KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 准噶尔盆地荒漠灌丛地上形态建成与地下根系竞争关系 | |
| Alternative Title | The relationship between aboveground crown ontogeny and belowground root compeletition of desert shrub in the Jungger Basin of central Eurasia |
| 郑新军 | |
| Subtype | 博士 |
| Thesis Advisor | 李彦 |
| 2019-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学博士 |
| Keyword | 荒漠灌丛 异速生长模型 氢氧稳定同位素 水力生态位隔离 desert shrub allometric model stable hydrogen and oxygen isotopes hydraulic niche segregation |
| Abstract | 背景和研究意义： 亚洲中部山地-盆地系统孕育的天然和人工绿洲和谐共生是当地社会经济健康运行的根基，然而随着水土资源开发的大跃进，更多的天然植被被人工绿洲所代替，并且更多水资源用于灌溉，使得作为人工绿洲生态屏障的外围依赖地下水的灌丛植被处于空前危机中。因此，研究绿洲外围灌丛地上形态建成与植物-水分关系具有重要的理论和现实意义。科学假设：（1）土壤―水库‖可以分为来源于当季降水的浅层土壤―生长库‖和来源于非当季降水和地下水的深层土壤―维持库‖；（2）降水不能满足作为生态屏障的绿洲外围灌丛植被建群种的生长和生活需要，需要其他水源输入；（3）灌丛地上形态建成和异速生长关系受到地下特别是水资源的影响和限制；（4）共存荒漠灌丛物种通过根系垂直分异和地下资源的分割利用形成共存机制。研究样地和材料：准噶尔盆地东南部三工河流域人工绿洲外围中国科学院阜康荒漠生态站内柽柳混生灌丛群落 4 种盐生灌木西伯利亚白刺、琵琶柴、唐古特白刺和多枝柽柳。研究内容：（1）氢氧稳定同位素分馏混合过程的统计规律；（2） 混生荒漠灌丛异速生长关系及其生物与非生物影响因素；（3）混生荒漠灌丛对土壤水竞争策略和共存机制。研究方法和手段：（1）植被地上调查和地下根系挖掘；（2） 灌丛异速生长模型；（3） 氢氧稳定同位素技术；（4）植物叶水势和叶面积测定；（5） IsoSouce和 beta 概率分布模型估算潜在水源贡献和根系平均吸水深度。研究结果：（1）全球大气降水线（8.2）、地区大气降水线（7.53）、土壤蒸发线（3.05）、植物根吸水线（2.89）、多枝柽柳植物蒸腾线（1.71）的斜率依次降低， 深居内陆的本地区降水中的 δ18O 仍然存在降水量效应，主要与云下二次蒸发有关。（2） 4 种混生灌丛高度和半径都显著符合简单和拓展异速生长模型，拥有相同的初始灌丛异速生指数，相似的灌丛异速生长指数轨迹，发现简单异速生长指数与拓展异速生长指数的平均值存在显著线性关系。（3） 4 种混生荒漠灌丛根系最大深度对应着在土壤剖面上夏季干旱期 3 个相对分布湿润区间 0.8–1.0m、 2.2–2.4 m 和地下水位埋深附近。（4） 4 种混生荒漠灌丛的黎明前叶水势平均值与处于灌丛异速生长尺度指数时的灌丛半径存在显著的正相关关系，同时， 黎明前叶水势与灌丛平均吸水深度存在显著线性关系。结论：（1）环境中水的氢氧稳定同位素只在发生相变界面发生显著分馏，在各相态内部只发生混合或者分馏效应不显著，带有其来源标记特征，是鉴定其来源的有力工具；（2）在水分受限生态系统中地下资源特别是土壤水分可供给性的确影响着灌丛地上部分形态建成和异速生长关系；（3）共存灌丛物种通过根系垂直分异和地下资源的分割利用形成共存机制。 |
| Other Abstract | Background and study importance: The foundation of the healthy operation oflocal social and economic system is the harmonious symbiosis of natural and artificialoasis in the mountain-basin landscape system of the hinterland of Eurasia. However,with the exploitation of land and water resources, the more natural vegetation hasreplaced by artificial oasis, and much more water has been used to be irrigated, and asa result, as the ecological barrier, the shrub vegetation dependent on the groundwateris at the brim of the crisis. Thus, it is great theoretical and practical important to studythe relationship between the aboveground building of shrub and the plant-waterrelationship outside the oasis.Hypothesis: (1) There are two soil water pools: a growth pool that located inshallow soil layers, and a maintenance pool that is often in deeper soil layers. (2) Thelocal precipitation lonely cannot but the extra water resources additionally canmaintain the growth of the shrub vegetation outside the oasis, and the extra waterresources. (3) The building and the allometric relationship of the shrub abovegroundare limited and impacted by the belowground especially by the soil water resources.(4) The coexisting of the desert shrubs is through different strategies of wateracquisition such as different rooting depth.Study object and site: There are four shrubs species: Nitraria tangutorum,Reaumuria songarica, N. sibirica and Tamarix ramosissima. The study quadrat of 100m × 100 m is sited at 44°17′N, 87°56′E (475 m a.s.l), inside the Fukang Station ofDesert Ecology, Chinese Academy of Sciences, at the northern foot of Peak Bogda, atthe southern edge of the Gurbantonggut Desert of Junggar Basin, central Eurasia.Study content: (1) The stastitical law of stable hydrogen and oxygen during theprocesses of fractionation and mixing; (2) the abiotic and biotic factors of crownallometric relationship of co-existing desert shrubs; (3) the competitive strategy forsoil water and the co-existing mechanism of co-existing desert shrubs.Study methods and techneques: (1) Aboveground vegetation inveastation andbelowground root excavatation; (2) simple and expanded allometric models on shrubcrown; (3) stable hydrogen and oxygen isotopic techneques; (4) leaf water potentialand biomass measurement; (5) estimating the contribution of potential water sourceson plant water using through IsoSource Model and the average root uptake waterdepth through the Beta possibility distribution model.Important finding: (1) There is a downward trend from the slope of GlobalMeteoric Water Line (8.2), Local Meteoric Water Line (7.53), Soil Evaporative WaterLine (3.05), Root Uptake Water Line (2.89) to Leaf Transpiring Water Line (1.71) of T.ramosissima; there is also the amount effect on δ18O in precipitation water in thishinterland, which is linkage with the raindrop secondary evaporation below the cloud.(2) The relationship between the crown radius and height both fit significantly thesimple and expanded allometric model for the four coexisting shrub; the fourco-existing shrub species possesses a common initial crown allometric exponent; asimilar trajectory of the crown allometric scaling exponent with crown radius; there isa significant linear relationship between the average crown allometric exponents fromthe simple and expanded allometric models. (3) The root depth maxima of the fourco-existing species correspond to the three water moisture abundant intervals insummer: 0.8–1.0 m, 2.2–2.4 m and groundwater level. (4) Leaf water potential atpre-dawn is significantly positively related to the radius when the crown allometricscale index maximum for the co-existing shrub; there is a positive linear relationshipbetween the leaf water potential at pre-dawn and the average root uptake depth.Conclusion: (1) Stable hydrogen and oxygen isotopes in environment ispowerful tool to identify potential water resources, because there is an only significantfractionation effect when the phase of water only, changes, but no significantfractionation effect and only mixture effect under the other situations, which wouldkeep the characteristic from their courses. (2) Belowground resources and especiallysoil water availability do dominate the shrub aboveground crown ontogeny andallometric relationship in these water-limited ecosystems. (3) The species coexistence mechanism is the hydraulic niche segregation formed the different root verticaldistribution pattern with different belowground resources uptake strategies. |
| Subject Area | 生态学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15314 |
| 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 | 郑新军. 准噶尔盆地荒漠灌丛地上形态建成与地下根系竞争关系[D]. 北京. 中国科学院大学,2019. |
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