BGD

Biogeosciences Discussions

BGD

Biogeosciences Discuss.

1810-6285

Göttingen, Germany

10.5194/bg-2019-29

Effects of nitrogen deposition on growing-season soil methane sink across global forest biomes

Enzai

https://orcid.org/0000-0002-5519-0150

¹ ² Xia

Nan

² de Vries

Wim

³ ⁴

State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China

School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China

Wageningen University and Research, Environmental Research, PO Box 47, NL-6700 AA Wageningen, the Netherlands

Wageningen University and Research, Environmental Systems Analysis Group, PO Box 47, NL-6700 AA Wageningen, the Netherlands

161015

National Natural Science Foundation of China

41877328

2017-ZY-07

19 02 2019

2019 1 16

2019

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/

This article is available from https://bg.copernicus.org/preprints/bg-2019-29/

The full text article is available as a PDF file from https://bg.copernicus.org/preprints/bg-2019-29/bg-2019-29.pdf

Anthropogenic alteration of global nitrogen (N) deposition has resulted in profound impacts on soil fluxes of greenhouse gases in terrestrial ecosystems. However, the response of soil methane (CH4) flux to N deposition remains poorly quantified in global forest. Based on a synthesis of experimental results from literature, we evaluated the effects of N deposition on growing-season soil CH4 flux across forest biomes. A distinction was made between low-level N addition that is comparable with the worldwide range in N deposition (< 60 kg N−1 yr−1) and high-level N addition (> 60 kg N−1 yr−1. The results showed that growing-season soil CH4 flux was significantly affected by N additions, the value being dependent on the N addition level and forest biome. Low-level N addition significantly increased growing-season soil CH4 uptake in boreal forest, while an opposite effect occurred in temperate and subtropical forests. However, high-level N addition significantly decreased growing-season soil CH4 uptake across boreal, temperate, and subtropical forests. At biome scale, current N deposition was estimate to increase growing-season soil CH4 sink by 0.029 Tg CH4 in boreal forest, while it decreased growing-season soil CH4 sink by 0.025 Tg CH4 and 0.051 Tg CH4 in temperate and subtropical forests, respectively. This work improves our understanding of biome-specific effect of N deposition on soil CH4 uptake and identifies knowledge gaps in the effect of N deposition on soil CH4 flux in tropical forest.