Patterns of Soil N-15 and Total N and Their Relationships with Environmental Factors on the Qinghai-Tibetan Plateau | |
Yu Gui-Rui | |
刊名 | PEDOSPHERE |
2014 | |
卷号 | 24期号:2页码:232-242 |
关键词 | desert steppe nitrogen isotope composition nutrient availability soil nitrogen |
通讯作者 | Wang, SQ |
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. |
收录类别 | SCI |
资助信息 | National Basic Research Program (973 Program) of China 2010CB833503;Chinese Academy of Sciences for Strategic Priority Research Program XDA05050602;Key Projects in the National Science and Technology Pillar Program 2013BAC03B03;Open Research Fund of Chinese Academy of Sciences O8R8B161PA |
公开日期 | 2014-07-08 |
内容类型 | 期刊论文 |
源URL | [http://ir.igsnrr.ac.cn/handle/311030/28968] |
专题 | 地理科学与资源研究所_生态系统研究网络观测与模拟重点实验室_CERN水分分中心 |
推荐引用方式 GB/T 7714 | Yu Gui-Rui. Patterns of Soil N-15 and Total N and Their Relationships with Environmental Factors on the Qinghai-Tibetan Plateau[J]. PEDOSPHERE,2014,24(2):232-242. |
APA | Yu Gui-Rui.(2014).Patterns of Soil N-15 and Total N and Their Relationships with Environmental Factors on the Qinghai-Tibetan Plateau.PEDOSPHERE,24(2),232-242. |
MLA | Yu Gui-Rui."Patterns of Soil N-15 and Total N and Their Relationships with Environmental Factors on the Qinghai-Tibetan Plateau".PEDOSPHERE 24.2(2014):232-242. |
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