暖化湿地土壤磷素与微生物群落的响应特征及其生态关联性研究

发布时间：2017-12-28 06:18

本文关键词：暖化湿地土壤磷素与微生物群落的响应特征及其生态关联性研究　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：湿地生态系统在水源涵养、气候调节及生物多样性保护等方面具有独特的生态功能,而在全球气候变暖背景下,湿地生态系统受到了广泛的影响,这包括对湿地土壤生源要素循环的影响。磷素被认为是引起水体富营养化的关键限制因子,同时湿地土壤磷素生物地球化学循环与水体富营养化具有密切关系。众所周知,微生物在湿地土壤磷素生物地球化学循环过程中扮演着重要角色,而湿地土壤微生物对气候暖化的响应也呈现出不确定性。因此,本研究以暖化湿地微宇宙生境研究平台为基础,选取了长三角南区6处具有不同磷库特征的湿地区域作为研究对象,采用了高通量测序技术及核磁共振技术分别对土壤微生物群落物种组成,不同磷素形态进行了表征分析,同时从统计学角度阐释了暖化条件下不同磷素形态的动态变化与微生物响应的关联性,以期探究暖化条件下湿地土壤磷库与微生物群落动态响应特征及其生态关联性。本研究取得的主要结论如下:(1)在季节尺度和全年尺度上,暖化诱导下发生显著性差异的物种主要集中在放线菌门、变形菌门、厚壁菌门、拟杆菌门、硝化螺旋菌门、绿弯菌门和浮霉菌门等。在春季,暖化作用导致了低营养土壤的酸杆菌门的相对丰度显著下降11%,而中等营养土壤的硝化螺旋菌门的相对丰度显著升高43%。在夏季,暖化作用导致了中等营养土壤的拟杆菌门的相对丰度显著下降33%,而绿弯菌门的相对丰度显著升高7%。在秋季,暖化作用分别导致了低营养、中等营养和高营养三种不同营养土壤的厚壁菌门的相对丰度显著下降80%、74%和72%。同时低营养土壤的酸杆菌门和绿弯菌门的相对丰度分别显著上升7%和42%,中等营养土壤的变形菌门、酸杆菌门和绿弯菌门的相对丰度分别显著升高18%、24%和12%,高营养土壤的变形菌门的相对丰度显著升高43%。在冬季,暖化作用导致了低营养和中等营养土壤的硝化螺旋菌门的相对丰度分别显著升高54%和66%。在全年尺度下,暖化作用导致了低营养、中等营养和高营养三种不同营养土壤的厚壁菌门的相对丰度分别显著下降63%、50%和56%。低营养土壤的绿硫菌门和浮霉菌门的相对丰度显著升高30%和13%,中等营养土壤的拟杆菌门的相对丰度显著下降3 3%,而硝化螺旋菌门和变形菌门的相对丰度分别显著升高56%和8%。高营养土壤的浮霉菌门和变形菌门的相对丰度分别显著升高29%和13%。(2)核磁共振分析结果表明低营养、中等营养和高营养三种不同营养土壤的磷素形态主要以正磷酸盐和磷酸单酯为主。暖化诱导下,三种不同营养土壤的磷素形态在季节尺度和全年尺度上均呈现出不同的响应特征。在春季,暖化作用导致了高营养土壤的正磷酸盐的相对丰度显著下降31%,而磷酸二酯的相对丰度显著升高113%。在夏季,暖化作用导致了低营养土壤的焦磷酸盐和多聚磷酸盐的相对丰度分别显著下降38%和40%。在秋季,暖化作用下没有磷素形态表现出显著性差异,在冬季,暖化作用导致了高营养土壤的膦酸脂的相对丰度显著升高136%。在全年尺度下,暖化作用导致了高营养土壤的磷酸二酯和焦磷酸盐的相对丰度分别显著升高60%和86%,中等营养土壤的磷酸单酯、膦酸脂、焦磷酸盐和多聚磷酸盐的相对丰度分别显著升高13%、46%、37%和23%。而中等营养和高营养土壤的正磷酸盐的相对丰度分别显著下降10%和16%。(3)暖化诱导下,中等营养和高营养土壤的变形菌门的显著升高与正磷酸盐的显著下降具有显著的负相关性,同时分别与高营养土壤的磷酸二酯和中等营养土壤状态下的磷酸单酯的显著升高具有显著的正相关性。(4)因此,本研究表明暖化作用对湿地土壤微生物群落及磷素形态具有显著的影响效应,同时暖化诱导下湿地土壤微生物群落组成的显著性变化能够导致磷库不同组分发生潜在变化,这对认识全球气候暖化背景下湿地土壤磷素生物地球化学循环具有重要意义。
[Abstract]:Wetland ecosystem has unique ecological functions in water conservation, climate adjustment and biodiversity protection. Under the background of global warming, wetland ecosystems have been widely affected, including the influence of the circulation of natural elements in wetland soil. Phosphorus is considered to be a key limiting factor for water eutrophication. Meanwhile, the phosphorus biogeochemical cycle in wetland soil is closely related to water eutrophication. As we all know, microorganisms play an important role in the process of phosphorus biogeochemical cycling in wetland soil, and the response of wetland soil microorganisms to climate warming is also uncertain. Therefore, the study on warming wetland microcosm habitat research platform as the basis, select the wetland area of the Yangtze River Delta District 6 with different phosphorus characteristics as the research object, using high-throughput sequencing and NMR techniques of microbial species composition, different forms of phosphorus were characterized and analyzed, at the same time from the statistics perspective of warming related changes and microbial responses to different phosphorus conditions, in order to explore the warming conditions of wetland soil phosphorus and microbial community dynamic response characteristics and ecological relevance. The main conclusions of this study are as follows: (1) on seasonal scale and annual scale, species with significant difference under warming are mainly concentrated on actinomycetes, Proteobacteria, thick walled bacteria, Bacteroides, nitrifying Spirillum, green curved bacteria and floating mold. In spring, the relative abundance of acid bacilli decreased significantly by 11%, while the relative abundance of nitrifying Spirillum increased by 43%. In summer, the relative abundance of the bacteriomibacillum in the medium nutrient soil decreased by 33% in the summer, while the relative abundance of the phylum green was significantly increased by 7%. In autumn, the relative abundance of the thick walled phylum decreased by 80%, 74% and 72%, respectively, in three different nutrient soils, namely, low nutrition, middle nutrition and high nutrition. At the same time, the relative abundance of low nutrient soil acidobacteria and Chloroflexi were significantly increased by 7% and 42%, the relative abundance of Proteobacteria and acidobacteria and Chloroflexi medium nutrient soil were significantly increased in 18%, 24% and 12%, the relative abundance of Proteobacteria high nutrient soil significantly increased 43%. In winter, the relative abundance of nitrifying spirals in low and medium nutrient soils increased by 54% and 66%, respectively. Under the annual scale, the relative abundance of the thick walled bacteria decreased by 63%, 50% and 56%, respectively, in the three nutrient soils with low nutrition, middle nutrition and high nutrition. The relative abundance of green sulfur bacteria door and floating mold door increased significantly by 30% and 13% in low nutrient soil. The relative abundance of Bacteroides in medium nutrient soil decreased by 33%, while the relative abundance of nitrifying Spirillum and Proteobacteria increased by 56% and 8%, respectively. The relative abundance of floating fungi and deformable bacteria in high nutritive soil increased by 29% and 13%, respectively. (2) the results of nuclear magnetic resonance analysis showed that the forms of phosphorus in three nutrient soils were mainly orthophosphate and monophosphate. Under the induction of warming, the phosphorus forms of three different nutrient soils showed different response characteristics on the seasonal scale and the annual scale. In spring, the relative abundance of orthophosphate in high nutritive soil decreased significantly by 31%, while the relative abundance of phosphate two ester increased by 113%. In summer, the relative abundance of pyrophosphate and polyphosphate in low nutrient soils decreased by 38% and 40%, respectively. In autumn, there was no significant difference in phosphorus form under warming. In winter, warming increased the relative abundance of phosphonate in high nutrient soil by 136%. In the annual scale, warming led to a relatively high abundance of soil nutrient phosphate ester and two pyrophosphate respectively increased 60% and 86%, medium nutrient soil phosphate monoester, phosphonic acid grease, pyrophosphate and polyphosphates were significantly increased relative abundance of 13%, 46%, 37% and 23%. The relative abundance of orthophosphate in medium and high nutritive soils decreased by 10% and 16%, respectively. (3) warming induced by Proteobacteria, medium nutrition and high nutrition soil significantly increased significantly with the decrease of phosphate has significant negative correlation with phosphate ester, respectively at the same time high nutrition soil two and medium nutrient soil under the condition of phosphate monoester increased significantly with a significant positive correlation. (4) therefore, this study shows that warming effect has remarkable effect on wetland soil microbial community and phosphorus, while significant warming induced changes of soil microbial communities in wetland. It can lead to different group P database of potential changes, the understanding of global warming under the background of soil phosphorus in wetland biogeochemical cycle has important significance.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154.3

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