發(fā)布時(shí)間：2018-01-23 18:14

  本文關(guān)鍵詞： 北極 長(zhǎng)江口 黃河口濕地 馬來西亞河流 生物硅 植硅體 硅藻 溶解　出處：《國(guó)家海洋局第一海洋研究所》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：硅元素因其巨大的儲(chǔ)量以及與碳循環(huán)的密切聯(lián)系,成為陸海相互作用、區(qū)域生物地球化學(xué)循環(huán)與氣候變化研究的關(guān)鍵元素。生物硅(BSi)是地表和水體中硅循環(huán)中的實(shí)際參與者,也是陸源硅向海洋輸送的重要載體,其現(xiàn)存量、輸送及轉(zhuǎn)化機(jī)制是硅循環(huán)研究中的關(guān)鍵環(huán)節(jié)。本文選擇四個(gè)代表性區(qū)域——北極新奧爾松地區(qū)、黃河口濕地、長(zhǎng)江口、馬來西亞河流,對(duì)不同生境內(nèi)生物硅的含量、組成進(jìn)行分析,并對(duì)生物硅在不同鹽度水體中的溶解動(dòng)力學(xué)過程進(jìn)行了初步研究,旨在揭示不同溫度帶生物硅的組成、來源及溶解動(dòng)力過程,為區(qū)域硅循環(huán)提供科學(xué)依據(jù)。主要結(jié)論如下:(1)不同生境中的生物硅含量不同:北極新奧爾松地區(qū)表層土壤中,BSi的含量為5.60-9.97 mg/g,均值為7.56 mg/g;黃河口濕地表層土壤中,生物硅含量為2.48-19.3 mg/g,均值為9.91 mg/g;長(zhǎng)江口地區(qū),表層水體中生物硅含量為2.39-44.9μmol/L,均值為15.2μmol/L,B3和C5柱狀樣沉積物中生物硅均值分別為2.73 mg/g和3.86 mg/g;沉積物馬來西亞河流近岸沉積物中,BSi含量為5.17-10.2 mg/g,平均含量為8.55 mg/g。BSi含量與分布具有一定的季節(jié)性和區(qū)域性,受地表植被、p H及土壤粒徑等因素的影響。河口地區(qū),BSi的含量與分布受海洋與河流的共同影響。(2)長(zhǎng)江口水體、沉積物及馬來西亞河流沉積物中的活性硅不同程度地發(fā)生了反風(fēng)化過程;長(zhǎng)江口水體和馬來西亞河流沉積物中生物硅的反風(fēng)化現(xiàn)象并不明顯,而長(zhǎng)江口沉積物中約有28%的生物硅參與反風(fēng)化過程。(3)研究區(qū)域的生物硅顆粒主要由植硅體、浮游植物、海綿骨針構(gòu)成,不同生境中不同形態(tài)生物硅的貢獻(xiàn)比例不同。陸源生物硅(植硅體)是生物硅的主要貢獻(xiàn)者,不同地區(qū)有不同的特征植硅體出現(xiàn);部分河口區(qū)站位硅藻的貢獻(xiàn)量較大。(4)生物硅的形態(tài)觀測(cè)結(jié)果顯示,植硅體有明顯的侵蝕痕跡,且含有大量硅藻碎片,反映了生物硅在輸送過程中的溶解現(xiàn)象。此外,植硅體成分分析結(jié)果表明,除Si、O兩種主要元素外,還有部分C、Al、K、Mg、Fe等元素,為植硅體參與自成巖反風(fēng)化過程及碳封存作用提供了直接證明。此外,約占植硅體5%干重的碳被封存于熱帶地區(qū)河流沉積物的生物硅中。(5)生物硅顆粒在不同鹽度水體中的溶解趨勢(shì)相同,均在培養(yǎng)初期大量溶解,其后比溶解速率急劇下降,最終維持在較為穩(wěn)定的狀態(tài)。在穩(wěn)定狀態(tài)下,鹽度為5的培養(yǎng)體系中生物硅的溶出量和比溶解速率最大。
[Abstract]:Because of its huge reserves and close relationship with the carbon cycle, silicon has become the interaction between land and sea. Biogeochemical cycle and climate change are the key elements in the study of regional biogeochemical cycle. Biological silicon (BSi) is a practical participant in the silicon cycle in the surface and water, and is also an important carrier for the transport of terrestrial silicon to the ocean. Transport and transformation mechanism is the key link in the study of silicon cycle. In this paper, four representative regions, namely, the New Olsson region in the Arctic, the Yellow River Estuary Wetland, the Yangtze River Estuary, and the Malaysian River are selected. The content and composition of biological silicon in different living areas were analyzed and the dissolution kinetics of biological silicon in different salinity water was studied in order to reveal the composition of biological silicon in different temperature zones. The source and dissolution dynamics provide scientific basis for the regional silicon cycle. The main conclusions are as follows: the biological silicon content in different habitats is different: in the surface soil of the new Olsson area in the Arctic. The content of BSi was 5.60-9.97 mg / g, the mean value was 7.56 mg / g; In the surface soil of the Yellow River Estuary wetland, the content of biological silicon is 2.48-19.3 mg / g, the mean value is 9.91 mg / g; In the Changjiang Estuary, the content of biological silicon in the surface water is 2.39-44.9 渭 mol / L, with an average of 15.2 渭 mol/L. The mean values of biological silicon in B3 and C5 columnar sediments were 2.73 mg/g and 3.86 mg / g, respectively. The content of BSi in sediments of Malaysian rivers is 5.17-10.2 mg/g. The average content and distribution of 8.55 mg/g.BSi are seasonal and regional, which are affected by the factors such as vegetation pH and soil particle size. The content and distribution of BSi are influenced by ocean and river. (2) the reverse weathering process of active silicon in Yangtze Estuary, sediment and Malaysian river sediment has taken place in varying degrees. The reverse weathering of biological silicon in the Yangtze Estuary and Malaysian river sediments is not obvious. In the Yangtze Estuary sediment, about 28% of the biological silicon involved in the reverse weathering process. 3) the biological silicon particles in the study area are mainly composed of phytoplankton, phytoplankton and spongy bone needle. The contribution ratio of biological silicon in different habitats is different. Terrestrial biogenic silicon (phytosilicon) is the main contributor of biological silicon, and there are different characteristics of phytosilicon in different regions. The morphological observation of biosilicon showed that the phytolith had obvious erosion trace and contained a large number of diatom fragments. It reflects the dissolution of biogenic silicon in the transportation process. In addition, the results of phytosilicon composition analysis show that in addition to the two main elements of Sio, there are also some elements, such as C _ (Al) Al _ (K) K _ (+) mg _ ((Fe)). It provides a direct proof for the phytonite to participate in the process of diagenetic reverse weathering and carbon sequestration. Carbon, which accounts for about 5% dry weight of the phytosilicon body, was sequestered in the biogenic silicon of river sediments in tropical regions.) the dissolution trend of biogenic silicon particles in different salinity water was the same, and they were dissolved in a large amount at the early stage of culture. The dissolution rate and specific dissolution rate of biological silicon in the culture system with salinity of 5 were the largest.
【學(xué)位授予單位】：國(guó)家海洋局第一海洋研究所
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P593

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本文編號(hào)：1457918