Microbial phosphorus cycling in forest soils as dependent on carbon, nitrogen and phosphorus availability

森林土壤中的微生物磷循环取决于碳、氮和磷的可用性

• 批准号: 240974630
• 负责人: Professorin Dr. Marie Anneke Spohn
• 金额: --
• 依托单位: Swedish University of Agricultural Sciences
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/240974630?language=en
• 关键词: Microbial; phosphorus; cycling; forest; soils

Microbial phosphorus (P) cycling is crucial for forest nutrition. Previous research focused on microbial biomass P stocks and phosphatase activity, but little is known about the rates of microbial P cycling processes such as solubilization of bound P, turnover of P in the microbial biomass, and net P mineralization. The objective of this project is to gain understanding of microbial P cycling depending on carbon (C), nitrogen (N) and P availability in beech forest soils. The general hypothesis of the project is that rates of microbial P cycling depend strongly on C and P availability. We will, first, study net P mineralization rates, phosphatase activity and microbial P immobilization in a full factorial N and P application experiment in beech forests. We will, second, quantify the mean residence time of C and P in the microbial biomass by labeling microbial DNA with 14C and 33P in a girdling experiment and in forest soils differing in P availability. Third, we will determine the capacity of microbial communities to solubilize P based on incubation experiments with soil extracts and added mineral P. This will be the first study to determine the mean residence time of C and P in the microbial biomass by labeling microbial DNA with 14C and 33P. The main value of the project will be that it relates rates of microbial P cycling in forest soils to C, N and P availability.

微生物磷（P）循环对于森林营养至关重要。先前的研究集中在微生物生物量P库存和磷酸酶活性上，但对微生物P循环过程的速率（例如结合P的溶解度，微生物生物量P的溶解度）和净P矿化的速率知之甚少。该项目的目的是根据山毛榉森林土壤中的碳（C），氮（N）和P的可用性来了解微生物P循环。该项目的总体假设是，微生物P循环的速率在很大程度上取决于C和P的可用性。首先，我们将在山毛榉森林的完整阶乘N和P应用实验中研究净P矿化速率，磷酸酶活性和微生物P固定化。其次，我们将通过在束束实验和p供应量不同的森林土壤中标记微生物DNA的平均C和P在微生物生物量中的平均停留时间。第三，我们将根据与土壤提取物的孵育实验并添加矿物。这将是第一个通过将微生物DNA用14c和33p标记微生物DNA的第一个研究，确定微生物群落溶解P的能力。该项目的主要价值是它将森林土壤中微生物P循环的速率与C，N和P的可用性联系起来。