KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 塔克拉玛干沙漠南缘滴灌防护林和自然群落植物水分利用效率及环境适应性 | |
| Alternative Title | Water use efficiency and ecological adaptation strategies of plant in shelterbelt and natural communities in south fringe Taklamakan Desert, China |
| 邢鹏 | |
| Subtype | 硕士 |
| Thesis Advisor | 马剑英 |
| 2019-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学硕士 |
| Keyword | 防护林 自然群落 水势 光合特征 水分利用效率 环境适应性 Shelterbelt Natural community Water potential Photosynthetic characteristics Water use efficiency Ecological adaption strategies |
| Abstract | 干旱区植物的生长和生存主要受水分限制，防护林是干旱区绿洲得以稳定存在的生态屏障，滴灌方式对防护林植物进行水分补给是维持人工生态屏障稳定性的重要手段。本研究通过测定塔克拉玛干沙漠南缘滴灌防护林多枝多枝柽柳和自然群落多枝柽柳、沙拐枣、花花柴和骆驼刺的气体交换参数、稳定性碳同位素值、土壤和植物养分含量等指标，对比分析不同水分条件下两个群落植物的光合特征、水分利用效率及生态化学计量特征，研究不同生境下防护林和自然群落植物的水分利用模式和环境适应机制，为保护和恢复干旱区自然生态系统、维护荒漠绿洲防护林体系的稳定性提供科学理论依据和数据支持。初步研究结果如下：(1)自然群落多枝柽柳清晨和正午水势明显低于滴灌群落多枝多枝柽柳，表明其遭受到严重的水分胁迫；长期的灌溉改变了土壤的水分和盐分含量， 使得滴灌群落各点 0 – 40 cm 范围内土壤中有机碳(SOC)、 全氮(TN)和全磷(TP)含量波动较大，间接导致滴灌群落多枝柽柳叶片碳(C)、和磷(P)含量均高于自然群落多枝柽柳，这与人为灌溉加速了土壤表层凋落物的分解和生物化学循环，有助于土壤中养分的积累有关； 自然群落表层土壤的 SOC、 TN 和 TP 含量较高；同时自然群落中多枝柽柳相比于滴灌群落多枝柽柳叶片有较高的 C/N 和 C/P 值， 两个不同群落中多枝柽柳 N/P > 16，环境条件的差异导致两个不同群落的养分利用策略不同，两个群落的多枝柽柳在生长发育过程中均受 P 元素的限制。(2)滴灌群落多枝柽柳净光合速率(A)、气孔导度(gs)、胞间 CO2 浓度(Ci)、 最大光合速率(Amax)和瞬时水分利用效率均明显低于自然群落多枝柽柳， 说明自然群落多枝柽柳的光合能力较强。相比于拥有较好水分条件的滴灌群落，长期的干旱胁迫使得自然群落多枝柽柳瞬时水分利用效率较高。滴灌群落多枝柽柳的稳定碳同位素值(δ13C)-26.53%比自然群落多枝柽柳的 δ13C 值-24.88%偏正， 表明滴灌群落多枝柽柳在长期咸水灌溉造成的盐分胁迫下拥有较高的长期水分利用效率。自然群落沙拐枣较高的长期水分利用效率与其为 C4 植物有关。(3)滴灌群落和自然群落多枝柽柳叶片氮(N)含量均与长期水分利用效率显著负相关，说明在盐分和水分胁迫条件下两个群落植物氮的利用能力下降而长期水分效率增强。受盐分和水分胁迫影响， 滴灌和自然群落多枝柽柳根系分布较深，无法有效利用浅层土壤中的 P 元素。 滴灌和自然群落多枝柽柳水分-养分之间的耦合效应以应对盐分和水分的胁迫。总之，现行的灌溉模式虽能提供防护林植物生长所需水分，但土壤盐分的积累可能会影响防护林体系的长期稳定性。 |
| Other Abstract | The growth and survival of plants in arid areas are mainly restricted by water. Dripirrigation is an important means to maintain the stability of artificial ecological barrier.This research through the determination of the south fringe of the Taklamakan desertdrip Tamarix ramosissima shelterbelt and natural community Calligonum mongolicum,Karelinia caspica, Alhagi sparsifolia, and gas exchange parameters, stable carbonisotope values of leaf, soil and plant ecological characteristics of chemical measurement.Research the two communities under different water conditions of plant photosyntheticcharacteristics and water use efficiency and nutrient content, and discusses theprotection forest and natural communities under different habitat the ability of wateruse and environmental adaptation mechanism of plants. Therefore, it is of greattheoretical significance to study the water use efficiency of shelterbelt plants in aridareas to better understand the competition between plants and the water use model, tounderstand the response of shelterbelt plants to water stress, and to discuss therelationship between plants and the environment in different habitats in arid areas. Theresults show that:(1) Because the influence of irrigation and soil salinity, the water potential of T.ramosissima in drip irrigation community is generally low; The natural community ofT. ramosissima has lower water potential in early morning and noon than other plants,which indicates that it has suffered from severe water stress. Long-term irrigationenvironment makes SOC, TN and TP fluctuate greatly within the range of 0 - 40 cm insoil at each point of drip irrigation community. The TP content of SOC, TN and TP atB site is slightly higher than that at other points. The original living environment wasconducive to the accumulation of SOC, TN and TP in the surface soil of naturalcommunities.Differences in water conditions indirectly led to higher content of C, P inleaves of T. ramosissima in drip irrigation community. The C/N and C/P values ofnatural community T. ramosissima were higher than those of drip irrigation community.The difference of environmental conditions between the two different communities is different. The differences in environmental conditions lead to different nutrientutilization strategies of the two communities. Natural community plants and dripirrigation community T. ramosissima N/P > 16, indicating that both were restricted byP element.(2) The net photosynthetic rate (A), stomatal conductance (gs), intercellular CO2concentration (Ci), maximum photosynthetic rate (Amax) and instantaneous water useefficiency of T. ramosissima in the drip irrigation community were significantly lowerthan those of the natural community. The photosynthetic capacity of T. ramosissima inthe community is strong. Compared with the drip irrigation community with betterwater conditions, the long-term drought stress makes the natural community T.ramosissima instantaneous water use efficiency higher. The stable carbon isotope value(δ13C)-26.53% of the drip irrigation community is more positive than the δ13C value ofthe natural community T. ramosissima -24.88%, indicating that the drip irrigationcommunity has high long-term moisture under the salt stress caused by long-term saltwater irrigation. usage efficiency.(3) Nitrogen (N) content in the drip irrigation community and natural communitywas significantly negatively correlated with long-term water use efficiency, indicatingthat under the conditions of salt and water stress, the nitrogen utilization capacity of thetwo communities decreased and the long-term water efficiency increased. Under theinfluence of salt and water stress, the root system of drip irrigation and naturalcommunity T. ramosissima was deeply distributed, and the P element in shallow soilcould not be effectively utilized. The coupling effect between drip irrigation and thewater-nutrients of the natural community T. ramosissima to cope with salt and waterstress. In short, although the current irrigation model can provide the water needed forthe growth of shelter forest plants, the accumulation of soil salinity may affect the longterm stability of the shelter forest system. |
| Subject Area | 植物学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15366 |
| 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 | 邢鹏. 塔克拉玛干沙漠南缘滴灌防护林和自然群落植物水分利用效率及环境适应性[D]. 北京. 中国科学院大学,2019. |
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