caa a22 4500 606217800 CHVBK 20210128101109.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s11104-014-2353-9 doi (NATIONALLICENCE)springer-10.1007/s11104-014-2353-9 Direct and indirect effects of nitrogen additions on fine root decomposition in a subtropical bamboo forest [Elektronische Daten] [Li-hua Tu, Yong Peng, Gang Chen, Hong-ling Hu, Yin-long Xiao, Ting-xing Hu, Li Liu, Yi Tang] Aims: As an important contributor to carbon (C) flux in the global C cycle, fine root litter in forests has the potential to be affected by the elevated nitrogen (N) deposition observed globally. However, the direct effects (on current fine root decomposition) and indirect effects (on root quality and subsequent decomposition) of N deposition on fine root decomposition are poorly understood. Methods: We conducted a 5-year field experiment in a Pleioblastus amarus bamboo forest in southwestern China. In the first 3years of the experiment, N-treated sites (0, 50, 150, and 300kgNha−1year−1, respectively) and fine roots under two N regimes (0 and 150kgNha−1year−1; 0N-Root/+N-Root, respectively) were prepared. Next, these two fine root treatments were applied to a 2-year decomposition experiment in the N-treated sites under continuous N treatment. Results: Nitrogen additions increased fine root density, concentrations of N, P, and lignin in fine roots, and concentrations of TOC, TN, NH4 +-N and NO3 −-N in the soil, and decreased the soil pH. The decomposition constant k decreased under N addition treatments, and the decomposition rate of + N-Root was lower than that of 0N-Root, suggesting that both the direct and indirect effects of N additions on fine root decomposition rates were negative. Both N addition and root substrate changes led to an increase in the residual lignin content during decomposition. Nitrogen additions significantly decreased the loss of C, N, P, K, Ca and Mg during decomposition. Conclusions: The changes in the soil environment and increased root lignin concentration as a result of N additions may be the mechanism underlying the negative direct and indirect effects observed. Elevated fine root biomass input and slower degradation rates may be a potential mechanism explaining the increase in soil TOC and TN under N treatment. Springer International Publishing Switzerland, 2014 Nitrogen deposition nationallicence Root decomposition nationallicence Litter substrate nationallicence Lignin nationallicence Bamboo nationallicence Tu Li-hua College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Peng Yong College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Chen Gang College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Hu Hong-ling College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Xiao Yin-long College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Hu Ting-xing College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Liu Li Personnel Department, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Tang Yi College of Horticulture, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut Plant and Soil Springer International Publishing 389/1-2(2015-04-01), 273-288 0032-079X 389:1-2<273 2015 389 11104 https://doi.org/10.1007/s11104-014-2353-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-014-2353-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tu Li-hua College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 700 1- Peng Yong College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 700 1- Chen Gang College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 700 1- Hu Hong-ling College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 700 1- Xiao Yin-long College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 700 1- Hu Ting-xing College of Forestry, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 700 1- Liu Li Personnel Department, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 700 1- Tang Yi College of Horticulture, Sichuan Agricultural University, 625014, Ya'an, Sichuan, People's Republic of China aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 389/1-2(2015-04-01), 273-288 0032-079X 389:1-2<273 2015 389 11104