『Abstract
　Nitrite (NO2^-) is an intermediate in a variety of soil N cycling processes. However, NO2^- dynamics are often not included in studies that explore the N cycle in soil. Within the presented study, nitrite dynamics were investigated in a Nothofagus betuloides forest on an Andisol in southern Chile. We carried out a ¹⁵N tracing study with six ¹⁵N labeling treatments, including combinations of NO3^-, NH4⁺ and NO2^-. Gross N transformation rates were quantified with a ¹⁵N tracing model in combination with a Markov chain Monte Carlo optimization routine. Our results indicate the occurrence of functional links between (1) NH4⁺ oxidation, the main process for NO2^- production (nitritation), and NO2^- reduction, and (2) oxidation of soil organic N, the dominant NO3^- production process in this soil, and dissimilatory NO3^- reduction to NH4⁺ (DNRA). The production of NH4⁺ via DNRA was approximately ten times higher than direct mineralization from recalcitrant soil organic matter. Moreover, the rate of DNRA was several magnitudes higher than the rate of other NO3^- reducing processes, indicating that DNRA is able to outcompete denitrification, which is most likely not an important process in this ecosystem. These functional links are most likely adaptations of the microbial community to the prevailing pedo-climatic conditions of this Nothofagus ecosystem.

Keywords: Nothofagus betuloides; ¹⁵N tracing model; Nitrite (NO2^-); N retention; Dissimilatory nitrate reduction to ammonium (DNRA); Markov chain Monte Carlo sampling』

Abbreviations
Introduction
Materials and methods
　Study site
　¹⁵N tracing experiment
　Soil organic matter fractionation
　¹⁵N tracing model
　Statistical analysis
　Presentation of results and model set-up
Results
　N pool sizes and ¹⁵N enrichments
　Gross N transformation rates
　Correlations among N transformation rates
Discussion
　Turnover of NH4⁺
　Production and consumption of NO3^-
　Dynamics of NO2^-
　　Production of NO2^-
　　Consumption of NO2^-
Conclusions
References