Papers by Takejiro Takamatsu
Ferromanganese crusts were sampled from the surface of a stone collected at a depth of 20 m in th... more Ferromanganese crusts were sampled from the surface of a stone collected at a depth of 20 m in the northern part of Lake Biwa, Japan. These samples were analysed for 37 elements by neutron activation, X-ray fluorescence, and ICP-AE. The crusts were found to be enriched with Ba, P, B, As, and sometimes with Co, Ni, Cu and Sb. The elements were classified into 4 groups based on the varieties of host minerals (Fe-oxides, Mn-oxides or allochthonous materials) in which they were incorporated : elements mainly associated with 1) Mn-oxides : Ba, Ni, Cs, Sr and Co ; 2) Fe-oxides : P, B and As; 3) allochthonous materials : Na, K, Rb, Al, Ti, Sc, Hf and Th ; and 4) Mn-oxides plus allochthonous materials : rare earth elements and major heavy metals. The elemental compositions in the Lake Biwa concretions, including the crusts and Mn-deposits studied previously by these authors, were compared with those in other freshwater and oceanic concretions. As a result, the concentrations of rare earth elements and major heavy metals were found to be much lower, whereas those of B, P and As were higher in the Lake Biwa than in the oceanic concretions. These differences could be well explained in terms of the effects of sea salt, growth rates of the concretions, and pH of the formation environment.
Japan Geoscience Union, 2017
The sources of Ca in Japanese forest ecosystems have been assumed to be sea salt, bedrock, and Ko... more The sources of Ca in Japanese forest ecosystems have been assumed to be sea salt, bedrock, and Kosa (Asian dust). Volcanic ash may also be an important contributor of Ca in volcanic areas. In our previous study (Koshikawa et al. 2016), an attempt was made to estimate the contribution of volcanic ash to Sr and Ca in stream waters and plants in a granite watershed. The fraction of atmospherically derived Sr in the stream water was evaluated using Sr/Cl ratio of stream water and atmospheric precipitation. Then, the fractions of Sr in stream water derived from granite and volcanic ash were estimated using Sr isotope ratios. The results confirmed that information about the Sr-isotopic composition is useful for determining the sources and contributions of Sr and Ca in stream waters and plants, even in complex systems containing volcanic ash and bedrock weathered products. Now, we are planning to apply this estimation to other regions where the Ca supply from parent materials is anticipate...
Analytical Sciences, 2019
To evaluate the mobility and bioavailability of 137 Cs in soils, we compared the extraction of 13... more To evaluate the mobility and bioavailability of 137 Cs in soils, we compared the extraction of 137 Cs with stable Cs and ammonium solutions from 137 Cs-contaminated minerals and soils. The extraction yields of 137 Cs with stable Cs were significantly lower than those with ammonium for minerals with frayed edge sites, but such differences were not observed for minerals without frayed edge sites. The amount of 137 Cs extracted with stable Cs from soils was lower than, or equal to, that extracted with ammonium. The above results suggest that stable Cs extracted the 137 Cs from easily accessible sites. Plant available 137 Cs was assessed using Kochia (Bassia scoparia) cultivated in pots of contaminated soils, and compared with soil parameters including extractable 137 Cs and K, and radiocesium intercept potential. The 137 Cs/K ratio extracted with stable Cs solution was found to be a potential index for evaluation of the easily mobile and bioavailable fraction of 137 Cs in soil.
The Science of the total environment, Jan 28, 2018
High concentrations of nitrate have been detected in streams flowing from nitrogen-saturated fore... more High concentrations of nitrate have been detected in streams flowing from nitrogen-saturated forests; however, the spatial variations of nitrate leaching within those forests and its causes remain poorly explored. The aim of this study is to evaluate the influences of catchment topography and coniferous coverage on stream nitrate concentrations in a nitrogen-saturated forest. We measured nitrate concentrations in the baseflow of headwater streams at 40 montane forest catchments on Mount Tsukuba in central Japan, at three-month intervals for 1 year, and investigated their relationship with catchment topography and with coniferous coverage. Although stream nitrate concentrations varied from 0.5 to 3.0 mgN L, those in 31 catchments consistently exceeded 1 mgN L, indicating that this forest had experienced nitrogen saturation. A classification and regression tree analysis with multiple environmental factors showed that the mean slope gradient and coniferous coverage were the best and se...
Scientific Reports, 2017
Ecosystems of suburban landscapes (i.e., forest, inland water ecosystem) are threatened by high n... more Ecosystems of suburban landscapes (i.e., forest, inland water ecosystem) are threatened by high nitrogen (N) loadings derived from urban air pollutants. Forest ecosystems under high chronic N loadings tend to leach more N via streams. In the northern suburbs of Tokyo, N deposition loading on terrestrial ecosystems has increased over the past 30 years. In this region, we investigated nitrate concentrations in 608 independent small forested catchment water samples from northeastern suburbs of Tokyo. The nitrate concentrations varied from 0.07 to 3.31 mg-N L−1 in this region. We evaluated the effects of N deposition and catchment properties (e.g., meteorological and topographic factors, vegetation and soil types) on nitrate concentrations. In the random forest model, simulated N deposition rates from an atmospheric chemistry transportation model explained most of the variance of nitrate concentration. To evaluate the effects of afforestation management in the catchment, we followed a m...
SpringerPlus, 2016
To investigate the nitrification potential of phyllospheric microbes, we incubated throughfall sa... more To investigate the nitrification potential of phyllospheric microbes, we incubated throughfall samples collected under the canopies of Japanese cedar (Cryptomeria japonica) and analyzed the transformation of inorganic nitrogen in the samples. Nitrate concentration increased in the unfiltered throughfall after 4 weeks of incubation, but remained nearly constant in the filtered samples (pore size: 0.2 and 0.4 µm). In the unfiltered samples, δ(18)O and δ(15)N values of nitrate decreased during incubation. In addition, archaeal ammonia monooxygenase subunit A (amoA) genes, which participate in the oxidation of ammonia, were found in the throughfall samples, although betaproteobacterial amoA genes were not detected. The amoA genes recovered from the leaf surface of C. japonica were also from archaea. Conversely, nitrate production, decreased isotope ratios of nitrate, and the presence of amoA genes was not observed in rainfall samples collected from an open area. Thus, the microbial nitr...
Limnology, 2007
Extensive chemical data for the Lake Biwa sediments were examined with statistical factor analysi... more Extensive chemical data for the Lake Biwa sediments were examined with statistical factor analysis to fi nd any correlation patterns among elements and among samples. Based on those patterns, a series of x-y correlation plots of the concentrations of selected elements was constructed to see in detail how the concentrations of elements vary among different sample groups and explain the observed variation patterns.
Limnology, 2010
The average composition of water, bottom sediments, manganese (Mn) crusts, and Mn concretions fro... more The average composition of water, bottom sediments, manganese (Mn) crusts, and Mn concretions from Lake Biwa (the largest freshwater lake in Japan) are re-examined, in conjunction with those of seawater, oceanic pelagic clay, and deep-sea Mn nodules. The purpose is to gain additional insights into the geochemical behaviors of elements in Lake Biwa and the ocean, which are quite different in ionic strength (or salinity), pH, water residence times, sediment accumulation rates, carbon fluxes to sediments, and the redox potential in sediments. Excluding a few millimeters of oxic surface sediment, there is no appreciable accumulation of Mn in the Lake Biwa bottom sediments due to reducing condition there. Consequently, other B-type cations [such as iron (Fe), gallium (Ga), copper (Cu), lead (Pb), cobalt (Co), tin (Sn), and bismuth (Bi), with subshell valence electron configuration of d 1-10 ] are also less concentrated in the lake sediments than in the oceanic pelagic clay. In turn, B-type cations have much higher dissolved concentrations in the lake water than in the ocean. The rare earth elements (REE) mainly form organic complexes in the lake water and carbonate complexes in the ocean. REE are mostly associated with detritus aluminosilicate phases in Lake Biwa sediments but with phosphate phases in deep-sea sediments. Fe and Mn oxide phases are clearly separated in marine Mn nodules and crusts but not in Mn crusts and concretions from Lake Biwa. Useful parameters such as the enrichment factor (E Al ) and logarithms of the distribution coefficient (log K d ) of elements between solid and liquid phases were estimated in both systems for further discussions.
Japanese Journal of Limnology (Rikusuigaku Zasshi), 1976
neutron activation analysis was performed on the 200-meter core samples as well as on the bottom ... more neutron activation analysis was performed on the 200-meter core samples as well as on the bottom surface ones, in order to find out the correlation between the sedimentary environments and
Journal of the Japanese Society of Revegetation Technology, 2013
Water, Air, & Soil Pollution, 2005
Copper complexing capacity (CuCC) and conditional stability constants (K ) of the complexes were ... more Copper complexing capacity (CuCC) and conditional stability constants (K ) of the complexes were analyzed for throughfall collected in Japanese cypress (Chamaecyparis obtusa), Japanese cedar (Cryptomeria japonica), Japanese red pine (Pinus densiflora), and bamboo-leafed oak (Quercus myrsinaefolia) groves (soil: light-colored Andosol) located in a suburban area of Japan (Tsukuba, Ibaraki). The method was based on the titration of throughfall samples with standard Cu 2+ solution using a Cu 2+ -selective electrode, followed by data analysis using the van den Berg-Ruzic plot (1:1type complexes were assumed). CuCCs (µM) obtained were in the order: C. obtusa (7.1 ± 5.1) ≤ C. japonica (9.6 ± 5.6) < P. densiflora (15.9 ± 16.4) < Q. myrsinaefolia (29.3 ± 23.9). In addition, ratios of CuCC/DOC (µmol mg -1 C) were in the order: C. obtusa (0.42 ± 0.26) ∼ = C. japonica (0.42 ± 0.22) ∼ = P. densiflora (0.55 ± 0.38) Q. myrsinaefolia (2.0 ± 1.3), and the ratios in the throughfall of Q. myrsinaefolia were about 4 times higher than those in the throughfall of other tree species. On the other hand, log K was almost the same for all tree species (about 5.5). CuCC and also CuCC/DOC increased in spring and autumn, and decreased in summer and winter, indicating that organic matter with metal complexing capacity, released from trees, changed seasonally not only in quantity but also in quality. Since throughfall accelerated the leaching of metals from grove soil and artificial material (e.g. alloy) placed in the groves, it may be involved in the behavior of metals in the plant-soil ecosystem.
Water, Air, and Soil Pollution, 2005
Because of concerns about the toxicity of lead (Pb), the use of antimony (Sb), indium (In), silve... more Because of concerns about the toxicity of lead (Pb), the use of antimony (Sb), indium (In), silver (Ag), and other heavy metals are on the increase as its replacement in many kinds of industrial products, particularly in solders. In the present study, effects of Pb, Cu, Sb, In, and Ag contamination on bacterial growth inhibition in PTYG (peptone, tryptone, yeast extract, glucose) liquid media, soil dehydrogenase activity, concentrations and compositions of phospholipids fatty acids (PLFA) were assessed. Survival rates of bacterial colony-forming units were lower in the presence of various concentrations of Pb, Cu, Sb, In, Ag, Zn and Ni than in their absence. Soil dehydrogenase activity in Arenic Eutric Regosol was much decreased when the concentrations of Pb and Cu were 50 times their natural abundance and when Ag was at 100 times its natural abundance. Soil dehydrogenase activity was also much decreased in Eutric Cambisol when Cu was 50 times, and Ag was 100 times, their natural abundances. In contrast, Sb and In did not affect soil dehydrogenase activity at any concentration or in any type of soil. Concentrations and composition of PLFA did not show any conspicuous change. Cu, Sb, In and, especially, Ag, which are increasingly being used to replace Pb, should be considered to be potentially toxic. However, when evaluating the impact of waste metals on the environment, heavy metal solubility, speciation and interaction with organic matter in soil must be considered.
Water Research, 1986
Alkaline earth cations, Ba 2+, Sr 2+, Ca 2+, Mg 2+ and transition metal ions, Mn 2+, Co 2+, Ni 2+... more Alkaline earth cations, Ba 2+, Sr 2+, Ca 2+, Mg 2+ and transition metal ions, Mn 2+, Co 2+, Ni 2+, cause hydrous manganese(IV) oxide (HMO) to strongly adsorb phosphate between pH 6 and 9 depending on the cation. The effectiveness of the alkaline earth cations to cause P adsorption was Ba 2+ > Sr 2+ > Ca 2+ > ig 2+, which is the same order as their affinities for the oxide. Changes with time were found in the abilities of the transition metals to cause P adsorption onto HMO and this may be due to conversion of the adsorbed cation to its oxide. A new potential role for HMO as an adsorbent of phosphate in natural waters was indicated.
Water Research, 1988
ABSTRACT The precipitation mechanisms of Mn(II) were studied from the viewpoint of adsorption ont... more ABSTRACT The precipitation mechanisms of Mn(II) were studied from the viewpoint of adsorption onto suspended solids (SS) and microbial oxidation of Mn in Lake Biwa. In aerobic water samples maintained in the laboratory, the concentration of dissolved Mn [Mn(II)] decreased at pH &gt; 7 by microbially mediated oxidation. Filtration, autoclaving and irradiation of u.v. light of the water samples and the addition of NaN3 inhibited the precipitation of Mn(II). The adsorption of Mn(II) onto SS was also appreciable at pH &gt; 7, and attained equilibrium within at least 30 min. The oxidation rate of Mn(II) was much less than the adsorption rate. In various environments of the lake (bottom water, sediment surface, river mouth, etc.) the initial adsorption of Mn(II) and subsequent slow oxidation mediated by bacteria may be essential to the mechanisms of Mn(II) precipitation.
Proceedings of the Japan Academy, Series B, 1985
In our previous papers , the vertical and horizontal distributions of various types of elements a... more In our previous papers , the vertical and horizontal distributions of various types of elements are described on short cores taken from more than thirty sampling stations covering the whole basin of Lake Biwa. Those papers give the following conclusions ; (1) Mn, As, P, Sb, Ni, Cu, Zn, Pb and ignition loss exhibit positive correlations with the water depth of sampling stations. Among those, concentrations of Mn and As show excellent ccrrelations with the water depth of sampling sites. Concentrations of Na and Hf in sediments have negative cor=relations with the water depth. (2) Concentrations of Sc and rare earths reflect the differences of source materials in the east and the west coasts to a certain extent. The present paper describes the vertical distribution profiles of Mn, As, P, Na, Hf and Al in the 1400 meter long core drilled from Lake Biwa and the classification of the paleoenvironment is discussed with respect to the change of water depth which is estimated based on the relation between concentrations of NIn and As and the water depth. Limitations of applicability of these relations will also be described. Results and discussions. Correlations between the water depth and concentrations o f Mn and As in sediments as possible measures for paleo-water depth. In Fig. , concentrations of Mn and As are plotted as functions of the water depth at sampling stations where short sediment cores were taken as described in the previous paper . The concentrations of Mn and As cited here are those of sediment layers 10 centimeter below the core tops. In those layers, diagenesis of bottom surface sediments at the early stage has been completed and the influence by anthropogenic pollution is not significant, if any. Except for a few points, smooth correlations can be obtained for both Mn and As. Quatratic functions can well be fitted to yield the following equations WD--1477X~~n+915XMn-48.7 WD = -0. 045XAS + 4. where WD refers to the water depth calculated, XMn to the concentration of Mn (%) and XAS to that of As (mg/kg) .
Proceedings of the Japan Academy. Ser. B: Physical and Biological Sciences, 1977
The newly obtained 1000 meter core samples from Lake Biwa were analysed for inorganic components ... more The newly obtained 1000 meter core samples from Lake Biwa were analysed for inorganic components by three different methods, namely, neutron activation analysis, X-ray fluorescence spectrometry and atomic absorption spectrophotometry. More than thirty elements could be determined by these methods. Samples analysed by neutron activation and by X-ray fluorescence were chosen at about three meter intervals along the core from 209 meters to 682 meters in drilled length. Mercury analysis was performed on samples chosen at about one meter intervals, from 252 meters to 484 meters of the drilled length of the boring. The present paper describes the analytical procedures and the results obtained, which are discussed in comparison with those results on the 200 meter core reported previously , 1975). Experimentals. Sample handling. Samples for inorganic analysis were taken out with clean plastic tools from the cores which were preliminarily cut symmetrically into two along the vertical direction. Care was taken to collect only the inner part of cores in order to avoid possible contaminations during the boring and cutting operations. Sediment samples thus obtained were taken into clean vials equipped with polyethylene stoppers and stored in a chilled room. Before the analysis, a part of sediments was taken out of a vial and air dried. In the case of mercury analysis, however, wet samples were used. Neutron Activation Analysis. Non-destructive analysis was performed. The same procedure was used as has been reported elsewhere . Elements which have been determined are Na, K,
New Phytologist, 2007
Leaf nitrogen (N) and phosphorus (P) concentrations are correlated in plants. Higher-level phylog... more Leaf nitrogen (N) and phosphorus (P) concentrations are correlated in plants. Higher-level phylogenetic effects can influence leaf N and P. By contrast, little is known about the phylogenetic variation in the leaf accumulation of most other elements in plant tissues, including elements with quantitatively lesser roles in metabolism than N, and elements that are nonessential for plant growth. Here the leaf composition of 42 elements is reported from a statistically unstructured data set comprising over 2000 leaf samples, representing 670 species and 138 families of terrestrial plants. Over 25% of the total variation in leaf element composition could be assigned to the family level and above for 21 of these elements. The remaining variation corresponded to differences between species within families, to differences between sites which were likely to be caused by soil and climatic factors, and to variation caused by sampling techniques. While the majority of variation in leaf mineral composition is undoubtedly associated with nonevolutionary factors, identifying higher-level phylogenetic variation in leaf elemental composition increases our understanding of terrestrial nutrient cycles and the transfer of toxic elements from soils to living organisms. Identifying mechanisms by which different plant families control their leaf elemental concentration remains a challenge.
Limnology and Oceanography, 1995
A mesocosm was installed in the Seto Inland Sea where outbreaks of Chattonella antiqua (red tide)... more A mesocosm was installed in the Seto Inland Sea where outbreaks of Chattonella antiqua (red tide) have frequently been observed. An artificial, shallow (6-m depth) nutrient stratification analogous to that observed with C. antiqua in nature was imposed. The initial bottom temperature of 20-22°C was optimum for C. antiqua excystmcnt as seeding, and the surface temperature of 25-27°C was optimum for growth. Excess nitrogen and phosphate compared with silicate changed the phytoplankton community from a mixture of diatoms and dinoflagellates to one of dinoflagellate dominance. Absence of copper toxicity was essential for growth of C. antiqua. Cessation of vertical circulation promoted accumulation of dinoflagellates at the water surface, and selective grazing toward small-size dinoflagellates by zooplankton controlled the population of dinoflagellates. C. antiqua could reach a depth of 7.5 m during diel vertical migration, and its migration speed was -0.8 m h-l; upward and downward speeds were the same. Outbreaks of C. antiqua were favored by artificial eutrophication and subsequent maintenance of a stable, shallow nutricline at a depth (6 m) such that C. antiqua could take up nutrients in the nutrient-rich lower layer at night. Chattonella antiqua (Hada) Ono (Raphidophyceae, spindle shape, 50-l 30 pm long) is the flagellate that causes most red tides in summer in the Seto Inland Sea of Japan; this flagellate caused severe damage to aquacultured yellowtail during the 1970s and 1980s. In the Seto Inland Sea, heavy rains from mid-June to mid-July supply large amounts of freshwater and nutrients; the nutrients are distributed throughout the water column by -20 July. Concentrations of POd3-and N are -0.1 and 3 PM at the surface and -0.5 and 5 PM at the bottom (20 m). A 2-3-week period of hot sunny weather follows, and inhibition of vertical mixing leads to stable salinity and temperature stratification. Phosphate and N in the surface waters are rapidly utilized (mainly by diatoms) at the beginning of August and could be limiting for C. antiqua, although -0.5 PM P043-and 5 PM N remain available below the nutricline. In 5 yr of observation, the presence of a shallow P-Cline (5-7 m) was most characteristic in 1987, the year of the C. antiqua outbreak,
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Papers by Takejiro Takamatsu