Project Details
Projekt
Microbial phosphorus cycling in forest soils as dependent on carbon, nitrogen and phosphorus availability
Applicant
Professorin Dr. Marie Anneke Spohn
Subject Area
Soil Sciences
Term
from 2013 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 240974630
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.
DFG Programme
Priority Programmes
