SP05: Soil nutrient dynamics

SP05：土壤养分动态

• 批准号: 531180191
• 负责人: Professorin Dr. Yvonne Oelmann
• 金额: --
• 依托单位: Arbeitsgruppe Geoökologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/531180191?language=en
• 关键词: SP05; Soil; nutrient; dynamics

With ongoing climate change, the frequency of extreme events is increasing. Extreme events such as floods or droughts affect the availability of water and, thus, inevitably impact nutrient cycling in soils. The majority of grassland studies reported a nutrient flush in soil upon rewetting after drought which is eventually followed by nutrient leaching losses compromising water quality after droughts. The nutrient flush is linked to nutrient dynamics of plants and soil microorganisms and is determined by opposing processes during the drought (= resistance) and after the subsequent rewetting (= recovery).In this context, the objectives of our subproject (SP05) are (i) to assess the resistance and recovery of soil microbial nutrient dynamics during and after a drought, respectively, (ii) to test the effect of plant diversity on the resistance and recovery of microbial nutrient dynamics in soil and link this to other organisms (plants, soil fauna), and (iii) to test the long-term effect of plant diversity on soil nutrient dynamics under extreme events. We hypothesize that the soil microbial community reduces nutrient uptake and is prone to nutrient release during drought but rapidly takes up nutrients after a drought. In other words, microbial nutrient pools in soil quickly recover after drought and furthermore, faster at high as compared to low plant diversity. Particularly at high plant diversity, the nutrient dynamics of soil microorganisms and other organisms are complementary, i.e. temporally asynchronous. Consequently, plant diversity stabilizes nutrient dynamics in spite of frequent extreme events in the long run.To test these hypotheses, our research will be based on the common research platforms (ResCUE Experiment; Main Experiment). Furthermore, we will rely on data of different temporal resolutions to assess nutrient dynamics related to resistance, recovery and stability. We will use state-of-the-art methods (soil microbial nutrient concentrations), stable isotope labeling and natural abundance levels of stable isotopes. Our SP will benefit from synergies arising from cooperation with the other SPs involved in the Research Unit. Overall, SP05 will contribute facets of multifunctional stability to test the central hypothesis that multifunctional stability is highest in high-diversity plots due to a variety of forms of ecological complementarity. Ultimately, stabilizing effects of plant diversity by ecological complementarity are expected to minimize drought-induced nutrient flushes and thus, to maintain tight nutrient cycles. In view of contemporary climate change, plant diversity could mitigate the risk of detrimental effects on water bodies that accompany extreme events.

随着气候变化的持续，极端事件的频率正在增加。洪水或干旱等极端事件会影响水的供应，从而不可避免地影响土壤中的养分循环。大多数草地研究报告了干旱后再湿润时土壤中的养分冲刷，干旱后养分淋溶损失最终损害水质。养分冲刷与植物和土壤微生物的养分动态有关，并由干旱期间的相反过程决定（=电阻）和随后的再润湿后，（=恢复）。在这种情况下，我们的子项目（SP 05）的目标是：（i）分别评估干旱期间和之后土壤微生物养分动态的抵抗力和恢复，（二）测试植物多样性对土壤中微生物养分动态的抵抗力和恢复的影响，并将其与其他生物（植物、土壤动物）联系起来;（三）测试极端事件下植物多样性对土壤养分动态的长期影响。我们假设，土壤微生物群落减少养分吸收，并在干旱期间易于养分释放，但在干旱后迅速吸收养分。换句话说，土壤中的微生物营养库在干旱后迅速恢复，而且与低植物多样性相比，高植物多样性更快。特别是在植物多样性高的情况下，土壤微生物和其他生物的养分动态是互补的，即时间异步的。因此，从长期来看，即使极端事件频繁发生，植物多样性也能稳定养分动态。为了验证这些假设，我们的研究将基于共同的研究平台（ResCUE实验;主要实验）。此外，我们将依靠不同时间分辨率的数据来评估与抗性、恢复和稳定性相关的营养动态。我们将使用最先进的方法（土壤微生物营养浓度），稳定同位素标记和稳定同位素的自然丰度水平。我们的SP将受益于与研究部门其他SP合作产生的协同效应。总的来说，SP 05将有助于多功能稳定性的方面来测试的中心假设，即多功能稳定性是最高的高多样性的地块，由于各种形式的生态互补性。最后，植物多样性的生态互补性的稳定作用，预计将尽量减少干旱引起的养分冲刷，从而保持严密的养分循环。鉴于当代气候变化，植物多样性可以减轻极端事件对水体产生有害影响的风险。