Nitrogen and Phosphorus Cycling

氮磷循环

• 批准号: 172133814
• 负责人: Professorin Dr. Yvonne Oelmann
• 金额: --
• 依托单位: Institut für Geographie und Geoökologie (IFGG)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/172133814?language=en
• 关键词: Nitrogen; Phosphorus; Cycling

Feedbacks of plant diversity on nutrient cycling in soil under grassland e.g., mediated through organic matter input and adapted microbial communities, might occur after an initial period of establishment. In the Jena Experiment, increased C and N storage in soil under highly diverse mixtures resulted in a shift from negative to positive correlations between plant diversity and concentrations of plant-available chemical N species in soil after five years. Simultaneously, the P pool in soil decreased. Up to now, no longer-term observations of the development of biodiversity-soil nutrient pool relationships exist. We propose to elucidate the underlying processes of accumulation and enhanced release of N in soil with time as related to plant diversity i.e., gaseous N deposition, uptake of groundwater by plants, and gross N mineralization, and to continue monitoring the biodiversity-N and P cycling relationships. We will determine NO2-derived N in SOM with a 15NO2-labeling experiment, plant uptake of NO3 - from groundwater with isotopically labeled SeO4 2-, and in-situ gross mineralization with the 15N pool dilution method. We will continue our 8-yr data set of above and belowground water and nutrient fluxes using established rain collectors and suction plates at all plots of the Main Experiment. We mainly contribute to the Tracer Experiment (6.2) and the Main Experiment (6.3) of the proposed research unit but also provide available N and P concentration data to two other experiments (6.1, 6.4).

植物多样性对草地土壤养分循环的反馈，通过有机物质输入和适应微生物群落介导的，可能发生在建立的初始阶段之后。在耶拿实验中，增加C和N存储在土壤中的高度多样化的混合物导致植物多样性和植物可用的化学N物种在土壤中的浓度之间的负相关性转变为正相关性五年后。同时，土壤磷库减少。到目前为止，还没有对生物多样性与土壤养分库之间关系的发展进行长期观察。我们建议阐明与植物多样性相关的土壤中氮素积累和释放增强的潜在过程，即，气态氮沉降、植物对地下水的吸收和总氮矿化，并继续监测生物多样性与氮和磷循环的关系。我们将确定NO2-衍生的N在SOM与15 NO2-标记实验，植物吸收NO3 -从地下水与同位素标记的SeO 4 2-，和原位总矿化与15 N池稀释法。我们将继续我们的8年数据集的地上和地下水和养分通量，在主要实验的所有地块建立雨水收集器和吸力板。我们主要为拟议研究单元的示踪实验（6.2）和主实验（6.3）做出贡献，但也为其他两个实验（6.1，6.4）提供可用的N和P浓度数据。