Nutrient dynamics along the litter – mineral soil continuum

沿凋落物的养分动态 â 矿质土壤连续体

• 批准号: 502049264
• 负责人: Professorin Dr. Friederike Lang
• 金额: --
• 依托单位: Professur für Bodenökologie
• 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/502049264?language=en
• 关键词: Nutrient; dynamics; along; litter; mineral

Slow turnover of the forest floor (FF) is often assumed to be related to immobilisation of nutrients within the organic matter. This is in contrast to the overall hypotheses of FOR 5315 that thick FF represents some kind of adaptation to low nutrient supply by mineral soils. With our project we investigate under which conditions slow turnover of FF material might be an advantage. Our objective is to determine which processes control the relevance of the FF for tree nutrition as compared to the mineral topsoil. We test the hypotheses that (1) at nutrient poor sites the turnover of C is lower than the turnover of P and N, (2) admixture of minerals to FF material and subsequent biotic formation of SOM-mineral associations decreases the pool of organically bound P+N and of easily mobilisable P+N, and (3) that in Norway spruce (Picea abies), FF will contribute more to N and P uptake than in maple (Acer pseudoplatanus) while beech (Fagus sylvatica) will be more plastic across site types: similar to maple on rich sites, and similar to spruce on poor sites. To test our hypotheses, we will study the mobilization kinetics of the macronutrients from FF and A horizons using soil dialysis, we will apply the novel approach of litter and OF bags with admixture of the respective minerals, and we will analyse the mobilization of N from labelled litter in the mesocosm approach for the three tree species. Installing labelled mesocosms at the controlled conditions of a tree species experiment will complement our analyses. In cooperation with the partners of the RU we will be able to explore the impact of the microbial community, root-mycorrhizal exudates, and soil faunal groups on the mobilisation of nutrients from the FF. Integration all our results, we will provide information on the role of FF for the nutrition of beech, maple and spruce at the different sites and how this is related to the FF morphology. With the synthesis of our project we will contribute to the RU cross cutting question on nutrients. We will know under which conditions and for which tree species longer residence time of nutrients in FF is of benefit.

森林地面（FF）的缓慢周转通常被认为是与有机质内营养物质的固定化有关。这与FOR 5315的总体假设相反，即厚FF代表了对矿质土壤低养分供应的某种适应。在我们的项目中，我们调查了FF材料的缓慢周转在哪些条件下可能是有利的。我们的目标是确定哪些过程控制的FF树木营养的相关性相比，矿物表土。我们检验了以下假设：（1）在养分缺乏的地点，C的周转低于P和N的周转，（2）矿物与FF物质的混合物以及随后的SOM-矿物联合体的生物形成减少了有机结合的P + N和易于动员的P + N的库，以及（3）在挪威云杉中，（云杉），FF将有助于更多的N和P的吸收比枫树（槭pseudoplatanus），而山毛榉（山毛榉）将更多的塑料在不同的网站类型：类似于枫树丰富的网站，并类似于云杉在贫穷的网站。为了验证我们的假设，我们将研究动员动力学的大量营养元素从FF和A的视野，使用土壤透析，我们将采用新的方法的凋落物和OF袋与混合物的各自的矿物质，我们将分析动员的N标记凋落物中的围隔方法的三个树种。在树种实验的受控条件下安装标记的中生态系统将补充我们的分析。通过与RU的合作伙伴合作，我们将能够探索微生物群落，根菌根分泌物和土壤动物群对FF养分动员的影响。整合我们所有的结果，我们将提供信息的作用，FF的营养山毛榉，枫树和云杉在不同的网站，这是如何与FF形态。随着我们项目的综合，我们将有助于RU关于营养素的交叉问题。我们将知道在哪些条件下，哪些树种更长的营养物质在FF中的停留时间是有益的。