Impact of long-term N deposition on nitrogen transformation and translocation in a northern peatland

长期氮沉降对北部泥炭地氮转化和易位的影响

• 批准号: 43824071
• 负责人: Professor Dr. Christian Blodau (†)
• 金额: --
• 依托单位: Department Hydrogeologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/43824071?language=en
• 关键词: Impact; long; term; deposition; nitrogen

Large areas of peatlands have been exposed to elevated atmospheric N deposition. When sustained chronic inputs of N lead to “nitrogen saturation”, N is lost from the soil, and environmental pollution will inevitably occur. Ombrotrophic, Sphagnum-dominated peatlands are exclusively fed by wet and dry atmospheric deposition and are very sensitive to increased atmospheric N input. It is thus of great scientific interest to examine the changes in N mass balances and cycling induced by anthropogenic N input. Little is currently known about the changes in the fate and mobility of N following chronic N pollution. The proposed project seeks to clarify the pathways of N transformations and N mobility in different pools under different long-term nutrient fertilization and changing plant cover through combined application of 15N as an isotopic tracer and HYDRUS modeling. The mechanisms of N retention by soil and plants will be elucidated and N saturation thresholds will be estimated by empirical analyses and modeling. Results from this study will improve our understanding of the fate of N under increasing N load, thereby enhance our ability to predict the future response of the N balance and cycle in northern peatlands.

大片泥炭地暴露在大气氮沉积升高的环境中。当持续的长期氮素输入导致“氮素饱和”时，土壤中的氮素就会流失，不可避免地会造成环境污染。广泛营养的泥炭地以泥炭藻为主，完全由干湿大气沉积提供养分，对大气N输入的增加非常敏感。因此，研究人为N输入引起的N物质平衡和循环的变化具有重要的科学意义。目前，人们对慢性氮污染后氮的去向和移动性的变化知之甚少。该项目旨在通过15N作为同位素示踪剂和Hydrus模型的结合应用，阐明不同长期养分施肥和改变植被覆盖下不同池塘中N的转化和迁移的途径。通过经验分析和模型模拟，将阐明土壤和植物保持氮素的机制，并估计氮素饱和阈值。这项研究的结果将加深我们对氮负荷增加下N的去向的理解，从而提高我们预测北方泥炭地未来N平衡和N循环的响应的能力。