Patterns of Soil N-15 and Total N and Their Relationships with Environmental Factors on the Qinghai-Tibetan Plateau
文献类型：SCI/SSCI论文
| 作者 | Zhou L. ; Song M. H. ; Wang S. Q. ; Fan J. W. ; Liu J. Y. ; Zhong H. P. ; Yu G. R. ; Gao L. P. ; Hu Z. M. ; Chen B. ; Wu W. X. ; Song T. |
| 发表日期 | 2014 |
| 关键词 | desert steppe nitrogen isotope composition nutrient availability soil nitrogen organic-matter turnover natural-abundance delta-n-15 brazilian amazon basin isotopic composition terrestrial ecosystems precipitation gradient nitrogen limitation forest soils plant carbon |
| 英文摘要 | The patterns of soil nitrogen (N) isotope composition at large spatial and temporal scales and their relationships to environmental factors illustrate N cycle and sources of N, and are integrative indicators of the terrestrial N cycle and its response to global change. The objectives of this study were: i) to investigate the patterns of soil N content and natural abundance of N-15 (delta N-15) values in different ecosystem types and soil profiles on the Qinghai-Tibetan Plateau; ii) to examine the effects of climatic factors and soil characteristics on the patterns of soil N content and soil delta N-15 values; and iii) to test the relationship between soil delta N-15 values and soil C/N ratios across ecosystems and soil profiles. Soil profiles were sampled at 51 sites along two transects 1 875 km in length and 200 km apart and distributed in forest, meadow and steppe on the Qinghai-Tibetan Plateau. Each site was sampled every 10 cm from a soil depth of 0 to 40 cm and each sample was analyzed for soil N content and delta N-15 values. Our results indicated that soil N and delta N-15 values (0-40 cm) in meadows were much higher than in desert steppe. Soil N decreased with soil depth for each ecosystem, while variations of soil delta N-15 values along soil profiles were not statistically significant among most ecosystems but for mountain meadow, lowland meadow, and temperate steppe where soil delta N-15 values tended to increase with soil depth. The parabolic relationship between soil delta N-15 values and mean annual precipitation indicated that soil delta N-15 values increased with increasing precipitation in desert steppe up to 500 mm, and then decreased with increasing precipitation across all other ecosystems. Moreover, the parabolic relationship between delta N-15 values and mean annual temperature existed in all individual ecosystem types. Soil N and delta N-15 values (0-40 cm) increased with an increase in soil silt and clay contents. Furthermore, a threshold of C/N ratio of about 11 divided the parabolic relationship between soil delta N-15 values and soil C/N ratios into positive (C/N < 11) and negative (C/N > 11) parts, which was valid across all ecosystems and soil profiles. The large explanatory power of soil C/N ratios for soil delta N-15 values suggested that C and N concentrations, being strongly controlled by precipitation and temperature, were the primary factors determining patterns of soil delta N-15 on the Qinghai-Tibetan Plateau. |
| 出处 | Pedosphere |
| 卷 | 24 |
| 期 | 2 |
| 页 | 232-242 |
| 收录类别 | SCI |
| 语种 | 英语 |
| ISSN号 | 1002-0160 |
| 源URL | [http://ir.igsnrr.ac.cn/handle/311030/29358]  |
| 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 | Zhou L.,Song M. H.,Wang S. Q.,et al. Patterns of Soil N-15 and Total N and Their Relationships with Environmental Factors on the Qinghai-Tibetan Plateau. 2014. |
入库方式： OAI收割
来源：地理科学与资源研究所
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