KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 塔南自然植物沙包中凋落物分解特性与土壤因子的关系 | |
| Alternative Title | Relationship between decomposition characteristics of litters and soil factors in natural vegetation cones of tanan |
| 郭平林 | |
| Subtype | 硕士 |
| Thesis Advisor | 曾凡江 |
| 2020-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学硕士 |
| Keyword | 自然沙包 植物凋落物 热解指纹 土壤微生物 塔克拉玛干沙漠南缘 Natural cones Plant litter Pyrolytic fingerprints Soil microorganism The southern edge of the taklimakan desert |
| Abstract | 植物参与的碳循环是生物地球化学循环的重要部分。凋落物的分解是植物参与碳循环的关键。有关凋落物分解的研究大都集中于表层凋落物的短期分解过程和机制，以及土壤有机碳转化过程等方向，对于底层凋落物的长期分解过程的研究较少。多枝柽柳（Tamarix ramosissima Lbd.）和疏叶骆驼刺（Alhagi sparsifoliaShap.）（以下简称“骆驼刺”） 和花花柴（Karelinia caspia(Pall.)Less）是塔克拉玛干沙漠南缘（以下简称“塔南”） 广泛分布的耐盐耐旱植物， 也是塔南自然植被的建群物种。这些植物形成的沙包中埋藏了大量的凋落物。但是对于沙包中凋落物分解特性以及周转速率尚不清楚。 因此，本研究以塔南三种自然植物沙包为研究对象，利用热裂解气相色谱质谱(Py-GC-MS/MS)技术，解析了凋落物的热解产物指纹，分析凋落物的热解产物在剖面上的变化规律；结合释光测年技术，分析剖面上时间序列；并通过宏基因测序技术，分析土壤剖面上凋落物不同分解阶段的土壤真菌和细菌群落组成。目的是揭示荒漠植物凋落物分解特征和差异，及其与土壤因子的关系; 阐明荒漠区凋落物分解与环境因子的关系; 探讨塔南地区凋落物的分解和转化时期。 这将进一步加强我们对干旱荒漠生态区中凋落物分解和有机碳储存的认识，其结果对保护和恢复荒漠植被具有科学指导意义。本研究主要结果如下：1、 三种凋落物的热解产物和分解速率不同。其中多枝柽柳含有较多的酚类化合物；花花柴茎的热解产物的含氮化合物（主要是咪唑类）高于骆驼刺和多枝柽柳，花花柴叶片的酚类化合物含量占在所有组分的 16%左右；骆驼刺叶片脂肪酸含量高，茎的木质化程度高。 结合测年数据发现凋落物的分解速率多枝柽柳＞花花柴＞骆驼刺， 骆驼刺分解较慢可能与骆驼刺沙包的沉积速度有关。2、三种沙包中土壤微生物多样性没有随土壤深度加深而降低的规律。三种沙包土壤真菌多样性在剖面山呈锯齿状分布，且有向下的趋势；土壤细菌在底层较高。多枝柽柳沙包土壤细菌在 80cm 和 180cm 出较高的多样性较大，骆驼刺和花花柴沙包土壤细菌分别在 120cm 和 180cm 处的多样性较大。3、自然植物沙包中凋落物分解周期不止一个，不同剖面深度的凋落物可能处于不同的分解周期。三种凋落物在垂直空间上有相似的分解规律。三种植物凋落物的热解产物，凋落物的碳氮比和土壤的碳氮比呈现同样的规律—向下的周期性波动。在凋落物分解的过程中， 每一个变化周期内的化学计量学都与凋落物分解养分释放的规律一致。这种周期性分解的时间跨度，与古气候变化的周期一致，气候因子可能决定沙包凋落物的周期性分解规律。4、通过构建结构方程模型，发现凋落物碳氮比，土壤含水率和微生物多样性能够解释三种荒漠植物凋落物五种组分变化的 83%。土壤含水率与土壤真菌多样性显著正相关；短链烷烯烃、氨基酸、脂肪酸等随着真菌多样性的增加而增加，随细菌多样性的增加而降低。而凋落物的碳氮比值与凋落物短链烷烯烃、氨基酸、脂肪酸等组分呈负相关关系。其原因可能是随着 C/N 比值的增加，氮素的固持作用加强，而氨基酸、脂肪酸和短链烷烯烃等可能是微生物固持元素的中间状态。 |
| Other Abstract | The carbon cycle in which plants participate is an important part of thebiogeochemical cycle.The decomposition of litter is the key for plants to participate inthe carbon cycle. Most studies on decomposition of litters focus on the short-termdecomposition process and mechanism of surface litters, as well as the conversionprocess of soil organic carbon, etc., and few studies on the long-term decompositionprocess of bottom litters. Tamarix ramosissima Lcdcb， Alhagi sparsifolia shapes.(hereinafter referred to as " Alhagi sparsifolia ") and Karelinia caspia (Pall.) Less is abroad distribution of tower south of salt-tolerant drought-tolerant plants, which areedoficator species of natural vegetation on the southern edge of taklamakan desert(hereinafter referred to as "tanan"). There is a lot of litter buried in the cones formedby these plants, but the decomposition characteristics and turnover rate of the litter inthe cones are not clear. Therefore, cones of three natural plants in tanan were taken asthe research object in this study, and pyrolysis gas chromatography-ms/MStechnology was used to analyze the pyrolysis product fingerprints of litters andanalyze the change rules of the pyrolysis products of litters on the profile； The timeseries on the soil profile was analyzed with the light release dating technique；Through macro gene sequencing technology, the composition of soil fungi andbacteria community in different decomposition stages of litters in soil profile wasanalyzed. The aim is to reveal the decomposition characteristics and differences ofdesert plant litter and its relationship with soil factors， and the relationship betweendecomposition of litters and environmental factors in desert areas are analyzed andsummarized, and the decomposition and transformation of litters in tanan area werediscussed. This will further enhance our understanding of litter decomposition andorganic carbon storage in arid desert ecologies.The results have scientific guidingsignificance for the protection and cultivation of desert vegetation.The main results of this study are as follows:1. Different plant litters have different pyrolysis products and differentdecomposition rates in cones. Tamarix ramosissima has more phenolic compounds ;The nitrogenous compounds (mainly imidazoles) in the pyrolysis products of thestems of Karelinia caspia were higher than that of Alhagi sparsifolia and Tamarixramosissima, and the content of phenolic compounds in the leaves of Karelinia caspiaaccounted for about 16% of all components. The content of fatty acids in the leaves ofAlhagi sparsifolia and the lignification of the stems were high. And the weightedEuclidean distance per unit time of litters was taken as the decomposition constant (C),and its value increased with the decomposition degree. The results showed that thelitters in Tamarix ramosissima cones decomposed the fastest, followed by Kareliniacaspia, and the slowest is Alhagi sparsifolia. The deposition rate of the Alhagisparsifolia cones was the slowest among the three.2. The soil microbial diversity in the three cones did not decrease with the depthof soil profile. The diversity of the three sandbag soil fungi was serrated in the profilemountain, and the trend was downward. And soil bacteria are higher at the bottom.The diversity of soil bacteria in the cone of Tamarix ramosissima was higher at 80cmand 180cm, and the diversity of soil bacteria in the cone of Karelinia caspia andAlhagi sparsifolia was higher at 120cm and 180cm respectively.3. There is more than one decomposition cycle of litters in natural plant cones.Litters at different depth of section may be in different decomposition cycles. Thethree litters have similar decomposition rules in vertical space. The pyrolysis productsof the three kinds of plant litters, the carbon-nitrogen ratio of the litters, thecarbon-nitrogen ratio of the soil in the soil showed the same regular trend ofdownward cyclical fluctuations in the profile； In the process of decomposition oflitters, the chemometrics in each change period are consistent with the law ofdecomposition nutrient release of litters. The time span of such periodicdecomposition is consistent with the period of climate change in the region. So theclimate factor may determine the periodic decomposition rule of litter in cones.4. Through the construction of structural equation model, it was found that thecarbon and nitrogen ratio of litters, soil moisture content and microbial diversity could explain 83% of the variation of five components of litters of three desert plants.Soilmoisture content was positively correlated with soil fungal diversity. Short chain alkylcompounds, amino acids and fatty acids increased with the increase of fungaldiversity and decreased with the increase of bacterial diversity.The carbon-nitrogenratio of litters was negatively correlated with Short chain alkyl compounds, aminoacids, fatty acids and other components of litters. The reason may be that with theincrease of C/N ratio, the N retention is strengthened, while amino acid fatty acids andShort chain alkyl compounds may be the intermediate states of microbial N retention. |
| Subject Area | 植物学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15419 |
| Collection | 中国科学院新疆生态与地理研究所 研究系统 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 郭平林. 塔南自然植物沙包中凋落物分解特性与土壤因子的关系[D]. 北京. 中国科学院大学,2020. |
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