controlled by mineral particles throughout the year, so that a typical anthropogenic-derived element like Pb was very rarely detected. Even V, Cr and Zn which have been generally considered to be typical anthropogenic-derived elements, showed crustal-like behaviors. A concentration ratio of Si/Al showed markedly a uniqueness of the basaltic aerosol. From a comparison with atmospheric aerosol Si/Al ratio in granitic region being an exact opposite geology, a correlation plot of Si/Al ratio against Si concentration was made. It showed a big regional difference available for source identification of atmospheric soil particles. The chemical and geological characteristics of the basaltic aerosol are very useful for the novel characterization of atmospheric soil particles.     

Aerosol and Precipitation Chemistry during the Summer at the Summit of Mt. Fuji, Japan (3776m a.s.l.)

Aerosol and precipitation samples were obtained at the summit of Mt. Fuji, the highest peak (3776m a.s.l.) in Japan, in the summers of 1997, 1998, and 1999. The mountaintop might be affected by valley wind during the afternoon, but is located in the free troposphere during the morning. The temporal variations of chemical species in the aerosol and precipitation samples correspond with meteorological conditions. The SO₄ ^2? in the aerosol and precipitation exhibits high concentration with low temperature air mass, indicating the influence of long range transport from the Asian Continent. The contribution of the free troposphere to the chemical species obtained at the summit is estimated to be at least 30% during the summer season.     

日本御岳等地非饱和泥石流的流动机理(上)

<正> 一、前言 1983年9月长野县西部地震,使御岳发生了3600万m~3的大滑坡,其中2500万m~3的土体滑出约9km,堆积在王龙川干流河床比降4度以下的地方。据日本主要报纸和电视台报道,这次滑坡与通常的泥石流不同,其滑动土体为非饱和状态,属粉状流。 粉状流是由于孔隙气压过剩致使土体有效摩擦角减小而发生的滑动现象。过剩孔隙气压的作用方式有两种:一种是象气垫船那样,粉状体附着在气垫上;另     

Cloud Water Deposition to Forest Canopies of Cryptomeria Japonica at Mt.Rokko, Kobe, Japan

Cloud water deposition to canopies of Cryptomeria japonica at Mt.Rokko, Kobe, Japan, was estimated from throughfall measurements and fog water collections carried out during a full year. Annual cloud frequency was 11.5–15.5% and liquid water content (LWC) was 0.059 g/m³. Since cloud water deposition on to forest canopies was significantly correlated with the amount of fog water collected, the former parameter could be quantitatively derived from throughfall measurements. Annual cloud water deposition on to Cryptomeria canopies was 1420–2860 mm (Av. 2140 mm), corresponding to 90–180% (Av. 122%) of annual rainfall. The rate of deposition was higher at the mountain ridge and the forest edge than at the mountain side and the forest interior. Annual deposition of SO₄ ^2?, NO₃ ^?, H⁺ and NH₄ ⁺ from cloud water was estimated as 204, 153, 2.5 and 58 kg/ha, respectively, equivalent to 5.8–11.7 times the corresponding deposition via rain. The values are equal to, or exceed, the maximum deposition reported for Appalachian forests in the eastern United States. Multiple regression analyses indicate that cloud water deposition on to Cryptomeria canopies was significantly correlated with the following three parameters: cloud frequency, LWC, and wind speed. Thus, these three factors apparently control cloud water deposition on to forest canopies.     

Chemical Characteristics of Fog Water at Mt. Tateyama, Near the Coast of the Japan Sea in Central Japan

Measurements of the chemical composition of fog water at Murododaira (altitude, 2,450 m), on the western slope of Mt. Tateyama near the coast of the Japan Sea, were performed each autumn from 2004 through 2007. Strong acidic fogs (pH?<?4) containing high concentrations of nssSO ₄ ^2? were frequently observed in the autumn of 2005, when the air mass at Mt. Tateyama originated mainly from the polluted regions of Asia. The ratio of NO ₃ ^? /nssSO ₄ ^2? in fog water was relatively high in 2004 and 2007. High concentrations of nssCa²⁺ derived from dust particles were detected in 2006. Background Kosa particles might have been predominant in the free troposphere and could have neutralized acidic fogs in the autumn of 2006. High concentrations of sea-salt components were also observed in October 2005. The sea-salt particles might have been transported from the Pacific Ocean by a strong typhoon, and significant Mg²⁺ loss was observed. Peroxides higher than 100 μM, which are seriously harmful to vegetation were sometimes detected.     

Rainfall,Stemflow, and Throughfall Chemistry at Urban- and Mountain-facing Sites at Mt. Gokurakuji,Hiroshima, Western Japan

Rainfall, stemflow, and throughfall were collected from 1996 to 1999 at two types of forest sites: (1) forests near the traffic roads and urban areas and (2) forests away from the urban areas at Mt. Gokurakuji, Hiroshima, western Japan in order to estimatethe effects of anthropogenic activities on atmospheric deposition. Rainfall deposition for major ions showed small differences between the sites. The NO₃ ^- and SO₄ ^2-concentrations in stemflow were higher at the urban-facing slope than at the mountain-facing slope. Throughfall deposition of NO₃ ^- and SO₄ ^2- was also higher at urban-facing slopes. Net throughfall (NTF) deposition (throughfall minus rainfall) of NO₃ ^- and SO₄ ^2- accounted for 77 and50% of the total throughfall deposition on urban-facing slopes, respectively, while it accounted for 44 and 23% on themountain-facing slopes, respectively. These results indicated a higher contribution from dry deposition on urban-facing slopes compared to mountain-facing slopes. Atmospheric N (NO₃ ^- +NH₄ ⁺) deposition from throughfall was estimated to be around 17–26 kg N ha^-1 yr^-1 on urban-facing slopes, which was greater than the threshold of N deposition that could cause nitrogen leaching in Europe and the United States. The highload of atmospheric N deposition may be one of the factors bringing about the decline of pine forests on urban-facing slopesof Mt. Gokurakuji.     

Acid deposition at the summit of Mt. Fuji: Observations of gases,aerosols and precipitation in summer,1993 and 1994

Intensive observations of chemical species in aerosols, gases and other samples at the summit of Mt. Fuji and at Tarobo (at 1300m on the mountain'ts southern slope) was performed from July 28 to Aug. 3, 1993 and from July 25 to 30,1994. The most interesting observation was the abrupt increase in the sulfate concentration in aerosol collected in July, 1993 just after the typhoon (number 9306) passed the Japanese archipelago and the wind direction shifted from south to west. Chemical analysis indicated this aerosol was acidic. In contrast, the summit aerosol observed in 1994 was not acidic following a less dramatic rise in sulfate content. Back trajectory analyses were used to extrapolate from these measurement to an inventory of polluted air over the Asian Continent. The concentrations of gaseous SO₂ and HCl remained low during both observation periods, with some higher concentrations of NH₃.     

Influences of Forest Decline on Various Properties of Soils at Mt. Hirugatake, Tanzawa Mountains, Kanto District, Japan

At Mt. Hirugatake in the Tanzawa Mountains, Kanto district, Japan, the deciduous broadleaved forests have rapidly declined. In our previous studies, we reported that the amount of soil organic matter had significantly decreased at the early and final stages of forest decline, and that the soil microbial biomass also showed a large decrease at these stages, suggesting that the composition of soil organic matter might have also changed with forest decline. To clarify the influences of forest decline on the composition of soil organic matter, the amount of humic substances, optical properties of humic acid, and the amount of soil carbohydrates in surface soils at different stages of forest decline were investigated. The amounts of humic acid and fulvic acid decreased to a lesser extent at the early and middle stages of forest decline, and showed a significant decrease at the final stage. As the amount of humin significantly decreased at the early stage, it was plausible that the distinct decrease in the total carbon content of the soil surface horizons at the early stage of forest decline was induced by the decrease in the amount of humin, and at the final stage, by the decrease in the amounts of humic acid and fulvic acid. The amount of soil carbohydrates did not change appreciably with forest decline although the soil organic matter content markedly decreased. It was suggested that most of the carbohydrates in the soil surface horizons were in a stabilized form consisting of complexes with humic substances, metals, and minerals, and would not be affected by the environmental changes associated with forest decline.     

Elevational Patterns of Acid Deposition into a Forest and Nitrogen Saturation on Mt. Oyama, Japan

Virgin fir trees have been dying on Mt. Oyama, which is located in the southwestern part of Kanto Plain, although the frequency of death seems to be reducing recently. We report elevational patterns of acid deposition in precipitation and throughfall under fir and cedar canopies and nitrogen saturation in the forest ecosystem on Mt. Oyama. The deposition fluxes of major inorganic ions in precipitation were nearly constant regardless of elevation except for hydrogen and ammonium ions, whereas the deposition fluxes of all major inorganic ions in throughfall among cedar increased. The 5-year average of annual nitrate deposition in precipitation from 1994 to 1998 showed 19.3 – 23.5 kg ha^?1 yr^?1 (annual inorganic total N deposition: 9.6 – 10.7 kgN ha^?1 yr^?1) at four sites ranging in elevation from 500 to 1252 m, whereas the deposition in both cedar and fir throughfall was over 6 times greater than that in precipitation. The average soil surface nitrate concentration in 1998 was 140 µg g^?1 (the range: 21.1 – 429 µg g^?1, n=80) and the 7-year average of nitrate concentration in stream water from 1992 to 1998 was 4.81 mg L^?1 (the range: 2.38 – 20.6 mg L^?1, n=317). Our results indicate that nitrogen saturation is occurring in the forest ecosystem because of high N deposition, probably via acid fog, on Mt. Oyama.     

A chlorite-smectite intergrade in soil derived from pyroxene andesite altered hydrothermally in Mt. Kunimidake,Fukui, Central Japan

The interlayered hydroxy-aluminum of a chlorite-smectite intergrade in a dark-red soil derived from a pyroxene andesite altered by hydrothermal action was extracted easily by boiling treatments using both sodium-citrate and ammonium-fluoride solutions. Moreover, this interlayered aluminum was released partially by using a dithionite-citrate-bicarbonate system and an acid ammonium-oxalate solution which were prepared originally for removing the coexistent sesquioxides from soils.     

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.     

Fog and Precipitation Chemistry at Mt. Rokko in Kobe, April 1997-March 1998

Fog water and precipitation were collected and analyzed to study fog and precipitation chemistry. The research was carried out through one year from April 1997 to March 1998 at Mt. Rokko in Kobe. Higher fog occurrence and larger volume of fog water were observed in summer, corresponding to the trend of seasonal variation in precipitation amount. The annual mean pH value of fog water (3.80) was lower by ca. one pH unit than that of precipitation (4.74). The concentration of chemical species in fog water was ca. 7 times that in precipitation. The highest anion and cation concentrations were SO₄ ^2? and NH₄ ⁺ in fog water and Cl^? and Na⁺ in precipitation, although the Cl^?/Na⁺ equivalent ratio in both fog water and precipitation was almost the same value as that in sea water. It is considered that in the longest fog event, NH₄ ⁺ and nss-SO₄ ^2? in fog water mainly scavenged as (NH₄)₂SO₄, mainly derived from (NH₄)₂SO₄ (aerosol) in the atmosphere, NH₃ was scavenged at the growing stage, and SO₂ was also scavenged after the mature stage. NO₃ ^? in this fog event was mainly absorbed as HNO₃.     

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.     

Fog Water Chemistry at Mt. Oyama and its Dominant Factors

We have observed acid fog in Mt. Oyama since 1988. Fog events occur frequently in Mt. Oyama; 47% of the time the mountain top is covered with fog. The pH of fog is lower than that of rain collected at the fog sampling station by about 1 unit and the lowest pH was 1.95. We have also collected gas and aerosol components at the station and observed fog events by a video camera from the mountain base, where there is an air pollution monitoring station. The air quality at the fog sampling station was affected by not only the air quality at the base but also the wind direction, valley or mountain wind. It is ascertained by using back trajectory analyses that polluted air masses are transported to the base from the Kanto plains or other big urban areas, Osaka and Nagoya. When the base is polluted, the relative humidity increases, and the valley wind blows, acid fog is formed at the mountainside. In the acid fog, nitrate ion is the most abundant anion. Nitrate ion concentration correlates well with hydrogen ion concentration. The annual mean total ion concentration has not changed much since 1988, but the concentration ratio of nitrate ion to sulfate ion has increased in recent years. The nitric acid gas concentration in the station is comparable to that in urban areas, while other gas concentrations are much lower.     

Effect of volcanic fumes from Mt. Oyama,Miyakejima Island,on atmospheric deposition,soil solution,and soil properties in Kumagaya,central Japan

Abstract

The chemical nature of Mn in the leaves of Acanthopanax seiadophylloides, Ilex crenata var. paludosa and Kalopanax pictus was investigated.

Successive extraction of freeze-dried and fresh leaf sam pies with various solvents showed that the major portion of Mn (>90%) was extractable with water and 0.2 M HCl.

Electron probe X-ray microanalysis was performed with the fresh leaf tissues of Mn hyper accumulator A. seiadophylloides, before and after shaking with distilled water, 80% methanol and 1 M HCl. Water removed large parts of Mn in the tissue as a whole except in the region of the epidermis. A negligible amount of Mn was removed by 80% methanol; on the other hand, 1 M HCl removed almost all of the Mn in the tissues.

Paper electrophoretic experiments conducted with water and 0.2 M HCl extracts using pyridine-acetic acid buffer (pH 6.5) indicated that Mn in the extracts behaved similarly to Mn²⁺, presumably due to the labile nature of Mn components in the tissues.     

云南昌宁蔗区不同耕层土壤养分的垂直分布

研究了蔗园土壤养分的垂直分布特征。结果表明:(1)不管是在旱地蔗园还是在水田蔗园,0～30cm土层的有机质、水解氮、速效磷、速效钾等主要养分含量明显高于30～60cm的土层,但全氮、全磷、全钾在0～30cm土层与30～60cm土层之间没有明显的变化。(2)旱地蔗园的有效铁、有效锰和有效铜0～30cm土层比30～60cm土层高,有效锌含量在0～30cm的土层与30～60cm的土层之间变化不大。     

Vertical Distribution of Trace Metals in Natural Soil Horizons from Japan Part 2: Effects of Organic Components in Soil

The association of Al, Mn, Fe, Ba, Zn, Cr, Ni, Co and Pb withsoil organic matter (SOM) was investigated in three Japanesesoils. Organically bound metals were assayed by elementalanalysis of a fraction extracted with acidified hydrogenperoxide (H₂O₂) and the humic acid extracted withalkaline reagent, from soil sampled at various depths of solums.A Dystric Cambisol showed higher extractability with acidifiedH₂O₂ for most of the metals than a Humic Andosol and an Orthic Acrisol. A Humic Andosol had more metals associated with humicacid than the other two soils.Cu showed high extractability with acidified H₂O₂ andalso significant association with humic acid, while Pb showedhigh extractability with acidified H₂O₂ but itsassociation with humic acid was relatively low among the metalsinvestigated. As humic acid is highly resistant to weathering,retention of Cu with SOM may last longer than that of Pb.The binding of metals with SOM probably has contributed to theaccumulation of some metals in organic-rich shallow horizons of soil. Such metals were Zn, Cu, Ni and Pb in a Dystric Cambisol,Cu in a Humic Andosol, and Pb and Cu in an Orthic Arisol.     

Chemistry of Fog Water Collected in the Mt. Rokko Area (Kobe City, Japan) between April 1997 and March 2001

Fog chemistry was studied for four years (April 1997–March 2001) at Mt. Rokko (altitude 931 m) in Kobe, Japan. A collection of samples was obtained at a mountainous site close to a highly industrialized area. The samples were collected by an active string-fog collector. The summer fog was dense and frequent. The geography of Mt. Rokko is linked to the seasonality of the occurrence and the thickness of the fog. Among the meteorological parameters, the relative humidity was important for the occurrence of fog. The correlation of the concentrations of the components in fog water indicated that (NH₄)₂SO₄ and/or NH₄HSO₄ were involved in the process of the formation of fog drops in the atmosphere. The concentration of the components decreased with an increase in the liquid water content (LWC) of the fog, and the seasonal variation of the concentration of some components depended on the seasonal variation of the LWC. The equivalent ratio of NO₃ ^? to non-sea salt (nss?) SO₄ ^2? was considerably larger than that in precipitation. Ammonium ion accounted for the largest percentage of cations, which indicates that NH₄ ⁺ was an important counter cation for NO₃ ^? and nss-SO₄ ^2?. A unique fog event in which the air pollutants seemed to be scavenged stoichiometrically was sometimes observed. The methodology used for collecting fog water at 60 mL intervals provided detailed information.     

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.     

伊犁河谷山地北坡土壤特性及植被群落多样性垂直分布格局

基于对伊犁河谷山地北坡垂直地带植被多样性和土壤生境的调查分析数据,采用Pearson相关系数法、主成分法和DCA排序法分析了物种多样性指数与环境因子之间的关系。结果表明:根据其植被带和土壤带沿不同海拔将其分为针叶林、山地草原、落叶阔叶林和荒漠草原;其总的物种丰富度和Simpson指数与海拔呈现先升高后降低,再升高的格局,不同海拔植被群落丰富度指数之间差异均显著(p0.05),Shannon-Wiener指数随海拔的增加呈先增加后降低的趋势,Pielou均匀度指数随海拔的增加呈先降低后增加,然后降低的格局。犁河谷山地北坡土壤有机质和有效氮含量随海拔的增加而增加的趋势,基本表现为针叶林山地草原落叶阔叶林荒漠草原,其中不同海拔植被群落土壤有机质含量之间差异均显著(p0.05),土壤有效磷含量没有明显的垂直变化规律,土壤有效钾含量随海拔的增加呈先增加后降低的趋势,基本表现为山地草原针叶林落叶阔叶林荒漠草原。犁河谷山地北坡土壤pH值随海拔的增加而降低的趋势,基本表现为荒漠草原山地草原落叶阔叶林针叶林,土壤电导率、全盐和总盐含量均随海拔的增加呈先增加后降低的格局,基本表现为山地草原落叶阔叶林荒漠草原针叶林。主成分的结果分析表明,第一主成分负荷值最高的分别为土壤全盐、总盐、电导率,可称为土壤盐分因子;第二主成分负荷值最高的分别为土壤有效氮、有机质和pH值,可称为保肥、供肥因子。DCA排序结果表明,沿着DCA第一轴,随着海拔逐渐降低,土壤有机质、有效氮和有效钾等土壤养分的含量逐渐下降,而pH值和电导率逐渐上升;沿着DCA第二轴,随着海拔逐渐降低,土壤总盐和全盐含量逐渐增加,而土壤有效磷含量却逐渐降低。由此可知,犁河谷山地北坡植物群落多样性的垂直分布格局是由海拔为主的多种环境因子综合作用的结果,而土壤养分和盐分随海拔的变化与植被带不尽一致,可能它们之间的同步变化存在一定的滞后期。