Modeling biological nitrogen fixation in global natural terrestrial ecosystems
Open Access
- 13 July 2020
- journal article
- research article
- Published by Copernicus GmbH in Biogeosciences (online)
- Vol. 17 (13), 3643-3657
- https://doi.org/10.5194/bg-17-3643-2020
Abstract
Biological nitrogen fixation plays an important role in the global nitrogen cycle. However, the fixation rate has been usually measured or estimated at a particular observational site. To quantify the fixation amount at the global scale, process-based models are needed. This study develops a biological nitrogen fixation model to quantitatively estimate the nitrogen fixation rate by plants in a natural environment. The revised nitrogen module better simulates the nitrogen cycle in comparison with our previous model that has not considered the fixation effects. The new model estimates that tropical forests have the highest fixation rate among all ecosystem types, which decreases from the Equator to the polar region. The estimated nitrogen fixation in global terrestrial ecosystems is 61.5 Tg N yr−1 with a range of 19.8–107.9 Tg N yr−1 in the 1990s. Our estimates are relatively low compared to some early estimates using empirical approaches but comparable to more recent estimates that involve more detailed processes in their modeling. Furthermore, the contribution of nitrogen made by biological nitrogen fixation depends on ecosystem type and climatic conditions. This study highlights that there are relatively large effects of biological nitrogen fixation on ecosystem nitrogen cycling. and the large uncertainty of the estimation calls for more comprehensive understanding of biological nitrogen fixation. More direct observational data for different ecosystems are in need to improve future quantification of fixation and its impacts.Keywords
This publication has 115 references indexed in Scilit:
- Reactive nitrogen inputs to US lands and waterways: how certain are we about sources and fluxes?Frontiers in Ecology and the Environment, 2013
- Modelling temperature acclimation effects on the carbon dynamics of forest ecosystems in the conterminous United StatesTellus B: Chemical and Physical Meteorology, 2013
- The interactive effects of temperature and light on biological nitrogen fixation in boreal forestsNew Phytologist, 2012
- Facultative nitrogen fixation by canopy legumes in a lowland tropical forestOecologia, 2010
- Using an Ecophysiological Analysis to Dissect Genetic Variability and to Propose an Ideotype for Nitrogen Nutrition in PeaAnnals of Botany, 2007
- Nitrogen Cycles: Past, Present, and FutureBiogeochemistry, 2004
- Modeling soil thermal and carbon dynamics of a fire chronosequence in interior AlaskaJournal of Geophysical Research: Atmospheres, 2002
- Nitrogen-fixing plants in a cut-over lodgepole pine stand of southern British ColumbiaCanadian Journal of Forest Research, 1989
- Distribution and cycling of nutrients in Pinus radiata as affected by past lupin growth and fertiliserForest Ecology and Management, 1986
- Nitrogen fixation and accretion by wax myrtle (Myrica cerifera) in slash pine (Pinus elliottii) plantationsForest Ecology and Management, 1983