KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 荒漠开垦对土壤微生物群落结构和多样性的影响 | |
| 王银亚 | |
| Subtype | 硕士 |
| Thesis Advisor | 马健 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 生态学 |
| Keyword | 古尔班通古特沙漠 开垦年限 微生物群落 磷脂脂肪酸 |
| Abstract | 土壤微生物在维持生态系统稳定和功能方面起着重要作用，其群落结构及多样性特征是评价土壤质量的重要指标。土地利用方式或管理措施的改变，会显著影响土壤养分状况与土壤微生物群落结构和多样性。在干旱区，当荒漠开垦为农田，极显著地改变了土地利用方式和覆被，相应地引起植被、凋落物、土壤养分与水分等一系列的变化，这些变化必然引起土壤微生物群落结构和多样性的改变，进而影响到土壤功能，甚至是土壤质量与环境效应。然而，当前干旱区土壤微生物的相关研究主要围绕灰漠土与细菌群落展开，不能涵盖新疆复杂的土壤类型与作物耕作历史，其研究结论需要进一步验证。而且，土壤微生物群落对荒漠开垦的响应如何，存在怎样的效应，目前尚不清楚。本研究以古尔班通古特沙漠南缘典型流域（玛纳斯河、吉木萨尔河、三工河、四工河、水磨河）的绿洲农田与毗邻荒漠土壤为研究对象，采用磷脂脂肪酸(PLFA)方法分析不同开垦年限的土壤微生物生物量与群落结构和多样性变化特征。 结果表明：（1）荒漠开垦后，土壤微生物总PLFA含量、真菌PLFA、细菌PLFA、革兰氏阳性菌(G+)和革兰氏阴性菌(G—)PLFA含量均显著增加。（2）土壤微生物群落结构发生了显著变化：荒漠开垦前5a，由于细菌PLFA与G— PLFA增长更为强烈，使得真菌PLFA/细菌PLFA比值降低了48%，G+ PLFA /G— PLFA比值(革兰氏阳性菌与革兰氏阴性菌的PLFA比值)降低了67%。但随着开垦年限的延长，这两个比值没有显著变化，表明与开垦年限相比，荒漠的开垦行为对土壤微生物群落结构有着更加强烈的影响。（3）随着开垦年限的增加，土壤微生物群落多样性总体呈上升趋势。虽然荒漠在开垦50a后多样性指数略有下降，但仍远高于荒漠土壤。（4）土壤微生物总PLFA含量和大部分菌群PLFA含量与土壤电导呈显著负相关关系，与全氮和有机碳呈显著正相关关系。荒漠在开垦过程中由于灌溉增加了土壤水分且降低了土壤盐分，同时全氮和有机碳含量增加，这些改变是土壤微生物群落变化的主要原因。本研究暗示，荒漠开垦有助于土壤微生物的改善，有利于土壤质量的提高。 |
| Other Abstract | Soil microbes play an important role in maintaining ecosystem stability and function, community structure and diversity of its features is an important indicator of soil quality evaluation. In arid areas, desert when reclaimed farmland, significantly changed the way the land use and cover, correspondingly cause a series of changes in vegetation, litter, and other soil nutrients and moisture, these changes would inevitably lead to soil microbial community structure and diversity sex change, thereby affecting the function of the soil, and even soil quality and environmental effects. Use patterns or changes in land management measures, will significantly affect the soil nutrient status and soil microbial community structure and diversity. However, the current research in arid zones Microbial revolves around gray desert soil bacterial communities expand, can not cover the complexity of Xinjiang soil type and cropping history, its findings need further verification. Also, in response to desert reclamation of soil microbial community how the presence of what effect is unclear. Soil microbial biomass、community structure and microbial diversity were analyzed by using phospholipid fatty acid（PLFA）methods, based on the soil of oasis field typical basins (Manas River Basin, Jimsar river, Sangong river、Sigong river, shuimo River) and the adjoining desert in the southern Gurbantunggut Desert. Major findings:(1)The total PLFAs 、Fungi PLFA、Bacteria PLFA、Gram-positive bacteria PLFA(G+) and Gram-negative bacteria PLFA(G—) had generally increased after reclamation of desert; (2)Microbial community structure has undergone significant changes: In the early desert reclamation (3a), fungal PLFA / bacterial PLFA ratio decreased 48%, G+ PLFA / G— PLFA ratio (Gram-positive bacteria and Gram-negative bacteria PLFA ratio) reduce 67%. (3)But with the extension of cultivation years, these two ratios did not change significantly, suggesting that compared with reclamation, desert reclamation behavior have a more intense effect on the soil microbial community. In addition, the soil microbial community diversity overall upward trend with years of use. (4)The diversity index showed a slight decrease after reclamation of 50 years but still higher than the desert soil. The total soil microbial PLFA and most bacteria PLFA content had significant negative correlation with soil conductivity and had significantly positive correlation with total nitrogen and organic carbon. Desert in the reclamation process due to irrigation increased soil moisture and reduces soil salinity, while total nitrogen and organic carbon content increased, these changes are the main reason for change of soil microbial communities. This study suggests that desert reclamation help improve soil microorganisms, help to improve soil quality. |
| Subject Area | 生态学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14706 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中科院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 王银亚. 荒漠开垦对土壤微生物群落结构和多样性的影响[D]. 北京. 中国科学院大学,2016. |
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