生物结皮对五种维管植物种子萌发、幼苗存活与生长的影响
文献类型：学位论文
| 作者 | 聂华丽 |
| 学位类别 | 硕士 |
| 答辩日期 | 2008 |
| 授予单位 | 中国科学院．新疆生态与地理研究所 |
| 导师 | 张元明，中科院新疆生态与地理研究所 |
| 关键词 | 生物结皮 |
| 其他题名 | The effect of biological crust on seed germination,seedling survival and growth of five vascular plants |
| 中文摘要 | 生物结皮广泛的分布在干旱、半干旱区，它的存在有着重要的生态学意义。国内外对生物结皮在干旱、半干旱区内的生态功能作了大量的研究，主要包括生物结皮对土壤水文过程的影响，生物结皮在土壤抗蚀性中的作用，生物结皮与维管植物之间的相互作用及其作用机理。然而目前关于生物结皮与种子植物之间关系的研究结果还存在争议。古尔班通古特沙漠位于温带气候条件下的准噶尔盆地，是中国最大的固定和半固定沙漠。该沙漠广泛发育的生物结皮, 是除种子植物以外固定沙面的重要生物因子。结皮影响土壤养分的积累和土壤水分分配特征，从而对种子植物定居产生重要影响。本文以广布在古尔班通古特沙漠的黑色结皮（苔藓和地衣的混生结皮）为研究对象，通过萌发实验及种子形态特征，从古尔班通古特沙漠中的十五种植物选取了具代表性的五种维管植物作为供试物种，包括白梭梭、蛇麻黄、角果藜、涩芥和狭果鹤虱，通过室内盆栽实验在有结皮和无结皮覆盖的两种土壤基质上，对五种植物进行连续的培养观测，初步研究了生物结皮分别对五种维管植物种子萌发、幼苗建成与存活以及植株生长整个生长阶段的影响。探讨古尔班通古特沙漠生物结皮对种子植物多样性的影响，以期为温带荒漠生物多样性保育工作提供基础的理论。本文主要研究结果如下： 1.生物结皮对种子萌发的影响生物结皮的存在减少了维管植物种子的萌发率，降低了种子的萌发速率，总体而言，生物结皮对维管植物种子的萌发起到不同程度的抑制作用。种子本身的生物学特性是生物结皮影响种子萌发的一个重要因素。相同水分条件下，种子萌发可利用水分在不同形态的种子间有所差异，使得生物结皮对不同种子萌发有所差异。因此生物结皮对维管植物种子萌发的影响主要是与水分条件和种子的形态相关。 2.生物结皮对幼苗建成与存活的影响总体而言，生物结皮对维管植物幼苗的建成不存在抑制作用，主要是促进作用或无影响。无论干燥还是湿润条件下，幼苗一旦定居，生物结皮对其存活就无显著的影响。 3.生物结皮对植物生长的影响相对于裸沙，生物结皮的存在能够改善土壤表层的水分和养分条件，增加维管植物单株地上、地下生物量，促进了植株体的生长速率，并且促进了一年生草本植物的开花和结实。荒漠植株快速的生长使其根部能更好利用土壤下层的水分，从而利于这些植物种群的建成。 4.生物结皮对植物元素吸收的影响在苔藓－地衣结皮影响下，显著促进了植物对N的吸收；而对Cu、Fe、Ca、Na、Mn、Zn、K这些元素吸收的影响因种而异，即某些植物促进了对这些元素的吸收，而另一些植物则抑制了对它们的吸收；同时生物结皮的存在抑制了某些植物体对Mg与P的吸收。本研究表明，在干旱、半干旱区，生物结皮对不同种的维管植物影响不同；对同种植物不同生活史阶段的影响亦不同。生物结皮的存在对维管植物生长的早期阶段（种子萌发）存在抑制作用，而植物生长一旦突破萌发阶段，发育到后期，生物结皮对其幼苗建成、存活及生长则不再存在抑制作用，其主要是促进作用或无影响。促进作用主要是由于生物结皮的存在改善了土壤表层0-5cm的养分及水分状况；而无影响可能是由于一些植物的生长已超出了生物结皮的影响范围。Biological crust is a universal and common feature in arid and semi-arid regions and its appearance profoundly affects soil properties, more and more attention has been paid on the ecological function in these regions, such as hydrology processes, soil physical and chemical characteristics, soil nutrition and soil pH, their effects on soil stability, especially the relationship between vascular plants and crust. However, the interaction between biological crust and vascular plants is controversial and experimental evidence is limited. As the largest fixed and semi-fixed desert in China, the Gurbantonggut Desert is located in the Junggar Basin, which is typical of temperate deserts in the world. There is an abundant biological crust on the sand surface of the desert, which serves as one of the biological factors contributing to the sand fixation besides plants. Biological crust has profound impact on the soil hydrological processes, soil water environment and soil fertility, thus it affects the establishment and survival of vascular plants. In this study, we selected five vascular plants with different seed morphological characteristics from fifteen species plants in Gurbantonggut Desert, such as Haloxylon persicum, Ephedra distachya, Ceratocarpus arenaarius, Malcolmia africana and Lappula semiglabra. Under laboratory condition, we experimentally investigate the effect of biological crust on whole life history of five vascular plants, including seed germination, seedling survival and plant growth. The mean conclusions are followed as: The effect of biological crust on seed germination indicated that biological crust had negative effect on the speed of seed germination and rate of seed germination. The result showed that the effect of biological crusts on germination is correlated with seed morphological characteristics of vascular plants. Thus the effect mainly lied on both water condition and biological characteristics of vascular plant seeds. Generally speaking, the effect of biological crust on seedling establishment was mainly positive or irrelevant but no negative. Once the seedling establishment, there was no significant effect on seedling survival. The effect of biological crust on plant growth indicated that in contrast to shifting sand, biological crust had positive effect on nutrient and water condition of the early seedling. Dry weights of five plants in pots with biological crust were higher than in pots without biological crust. Biological crust can accelerate speed of plants growth. Biological crust increased the N content of associated vascular plants. Uptake of Cu, Fe, Ca, Na, Mn, Zn and K was variable among different plant in the presence of the biological crust. Biological crust was generally negatively associated with Mg and P levels in associated seed plant tissue. In generally, the results showed that the effect of biological crust on both different vascular plants and different life history stages of one plant were variable in arid and semi-arid regions. There was negative effect on germination, but the effect of biological crust on other stages of plants, such as seedling establishment, seedling survival and growth, was mainly positive or irrelevant but no negative. Biological crust improved nutrient and water condition of 0-5cm soil surface, thus there was positive effect. Biological crust had no significant effect on some stages of plants, because some plants growth exceeded the range that effect of biological crust. |
| 学科主题 | 植物生理学 |
| 语种 | 中文 |
| 公开日期 | 2010-11-12 |
| 页码 | 共53页 |
| 源URL | [http://ir.xjlas.org/handle/365004/8064]  |
| 专题 | 新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据) |
| 推荐引用方式 GB/T 7714 | 聂华丽. 生物结皮对五种维管植物种子萌发、幼苗存活与生长的影响[D]. 中国科学院．新疆生态与地理研究所. 2008. |
入库方式： OAI收割
来源：新疆生态与地理研究所
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