| 氮素对内蒙古典型草原羊草种群的影响 |
| |
| 引用本文： | 潘庆民,白永飞,韩兴国,杨景成.氮素对内蒙古典型草原羊草种群的影响[J].植物生态学报,2005,29(2):311-317. |
| |
| 作者姓名： | 潘庆民 白永飞 韩兴国 杨景成 |
| |
| 作者单位： | (中国科学院植物研究所内蒙古草原生态系统定位研究站，北京100093) |
| |
| 基金项目： | 国家自然科学基金，中国科学院知识创新工程项目 |
| |
| 摘 要： | 为了研究氮素对内蒙古典型草原植物种群的影响，在中国科学院内蒙古草原生态系统定位研究站，实施了长期的氮素添加试验。就两年来不同梯度氮素处理对羊草(Leymus chinensis)种群的影响进行了分析。结果表明，氮素对羊草种群具有显著的调节效应，随着氮素梯度的增加，羊草种群密度、种群高度、地上生物量、地下生物量、总生物量均显著增加，羊草种群地下生物量／地上生物量比值逐渐降低。氮素对羊草种群构件的生物量分配有显著影响，随着氮素梯度的增加，羊草种群生物量向根茎的分配比例显著降低，向叶片和根系的分配比例显著提高。羊草种群的相对密度和相对生物量也随着氮素梯度的增加而显著提高。
|
| 关 键 词： | 典型草原 羊草 种群 生物量 资源分配 养分添加 |
| 修稿时间： | 2004年3月3日 |
EFFECTS OF NITROGEN ADDITIONS ON A LEYMUS CHINENSIS POPULATION IN TYPICAL STEPPE OF INNER MONGOLIA |
| |
| PAN Qing-min,BAI Yong-Fei,HAN Xing-Guo,YANG Jing-Cheng.EFFECTS OF NITROGEN ADDITIONS ON A LEYMUS CHINENSIS POPULATION IN TYPICAL STEPPE OF INNER MONGOLIA[J].Acta Phytoecologica Sinica,2005,29(2):311-317. |
| |
| Authors: | PAN Qing-min BAI Yong-Fei HAN Xing-Guo YANG Jing-Cheng |
| |
| Affiliation: | (Inner Mongolia Grassland Ecosystem Research Station, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China) |
| |
| Abstract: | Leymus chinensis, a rhizomatous graminoid, is a dominant species in the grasslands of northern China. The characteristics of L. chinensis populations have been well documented in many research papers. Because of overgrazing, grasslands of northern China have become degraded since the 1980s. As a result, the density and biomass of L. chinensis populations have decreased significantly. Fertilization is a common technique for management of pastures in many countries; however, it is not widely used in the grasslands of China. Nitrogen is an important driver of community succession in grassland ecosystems, but the response of L. chinensis populations to nitrogen additions in typical steppe, a semiarid area of northern China, remains unclear. We conducted a sequential nitrogen addition experiment in a lightly degraded grassland plot that was fenced in 1999. Nitrogen (NH4NO3) was applied on July 5 for two years at application rates of: 0, 1.75, 5.25, 10.5, 17.5, and 28 g N·m-2,respectively. There were 9 replicate 5 m×5 m plots of each of the six treatments with each plot spaced 1 m apart. A completely randomized design was used for this experiment. Before the experiment, soil samples were collected and dry bulk density, pH, soil nitrogen and soil carbon were analyzed. After two years of nitrogen fertilization, we measured the density, height, aboveground biomass and belowground biomass of L. chinensis in each plot. The results showed that L. chinensis population characteristics were highly responsive to nitrogen additions. With an increase in nitrogen application rates, the density, height, aboveground biomass, belowground biomass and total biomass of L. chinensis increased significantly whereas the ratio of aboveground biomass/belowground biomass decreased. The allocation of biomass among plant parts was significantly affected by nitrogen additions: the proportion of biomass allocated to rhizomes decreased remarkably with increasing nitrogen rates whereas that allocated to leaves and roots increased significantly. The relative biomass and relative density of L. chinensis also increased with increasing nitrogen additions. In summary, adding nitrogen to lightly degraded grassland not only increased the density and biomass of L. chinensis population but changed the resource partitioning among plant parts as well. |
| |
| Keywords: | Typical steppe Leymus chinensis Population Biomass Resource allocation Nitrogen fertilization |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《植物生态学报》浏览原始摘要信息 |
|
点击此处可从《植物生态学报》下载免费的PDF全文 |
|
