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11.
Wasaki J Rothe A Kania A Neumann G Römheld V Shinano T Osaki M Kandeler E 《Journal of environmental quality》2005,34(6):2157-2166
White lupine (Lupinus albus L.) was used as a phosphorus (P)-efficient model plant to study the effects of elevated atmospheric CO(2) concentrations on (i) P acquisition, (ii) the related alterations in root development and rhizosphere chemistry, and (iii) the functional and structural diversity of rhizosphere microbial communities, on a P-deficient calcareous subsoil with and without soluble P fertilization. In both +P (80 mg P kg(-1)) and -P treatments (no added P), elevated CO(2) (800 micromol mol(-1)) increased shoot biomass production by 20 to 35% and accelerated the development of cluster roots, which exhibit important functions in chemical mobilization of sparingly soluble soil P sources. Accordingly, cluster root formation was stimulated in plants without P application by 140 and 60% for ambient and elevated CO(2) treatments, respectively. Intense accumulation of citrate and increased activities of acid and alkaline phosphatases, but also of chitinase, in the rhizosphere were mainly confined to later stages of cluster root development in -P treatments. Regardless of atmospheric CO(2) concentrations, there was no significant effect on accumulation of citrate or on selected enzyme activities of C, N, and P cycles in the rhizosphere of individual root clusters. Discriminant analysis of selected enzyme activities revealed that mainly phosphatase and chitinase contributed to the experimental variance (81.3%) of the data. Phosphatase and chitinase activities in the rhizosphere might be dominated by the secretion from cluster roots rather than by microbial activity. Alterations in rhizosphere bacterial communities analyzed by denaturing gradient gel electrophoresis (DGGE) were related with the intense changes in root secretory activity observed during cluster root development but not with elevated CO(2) concentrations. 相似文献
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Van Thinh Nguyen Matsumoto Masaru Zaw Myo Kuwahara Yoshihiro Xie Yiping Ozaki Akinori Kurosawa Kiyoshi 《Environmental geochemistry and health》2022,44(10):3249-3263
Environmental Geochemistry and Health - The arsenic-contaminated groundwater has attracted attention in much south and southeast Asian deltas, however, mainly on the deep aquifers. Here, arsenic... 相似文献
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Mitsuru Sasaki Kana Yamamoto Motonobu Goto 《Journal of Material Cycles and Waste Management》2007,9(1):40-46
In this study, hydrothermal electrolysis experiments using glucose (a biorelated substance) as a starting material were carried
out using a specially designed autoclave at 250°C. We could understand the fundamental reaction behavior of glucose under
these conditions through various kinds of experiments and product analyses. Another series of experiments using pressurized
CO2 as an electrolyte was conducted to discover whether it is possible to use CO2 as an alternative electrolyte to the conventional KCl electrolyte, with a view to lowering the environmental impact of the
process. It was found that pressurized CO2 was useful as an environmentally friendly electrolyte, although there were still some problems in terms of the reaction efficiency. 相似文献
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Nigussie Haregeweyn Atsushi Tsunekawa Mitsuru Tsubo Derege Meshesha Enew Adgo Jean Poesen Brigitta Schütt 《Regional Environmental Change》2016,16(4):951-966
In the drylands of the Upper Blue Nile basin, high climate variability and land degradation are rampant. To enhance adaptive capacity in the region, various soil and water conservation interventions have been implemented. Moreover, water resources development schemes such as the Grand Ethiopian Renaissance Dam should be implemented by 2025. We modeled the effects of these interventions on surface runoff in the basin for both current and future (2025) basin conditions, using the runoff coefficient method in a spatially explicit approach. Under current conditions, we observed high spatial variability of mean annual runoff. The northeastern Blue Nile-1 sub-basin produces the highest mean annual runoff (391 mm or 10 × 109 m3), whereas the northwestern Blue Nile-2 sub-basin produces the lowest mean annual runoff (178 mm or 0.2 × 109 m3). The basin generates a total annual runoff volume of 47.7 × 109 m3, of which about 54 % comes from cultivated land. The strong association between land use and topography masked the direct effect of rainfall on runoff. By 2025, total annual runoff yield could decrease by up to 38 % if appropriate basin-wide soil and water conservation interventions and the Grand Ethiopian Renaissance Dam are implemented. However, the full effects of most physical structures will only last for 1 or 2 years without regular maintenance. The improved understanding of the dynamics of the Upper Blue Nile basin’s hydrology provided by the present study will help planners to design appropriate management scenarios. Developing the basin’s database remains important for a holistic understanding of the impacts of future development interventions. 相似文献
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Kaoru Saito Kazuhiko Nakamura Mutsuyuki Ueta Reiko Kurosawa Akio Fujiwara Hill Hiroki Kobayashi Masaya Nakayama Ayako Toko Kazuyo Nagahama 《Ambio》2015,44(4):572-583
We have developed a system that streams and archives live sound from remote areas across Japan via an unmanned automatic camera. The system was used to carry out pilot bird censuses in woodland; this allowed us to examine the use of live sound transmission and the role of social media as a mediator in remote scientific monitoring. The system has been streaming sounds 8 h per day for more than five years. We demonstrated that: (1) the transmission of live sound from a remote woodland could be used effectively to monitor birds in a remote location; (2) the simultaneous involvement of several participants via Internet Relay Chat to listen to live sound transmissions could enhance the accuracy of census data collection; and (3) interactions through Twitter allowed members of the public to engage or help with the remote monitoring of birds and experience inaccessible nature through the use of novel technologies. 相似文献
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Fluxes of carbon dioxide, methane and nitrous oxide in two contrastive fringing zones of coastal lagoon, Lake Nakaumi, Japan 总被引:9,自引:0,他引:9
We measured fluxes of carbon dioxide (CO(2)), methane (CH(4)), and nitrous oxide (N(2)O) simultaneously in two typical fringing zones, sandy shore and salt marsh, of coastal lagoon, Lake Nakaumi, Japan, in mid-summer 2003. Our aim was to quantify net the greenhouse gases (GHGs) fluxes and examine key factors, which control variation of the GHGs fluxes in the two sites. Net CO(2) and CH(4) fluxes were markedly different between the two sites; magnitudes and variations of the both fluxes in sandy shore were lower than those of salt marsh. Meanwhile, magnitude and variation of net N(2)O flux in the two sites were similar. In sandy shore, temporal and spatial variation of the three GHGs fluxes were highly controlled by water level fluctuation derived from astronomic tide. In salt marsh, spatial variation of the three GHGs fluxes were correlated with aboveground biomass, and temporal variation of CO(2) and CH(4) fluxes were correlated with soil temperature. The sum of global warming potential, which was roughly estimated using the observed GHGs fluxes, was ca. 174-fold higher in salt marsh than in sandy shore. 相似文献
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Wahyudiono Mitsuru Sasaki Motonobu Goto 《Journal of Material Cycles and Waste Management》2007,9(2):173-181
Water at hydrothermal and supercritical conditions is considered a promising solvent for the degradation of hazardous waste
into harmless compounds. Tar liquefaction experiments were conducted using a batch-type reactor at temperatures between 623 K
and 673 K and at pressures between 25 and 40 MPa. A reaction mechanism for tar liquefaction is proposed. Moreover, on the
basis of the experimental results, this method could become an efficient method for tar liquefaction, producing high yields
of valuable chemical intermediates. 相似文献