Throughfall reduction diminished the enhancing effect of N addition on soil N leaching loss in an old, temperate forest. (June 2020)

• Record Type: Journal Article
• Authors: Geng, Shicong; Chen, Zhijie; Ma, Shanshan; Feng, Yue; Zhang, Lei; Zhang, Junhui; Han, Shijie
• Is Part Of: Environmental pollution. Volume 261(2020)
• Publication Date: 2020-06
• Subjects: Korean pine -- N leaching -- Zero-tension pan lysimeter method -- Two-factor interaction -- Global environmental change; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.114090
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Soil nitrogen (N) leaching is recognized to have negative effects on the environment. There is a lack of studies on different simultaneously occurring drivers of environmental change, including changing rainfall and N deposition, on soil N leaching. In this study, a two factorial field experiment was conducted in a Korean pine forest with the following four treatments: 30% of throughfall reduction (TR), 50 kg N ha −1 yr −1 of N addition (N+), throughfall reduction plus N addition (TRN+) and natural forest (CK). The zero-tension pan lysimeter method was used to assess the response of soil N leaching loss to manipulated N addition and throughfall reduction. The results showed that the soil N leaching loss in natural forest was 5.0 ± 0.4 kg N ha −1 yr −1, of which dissolved organic nitrogen (DON) accounted for 48%. Compared to natural forest, six years of N addition (NH4 NO3, 50 kg N ha −1 year −1 ) significantly ( P < 0.05) increased soil N leaching losses by 122%, especially in the form of NO3 − ; a 30% reduction in throughfall slightly decreased N leaching losses by 23%; in combination, N addition and throughfall reduction increased N leaching losses by 48%. There was a strong interaction between N addition and throughfall reduction, which decreased N leaching loss by approximately 2.5 kg N ha −1 yr −1 . Our results indicated that drought would diminish the enhancing effect of N deposition on soil N leaching. These findings highlight the importance of incorporating both N deposition and precipitation and their impacts on soil N leaching into future N budget assessments of forest ecosystems under global environmental change. Graphical abstract: Image 1 Highlights: Low soil N leaching was detected in an old, temperate forest due to N limitation. DON leaching accounted for nearly half of soil total N leaching. Six years of N addition more than doubled soil N leaching. Throughfall reduction only slightly decreased soil N leaching. Throughfall reduction diminished the enhancing effect of N addition on soil N leaching. Abstract : A strong interaction was found between N addition and throughfall reduction in which throughfall reduction diminished the enhancing effect of N addition on soil N leaching.