Methane-rich fluids were recognized to be hosted in the reservoir volcanic rocks as primary inclusions. Samples were collected from core-drillings of volcanic gas reservoirs with reversed δ13C of alkane in the Xujiaw...Methane-rich fluids were recognized to be hosted in the reservoir volcanic rocks as primary inclusions. Samples were collected from core-drillings of volcanic gas reservoirs with reversed δ13C of alkane in the Xujiaweizi depression of the Songliao Basin. The volcanic rocks are rhyolite dominant being enriched in the more incompatible elements like Cs, Rb, Ba, Th, U and Th with relative high LREE, depleted HREE and negative anomalies of Ti and Nb, suggesting a melt involving both in mantle source and crustal assimilation. Primary fluids hosted in the volcanic rocks should have the same provenance with the magma. The authors concluded that the enclosed CH4 in the volcanics are mantle/magma-derived alkane and the reversed δ13C of alkane in the corresponding gas reservoirs is partly resulted from mixture between biogenic and abiogenic gases.展开更多
Microbial activity in soil is known to be controlled by various factors. However, the operating mechanisms have not yet been clearly identified, particularly under climate change conditions, although they are crucial ...Microbial activity in soil is known to be controlled by various factors. However, the operating mechanisms have not yet been clearly identified, particularly under climate change conditions, although they are crucial for understanding carbon dynamics in terrestrial ecosystems. In this study, a natural incubation experiment was carried out using intact soil cores transferred from high altitude(1 500 m) to low(900 m) altitude to mimic climate change scenarios in a typical cold-temperate mountainous area in Japan. Soil microbial activities, indicated by substrate-induced respiration(SIR) and metabolic quotient(q CO2), together with soil physicalchemical properties(abiotic factors) and soil functional enzyme and microbial properties(biotic factors), were investigated throughout the growing season in 2013. Results of principal component analysis(PCA) indicated that soil microbial biomass carbon(MBC) andβ-glucosidase activity were the most important factors characterizing the responses of soil microbes to global warming. Although there was a statistical difference of 2.82 ℃ between the two altitudes, such variations in soil physical-chemical properties did not show any remarkable effect on soil microbial activities, suggesting that they might indirectly impact carbon dynamics through biotic factors such as soil functional enzymes. It was also found that the biotic factors mainly controlled soil microbial activities at elevated temperature,which might trigger the inner soil dynamics to respond to the changing environment. Future studies should hence take more biotic variables into account for accurately projecting the responses of soil metabolic activities to climate change.展开更多
Global climate change effects will vary geographically, and effects on estuaries should be independently considered. This review of the impacts of climate change on the ecotoxicology of chemical contaminants aims to s...Global climate change effects will vary geographically, and effects on estuaries should be independently considered. This review of the impacts of climate change on the ecotoxicology of chemical contaminants aims to summarize responses that are specific to estuafine species. Estuarine organisms are uniquely adapted to large fluctuations in temperature, salinity, oxygen, and pH, and yet future changes in climate may make them more susceptible to chemical contaminants. Recent research has hig- hlighted the interactive effects of chemical and nonchemical stressors on chemical uptake, metabolism, and organism survival. Assessments have revealed that the nature of the interaction between climate variables and chemical pollution will depend on es- tuarine species and life stage, duration and timing of exposure, prior stressor exposure, and contaminant class. A need for further research to elucidate mechanisms of toxicity under different abiotic conditions and to incorporate climate change factors into toxicity testing was identified. These efforts will improve environmental risk assessment of chemical contaminants and manage- ment capabilities under changing climate conditions [Current Zoology 61 （4）： 641-652, 2015].展开更多
基金Supported by NSFC project No. 40372066 and SRFDP No. 20030183042
文摘Methane-rich fluids were recognized to be hosted in the reservoir volcanic rocks as primary inclusions. Samples were collected from core-drillings of volcanic gas reservoirs with reversed δ13C of alkane in the Xujiaweizi depression of the Songliao Basin. The volcanic rocks are rhyolite dominant being enriched in the more incompatible elements like Cs, Rb, Ba, Th, U and Th with relative high LREE, depleted HREE and negative anomalies of Ti and Nb, suggesting a melt involving both in mantle source and crustal assimilation. Primary fluids hosted in the volcanic rocks should have the same provenance with the magma. The authors concluded that the enclosed CH4 in the volcanics are mantle/magma-derived alkane and the reversed δ13C of alkane in the corresponding gas reservoirs is partly resulted from mixture between biogenic and abiogenic gases.
基金Supported by the Japan Science and Technology Agency(JST)Environmental Leadership Program(No.016100012)
文摘Microbial activity in soil is known to be controlled by various factors. However, the operating mechanisms have not yet been clearly identified, particularly under climate change conditions, although they are crucial for understanding carbon dynamics in terrestrial ecosystems. In this study, a natural incubation experiment was carried out using intact soil cores transferred from high altitude(1 500 m) to low(900 m) altitude to mimic climate change scenarios in a typical cold-temperate mountainous area in Japan. Soil microbial activities, indicated by substrate-induced respiration(SIR) and metabolic quotient(q CO2), together with soil physicalchemical properties(abiotic factors) and soil functional enzyme and microbial properties(biotic factors), were investigated throughout the growing season in 2013. Results of principal component analysis(PCA) indicated that soil microbial biomass carbon(MBC) andβ-glucosidase activity were the most important factors characterizing the responses of soil microbes to global warming. Although there was a statistical difference of 2.82 ℃ between the two altitudes, such variations in soil physical-chemical properties did not show any remarkable effect on soil microbial activities, suggesting that they might indirectly impact carbon dynamics through biotic factors such as soil functional enzymes. It was also found that the biotic factors mainly controlled soil microbial activities at elevated temperature,which might trigger the inner soil dynamics to respond to the changing environment. Future studies should hence take more biotic variables into account for accurately projecting the responses of soil metabolic activities to climate change.
文摘Global climate change effects will vary geographically, and effects on estuaries should be independently considered. This review of the impacts of climate change on the ecotoxicology of chemical contaminants aims to summarize responses that are specific to estuafine species. Estuarine organisms are uniquely adapted to large fluctuations in temperature, salinity, oxygen, and pH, and yet future changes in climate may make them more susceptible to chemical contaminants. Recent research has hig- hlighted the interactive effects of chemical and nonchemical stressors on chemical uptake, metabolism, and organism survival. Assessments have revealed that the nature of the interaction between climate variables and chemical pollution will depend on es- tuarine species and life stage, duration and timing of exposure, prior stressor exposure, and contaminant class. A need for further research to elucidate mechanisms of toxicity under different abiotic conditions and to incorporate climate change factors into toxicity testing was identified. These efforts will improve environmental risk assessment of chemical contaminants and manage- ment capabilities under changing climate conditions [Current Zoology 61 （4）： 641-652, 2015].
