城市化对物种遗传多样性影响的景观遗传学研究

发布时间：2018-06-29 06:55

本文选题：景观遗传学 + 景观格局　；参考：《辽宁大学》2017年硕士论文

【摘要】：随着我国城市化进程的加快,人类对自然环境的扰动日益严重。城市化导致景观格局的变化,改变物种生存环境,使得物种生境破碎或者丧失,进而,可能会对物种的遗传多样性造成重大的影响。然而,我们对此影响及可能的原因了解的较少。景观遗传学是景观生态学、种群遗传学和统计学等多学科融合而成的新兴学科,在物种保护与城市开发规划中有巨大的潜力。景观遗传学的发展使研究物种生存环境的改变对遗传多样性的影响成为可能。本研究以发展中城市与滨海县镇开发区域为研究对象,选取沈阳市和辽河三角洲为研究样本,用景观遗传学的原理和方法,探讨城市化对物种的遗传多样性影响及其可能的机制。以期为城市化进程中生物多样性的保护及持续利用提供科技支撑。近年来,沈阳市城市化进程加快,显著影响城市景观格局。本研究通过对比1992年与2013年的遥感影像,发现其建设用地面积增大,绿地、农田面积减小,而构成主体景观的绿地斑块密度指数增加183%、农田的斑块密度指数增加337%,表明景观类型呈现破碎化趋势。通过模型模拟表明,与1992年相比,2013年的鸟类遗传多样性呈显著降低趋势。由此推测,沈阳市快速发展导致的景观破碎,对鸟类遗传多样性影响显著。在通过模拟建立生态廊道,提高生境面积等一系列措施后,鸟类的遗传多样性得到明显改善。翅碱蓬是辽河三角洲区域代表性植被,其生长沿海区域被称为“红海滩”,但从1995年至2014年间其退化明显。本研究通过对其Landsat TM地图解译,发现该区域滩涂面积明显增加,且向海洋方向推进,河流变窄,农田增加,沿海建设用地所占面积增大。通过模拟研究,发现该区域景观格局使碱蓬遗传分化增大,遗传多样性降低。2014年对该区域碱蓬进行采样研究,通过生物遗传学实验,发现沿海区域与其余分布区域碱蓬有一定的遗传分化现象,其遗传结果与地理距离有正相关关系。Shannon信息指数(I)为0.771,Nei基因多样性指数(H)为0.450,显示其遗传多样性处于中低水平。该实验结果符合景观遗传学模拟结果。
[Abstract]:With the acceleration of urbanization in China, human disturbance to the natural environment is becoming more and more serious. Urbanization leads to the change of landscape pattern, changes the living environment of species, breaks or loses the habitat of species, and may have a significant impact on the genetic diversity of species. However, we do not know much about the effects and possible causes. Landscape genetics is a new subject of landscape ecology, population genetics and statistics, which has great potential in species protection and urban development planning. With the development of landscape genetics, it is possible to study the influence of species living environment on genetic diversity. In this study, the developing city and Binhai town development area were taken as the research objects, Shenyang and Liaohe Delta were selected as the research samples, and the principles and methods of landscape genetics were used. To explore the effect of urbanization on genetic diversity of species and its possible mechanism. In order to provide scientific and technological support for the conservation and sustainable utilization of biodiversity in the process of urbanization. In recent years, Shenyang City urbanization process accelerated, significantly affected the urban landscape pattern. By comparing the remote sensing images of 1992 and 2013, it is found that the construction land area increases, the green land area decreases, and the farmland area decreases. The patch density index of greenbelt and farmland increased by 183and 337respectively, which indicated that the landscape type showed a trend of fragmentation. Compared with 1992, the genetic diversity of birds decreased significantly in 2013. It is inferred that the landscape fragmentation caused by the rapid development of Shenyang has a significant effect on the genetic diversity of birds. After a series of measures, such as establishing ecological corridor and increasing habitat area, the genetic diversity of birds was obviously improved. Suaeda salsa is a typical vegetation in the Liaohe River Delta. Its growing coastal area is called "Red Beach", but it degraded obviously from 1995 to 2014. Based on the interpretation of Landsat TM map, it is found that the area of tidal flat in this area is obviously increasing, and the area is advancing toward the sea, the river becomes narrower, the farmland increases, and the area of coastal construction land increases. Through simulation study, it was found that the landscape pattern of Suaeda salsa increased genetic differentiation and decreased genetic diversity. In 2014, samples were collected from Suaeda salsa in this area, and biogenetic experiments were carried out. It was found that Suaeda salsa had a certain genetic differentiation phenomenon between coastal and other distribution areas. The genetic results were positively related to geographical distance. Shannon information index (I) was 0.771Nei gene diversity index (H) 0.450, indicating that the genetic diversity of Suaeda salsa was at low and middle level. The experimental results are consistent with the results of landscape genetics simulation.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q16

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