The information system of the French Peatland Observation Service: Service National d'Observation Tourbières – A valuable tool to assess the impact of global changes on the hydrology and biogeochemistry of temperate peatlands through long term monitoring     

Sébastien Gogo  Jean-Baptiste Paroissien  Fatima Laggoun-Défarge  Jean-Marc Antoine  Léonard Bernard-Jannin  Guillaume Bertrand  Philippe Binet  Stéphane Binet  Guillaume Bouger  Yohann Brossard  Thierry Camboulive  Jean-Pierre Caudal  Stéphane Chevrier  Geneviève Chiapiuso  Benoît D'Angelo  Pilar Durantez  Chris Flechard  André-Jean Francez  Didier Galop  Laure Gandois  Daniel Gilbert  Christophe Guimbaud  Louis Hinault  Adrien Jacotot  Franck Le Moing  Emilie Lerigoleur  Gaël Le Roux  Fabien Leroy  Alexandre Lhosmot  Qian Li  Elodie Machado Da Silva  Jean-Sébastien Moquet  Juanita Mora-Gomez  Laurent Perdereau  Thomas Rosset  Marie-Laure Toussaint 《水文研究》2021,35(6):e14244

Mitigating and adapting to global changes requires a better understanding of the response of the Biosphere to these environmental variations. Human disturbances and their effects act in the long term (decades to centuries) and consequently, a similar time frame is needed to fully understand the hydrological and biogeochemical functioning of a natural system. To this end, the ‘Centre National de la Recherche Scientifique’ (CNRS) promotes and certifies long-term monitoring tools called national observation services or ‘Service National d'Observation’ (SNO) in a large range of hydrological and biogeochemical systems (e.g., cryosphere, catchments, aquifers). The SNO investigating peatlands, the SNO ‘Tourbières’, was certified in 2011 ( https://www.sno-tourbieres.cnrs.fr/ ). Peatlands are mostly found in the high latitudes of the northern hemisphere and French peatlands are located in the southern part of this area. Thus, they are located in environmental conditions that will occur in northern peatlands in coming decades or centuries and can be considered as sentinels. The SNO Tourbières is composed of four peatlands: La Guette (lowland central France), Landemarais (lowland oceanic western France), Frasne (upland continental eastern France) and Bernadouze (upland southern France). Thirty target variables are monitored to study the hydrological and biogeochemical functioning of the sites. They are grouped into four datasets: hydrology, fluvial export of organic matter, greenhouse gas fluxes and meteorology/soil physics. The data from all sites follow a common processing chain from the sensors to the public repository. The raw data are stored on an FTP server. After operator or automatic processing, data are stored in a database, from which a web application extracts the data to make them available ( https://data-snot.cnrs.fr/data-access/ ). Each year at least, an archive of each dataset is stored in Zenodo, with a digital object identifier (DOI) attribution ( https://zenodo.org/communities/sno_tourbieres_data/ ).  相似文献   

Drying increases organic colloidal mobilization in the karst vadose zone: Evidence from a 15-year cave-monitoring study     

Jin Liao  Chaoyong Hu  Xiuli Li  Jiaoyang Ruan 《水文研究》2021,35(4):e14163

Understanding the hydrological processes of colloids within the karst vadose zone is vital to the security of karst groundwater and providing appropriate paleohydrological explanations of colloid-facilitated metals in speleothem. This study addresses the mobilization mechanisms driving colloidal organic matter (COM) transport in the karst vadose zone using a 15-year long monthly monitoring dataset from a cave drip point (HS4) in Heshang Cave, Qingjiang Valley, China. Variations in COM concentrations were reported as the fluorescence difference values of raw and filtered (<0.22 μm) samples at an excitation wavelength of 320 nm and emission wavelength of ~400 nm. A fluorescence humification index (HIX) lower than 0.8 and an autochthonous index (BIX) higher than 1.2 indicated that the origin of COM was mainly from the karst vadose zone, rather than the soil zone. The COM concentration varied from 0.001 to 0.038 Raman Unit (RU), with evident seasonal fluctuations. Rising limbs for COM values occurred prior to rising limbs within a dripwater hydrograph; moreover, the COM peak values corresponding to the beginning of the increasing hydrograph generally suggested that the mobilization of COM reflected the movement of the air–water interface (AWI) in the karst vadose zone rather than rainfall intensity or flow velocity. COM peak values were positively correlated with the antecedent drying duration and negatively correlated with HIX values. These phenomena may be explained by the increased amount of organic matter that was aggregated and absorbed on the surface of carbonate in the karst vadose zone during a longer drying duration. Moreover, the longer drying duration was also beneficial to autochthonous biological activity, which subsequently decreased the HIX value of the organic matter in the karst vadose zone. The movement of AWI and the drying duration are both controlled by the outside weather conditions. This study is therefore conducive to evaluating the security of karst groundwater in response to climate change, and challenges prevailing paleoclimate interpretations of colloid-facilitated metal abundance timeseries reported from speleothems.  相似文献   

从水体到沉积物:探寻有机质的沉积过程及其意义          下载免费PDF全文

蔡进功  曾翔  韦海伦  宋明水  王学军  刘庆 《古地理学报》2019,21(1):49-66

自然界中有机质分布广泛、类型多样且性质各异,不论在水体还是在沉积物(岩)中都扮演着重要的角色。因此,探讨各类型有机质聚集和沉积过程的差异性,对深化认识有机质沉积特征和演化规律具有重要的意义。生物体在生长过程中产生了许多有机质,包括生物体自身、生物残体、动物排泄物以及生物分泌的有机分子等,各类型有机质的性质差异极大。由于研究方法的不同,可将海洋中有机质划分为颗粒有机质(particulate organic matter,POM)和溶解有机质(dissolved organic matter,DOM),而DOM又可划分为胶体有机质(colloidal organic matter,COM)和真溶解有机质;从聚合体形式上看,又有海雪和悬浮体等存在形式。进一步分析发现有机质的形态包括生物体、生物残体、排泄物和有机质聚合体等,并且各类型有机质与无机矿物以不同的形式共存。此外,DOM与POM间存在一定的转化关系。这些性质和特征架起了不同类型有机质间聚集和沉积的桥梁。在沉积物(岩)中通过粒度或密度分级分离及孢粉相分析,也发现不同类型的有机质,如生物体、生物残体和无定形等,它们常与特定的无机矿物共生,如无定形多富集在黏粒级颗粒中,而生物体和生物残体多富集在粗颗粒中。进一步溯源发现沉积物(岩)中的各类有机质与生物有机质或海洋中有机质的类型极具相似性,这些特征展现各类型有机质在沉积过程中的差异性。综合有机质的形态、性质以及与矿物共生关系,认为有机质可通过机械沉积、化学沉积和生物沉积等3种不同的方式沉积保存,其中机械沉积的有机质以惰性的生物残体为主,化学沉积的有机质以活性极强的无定形为主,生物沉积有机质以活性较强的微生物和粘附物为主。有机质沉积方式及有机质特征、矿物—有机质间关系和保存条件的差异,决定了有机质的演化命运的不同,进而对有机质生烃以及碳循环产生重要的影响,因而应引起人们的高度关注。  相似文献   

烃源岩不同性质有机酸的分离及其检测方法     

杜佳宗  何蓓  蔡进功  雷天柱  刘庆  谢忠怀 《高校地质学报》2020,26(5):540-548

烃源岩中的有机酸来源于有机质，但有机质具有不同的赋存形式，有机酸具有不同性质，这将影响有机酸与不同赋存有机质的关系，进而影响分离和检测方法。文章在总结前人对有机质赋存形式和有机酸性质等特征的基础上，提出烃源岩中的有机酸并以非单一的形式存在，具有水溶性、脂溶性和难溶性有机酸三种类型，游离有机质中存在水溶性和脂溶性有机酸，而结合有机质中存在水溶性、脂溶性和难溶性有机酸。因此在检测方法上需采取分步分离的方法，且根据有机酸的性质选取合适的检测方法，即水溶性有机酸利用离子色谱检测，索氏抽提得到的脂溶性有机酸利用气相色谱—质谱检测，通过酸解抽提残渣得到的难溶性有机酸利用红外光谱检测，全面系统地认识烃源岩中有机酸含量和类型等特征。这对进一步探讨烃源岩各种类型有机酸特征和演化规律，深化烃源岩有机质生烃以及有机—无机相互作用等机理都具有重要意义。  相似文献   

黔北镇远牛蹄塘组黑色页岩沉积环境与有机质富集关系   总被引：1，自引：0，他引：1  

夏鹏  付勇  杨镇  郭川  黄金强  黄明勇 《地质学报》2020,94(3):947-956

通过矿物组分、主量元素、微量元素、碳氧同位素等特征，分析了黔北地区镇远县ZX井牛蹄塘组黑色页岩的岩相类型和不同岩相页岩的沉积环境及其与有机质富集间的关系。结果表明，牛蹄塘组下段以硅质页岩为主，TOC含量4. 96%~10. 10%；上段以富泥硅质页岩为主，TOC含量1. 43%~9. 04%。下段硅质页岩沉积于水流停滞的深水陆棚环境，沉积古水体为贫氧的还原状态；上段富泥硅质页岩沉积时期，仍为贫氧的还原环境，但水体滞留程度、还原性较下段硅质页岩沉积期弱。贫氧的还原环境是影响牛蹄塘组黑色页岩有机质富集的主要因素，热液作用和陆源碎屑对牛蹄塘组黑色页岩有机质富集的影响较小。  相似文献   

岩溶水硝酸盐污染原位修复试验     

叶进霞  夏春英  卜鸿志 《中国岩溶》2020,39(2):173-179

岩溶含水层的极不均一性特征使岩溶水溶质运移受构造、裂隙空间及其发育方向控制；因环境条件复杂，开展岩溶水污染原位修复技术难度较大，截止目前，国内尚未系统地开展岩溶含水层水污染原位修复研究工作。文章选择鲁中南山区典型岩溶发育及硝酸盐污染地段，施工组合钻孔建设修复试验工程，采用“乙醇+葡萄糖”液态碳源和“聚乙烯醇+淀粉颗粒”固态反应器分别进行岩溶水硝酸盐污染原位修复试验。结果表明:浓度500 mg?L－1、1 000 mg?L－1的“乙醇+葡萄糖”反硝化溶液对硝酸盐浓度的降解率分别为6.45 %和21.52 %；单位长度组成材料“聚乙烯醇3 kg+淀粉颗粒3 kg”、“聚乙烯醇2 kg+淀粉颗粒4 kg”的两种反硝化固态反应器对硝酸盐浓度的降解率分为33.91%和34.96%。试验证明在裂隙型岩溶地区采用孔组方案进行地下水污染原位修复技术可行、且能取得较显著效果。修复工程布设方式和试验成果对类似地区开展岩溶地下水污染原位修复具一定借鉴意义。   相似文献   

苔藓生物结皮层腐殖质组成变化特征研究          下载免费PDF全文

闫德仁  张胜男  吴振廷 《干旱区地理》2019,42(6):1354-1358

腐殖质组成是表征土壤化学性质的主要指标之一，在某种程度对评价风沙土的发育过程具有意义。采集了不同气候区沙地沙漠苔藓生物结皮层样品，采用重铬酸钾容量法和光密度法测定了苔藓结皮层腐殖质组成含量和胡敏酸吸光特性。结果表明：随着干燥指数的增加，苔藓结皮层有机质含量由14.93 g·kg^-1降低到9.89 g·kg^-1，腐殖酸总量由5.1 g·kg^-1降低到2.0 g·kg^-1，胡敏酸含量由2.9 g·kg^-1降低到 0.7 g·kg^-1，富里酸含量由2.2 g·kg^-1降低到1.3 g·kg^-1，胡敏酸与富里酸比值（HA/FA）由1.32降低到0.54，E₄/E₆比值则由4.28增加到5.83。苔藓结皮层腐殖质组成含量及胡敏酸吸光特性具有地带性变化趋势，并影响着生物结皮层及流动风沙土的发育演变过程。  相似文献   

全球主要河流流域碳酸盐岩风化碳汇评估   总被引：7，自引：0，他引：7  

李朝君  王世杰  白晓永  谭秋  李汇文  李琴  邓元红  杨钰杰  田诗琪  胡泽银 《地理学报》2019,74(7):1319-1332

碳酸盐岩风化吸收的大气CO₂主要以HCO₃ ^-形式连续地经由河流从大陆输送到海洋,成为陆地生态系统的重要碳汇。目前主要河流流域的碳酸盐岩风化碳汇估算存在不确定性,分布格局尚不清晰。基于GEMS-GLORI全球河流数据库提供的全球10万km ²以上主要河流流域多年平均监测数据,利用水化学径流法估算出全球主要河流流域碳酸盐岩对CO₂的吸收速率为0.43±0.15 Pg CO₂ yr ^-1,平均CO₂吸收通量为7.93±2.8 t km ^-2 yr ^-1。CO₂吸收通量在不同气候带下差异显著,热带和暖温带CO₂年吸收速率占全球主要河流流域年吸收速率的62.95%。冷温带CO₂年吸收速率占全球主要河流流域的33.05%,仅次于热带地区。本文划分出全球CO₂吸收通量的9个关键带,关键带的交汇处CO₂吸收通量较高。喀斯特出露流域碳酸盐岩对CO₂吸收通量的均值为8.50 t km ^-2 yr ^-1,约为非喀斯特流域的3倍。全球喀斯特出露流域碳酸盐岩风化碳汇在全球碳循环、水循环及碳收支平衡估算研究方面占据重要地位。  相似文献   

国际蓝碳合作发展与中国的选择   总被引：2，自引：0，他引：2  

赵鹏  胡学东 《海洋通报》2019,38(6):613-619

海洋储存了地球上93%的CO_2,是全球最大的碳库。发挥海洋固碳、储碳作用,对应对全球气候变化具有重要意义。《联合国气候变化框架公约》和《巴黎协定》是2020年后国际气候治理的基础,为国际蓝碳合作指明了方向,也提供了国际法依据。当前,国际蓝碳合作从科学研究向纳入国际气候治理方向不断推进,不少国际组织和国家已着手推动蓝碳国际规则制定。中国蓝碳资源分布广泛,特色鲜明,蓝碳发展起步阶段里中国的参与不仅是对全球应对气候变化的重要贡献,更有助于通过蓝碳合作增强我国在全球气候治理和海洋治理领域的影响力和话语权。我国蓝碳发展应从国内、国际两个方面着手。在国内夯实基础、补足短板,加强蓝碳基础研究和实践,建立蓝碳评估标准,加快蓝碳人才队伍建设。在国际上积极参与现有国际蓝碳计划,在"21世纪海上丝绸之路"等机制框架下开展双、多边蓝碳合作,推动全球蓝碳治理,从积极参与向适时引领发展。  相似文献   

Sedimentary and geochemical characterization of Middle–Late Miocene formations in the Neogene Tsugaru Basin,Japan by means of DTH27‐1 well sediment analysis     

Paolo Martizzi  Shun Chiyonobu  Hiroyuki Arato 《Island Arc》2020,29(1)

Middle–Late Miocene age siliceous formations outcropping along the northwestern side of Honshu Island are considered prospective source rocks for hydrocarbons. An analysis of geophysical, sedimentological, and geochemical properties is essential to evaluate the formations' source potential, and to understand the factors that determined the accumulation and preservation of organic matter. This study investigates the Middle–Late Miocene geological record of the Tsugaru back‐arc basin, located in the western part of Aomori prefecture, through an analysis of a 200 m long portion of a core from the DTH27‐1 well; this core is composed of the diatomaceous siltstones of the Akaishi Formation and the siliceous mudstones of the Odoji Formation. Sedimentological and geophysical characterization showed that the Akaishi Formation's diatomaceous siltstones are mostly massive and bioturbated, have low magnetic susceptibility, and demonstrate moderate natural radioactivity. Although the Odoji Formation's siliceous mudstones are massive, they have exceedingly low magnetic susceptibility and high natural radioactivity. Geochemical data from a Rock‐Eval Pyrolysis such as total organic carbon and generative potential (S1 + S2) revealed that, in the Tsugaru area, only the Odoji Formation is a likely prospective source rock for hydrocarbons. On the other hand, T_max values indicate that both the formations are thermally immature for generating hydrocarbons. The difference between the Akaishi and Odoji Formation in the sedimentological facies, in terms of the degree of bioturbation and the organic carbon content, indicates variations in lithological properties, such as porosity and grain size; moreover, this difference indicates a variation in the paleo‐oxygenation of bottom waters, with the transition from oxygen‐deficient conditions in the Middle Miocene to the more oxygenated conditions in the Late Miocene. Both the lithological and paleo‐environmental factors possibly influenced the organic richness in the two formations.  相似文献