Jansen-Willems, A.; Zawallich, J. & Müller, C. (2021): <b>Advanced tool for analysing 15N tracing data</b>. <i>Soil Biology and Biochemistry</i> <b>165</b>, 108532<br>DOI: <a href="http://dx.doi.org/10.1016/j.soilbio.2021.108532" target="_blank">http://dx.doi.org/10.1016/j.soilbio.2021.108532</a>.
Resource Description
Title:
Advanced tool for analysing 15N tracing data
FOR816dw ID:
33
Publication Date:
2021-12-19
License and Usage Rights:
DASIM data user agreement. (www.dasim.de/dataagreementp3.do)
Ntrace is a family of tools for the analysis of 15N tracing data sets, to quantify the simultaneous gross nitrogen (N) transformation rates in terrestrial ecosystems. Starting with the original publication of Ntrace in 2007, a number of specialised tools have been developed that cover a range of applications such as nitrite and gaseous N dynamics. While the capability of the tool has been extended to cover a range of applications, the underlying parameter optimisation algorithm, based on the Metropolis MCMC algorithm, has remained unchanged. However, in more computational demanding applications, this algorithm turned out to be very time consuming, and in some cases it was not even able to identify unambiguous parameter sets. The aim of this study was, to test a new global optimisation algorithm (GlobalSearch), by re-analysing some of the published datasets. In the evaluation, the speed of finding a suitable solution but in particular the accuracy of the new algorithm to obtain an adequate fit to the observations was taken into account. A new uncertainty calculation for the optimised parameters, based on the Levenberg-Marquardt method, has also been implemented. The new Ntrace tool was able to find an adequate fit for all tested datasets, in often a fraction of the time compared to the original MCMC algorithm. For all test cases the accuracy of the fit was at least as good as with the original model. This is partly due to a new algorithm's option to vary the initial pool size. In summary, the new Ntrace tool is quicker in finding suitable parameters for 15N tracing data sets. The fit to measured data is often improved over the original tool. Thus, we recommend the use of the new Ntrace tool for analysing 15N tracing data. The new tool is programmed in MATLAB and can easily be adapted to new applications.
Keywords:
| 15N tracing | N transformations | stable isotopes | nitrogen cycling | isotopic model | Ntrace |
Literature type specific fields:
ARTICLE
Journal:
Soil Biology and Biochemistry
Volume:
165
Page Range:
108532
Metadata Provider:
Individual:
Kristina Kleineidam
Contact:
email:
kristina.kleineidam@bot2.bio.uni-giessen.de
Justus-Liebig-University Giessen
Institute for Plant Ecology
Heinrich-Buff-Ring 26
35392 Giessen
Germany
