Effects of artificial nitrogen addition and reduction in precipitation on soil CO2 and CH4 effluxes and composition of the microbial biomass in a temperate forest. (18th June 2019)

• Record Type: Journal Article
• Authors: Yan, Guoyong; Xing, Yajuan; Lü, Xiao‐Tao; Xu, Lijian; Zhang, Junhui; Dai, Guanhua; Luo, Wei; Liu, Guancheng; Dong, Xiongde; Wang, Qinggui
• Is Part Of: European journal of soil science. Volume 70:Number 6(2019)
• Page Start: 1197
• Page End: 1211
• Publication Date: 2019-06-18
• Subjects: antagonistic effects -- CH4 uptake -- seasonal timescales -- soil carbon efflux -- soil microbial community; Soil science -- Periodicals; 631.4
• DOI: 10.1111/ejss.12812
• Languages: English
• ISSNs: 1351-0754

Abstract

Abstract: To understand the effects of artificially increased atmospheric nitrogen (N) and decreased precipitation on the soil microbial community and soil CO2 and CH4 efflux, a two‐factorial field experiment was carried out with the following treatments: (a) control, (b) N addition (+50 kg N ha −1 year −1 ), (c) decreased precipitation (−30% of throughfall) and (d) combined N addition and decreased precipitation (+50 kg N ha −1 year −1, −30% of throughfall). The N addition and decreased precipitation treatments had a positive effect on mean CO2 efflux (2.61 μmol CO2 m −2 s −1 for control, 4.26 μmol CO2 m −2 s −1 for N addition, 3.62 μmol CO2 m −2 s −1 for reduction in precipitation) and mean rates of CH4 uptake (0.00088 μmol CH4 m −2 s −1 for control, 0.00154 μmol CH4 m −2 s −1 for N addition, 0.00151 μmol m −2 s −1 for reduction in precipitation) during the growing season. The combined N addition and reduction in precipitation also led to increased soil CO2 efflux and CH4 uptake, but the combined response was weaker than the response to single variable treatments (3.10 μmol CO2 m −2 s −1 and 0.00130 μmol CH4 m −2 s −1 interaction), indicating antagonistic effects of the combined treatment. At the seasonal scale, changes in soil CO2 and CH4 efflux were complex, especially in the spring freezing and thawing period, during which pulses of CO2 efflux and CH4 uptake occurred. Decreased precipitation altered the composition of the bacterial community in the winter and growing seasons, and composition of the microbial community also showed a seasonal change. However, changes in microbial community structure under N addition, precipitation reduction and their interaction might be important factors leading to an increase or decrease in soil carbon efflux. Highlights: How global changes (N addition and decreased precipitation) affect soil C flux. Seasonal effects of global changes on soil C flux were analysed quantitatively. Decreased precipitation and N‐addition increased soil CO2 flux and decreased soil CH4 flux. Global changes regulate soil C flux by altering soil water, microbial and nutrient status.