独山子地区荒漠土的^14C年龄测定及意义

通过对独山子地区荒漠土碳酸盐淀积层的＾１４Ｃ年龄测定，探讨了碳酸盐淀积层碳的来源及其＾１４Ｃ年龄的可靠性问题，提出了根据碳酸盐淀积层的无机碳年龄，对确定土壤的年龄是有意义的。     

洞穴石笋的^14C年代学研究——石花洞研究系列之二

由于受“死碳”的影响,年轻洞穴碳酸盐的＾１４Ｃ测年始终受到限制,为此,建立了＾１４Ｃ法测定石笋生长速率及校正“死碳”影响的理论模式,从而将石笋的测年时限和精度大大提高。这一理论成功地运用于北京石花洞年轻石笋的定年。利用＾１４Ｃ法与石笋生长光性年际纹层推算的平均生长速率十分吻合,表明石笋Ｓ３１２的生长速率为０．０４２ｍｍ／ａ。＾２１０Ｐｂ法测定石笋顶部的年龄小于１００ａ,与＾１４Ｃ结果的外推年龄基本     

景泰老虎山活动断裂地区的第四纪地层的划分与对比研究

老虎山地区的第四系以山麓洪积与山区河流阶地沉积为主，￣１４Ｃ法、ＴＬ法和扩散方程法测定的近４０个年代样品表明：Ⅰ级阶地为全新统，阶地形成年龄为４０８６±１００ａ—４５７８±６０ａ；Ⅱ级阶地为晚更新世晚期沉积，阶地形成年龄为２３Ｋａ；Ⅲ级阶地为晚更新世早中期沉积，阶地形成年龄为７２Ｋａ；Ⅳ级阶地和Ⅴ级阶地为中更新世沉积，其阶地形成年龄分别为２１７±３５Ｋａ和３７８±６０Ｋａ；早更新统仅在局部出露，可能属早更新世早期的沉积。通过与兰州九洲台黄土剖面对比，发现Ⅰ—Ⅴ级阶地的形成年龄与标准剖面中的Ｓｏ、Ｓ＿２、Ｓ＿４等层古土壤形成年龄相一致。这说明河流层状地貌的形成。除了与构造抬升有关外，还与全球冷暖交替的大气候背景有着十分密切的内在联系     

^14C年龄测定中有关问题的探讨

新疆地震局＾１４Ｃ实验室为提供准确可靠＾１４Ｃ年代 数据,在选择,制备、测量本底苯,制备、测量糖碳苯,分析产品的淬灭对＾１４Ｃ年代的影响等方面进行了有效的试验与探讨。     

若尔盖盆地RM孔揭示的过去14万年古环境

根据青藏高原东部若尔盖盆地ＲＭ孔湖泊沉积物自生碳酸盐酸盐碳氧同位素,碳酸盐含量,木本花粉含量以及有机质量以及有机质含量分析,重建了１４万年以来的古气候与古环境过程,结果表明,１４万年来有５个气候环境显著变化时期,对应于深海氧同位素５个阶段。     

大布苏湖沉积剖面有机碳同位素特征与古环境

１９９４年９月,在吉林省大布苏湖湖盆东部,获取了总厚度为８．１０ｍ沉积剖面样品。以１０ｃｍ间隔采样,对样品中有机质成分及稳定碳同位素研究表明,沉积物中有机质主要来源于陆源高等植物,沉积物中有机物的δ＾１３Ｃ值指示了源生物的特征。在暖干时期,沉积物中有机质具有较高的δ＾１３Ｃ值;反之,冷湿时期,沉积物中有机质的δ＾１３Ｃ值降低,结合剖面碳酸盐含量及＾１４Ｃ年代分析表明,湖区１５０００年来经历了多期冷     

内蒙古湖相沉积14C年代测定中“硬水”影响的发现

对内蒙古科尔沁沙地巴克窑泡子湖相沉积物分别做了＾２１０Ｐｂ和＾１４Ｃ测年,比较这两种方法测定结果发现,＾１４Ｃ年龄比＾２１０Ｐｂ估计年龄偏老约２０００年,内蒙古其它湖泊的沉积物＾１４Ｃ测年资料一般也都存在年龄偏老问题,作者认为,这一现象主要是由干燥和半干燥地区湖泊“硬水”影响引起的。     

新疆14C年代测定及数据集（I＊）

主要介绍新疆维吾尔自治区地震局放射性同位素碳测年实验室的１４Ｃ测年原理,样品的前处理、样品的化学制备,低水平放射性测量方法及测定年代。首次公布一批１４Ｃ年代测定数据。     

泥炭样品不同有机组分的~(14)C测年的初步研究

分别用ＮａＣｌＯ、ＮａＯＨ溶液、Ｎａ４Ｐ２Ｏ７和ＮａＯＨ混合溶液和有机溶剂对采自延庆盆地大王庄两个泥炭样品进行前处理，每个样品获得１０个不同有机组分，对这些有机组分的１４Ｃ年龄测定值进行对比。以探讨泥炭等样品不同有机组分１４Ｃ测年的可靠性     

太湖沉积物中长链脂肪酸甲酯化合物的检出及意义

在太湖表层沉积物中检测出丰度较高的一系列长链脂肪酸甲酯化合物,采用标准图谱与质谱解析相结合的方法进行鉴定,长链脂肪酸甲酯化合物有类似正构烷烃的分布型式,碳数分布范围为Ｃ１４－Ｃ３４,主峰碳为Ｃ１６,具有明显的偶碳优势。     

Carbon sequestration processes and mechanisms in coastal mariculture environments in China

China is the global leader in mariculture production. Increasing sequestered marine carbon (also known as blue carbon) via mariculture activities is a promising approach for mitigating climate change and promoting the development of a low-carbon economy. Mariculture blue carbon is also considered an important component of China’s “sea granary”. In addition to shellfish and macroalgae yields, which represent carbon removed from mariculture environment, blue carbon also includes other important components, which have been largely neglected in the past, such as the carbon transformed by microbes, dissolved organic carbon (mainly referred to as recalcitrant dissolved organic carbon), and sedimentary particulate carbon. Hence, from different aspects, a comprehensive study on the formation processes and mechanisms of carbon sequestration is of great significance for comprehensively unveiling the carbon sequestration capability in coastal mariculture environment, which will contribute to the sustainable development of the fishery economy and construction of an ecological civilization. Moreover, it may add significant economic benefits to the future carbon-trading market.     

Controls on fluvial carbon efflux from eroding peatland catchments

Global peatlands store an unparalleled proportion of total global organic carbon but it is vulnerable to erosion into fluvial systems. Fluvial networks are being recognized as areas of carbon transformation, with eroded particulate organic carbon processed to dissolved organic carbon and CO₂. Existing studies indicate biodegradation and photodegradation as key processes controlling the transformation of organic carbon in fluvial systems, with initial concentrations of dissolved organic carbon (DOC) identified as a control on the rate of carbon mineralization. This study manipulates temperature and incident light intensity to investigate carbon mineralization rates in laboratory simulations of peatland sediment transport into fluvial systems. By directly measuring gaseous CO₂ emissions from sampled stream water, the relationship of temperature and light intensity with carbon efflux is identified. In simulations where sediment (as particulate organic matter, POM) is absent, temperature is consistently the dominant factor influencing carbon efflux rates. This influence is independent of the initial DOC concentration of the water sample. In simulations where POM was added, representing a peatland river receiving eroded terrestrial sediment, initial DOC concentration predicts 79% of the variation in total gaseous carbon efflux whereas temperature and light intensity predict 12% and 3%, respectively. When sampled stream water's mineralization rates in the presence of added POM are analysed independently, removing DOC as a model variable, the dominant variable affecting CO₂ efflux is opposite for each sample. This study presents novel data suggesting peatland erosion introduces further complexity to dynamic stream systems where rates of carbon transformation processes and the influence of specific environmental variables are interdependent. Anthropogenic climate change is identified as a leading risk factor perpetuating peatland erosion; therefore, understanding the fate of terrestrial sediment in rivers and further quantifying the benefits of protecting peatland soils will be of increasing importance to carbon budgeting and ecosystem function studies.     

The soil Microbial Carbon Pump as a new concept for terrestrial carbon sequestration

Soil is a huge terrestrial carbon pool, which has higher carbon storage than the sum of atmospheric and terrestrial vegetation carbon. Small fluctuations in soil carbon pool can affect regional carbon flux and global climate change. As soil organic carbon plays key roles in soil carbon storage and sequestration, studying its composition, sources and stability mechanism is a key to deeply understand the functions of terrestrial ecosystem and how it will respond to climate changes. The recently-proposed concept of soil Microbial Carbon Pump(MCP) emphasizes the importance of soil microbial anabolism and its contributions to soil carbon formation and stabilization, which can be applied for elucidating the source, formation and sequestration of soil organic carbon. This article elaborates MCP-mediated soil carbon sequestration mechanism and its influencing factors, as well as representative scientific questions we may explore with the soil MCP conceptual framework.     

How geomorphic context governs the influence of wildfire on floodplain organic carbon in fire-prone environments of the western United States

We draw on published studies of floodplain organic carbon storage, wildfire-related effects on floodplains in temperate and high latitudes, and case studies to propose a conceptual model of the effects of wildfire on floodplain organic carbon storage in relation to climate and valley geometry. Soil organic carbon typically constitutes the largest carbon stock in floodplains in fire-prone regions, although downed wood can contain significant organic carbon. We focus on the influence of wildfire on soil organic carbon and downed wood as opposed to standing vegetation to emphasize the geomorphic influences resulting from wildfire on floodplain organic carbon stocks. The net effect of wildfire varies depending on site-specific characteristics including climate and valley geometry. Wildfire is likely to reduce carbon stock in steep, confined valley segments because increased water and sediment yields following fire create net floodplain erosion. The net effect of fire in partly confined valleys depends on site-specific interactions among floodplain aggradation and erosion, and, in high-latitude regions, permafrost degradation. In unconfined valleys in temperate latitudes, wildfire is likely to slightly increase floodplain organic carbon stock as a result of floodplain aggradation and wood deposition. In unconfined valleys in high latitudes underlain by permafrost, wildfire is likely in the short-term to significantly decrease floodplain organic carbon via permafrost degradation and reduce organic-layer thickness. Permafrost degradation reduces floodplain erosional resistance, leading to enhanced stream bank erosion and greater carbon fluxes into channels. The implications of warming climate and increased wildfires for floodplain organic carbon stock thus vary. Increasing wildfire extent, frequency, and severity may result in significant redistribution of organic carbon from floodplains to the atmosphere via combustion in all environments examined here, as well as redistribution from upper to lower portions of watersheds in the temperate zone and from floodplains to the oceans via riverine transport in the high-latitudes. © 2019 John Wiley & Sons, Ltd.     

Coastal blue carbon: Concept,study method,and the application to ecological restoration

Coastal blue carbon refers to the carbon taken from atmospheric CO2; fixed by advanced plants(including salt marsh,mangrove, and seagrass), phytoplankton, macroalgae, and marine calcifiers via the interaction of plants and microbes; and stored in nearshore sediments and soils; as well as the carbon transported from the coast to the ocean and ocean floor. The carbon sequestration capacity per unit area of coastal blue carbon is far greater than that of the terrestrial carbon pool. The mechanisms and controls of the carbon sink from salt marshes, mangroves, seagrasses, the aquaculture of shellfish and macroalgae, and the microbial carbon pump need to be further studied. The methods to quantify coastal blue carbon include carbon flux measurements, carbon pool measurements, manipulative experiments, and modeling. Restoring, conserving, and enhancing blue carbon will increase carbon sinks and produce carbon credits, which could be traded on the carbon market. The need to tackle climate change and implement China's commitment to cut carbon emissions requires us to improve studies on coastal blue carbon science and policy. The knowledge learned from coastal blue carbon improves the conservation and restoration of salt marshes,mangroves, and seagrasses; enhances the function of the microbial carbon pump; and promotes sustainable aquaculture, such as ocean ranching.     

蓝藻水华衰亡对沉积物碳库有机碳组分的影响

湖泊沉积物碳库作为湖泊生态系统的重要组成部分,对湖泊碳循环起重要作用,而蓝藻水华衰亡过程对湖泊碳库稳定性影响研究较少本研究采集太湖蓝藻、湖水、沉积物样品,建立蓝藻水沉积物室内模拟实验系统,分析蓝藻水华衰亡过程中沉积物碳库易氧化有机碳(EOC)、惰性有机碳(ROC)、微生物量碳(MBC)、轻组有机碳(LFOC)和重组有机碳(HFOC)的变化规律,探究蓝藻水华衰亡过程对湖泊碳库稳定性的影响结果表明,蓝藻水华衰亡前期(1～9天),ROC缓慢下降,EOC和LFOC快速下降,MBC有所增加;衰亡中期(10～45天),沉积物TOC和ROC含量升高;衰亡末期(46～63天),HFOC和ROC等稳定有机碳进入一个从缓慢分解逐渐趋于稳定的阶段周期性的蓝藻水华暴发、衰亡和湖泊稳定性有机碳的日渐累积,最终会对沉积物碳库有机碳组分及其稳定造成显著影响.     

Removal of Pesticides in Drinking Water Treatment Entfernung von Pestiziden bei der Trinkwasseraufbereitung

The most effective process for the pesticide removal from a raw water is the adsorption on activated carbon except for polar substances. Activated carbon can be used as powdered carbon or granular carbon. However in both processes it has to be taken into account that the efficiency of the activated carbon adsorption is affected by the origin and the concentration of the natural organic background in the raw water and the initial concentration of the pesticide itself.     

Estimation of water requirement per unit carbon fixed by Eucalyptus camaldulensis in semi-arid land of Western Australia

Afforestation in arid land is a promising method for carbon fixation, but the effective utili-zation of water is highly important and required. Thus, the evaluation of the amount of water perunit carbon fixed with the tree growth is required to minimize the amount of water supplied to theplants. In this research, a tree is regarded as a carbon fixation reactor with inflows of water andnutrients from roots, and CO2 as the carbon source from leaves with outflow of water vapor fromleaves and accumulation in the tree itself. In the process of photosynthesis and respiration nutri-tional elements are dissolved in water flow in trees. They do not flow out by these reactions, butare accumulated in trees. Thus, we have treated the behaviour of nutrients as a marker to evaluatethe water/carbon ratio. Assuming that nutrient concentration is constant in sap, and the differences in the ratios ofnutrient to carbon in living trees and dead (i.e. litter fall, etc.) are negiected, the ratio of the usedwater to fixed carbon is given as the ratio of nutrient to carbon in the tree body divided by the ratioof nutrient to water in sap. However, some nutrients are translocated and concentrated within thetree and some may be discarded through litter fall. Thus it is important to examine which nutrientelement is the most suitable as the tracer. In this paper, the results of the above method applied to Eucalyptus camaldulensis in semi-arid land of Western Australia are shown. The value of water requirement per unit carbon fixationdetermined from potassium balance is between 421 kg-H2O/kg-C for mature trees and 285kg-H2O/k9-C for young trees, while the values from calcium balance are much larger than these.The cause of the discrepancy between these values is discussed based on the measured elementconcentrations in sap and trees and the plant physiology. Finally, the actual average value throughthe life of a tree is suggested to fall between the two values.     

Geomorphological controls on fluvial carbon storage in headwater peatlands

Geomorphological controls and catchment sediment characteristics control the formation of floodplains and affect their capacity to sequester carbon. Organic carbon stored in floodplains is typically a product of pedogenic development between periods of mineral sediment deposition. However, in organically-dominated upland catchments with a high sediment load, eroded particulate organics may also be fluvially deposited with potential for storage and/or oxidation. Understanding the redistribution of terrestrial carbon laterally, beyond the bounds of river channels is important, especially in eroding peatland systems where fluvial particulate organic carbon exports are often assumed to be oxidised. Floodplains have the potential to be both carbon cycling hotspots and areas of sequestration. Understanding of the interaction of carbon cycling and the sediment cascade through floodplain systems is limited. This paper examines the formation of highly organic floodplains downstream of heavily eroded peatlands in the Peak District, UK. Reconstruction of the history of the floodplains suggests that they have formed in response to periods of erosion of organic soils upstream. We present a novel approach to calculating a carbon stock within a floodplain, using XRF and radiograph data recorded during Itrax core scanning of sediment cores. This carbon stock is extrapolated to the catchment scale, to assess the importance of these floodplains in the storage and cycling of organic carbon in this area. The carbon stock estimate for the floodplains across the contributing catchments is between 3482-13460 tonnes, equating on an annualised basis to 0.8-4.5% of the modern-day POC flux. Radiocarbon analyses of bulk organic matter in floodplain sediments revealed that a substantial proportion of organic carbon was associated with re-deposited peat and has been used as a tool for organic matter source determination. The average age of these samples (3010 years BP) is substantially older than Infrared Stimulated Luminesence dating which demonstrated that the floodplains formed between 430 and 1060 years ago. Our data suggest that floodplains are an integral part of eroding peatland systems, acting as both significant stores of aged and eroded organic carbon and as hotspots of carbon turnover. © 2019 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.     

Terrestrial carbon cycle model-data fusion: Progress and challenges

The terrestrial carbon cycle is an important component of global biogeochemical cycling and is closely related to human well-being and sustainable development. However, large uncertainties exist in carbon cycle simulations and observations.Model-data fusion is a powerful technique that combines models and observational data to minimize the uncertainties in terrestrial carbon cycle estimation. In this paper, we comprehensively overview the sources and characteristics of the uncertainties in terrestrial carbon cycle models and observations. We present the mathematical principles of two model-data fusion methods, i.e., data assimilation and parameter estimation, both of which essentially achieve the optimal fusion of a model with observational data while considering the respective errors in the model and in the observations. Based upon reviewing the progress in carbon cycle models and observation techniques in recent years, we have highlighted the major challenges in terrestrial carbon cycle model-data fusion research, such as the "equifinality" of models, the identifiability of model parameters,the estimation of representativeness errors in surface fluxes and remote sensing observations, the potential role of the posterior probability distribution of parameters obtained from sensitivity analysis in determining the error covariance matrixes of the models, and opportunities that emerge by assimilating new remote sensing observations, such as solar-induced chlorophyll fluorescence. It is also noted that the synthesis of multisource observations into a coherent carbon data assimilation system is by no means an easy task, yet a breakthrough in this bottleneck is a prerequisite for the development of a new generation of global carbon data assimilation systems. This article also highlights the importance of carbon cycle data assimilation systems to generate reliable and physically consistent terrestrial carbon cycle reanalysis data products with high spatial resolution and longterm time series. These products are critical to the accurate estimation of carbon cycles at the global and regional scales and will help future carbon management strategies meet the goals of carbon neutrality.