| 来源类型 | Monograph (IIASA Interim Report) |
| 规范类型 | 报告 |
| Nitrogen dynamics in Turbic Cryosols from Siberia and Greenland. | |
| Wild B; Schnecker J; Barta J; Capek P; Guggenberger G; Hofhansl F; Kaiser C; Lashchinsky N | |
| 发表日期 | 2013 |
| 出版者 | IIASA, Laxenburg, Austria: IR-13-074 |
| 出版年 | 2013 |
| 语种 | 英语 |
| 摘要 | Turbic Cryosols (permafrost soils characterized by cryoturbation, i.e., by mixing of soil layers due to freezing and thawing) are widespread across the Arctic, and contain large amounts of poorly decomposed organic material buried in the subsoil. This cryoturbated organic matter exhibits retarded decomposition compared to organic material in the topsoil. Since soil organic matter (SOM decomposition is known to be tightly linked to N availability, we investigated N transformation rates in different soil horizons of three tundra sites in north-eastern Siberia and Greenland. We measurd gross rates of protein depolymerization, N mineralization (ammonification) and nitrification, as well as microbial uptake of amino acids and NH4^+ using an array of ^15N pool dilution approaches. We found that all sites and horizons were characterized by low N availability, as indicated by low N mineralization compared to protein depolymerization rates (with gross N mineralization accounting on average for 14% of gross protein depolymerization). The proportion of organic N mineralized was significantly higher at the Greenland than at the Siberian 44 sites, suggesting differences in N limitation. The proportion of organic N mineralized, however, did not differ significantly between soil horizons, pointing to a similar N demand of the microbial community of each horizon. In contrast, absolute transformation rates were significantly lower in cryoturbated than in organic horizons, with cryoturbated horizons reaching not more than 32% of the transformation rates in organic horizons. Our results thus indicate a deceleration of the entire N cycle in cryoturbated soil horizons, especially strongly reduced rates of protein depolymerization (16% of organic horizons) which is cosidred the rate-limiting step in soil N cycling. |
| 主题 | Evolution and Ecology (EEP) |
| 关键词 | Arctic tundra cryoturbation soil organic matter ecological stoichiometry nitrogen transformation protein depolymerazation nitrogen mineralization nitrification nitrogen availability |
| URL | http://pure.iiasa.ac.at/id/eprint/10693/ |
| 来源智库 | International Institute for Applied Systems Analysis (Austria) |
| 资源类型 | 智库出版物 |
| 条目标识符 | http://119.78.100.153/handle/2XGU8XDN/125919 |
| 推荐引用方式 GB/T 7714 | Wild B,Schnecker J,Barta J,et al. Nitrogen dynamics in Turbic Cryosols from Siberia and Greenland.. 2013. |
| 条目包含的文件 | ||||||
| 文件名称/大小 | 资源类型 | 版本类型 | 开放类型 | 使用许可 | ||
| IR-13-074.pdf（331KB） | 智库出版物 | 限制开放 | CC BY-NC-SA | 浏览 | ||
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