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岩溶生物地球化学研究的进展与问题 总被引：2，自引：1，他引：1
在CO2-水-碳酸盐岩活跃的代谢体系中,由于参与岩溶作用过程的二氧化碳来源复杂,因而研究碳酸盐岩环境中二氧化碳在生物介导下所耦联的物质循环过程及其与全球变化的关系成为岩溶生物地球化学学科的主要内容,并使其成为现代岩溶学的重要分支。在分析国内外岩溶学、地球化学、生物学等交叉学科研究成果的基础上,本文简要评述了基于岩溶生物地球化学特性的水土流失与石漠化过程,碳酸盐岩矿物在生物作用下的化学风化、元素释放规律以及控制元素循环的界面过程,碳酸盐岩区土壤－大气界面下的气体循环及其控制因素和过程,碳酸盐岩区有机污染物在环境中的来源、分布规律与降解,微型生物在岩溶水体碳循环过程中的作用等主题的主要研究进展和存在的科学问题。因此,需要以CO2为核心把岩溶环境中不同尺度上生物有机体参与的地球化学过程联系起来,但人们对生物有机体是如何通过协同作用而改变岩溶环境的,还了解得很少。如果能查明碳酸盐岩一土壤一水一生物相互作用产生的功能,岩溶生物地球化学将进一步拓展CO2-水-碳酸盐岩相耦合的岩溶作用过程,并在岩溶资源领域和全球变化领域有广阔的应用前景。因此,岩溶生物地球化学需要多学科的协同研究,特别是加强生物过程与岩溶过程的耦合研究,方能解决岩溶领域存在的生态环境问题。 相似文献
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碳酸盐岩在全球碳循环过程中的作用 总被引：22，自引：3，他引：22
碳酸盐岩是地球上最主要的碳库，开展全球变化研究应重视碳酸盐岩在岩溶作用过程中的地球化学动力学研究。这方面的科学问题有二个。第一是关于全球碳酸盐岩的碳库容量问题，尚须利用全球沉积岩和碳酸盐岩数据库，根据全球地质历史时期碳酸盐岩的分布面积、厚度和岩石成分等进行重新计算。其次是关于碳酸盐岩在岩溶作用过程中对全球碳循环的动力学贡献问题。一方面碳酸盐岩的溶蚀作用不仅关系到海洋ＣａＣＯ＿３的供给量而影响海洋中碳通量的平衡，而且还可直接回收大气圈中的ＣＯ＿２；另一方面由于钙华的沉积又可向大气圈释放ＣＯ＿２，而影响温空气体的变化。它们构成了大气温室气体源汇关系中不可忽视的一项。 相似文献
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碳酸盐岩是岩溶发育的物质基础,它记录着地球历史时期的环境变化,是地球最大的碳库,对地球大气和生命演变起到重要作用;现代全球岩溶分布面积2200万km~2,占陆地面积的15%,岩溶动力系统是地球表层系统的重要组成部分,全球25%的人口依赖岩溶地下水资源的供给,岩溶生态系统的脆弱性制约着区域经济社会发展;本文主要针对近30年以来,岩溶学科发展进行综述,包括岩溶动力学概念、内涵与发展,驱动岩溶发育的地质-生态机制,岩溶动力系统与碳循环新进展,岩溶动力系统与水循环新进展,岩溶动力系统与钙循环新进展;岩溶动力系统与全球环境变化研究发展展望(岩溶关键带下的资源环境效应及国际大科学计划的启动)。 相似文献
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现代岩溶学和全球变化研究 总被引：26，自引：2，他引：26
广泛的全球岩溶对比和地球系统科学理论的引入以及研究方法的解决，推动了现代岩溶学的发展，从而显示其在全球变化研究中的重要性。现代岩溶学的新发展在全球变化研究中具有两方面意义：一是岩溶作用在大气温室气体ＣＯ２源汇关系中的效应，初步估算全球岩溶作用每年可由大气回收６．０２×１０８ｔ碳；二是由岩溶记录提取高分辨率的环境变化信息。我国大陆岩溶不但面积辽阔，而且碳酸盐岩古老坚硬，新生代以来大幅度抬升以及未受末次冰期大陆冰盖的刨蚀破坏，因而保留第四纪环境变化的信息量很大。我国季风区水热配套，岩溶作用的季节和地区反差明显，极有利于进行岩溶作用与大气ＣＯ２源汇关系研究。我们应该充分发挥这种地域优势，为全球变化研究作出应有贡献 相似文献
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表层岩溶带的岩溶动力学特征及其环境和资源意义 总被引：57，自引：6，他引：51
表层岩溶带处于四大圈层的交汇带,碳－ 水－ 钙循环活跃,溶蚀和沉积化学反应都比较迅速,岩溶动力作用强烈而且对环境变化具有敏感性。表层岩溶带快速的岩溶过程以及对环境变化的敏感性,赋存大量短时间尺度的环境变化信息,可提高地质过程在全球环境变化研究的地位; 表层岩溶带碳－ 水－ 钙循环的活跃和与环境岩溶动力条件的相关性,使得表层岩溶带对环境 Ｃ Ｏ２ 的变化具有调节作用,从而对碳循环的研究具有重要意义;表层岩溶带的发育使南方岩溶区具有浅层岩溶水循环与地下管道水循环耦合的二次岩溶水循环的结构特征,加强了岩溶水的调 相似文献
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岩溶动力学的理论探索与实践 总被引：29，自引：3，他引：26
国土资源部岩溶动力学重点实验室的研究群体自1990年以来连续成功实施了3个国际岩溶对比计划项目,包括IGCP299、IGCP379、IGCP448,在岩溶形成、碳循环、岩溶生态和水资源等领域,为国际岩溶学术界提供了共同解决岩溶地区资源环境问题的机会,将地球系统科学思想引入现代岩溶学,建立岩溶动力学理论,有力地推动了国际岩溶学科的发展.目前正在执行的IGCP513"岩溶含水层与水资源"项目继续引领国际岩溶地质研究方向.相关成果为在中国桂林建立联合国教科文组织"国际岩溶研究中心"(IRCK)奠定了坚实基础.由此回顾了20多年来岩溶动力学理论在中国的发展过程.概述了其主要的科学成果和应用前景.指出了地球系统科学的引入、全球视野的研究和及时将理论用于解决岩溶地区的资源环境问题在现代岩溶学发展中的重要意义.经过20余年的不断探索,形成了岩溶动力学理论的基本思路,并创造性地总结了一套捕捉碳、水、钙循环的行踪的工作方法.通过全球对比,提出"岩溶形态组合"概念,将岩溶形态组合与岩溶形成环境条件建立对应关系,解决异质同相、同质异相这一令岩溶学者迷惘的问题.将岩溶学引入伞球变化研究,一方面把岩溶作用与全球碳循环紧密的联系在一起,通过对CO2H2O-CaCO3系统(岩溶动力系统)的定位观测,发现全球最大的碳库-碳酸盐岩体在伞球碳循环中仍甚活跃;另一方面,岩溶动力系统(KDS)对环境变化十分敏感,响应及时,其相关沉积物可记录全球变化.将岩溶地质过程与生态学联系在一起,将现代岩溶学理论的研究推向应用,与生产实践结合.在岩溶动力系统运行机制和运行规律、我国岩溶动力系统的类型划分和分布规律、在表生岩溶系统碳循环与大气CO2源汇关系、利用石笋记录重建古气候、古环境变化过程及中国西南岩溶生态系统研究等方面均获得了突出成果,如首次估算了我国和全球因碳酸盐岩溶蚀回收大气CO2的量,中国为1.774×107t/a,而全球为6.08×105t/a;证实了西南岩溶区典型表层岩溶泉水化学的季节、日变化与暴雨动态,表层岩溶泉水化学取样的频率需要重新审定,而且水文水化学的连续监测对于岩溶作用强度和岩溶作用碳循环的高精度评价是十分必要的;要了解岩溶系统水化学的变化,仅考虑水-岩相互作用是不够的,我们还必须重视CO2气体对岩溶系统中水化学变化的影响,即岩溶系统水化学动态的变化是CaCO3-H2O-CO2三者相瓦作用引起的,水-岩-气相互作用的概念必须引入岩溶水化学的研究中;揭示了过去0.16 Ma来亚洲季风和低纬度地区降雨变化的特征,说明太阳辐射强度增高,驱动了盛间冰期的出现,重建了荔波地区2.3 ka来古气候环境的演变历史,贵州董哥洞石笋提供了低纬度、低海拔地区,可较好定年,更接近水汽来源区的古气候变化的替代指标;石笋记录发现末次冰期以来存在有多次冷事件-Heinrich冷事件H1～H5跃变事件,新仙女木事件在我国南方的洞穴沉积物中具有显著的反映.对西南8省区市岩溶县、石漠化严重县统计和空间分布特征的分析研究表明地质地貌条件对岩溶区资源、环境和社会经济具有制约作用,认为西南岩溶区石漠化综合治理首先要在岩溶地质条件的基础上,结合气候、水文和社会经济状况,才能深入分析岩溶区石漠化的成因、危害和类型.划分出岩溶区石漠化综合治理区域8大区成为"西南岩溶石漠化综合治理规划大纲"编写的重要基础. 相似文献
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北京西山黑龙关泉域岩溶水系统边界与水文地质性质 总被引：6，自引：0，他引：6
北方岩溶水系统具有固定补给范围和资源要素,是岩溶地下水进行独立循环的基本单元,控制了岩溶水的运移富集、水化学演化特征、资源构成以及环境地质问题。开展岩溶水系统研究的首要任务是确定系统边界位置及其水文地质性质。以北京西山黑龙关泉域岩溶水系统为研究对象,采用地质学、岩溶动力学、流体动力学、水文地球化学、地球物理勘探等方法,确定黑龙关泉域岩溶水系统是由南部大石河背斜岩溶水子系统和北部百花山向斜南翼岩溶水子系统2个次级系统组成;其含水岩层分别为蓟县系铁岭组、雾迷山组和青白口系景儿峪组、奥陶系、寒武系碳酸盐岩。根据边界的水文地质性质可以划分为地表分水岭边界、地下分水岭边界、隔水边界、岩溶含水层深埋滞流性边界等类型。 相似文献
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岩溶关键带及其碳循环研究进展 总被引：1，自引：0，他引：1
岩溶关键带的范畴包含了大气-(降水)-植被-土壤-裂隙-基岩-水组成的“碳-水-钙”循环强烈的表层岩溶带以及岩溶管道-洞穴-地下河-隔水层组成的巨大岩溶地下空间,岩溶关键带碳循环是岩溶地球系统科学研究的前沿方向。总结概括了岩溶地球系统科学发展至今的岩溶关键带范畴内碳循环及其对大气CO2源汇效应的研究成果,包括早期碳运移模型、当前主流的区域岩溶碳汇量的计算方法和结果以及“生物碳泵”的新发现等,讨论了当前岩溶碳循环研究框架过于单一或不一致以及碳周转时间尺度等问题,提出应对岩溶关键带碳输入、赋存以及碳输出的各个环节做出系统化监测,通过联网在线高分辨率监测站点的建设以及“3S”技术实现点位到区域的研究,使岩溶碳汇在全球碳循环模型中的重要性更具说服力。 相似文献
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表层岩溶系统因碳酸盐岩－水－CO2(气)三相的化学动态不平衡过程而产生特殊的碳循环环节,参加循环的碳包括碳酸盐岩中的碳、大气和土壤空气CO2部分。中国南方表层岩溶系统的碳循环非常活跃,并敏感地响应岩溶动力因素的变化,从而促进了地球化学过程和生物化学过程的结合,成为大气CO2汇的重要项。中国南方表层岩溶系统的碳循环通过驱动环境的元素迁移,促进土壤有机质的积累,并影响植物所需要的矿物质营养元素的全量和有效态,进而影响岩溶区的植物物种、特有性和作物的发育。 相似文献
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典型岩溶水系统碳汇通量估算 总被引：6，自引：1，他引：5
现代岩溶学研究成果表明,碳酸盐岩在全球碳循环中响应极其迅速,水循环过程中的碳汇效应显著。本研究选取广西桂林寨底地下河系统、广西环江大安地下河系统、重庆北碚青木关地下河系统三个典型岩溶地下水系统,利用各系统地下河的流量和HCO3-浓度的监测资料,采用简单化学平衡模式法估算碳汇通量(CO2)。结果显示,寨底地下河系统的单位面积年碳汇通量为68.82 t/(km2.a),大安地下河系统的单位面积年碳汇通量为81.18 t/(km2.a),青木关地下河系统的单位面积年碳汇通量为100.07 t/(km2.a)。分析认为同一个岩溶水系统的结构特征和环境条件基本上是稳定的;地下河的流量和HCO3-浓度是影响岩溶碳汇强度的关键因素,尤其是地下河流量的变化对碳汇强度的影响显著;不同岩溶水系统的碳汇通量不但受水化学条件和地下水动力条件的控制,同时受土地利用变化的影响。该研究对于改进碳循环模型和评价岩溶地质碳汇有重要意义。 相似文献
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Zou Lin Dong Lin Ning Meng Huang Kangjun Peng Yongbo Qin Shujian Yuan Honglin Shen Bing 《中国地球化学学报》2019,38(4):481-496
The continent is the second largest carbon sink on Earth’s surface. With the diversification of vascular land plants in the late Paleozoic, terrestrial organic carbon burial is represented by massive coal formation, while the development of soil profiles would account for both organic and inorganic carbon burial. As compared with soil organic carbon, inorganic carbon burial, collectively known as the soil carbonate, would have a greater impact on the long-term carbon cycle. Soil carbonate would have multiple carbon sources, including dissolution of host calcareous rocks, dissolved inorganic carbon from freshwater, and oxidation of organic matter, but the host calcareous rock dissolution would not cause atmospheric CO2 drawdown. Thus, to evaluate the potential effect of soil carbonate formation on the atmospheric pCO2 level, different carbon sources of soil carbonate should be quantitatively differentiated. In this study, we analyzed the carbon and magnesium isotopes of pedogenic calcite veins developed in a heavily weathered outcrop, consisting of limestone of the early Paleogene Guanzhuang Group in North China. Based on the C and Mg isotope data, we developed a numerical model to quantify the carbon source of calcite veins. The modeling results indicate that 4–37 wt% of carbon in these calcite veins was derived from atmospheric CO2. The low contribution from atmospheric CO2 might be attributed to the host limestone that might have diluted the atmospheric CO2 sink. Nevertheless, taking this value into consideration, it is estimated that soil carbonate formation would lower 1 ppm atmospheric CO2 within 2000 years, i.e., soil carbonate alone would sequester all atmospheric CO2 within 1 million years. Finally, our study suggests the C–Mg isotope system might be a better tool in quantifying the carbon source of soil carbonate.
相似文献14.
《China Geology》2018,1(1):17-27
On the basis of proposing the existence of a karst carbon cycle and carbon sink at a watershed scale, this paper provides four pieces of evidence for the integration of geology and ecology during the carbon cycle processes in the karst dynamic system, and estimated the karst carbon sink effect using the methods of comparative monitoring of paired watersheds and the carbon stable isotope tracer technique. The results of the soil carbon cycle in Maocun, Guilin, showed that the soil carbon cycle in the karst area, the weathering and dissolution of carbonate rocks under the soil, resulted in a lower soil respiration of 25% in the karst area than in a non-karst area (sandstone and shale), and the carbon isotope results indicated that 13.46% of the heavy carbon of the limestone is involved in the soil carbon cycle. The comparative monitoring results in paired watersheds, suggesting that the HCO3- concentration in a karst spring is 10 times that of a rivulet in a non-karst area, while the concentration of inorganic carbon flux is 23.8 times. With both chemical stoichiometry and carbon stable isotopes, the proportion of carbon in karst springs derived from carbonate rocks was found to be 58.52% and 37.65% respectively. The comparison on carbon exchange and isotopes at the water-gas interface between the granite and carbonate rock basins in the Li River showed that the CO2 emission of the karst water is 10.92 times that of the allogenic water from the non-karst area, while the carbon isotope of HCO3- in karst water is lighter by 8.62‰. However, this does not mean that the karst water body has a larger carbon source effect. On the contrary, it means the karst water body has a greater karst carbon sink effect. When the karst subterranean stream in Zhaidi, Guilin, is exposed at the surface, carbon-rich karst water stimulated the growth of aquatic plants. The values of carbon stable isotopes in the same species of submerged plants gradually becomes heavier and heavier, and the 512 m flow process has a maximum range of 15.46‰. The calculation results showed that 12.52% of inorganic carbon is converted into organic carbon. According to the data that has been published, the global karst carbon sink flux was estimated to be 0.53-0.58 PgC/a, equivalent to 31.18%-34.41% of the global forest carbon sink flux. In the meanwhile, the karst carbon sink flux in China was calculated to be 0.051 PgC/a, accounting for 68% of its forest carbon sink flux. 相似文献
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The carbon cycle in a global sense is the biogeochemical process by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the earth. For epikarst systems, it is the exchange of carbon among the atmosphere, water, and carbonate rocks. Southern China is located in the subtropical zone; its warm and humid weather creates favorable conditions for the dynamic physical, chemical, and ecological processes of the carbon cycle. This paper presents the mechanisms and characteristics of the carbon cycle in the epikarst systems in south China. The CO2 concentration in soils has clear seasonal variations, and its peak correlates well with the warm and rainy months. Stable carbon isotope analysis shows that a majority of the carbon in this cycle is from soils. The flow rate and flow velocity in an epikarst system and the composition of carbonate rocks control the carbon fluxes. It was estimated that the karst areas in south China contribute to about half of the total carbon sink by the carbonate system in China. By enhancing the movement of elements and dissolution of more chemical components, the active carbon cycle in the epikarst system helps to expand plant species. It also creates favorable environments for the calciphilic plants and biomass accumulation in the region. The findings from this study should help in better understanding of the carbon cycle in karst systems in south China, an essential component for the best management practices in combating rock desertification and in the ongoing study of the total carbon sink by the karst flow systems in China. 相似文献
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It is recognized that karst processes are actively involved in the current global carbon cycle based on twenty years research, and the carbon sink occurred in karst processes is possibly an important part of “missing sink” in global carbon cycle. In this paper, an overview is given on karst carbon cycle research, and influence factors, formed carbon pools (background carbon sink) and sink increase potentials of current karst carbon cycle are analyzed. Carbonate weathering could contribute to the imbalance item (BIM) and land use change item (ELUC) in the global carbon cycle model, owing to its uptake of both atmospheric CO2 (carbon sink effect) and CO2 produced by soil respiration (carbon source reduction effect). Karst carbon sink includes inorganic carbon sink resulted from hydrogeochemical process and organic carbon sink generated by aquatic photosynthetic DIC conversion, forming relatively stable river (reservoir) water body or sediment carbon sink. The sizes of both sinks are controlled by terrestrial ecosystems and aquatic ecosystems, respectively. Desertification rehabilitation and carbon sequestration by aquatic plants are two effective ways to increase the carbon sink in karst area. It is estimated that the rate of carbon sink is at least 381 000 t CO2/a with vegetation restoration and afforestation in southwest China karst area, while the annual organic carbon sink generated by aquatic photosynthesis is about 84 200 t C in the Pearl River Basin. The development of a soil CO2 based model for assessment of regional dissolution intensity will help to improve the estimation accuracy of carbon sink increase and potential, thus provide a more clear and efficient karst sink increase scheme and pathway to achieve the goals of “double carbon”. With the deep investigation on karst carbon cycle, mechanism and carbon sink effect, and the improvement of watershed carbon sink measurement methods and regional sink increase evaluation approaches. Karst carbon sink is expected to be included in the list of atmospheric CO2 sources/sinks of the global carbon budget in the near future. 相似文献
17.
我国南方岩溶区与北方黄土区都是巨大的碳库。碳酸盐的溶蚀及再结晶是两个碳库与大气ＣＯ２交换的重要过程。碳的区域平衡是评价化学风化消耗或逸散ＣＯ２的基础。岩溶区与黄土区在地球化学风化的环境背景、溶蚀过程、产物运移和归宿等差异很大。黄土区化学风化消耗大气ＣＯ２通量较岩溶区小。目前评价两类地区土壤与大气ＣＯ２的源汇关系尚不成熟,需要定量认识土壤ＣＯ２与下伏碳酸盐岩溶蚀或与下伏黄土次生碳酸盐化作用。岩溶区湖泊沉积物中有机质分解产生的ＨＣＯ３－制约外源及内生碳酸盐溶解和自生碳酸盐形成。 相似文献
18.
Takuya Manaka Hiroyuki Ushie Daisuke Araoka Akihiko Inamura Atsushi Suzuki Hodaka Kawahata 《Aquatic Geochemistry》2013,19(4):281-302
The global carbon cycle, one of the important biogeochemical cycles controlling the surface environment of the Earth, has been greatly affected by human activity. Anthropogenic nutrient loading from urban sewage and agricultural runoff has caused eutrophication of aquatic systems. The impact of this eutrophication and consequent photosynthetic activity on CO2 exchange between freshwater systems and the atmosphere is unclear. In this study, we focused on how nutrient loading to lakes affects their carbonate system. Here, we report results of surveys of lakes in Japan at different stages of eutrophication. Alkalization due to photosynthetic activity and decreases in PCO2 had occurred in eutrophic lakes (e.g., Lake Kasumigaura), whereas in an acidotrophic lake (Lake Inawashiro) that was impacted by volcanic hot springs, nutrient loading was changing the pH and carbon cycling. When the influence of volcanic activity was stronger in the past in Lake Inawashiro, precipitation of volcanic-derived iron and aluminum had removed nutrients by co-precipitation. During the last three decades, volcanic activity has weakened and the lake water has become alkalized. We inferred that this rapid alkalization did not result just from the reduction in acid inputs but was also strongly affected by increased photosynthetic activity during this period. Human activities affect many lakes in the world. These lakes may play an important part in the global carbon cycle through their influence on CO2 exchange between freshwater and the atmosphere. Biogeochemical changes and processes in these systems have important implications for future changes in aquatic carbonate systems on land. 相似文献
19.
Cheng Zeng Vivian Gremaud Haitao Zeng Zaihua Liu Nico Goldscheider 《Environmental Earth Sciences》2012,65(8):2285-2297
About two hydrological years of continuous data of discharge, temperature, electrical conductivity and pH have been recorded
at the Glarey spring in the Tsanfleuron glaciated karst area in the Swiss Alps, to understand how glaciated karst aquifer
systems respond hydrochemically to diurnal and seasonal recharge variations, and how calcite dissolution by glacial meltwater
contributes to the atmospheric CO2 sink. A thermodynamic model was used to link the continuous data to monthly water quality data allowing the calculation of
CO2 partial pressures and calcite saturation indexes. The results show diurnal and seasonal hydrochemical variations controlled
chiefly by air temperature, the latter influencing karst aquifer recharge by ice and snowmelt. Karst process-related atmospheric
CO2 sinks were more than four times higher in the melting season than those in the freezing season. This finding has implication
for understanding the atmospheric CO2 sink in glaciated carbonate rock terrains: the carbon sink will increase with increasing runoff caused by global warming,
i.e., carbonate weathering provides a negative feedback for anthropogenic CO2 release. However, this is a transient regulation effect that is most efficient when glacial meltwater production is highest,
which in turn depends on the future climatic evolution. 相似文献