What are the main mechanisms affecting N flow through soil N pools in N saturated mountain soils?

(Co)investigator from the Department: Karolina Tahovská
Funding provider: GAAV
Duration: 2009 to 2011

Project goals: 
The aims of the project are 1) to describe N transformations in organic layers of N saturated and N non saturated soils using 15N tracer approach. Second aim is 2) to evaluate the effect of Al and Mn on N microbial assimilation by manipulative experiments. 3) determination and evaluation of concentrations, availabilities and speciation of Al and Mn in upper organic soils, as well as monitoring and evaluating their temporal variability.

Project description: 
This project is focused on N transformations in N saturated mountain forest soils, using 15N isotope labelling and molecular biology methods. The goal is to describe gross microbial N processes in soil (gross N mineralization and nitrification, respiratory/assimilatory nitrate reduction, and ammonium/ amino acid assimilation) and to quantify functional genes encoding enzymes of N assimilation (Nas, Gln). The N transformations may be influenced by toxic forms of Al and Mn in N saturated soils, therefore our next goal is to determine and evaluate the concentrations, availabilities and speciation of Al and Mn, with focus on toxicity and impact on N mineralization and N assimilation processes. The soil samples will be collected at Certovo and Plešné Lake watersheds in the National Park Šumava. The results will improve the knowledge on N transformations and fluxes in N saturated soils, as well as the knowledge about Al and Mn speciation in organic soil layers.