Symbiotic nitrogen fixation by legumes in two Chinese grasslands estimated with the (15)N dilution technique
文献类型：SCI/SSCI论文
| 作者 | Yang B. J. ; Qiao N. ; Xu X. L. ; Ouyang H. |
| 发表日期 | 2011 |
| 关键词 | (15)N tracer Alpine meadow Temperate steppe Kobresia humilis Leymus chinensis n-2 fixation altitudinal gradient communities alps nutrition dynamics |
| 英文摘要 | Symbiotic nitrogen (N) fixation by legumes was investigated using the (15)N dilution technique in two Chinese grasslands: one in the north-eastern Tibetan Plateau and the other in Inner Mongolia in China. A small amount (0.03 g N m(-2)) of (15)N labelled (NH(4))(2)SO(4) fertilizer was evenly distributed in two soils. One month after the (15)N addition, four legumes (Astragalus sp., Gueldenstaedtia diversifolia, Oxytropis ochrocephala and Trigonella ruthenica) in the alpine meadow and two legumes (Thermopsis lanceolata and Melissitus ruthenica) in the temperate steppe were collected. Several non-legume plant species were harvested as the reference. Above-ground biomass of legumes ranged from 8 to 24 g m(-2) in the alpine meadow and from 11 to 35 g m(-2) in the temperate steppe. The reference plants showed distinctly higher (15)N atom% excess than legumes (0.08% vs. 0.02% in the alpine meadow, 0.10% vs. 0.02% in the temperate steppe). The N derived from atmosphere (%Ndfa) ranged from 50 to 90% N in the alpine meadow, while it ranged from 85 to 92% in the temperate steppe. Based on the legume above-ground biomass, total symbiotic N(2)-fixation rate was estimated to be 1.00 g N m(-2) year(-1) in the alpine meadow and 1.15 g N m(-2) year(-1) in the temperate steppe. These N inputs by legumes can account for 9% of the gap between the N demand and the seasonal N release by mineralization in the alpine Kobresia grassland and 20% in the temperate Leymus grassland, respectively. Considering additional contribution of the root biomass, we suggest that biological N(2)-fixation by legumes plays an important role in the cycling of N in both Kobresia and Leymus grasslands on an annual scale. |
| 出处 | Nutrient Cycling in Agroecosystems |
| 卷 | 91 |
| 期 | 1 |
| 页 | 91-98 |
| 收录类别 | SCI |
| 语种 | 英语 |
| ISSN号 | 1385-1314 |
| 源URL | [http://ir.igsnrr.ac.cn/handle/311030/22614]  |
| 专题 | 地理科学与资源研究所_历年回溯文献 |
| 推荐引用方式 GB/T 7714 | Yang B. J.,Qiao N.,Xu X. L.,et al. Symbiotic nitrogen fixation by legumes in two Chinese grasslands estimated with the (15)N dilution technique. 2011. |
入库方式： OAI收割
来源：地理科学与资源研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。