| 氮磷添加引起青藏高原亚高寒草甸物种多样性丧失的机理研究 |
| Alternative Title | The mechanism of speciesloss under addition of nitrogen and phosphorus at sub-alpine meadow in Tibetan Plateau
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| 师瑞玲 |
| Thesis Advisor | 王刚
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| 2014-05-29
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| Degree Grantor | 兰州大学
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| Place of Conferral | 兰州
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| Degree Name | 硕士
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| Keyword | 亚高寒草甸
氮磷添加
光合速率
生产力
光竞争
功能群
物种多样性
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| Abstract | N元素沉降和P元素输入势必造成物种多样性的改变，并深刻地影响所涉区域生态系统的组成结构与功能。
本实验以青藏高原亚高寒草甸群落为研究对象，通过对单一的N添加、P添加和N、P共同添加的三种处理、每处理的三个水平、五个重复的实验，研究了元素添加对植物化学计量学和光合速率的影响以及对植物群落地上生产力和物种丰富度影响。
本文主要研究结果如下：
1.N添加后各物种的N:C值显著增大；P添加大部分物种的N:C值显著降低；N、P同时添加时，大部分物种N:C值显著增大。N添加后大部分物种的N:P值增加，P添加和N、P共同添加后大部分物种的N:P值降低。
2.N添加和N、P共同添加时披碱草和甘青蒿的光合速率有显著性上升，豆科植物和其他三种杂类草在每个施肥处理下的光合速率变化不显著
由此，我们得出以下结论：
1.N 添加和N、P共同添加后，禾草通过光合速率的上升增加了生物量的积累，进而通过竞争排除使杂类草的物种多样性减少。
2.N、P之间具有交互作用，且N、P之间的交互作用对群落的物种多样性和生产力的影响显著高于单一的N、P添加。 |
| Other Abstract | Nitrogen deposition and Phosphorus input will cause the changes of species richness and influence the structure and functions of the impacted systems profoundly.
We chose one site in Qinghai-Tibet Plateau sub-alpine meadows as the study object, with three kinds of treatments, which are N addition alone, P addition alone and N and P addition together. There were three levels in each treatments containing five replications. We studied that the impacts of elements addition on plant chemometrics and photosynthetic rate, then influence plant community aboveground primary production and the speciesrichness.
The major results as following:
1, N addition caused the N:C values of all six studied species significantly increased, while P addition caused the N:C values of most species significantly decreased. The N:C values of most species in the treatments of N and P addition together also increased. For N:P values, the values of most species increased in N addition treatments, while the values of most species decreased in P addition and N and P addition together treatments.
2, The photosynthetic rates of Elymus nutans Griseb and Artemisia tangutica Pamp in the treatments of N addition and N and P addition together significantly increased. The photosynthetic rates of Legume species and four species of forbs had no significant differences among all treatments.
Above all, we conclude that:
1. The increase in photosynthetic rates of Grass caused the accumulation in biomass, and then triggered the decline of the species richness of Forbs functional groups via competition exclusion when N added and N and P added together.
2. There are interaction between N and P elements, which has stronger impact on the species biodiversity and primary production than N or P added alone. |
| URL | 查看原文
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| Language | 中文
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| Document Type | 学位论文
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| Identifier | https://ir.lzu.edu.cn/handle/262010/221580
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| Collection | 生命科学学院
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Recommended Citation
GB/T 7714 |
师瑞玲. 氮磷添加引起青藏高原亚高寒草甸物种多样性丧失的机理研究[D]. 兰州. 兰州大学,2014.
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