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51.
52.
Application of stable isotope techniques in studies of carbon and nitrogen biogeochemical cycles of ecosystem 总被引:1,自引:1,他引:0
Zhigao Sun Xiaojie Mou Xinhua Li Lingling Wang Hongli Song Huanhuan Jiang 《中国地理科学(英文版)》2011,21(2):129-148
Stable isotope techniques have been proved useful as tools for studying the carbon (C) and nitrogen (N) biogeochemical cycles of ecosystem. This paper firstly introduced the basic principles and the distribution characteristics of stable isotope, then reviewed the recent advances and applications of stable isotope in the C and N biogeochemical cycles of ecosystem. By applying the 13 C natural abundance technique, ecologists are able to understand the photosynthetic path and CO 2 fixation of plants, the CO 2 exchange and C balance status of ecosystem, the composition, distribution and turnover of soil organic C and the sources of organic matter in food webs, while by using the 13 C labeled technique, the effects of elevated CO 2 on the C processes of ecosystem and the sources and fate of organic matter in ecosystem can be revealed in detail. Differently, by applying the 15 N natural abundance technique, ecologists are able to analyze the biological N 2 -fixation, the N sources of ecosystem, the N transformation processes of ecosystem and the N trophic status in food webs, while by using the 15 N labeled technique, the sources, transformation and fate of N in ecosystem and the effects of N input on the ecosystem can be investigated in depth. The applications of both C and N isotope natural abundance and labeled techniques, combined with the elemental, other isotope ( 34 S) and molecular biomarker information, will be more propitious to the investigation of C and N cycle mechanisms. Finally, this paper concluded the problems existed in current researches, and put forward the perspective of stable isotope techniques in the studies on C and N biogeochemical cycles of ecosystem in the future. 相似文献
53.
Phosphorus biological cycle in the different Suaeda salsa marshes of the Yellow River estuary, China
Zhigao Sun Xiaojie Mou Hanqin Tian Hongli Song Huanhuan Jiang Jinyong Zhao Wanlong Sun Wenguang Sun 《Environmental Earth Sciences》2013,69(8):2595-2608
Much uncertainty exists in the phosphorus (P) cycle in the marshes of the intertidal zone. This study explored the P cycling in the two Suaeda salsa marshes [middle S. salsa marsh (MSM) and low S. salsa marsh (LSM)] of the Yellow River estuary during April 2008 to November 2009. Results showed seasonal fluctuations and vertical distributions of P in different S. salsa marsh soils, and variations in P content in different parts of plants due to water and salinity status. The N/P ratios of the different S. salsa were 9.87 ± 1.23 and 15.73 ± 1.77, respectively, indicating that plant growth in MSM was limited by N, while that in LSM was limited by both N and P. The S. salsa litter in MSM released P to the environment throughout the year, while that in LSM immobilized P from the environment at all times. The P absorption coefficients of S. salsa in MSM and LSM were very low (0.0010 and 0.0001, respectively), while the biological cycle coefficients were high (0.739 and 0.812, respectively). The P turnovers among compartments of MSM and LSM showed that the uptake amounts of roots were 0.4275 and 0.0469 g m?2 year?1 and the values of aboveground parts were 1.1702 and 0.1833 g m?2 year?1, the re-translocation quantities from aboveground parts to roots were 0.8544 and 0.1452 g m?2 year?1, the translocation amounts from roots to soil were 0.0137 and 0.0012 g m?2 year?1, the translocation quantities from aboveground living bodies to litter were 0.3157 and 0.0381 g m?2 year?1, and the annual return quantities from litter to soil were less than 0.0626 and ?0.0728 g m?2 year?1 (minus represented immobilization), respectively. P was an important limiting factor in S. salsa marshes, especially in LSM. S. salsa was seemingly well adapted to the low-nutrient condition and the vulnerable habitat, and the nutrient enrichment due to the import of N and P from the Yellow River estuary would be a potential threat to the S. salsa marshes. 相似文献
54.
随着地震地层学的不断发展,层序地层学脱胎而出,成为当今沉积学界研究沉积层序、沉积体系域和海平面变化的有力途径。这一工作在国外研究已达到相当的水平,提交了一系列优秀的成果。近年来,由于有关层序地层学的理论和方法不断传入我国,从而也开始了这方面的研究工作。我们运用层序地层学的理论和方法,对中国南方三叠系进行了沉积层序、沉积体系域及与海平面变化关系的初步研究,获得了一些尚未十分成熟的成果。草写此文,以期能引起同行们的兴趣和共同探讨层序地层学这一新兴学科。 相似文献
55.
阿舍勒-冲乎尔火山沉积盆地是一个以火山岩并伴有陆源和内源沉积物的堆积场所,即该区泥盆纪地层是以事件作用的产物为其主要成分特点。显然,对其古地理的恢复、相的划分采用传统的相序分析方法是不合适的。作者认为要阐明该区泥盆纪的古地理面貌,必须在区域地层研究基础上,综合分析各种相标志和沉积物的特点,寻求它们的物理成因和地质成因解。在这一过程中,相的动力学分析显得尤为重要。本文在上述学术思想指导下,把本区泥盆纪的相分为成因相和环境相两大类,并对其中的微相进行了详细的阐述,从而为把沉积学的原理和方法应用了火山岩的搬运机制和堆积环境研究中提供了先期研究实例,同时为研究和恢复该区以至整个新疆北部泥盆纪的古地理格局打下了坚实的基础。 相似文献
56.
湘鄂赣二叠纪岩相古地理研究 总被引:4,自引:0,他引:4
湘鄂赣二叠纪沉积盆地是在华南陆块基础上发育而成,具有扬子克拉通北缘被动大陆边缘盆地、扬子克拉通盆地、湘赣板内拉张盆地和华夏克拉通边缘盆地等四类。根据古暴露等标志,建立了各类盆地的沉积层序,并进行了区域对比。在此基础上,本文着重运用层序地层编图法编制了湘鄂赣二叠纪岩相古地理图,深化了该区岩相古地理研究,详细建立了沉积体系域模式和岩相古地理演化特点和控制因素。 相似文献
57.
湘鄂赣二叠纪沉积盆地与层序地层 总被引:7,自引:2,他引:5
湘鄂赣二叠纪沉积盆地是在统一的陆板块——华南陆块基础上发展而来的.根据晚古生代以来的地壳活动情况、沉积物充填序列、沉积相带及空间配置,该区可以划分为四种沉积盆地,即扬子克拉通盆地、扬子克拉通北缘被动大陆边缘盆地、湘赣板内拉张盆地和华夏克拉通边缘盆地.由于不同沉积盆地中层序发展的主控因素及其相关效应的差异.从而决定了层序发育特点的差异.本文详细划分了各种沉积盆地的沉积层序和沉积体系域。并进行了区域对比.在此基础上,探讨了层序的成因. 相似文献
58.
牟传龙 《沉积与特提斯地质》1988,8(2):23-31
近年来,随着风暴流和风暴岩的新理论、新概念的不断引入,在分析沉积环境、沉积成矿作用时,不断提出了许多新思路,也不断地冲击和修正以往的传统认识,作者于1986年随同成都地矿所寒武系磷矿专题组①对滇东一带包括昆阳梅树村、海口、鸣矣河、晋宁王家湾、二街、八街、安宁白登、江川清水沟、宜良大滴水、寻甸先锋等矿区的磷矿进行了详细的研究,在下寒武统中谊村段及其相当的地层中发现了多层磷质风暴沉积物。本文拟概略介绍磷质风暴沉积物的标志、特征、剖面结构并初步探讨磷矿富集与风暴事件关系的沉积演化模式。 相似文献
59.
本文对黄海中南部10个沉积物样品和东海北部24个沉积物样品用等离子光谱做了Ba、Be、Co、Cr、Ga、Li、Mn、Nb、Ni、P、Pb、Sr、V、Zn、Y和Yb的分析,并对该区沉积物中元素的丰度和不同类型沉积物中微量元素的分布规律做了研究。通过对区内微量元素与主要元素的相关图解分析表明,大多数微量元素与主要元素Al、Mg、K呈正相关,其高值区与粘土沉积物相一致,低值区与粉砂质沉积物相吻合;Be、Sr、Mn的高含量与粘土沉积物无关 相似文献
60.
Sh. R. Bogoutdinov S. M. Agayan A. D. Gvishiani E. M. Graeva M. V. Rodkin J. Zlotnicki J. L. Le Mouél 《Izvestiya Physics of the Solid Earth》2007,43(7):597-609
The expert processing of monitoring data of large networks on hazardous natural phenomena becomes increasingly more complicated due to an increase in the initial data flow. An approach alternative to the visual recognition of signals is proposed. A number of recognition algorithms and results of their application to the analysis of geoelectric potential monitoring data are discussed. Data of monitoring La Fournaise Volcano (Réunion Island) obtained in the vicinity of the intense volcanic eruption of 1988 are used. The obtained results show that these algorithms are capable of recognizing anomalous segments of records and discriminating between several types of anomalies presumably associated with the effects of various physical factors (heavy atmospheric precipitation, hydrothermal processes, and so on). The algorithms proposed in this work can be used both for the automation of expert work in operating monitoring systems and in investigations aimed at the identification of typical morphologic sequences in time series of data of various origins. 相似文献