Responses of forest ecosystems to increasing N deposition in China: A critical review. (December 2018)

• Record Type: Journal Article
• Authors: Tian, Di; Du, Enzai; Jiang, Lai; Ma, Suhui; Zeng, Wenjing; Zou, Anlong; Feng, Chanying; Xu, Longchao; Xing, Aijun; Wang, Wei; Zheng, Chengyang; Ji, Chengjun; Shen, Haihua; Fang, Jingyun
• Is Part Of: Environmental pollution. Volume 243(2018)Part A
• Page Start: 75
• Page End: 86
• Publication Date: 2018-12
• Subjects: N deposition -- Forest -- Soil biogeochemistry -- Nutrient stoichiometry -- Microbial biomass -- China; 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.2018.08.010
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: China has been experiencing a rapid increase in nitrogen (N) deposition due to intensified anthropogenic N emissions since the late 1970s. By synthesizing experimental and observational data taken from literature, we reviewed the responses of China's forests to increasing N deposition over time, with a focus on soil biogeochemical properties and acidification, plant nutrient stoichiometry, understory biodiversity, forest growth, and carbon (C) sequestration. Nitrogen deposition generally increased soil N availability and soil N leaching and decreased soil pH in China's forests. Consequently, microbial biomass C and microbial biomass N were both decreased, especially in subtropical forests. Nitrogen deposition increased the leaf N concentration and phosphorus resorption efficiency, which might induce nutrient imbalances in the forest ecosystems. Although experimental N addition might not affect plant species richness in the overstorey, it did significantly alter species composition of understory plants. Increased N stimulated tree growth in temperate forests, but this effect was weak in subtropical and tropical forests. Soil respiration in temperate forests was non-linearly responsive to N additions, with an increase at dosages of <60 kg N ha −1 yr −1 and a decrease at dosages of >60 kg N ha −1 yr −1 . However, it was consistently decreased by increased N inputs in subtropical and tropical forests. In light of future trends in the composition (e.g., reduced N vs. oxidized N) and the loads of N deposition in China, further research on the effects of N deposition on forest ecosystems will have critical implications for the management strategies of China's forests. Graphical abstract: Image 1 Highlights: The responses of China's forests to increasing N deposition were reviewed. N deposition increased soil N availability and N leaching. N deposition decreased soil pH, microbial biomass C and N. N deposition increased leaf N content and phosphorus resorption. The effects of N deposition are context-dependent. Abstract : By synthesizing experimental and observational data, we reviewed the effects of N deposition on soil biogeochemical properties and acidification, plant nutrient stoichiometry, understory biodiversity, and carbon sequestration in China's forests.