AUTHOR=Yu Lijun , Zhang Qing , Tian Ye , Sun Wenjuan , Scheer Clemens , Li Tingting , Zhang Wen 

TITLE=Global variations and drivers of nitrous oxide emissions from forests and grasslands

JOURNAL=Frontiers in Soil Science

VOLUME=2

YEAR=2022

URL=https://www.frontiersin.org/journals/soil-science/articles/10.3389/fsoil.2022.1094177

DOI=10.3389/fsoil.2022.1094177

ISSN=2673-8619

ABSTRACT=<p>Nitrous oxide (N<sub>2</sub>O) emissions are highly variable due to the complex interaction of climatic and ecological factors. Here, we obtained <italic>in-situ</italic> annual N<sub>2</sub>O emission flux data from almost 180 peer-papers to evaluate the dominant drivers of N<sub>2</sub>O emissions from forests and unfertilized grasslands at a global scale. The average value of N<sub>2</sub>O emission fluxes from forest (1.389 kg Nha<sup>-1</sup>yr<sup>-1</sup>) is almost twice as large as that from grassland (0.675 kg Nha<sup>-1</sup>yr<sup>-1</sup>). Soil texture and climate are the primary drivers of global forest and grassland annual N<sub>2</sub>O emissions. However, the best predictors varied according to land use and region. Soil clay content was the best predictor for N<sub>2</sub>O emissions from forest soils, especially in moist or wet regions, while soil sand content predicted N<sub>2</sub>O emissions from dry or moist grasslands in temperate and tropical regions best. Air temperature was important for N<sub>2</sub>O emission from forest, while precipitation was more efficient in grassland. This study provides an overall understanding of the relationship between natural N<sub>2</sub>O emissions and climatic and environmental variables. Moreover, the identification of principle factors for different regions will reduce the uncertainty range of N<sub>2</sub>O flux estimates, and help to identify region specific climate change mitigation and adaptation strategies.</p>