title: Rainfall reduction amplifies the stimulatory effect of nitrogen addition on N2O emissions from a temperate forest soil.
abstract: Soil is a significant source of atmospheric N2O, and soil N2O emissions at a global scale are greatly affected by environment changes that include continuous deposition of atmospheric nitrogen and changing precipitation distribution. However, to date, field simulations of multiple factors that control the interaction between nitrogen deposition and precipitation on forest soil N2O emissions are scarce. In this study, we conducted a 2-year continuous assessment of N2O emissions from November 2012 to October 2014 at a nitrogen addition and rainfall reduction manipulation platform in an old broad-leaved Korean pine mixed forest at Changbai Mountain in northeastern China. We found that N2O emissions from control plots were 1.25 ± 0.22 kg N2O-N ha-1a-1. Nitrogen addition significantly increased N2O emissions, with the emission factor of 1.59%. A 30% reduction in rainfall decreased N2O emissions by 17-45%. However, in combination, nitrogen addition and rainfall reduction increased N2O emissions by 58-140%, with the emission factor of 3.19%, and had a larger promotional effect than the addition of nitrogen alone. Our results indicated that drought slightly decreases forest soil N2O emission; however, with increasing deposition of atmospheric N in temperate forest soils, the effect of drought might become altered to increase N2O emission.
authors.affiliation: Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.|University of Chinese Academy of Sciences, Beijing, 100039, China.
authors.forename: Shicong
authors.initials: S
authors.lastname: Geng
authors.affiliation: Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.|University of Chinese Academy of Sciences, Beijing, 100039, China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.
authors.forename: Shijie
authors.initials: S
authors.lastname: Han
authors.affiliation: Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.|University of Chinese Academy of Sciences, Beijing, 100039, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.
authors.forename: Junhui
authors.initials: J
authors.lastname: Zhang