Knowledge Resource Center for Ecological Environment in Arid Area
| 科尔沁沙地植物生长对风速和降水变化的响应 | |
| 其他题名 | Response of plant growth to wind-speed and precipitation changes in Horqin Sandy Land |
| 魏水莲 | |
| 出版年 | 2017 |
| 学位类型 | 硕士 |
| 导师 | 李新平 |
| 学位授予单位 | 中国科学院大学 |
| 中文摘要 | 降水是半干旱沙地植物生长发育最主要的生态制约因子，降水过程与格局的改变会影响沙地植物的生长特征以及水分、光合、呼吸和物质代谢等生理过程；同时风作为一种重要的环境因子，对沙地植物生长、发育、繁衍的整个过程都具有重要影响，直接或间接决定着沙地植被类型、分布和生产力，乃至植被资源的稳定和可持续利用。因此，在不同区域和环境背景下，综合考虑风和降水两种环境因素交互作用对沙地植物生长过程的影响作用，认识不同沙地植物对干旱风沙环境响应的普适性机理显得尤为重要。本文以科尔沁沙地植物为研究对象，通过风速和降水控制试验，开展风速和降水变化对沙地植物生长的影响研究。分析沙地植物种子萌发响应风吹和降水的变化特征；阐明风速和降水变化对沙地植物群落特征的影响；揭示沙地植物响应风速和降水变化的生理生态学机制；从而为该地区沙漠化防治，沙地植物选育及引种，以及沙地植被的稳定与恢复提供理论依据。主要研究结论如下：(1) 风速和降水变化对科尔沁沙地植物种子萌发及幼苗特征有重要影响。一方面，风速降低和降水增加可使沙地植物萌发物种数、幼苗平均高度及植被盖度增加，但会使幼苗密度降低。另一方面，风速降低可以提升猪毛菜的优势作用，而减弱五星蒿的优势作用；降水增加30%促进五星蒿种子萌发，限制猪毛菜种子萌发，降水增加60%则刚好相反。降水增加使物种Simpson优势度增加，其中降水增加30%使其显著增加。此外，二者交互作用对幼苗物种丰富度、Simpson优势度指数、Shannon-Wiener指数均有显著影响。(2) 风速降低和降水增加可使植物平均高度、植被盖度及优势植物高度显著增加。风速降低20%和40%使植被盖度分别增加23.6%、40.5%，降水增加30%和60%使植被盖度分别增加29.1%、39.6%。风速降低20%和降水增30%及其交互作用均有利于优势植物五星蒿密度、重要值的增加，风速降低40%和降水增加60%及其交互作用则对优势植物猪毛菜有利。风速降低和降水增加单因素处理对科尔沁沙地植物物种多样性无显著影响，但二者交互作用下，沙地植物物种多样性差异显著，风速降低40%和降水增加60%交互作用时物种多样性最大。(3) 随着风速降低和降水增加，沙地植物地上、地下生物量及总生物量显著增加，优势植物生物量也呈增加趋势，生物量大小顺序为：猪毛菜>五星蒿>狗尾草。风速降低20%和降水增加30%的交互作用能提高优势植物五星蒿的生物量，风速降低40%和降水增加60%的交互作用则有利于优势植物猪毛菜生物量的增加。风速降低40%使群落地下生物量/地上生物量比值降低10.7%，降水增加30%、60%分别使群落地下生物量/地上生物量比值降低15.8%、18.1%。地下生物量主要集中在0-20cm土层深度，占地下总生物量的68.25%；同一土层深度，风速降低20%和降水增加60%的交互作用能促进地下生物量的增加。(4) 风速降低和降水增加单因素处理下，优势植物细胞膜透性大小为：五星蒿>猪毛菜>狗尾草，风速降低使优势植物细胞膜透性呈下降趋势，降水增加使细胞膜透性显著增加。风速降低20%和降水增加60%交互作用下优势植物五星蒿细胞膜透性最大。优势植物细胞含水量的大小为：狗尾草<五星蒿<猪毛菜，风速降低使优势植物五星蒿茎、叶细胞含水量显著增加，降水增加则对优势植物细胞含水量无显著影响。 (5) 风速降低可以提高优势植物净光合速率，但降水增加可使优势植物的净光合速率、气孔导度和蒸腾速率均增加。风速降低处理，优势植物净光合速率的大小为：狗尾草>猪毛菜>五星蒿，且风速降低20%时净光合速率最大。降水增加处理下，优势植物净光合速率的大小为：狗尾草>猪毛菜>五星蒿，降水增加60%时最大。风速降低20%和降水增加30%的交互作用可使优势植物狗尾草净光合速率增加，风速降低20%和降水增加60%的交互作用则有利于优势植物猪毛菜净光合速率、气孔导度、蒸腾速率的增加。 (6) 风速降低和降水增加单因素处理下，优势植物水分利用效率的大小为：狗尾草>猪毛菜>五星蒿，风速降低20%有利于提高优势植物狗尾草、五星蒿植物的水分利用效率，降水增加使优势植物猪毛菜水分利用效率显著提高。风速降低20%和降水增加30%的交互作用可以提高优势植物五星蒿的水分利用效率。此外，随着优势植物生长时间的增加，优势植物狗尾草水分利用效率显著降低，优势植物五星蒿、猪毛菜水分利用效率显著增加。 |
| 英文摘要 | Precipitation is one of the critical factor in restricting plant growth, plant density, species number, and plant distribution pattern in semi-arid sandy land. The changes of precipitation process and pattern play an important role in affecting the growth characteristics and the physiological processes of sand plants, such as water absorption, photosynthesis, respiration, and metabolism. Wind is one of vital environment factor in influencing the whole processes of sand plants growth, development and reproduction, which directly and indirectly affect vegetation types, distribution and productivity, and even the stabilization and sustainable utilization of vegetation resources. Therefore, comprehensive consideration of the interaction of environmental factors for different regions and typical plants to study the influence of wind speed and precipitation changes on growth process of sand plants, and to reveal universal mechanism of different sand plants in response to sand environment are particularly important. In the present study, the controlled experiments of natural wind speed and precipitation were taken to study the effect of wind speed and precipitation variation on plants growth in Horqin Sandy Land.The present studies will analyze the seed germination and growth characteristics of sand plants in response to wind speed and precipitation variation, illustrate the effect of wind speed and precipitation changes on community characteristics of sand plant, and reveal the physiological ecology mechanism of sand plants in response to wind speed and precipitation changes. The purpose of this study is to provide some scientific rationales or theory for desertification control, breeding and introduction of sand plants, as well as stabilization and recovery of sand vegetation. The main results are as follows:(1) Wind speed and precipitation change had an important effect on the seed germination and seedling characteristics of plant in Horqin Sandy Land. On the one hand, wind speed decrease and precipitation enhancement increased the sand plant germination species number, seedling average height, but reduced seedlings density. On the other hand, wind speed decrease increased the advantage of Salsola collina, but reduced the advantage of Bassia dasyphylla. A 30% increase in precipitation promoted the seed germination of Bassia dasyphylla, limited seed germination of Salsola collina, however, which was opposite with the icrease 60% in precipitation. The species Simpson index increased with precipitation increased, and increased significantly when the precipitation increased by 30%. In addition, the interaction of wind and precipitation has a significant impact on seedling species richness, Simpson dominance index, and Shannon-Wiener index.(2) With the decrease in wind speed and the increase in precipitation, the plant average height, vegetation coverage and the height of dominant plant increased significantly. Under the decline 20% and 40% in wind speed,the vegetation coverage increased by 23.6%、40.5%, respectively. While increasing precipitation by 30%、60%, the plant coverage increased by 29.1%、39.6% , respectively. Wind speed decreased by 20% and precipitation increased by 30% and their interactions were conducive to increase dominant plant density and important value of Bassia dasyphylla, as well as wind speed reduced by 40% and precipitation increased by 60% and their interactions were benefit for dominant plants Salsola collina. In addition, individual wind speed reduction or precipitation increase had no significant influence on plant species diversity in Horqin sandy land, but their interaction had a significant difference on sand plant species diversity. The interaction of wind speed reduced by 40% and precipitation increased by 60% could promote the increase in species diversity.(3) With the decrease of wind speed and increase of precipitation, aboveground biomass, underground biomass and total biomass increased significantly, and the biomass of dominant plants were increased. The biomass of dominant plant were the sequence of Salsola collina > Bassia dasyphylla > Setaria viridis. The interaction of wind speed decreased by 20% and precipitation increased by 30% could improve plant biomass of Bassia dasyphylla, and the interaction of wind speed decreased by 40% and precipitation increased by 60% were conducive to dominant plant Salsola collina. Wind speed reduced by 40% resulted in the ratio of underground biomass/aboveground biomass reduced by 10.7%. While precipitation increased by 30% and 60%, the underground biomass/aboveground biomass ratio was reduced by 15.8% and 18.1%, respectively. The underground biomass of sandy land mainly concentrated in 0~20 cm soil depth, account for 68.25% of the total underground biomass. In the same soil layer depth, the interaction of wind speed reduced by 20% and precipitation increased by 60% promoted the increase in underground biomass.(4) With the single factor of wind speed decrease and precipitation increase, the cell membrane permeability of dominant plants was the sequence of: Bassia dasyphylla > Salsola collina > Setaria viridis. Wind speed decrease declined the cell membrane permeability of dominant plant, while precipitation increase had significant influence on increase cell membrane permeability. The cell membrane permeability of dominant plant Bassia dasyphylla was the largest under interaction of wind speed decreased by 20% and precipitation increased by 60%.The cell water content of dominant plants were the sequence of: Setaria viridis < Bassia dasyphylla < Salsola collina. Wind speed decrease could improve the cells water content of stem and leaf of dominant plant Bassia dasyphylla significantly, but precipitation increase had no significant effect on dominant plant cell water content.(5) Wind speed decrease enhanced the dominant plant net photosynthetic rate, and precipitation increase could improve the net photosynthetic rate, stomatal conductance and transpiration rate of dominant plants in Horqin Sandy Land.With the decrease of wind speed, the net photosynthetic rate of the dominant plants were the sequence of: Setaria viridis > Salsola collina > Bassia dasyphylla, and the net photosynthetic rate was maximum when the wind speed reduced by 20%. Under the treatment of precipitation increase, the net photosynthetic rate of dominant plants were the sequence of: Setaria viridis > Salsola collina > Bassia dasyphylla, and which was maximum when the precipitation increased by 60%.The interaction of wind speed reduced by 20% and precipitation increased by 30% could increase the net photosynthetic rate of dominant plant Setaria viridis. The interaction of wind speed decreased by 20% and precipitation increased by 60% was conducive to the enhancement of the net photosynthetic rate, stomatal conductance and transpiration rate of dominant plant Salsola collina. (6) With the single factor of wind speed decrease and precipitation increase, the water use efficiency of dominant plants was the sequence of: Setaria viridis > Salsola collina > Bassia dasyphylla. Wind speed reduced by 20% improved the water use efficiency of dominant plant of Setaria viridis and Bassia dasyphylla, and increased precipitation improved the water use efficiency of dominant plant Salsola collina significantly. The interaction of wind speed decreased by 20% and precipitation increased by 30% could improve the water use efficiency of dominant plant of Bassia dasyphylla. In addition, as the plants grow, the water use efficiency of dominant plant of Setaria viridis reduced significantly, while the water use efficiency of dominant plant of Bassia dasyphylla and Salsola collina increased significantly. |
| 中文关键词 | 风速变化 ; 降水变化 ; 沙地植物 ; 生理生态特征 ; 科尔沁沙地 |
| 英文关键词 | Wind speed variation precipitation changes sand plants eco-physiological characteristics Horqin Sandy Land |
| 语种 | 中文 |
| 国家 | 中国 |
| 来源学科分类 | 生态学 |
| 来源机构 | 中国科学院西北生态环境资源研究院 |
| 资源类型 | 学位论文 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/287968 |
| 推荐引用方式 GB/T 7714 | 魏水莲. 科尔沁沙地植物生长对风速和降水变化的响应[D]. 中国科学院大学,2017. |
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