Abstract: [Objective] The subtropical zone in south-central China has become the region with the greatest nitrogen (N) deposition in the world. Most moso bamboo (Phyllostachys edulis) plantations of China are distributed in the center of this region. The change of non-structural carbohydrate (NSC) in plant can reflect the effects of environmental factors on plant. However, the effects of N deposition on NSC content of moso bamboo remain unclear. The aim of this study is to estimate the effects of N deposition on the NSC contents of leaf, branch and trunk of moso bamboo at different growth stages.[Method] The experiment was conducted in moso bamboo plantations over a 32-month period and included 4 N content levels(30, 60, 90 kg·hm^-2a^-1 and zero as control)were applied in the study.Each N-content was replicated for 3 times.[Result] The soluble sugar and starch accounted for 80% and 20% of NSC, respectively. Bamboo leaf has the highest NSC content, 1.32 and 1.27 times higher than branch and trunk, respectively. The NSC content of branch and trunk of 3-year-old bamboo were significantly higher than that of 1-year-old bamboo (P< 0.05). No significant effect of moso bamboo age on the NSC content of leaf was observed (P> 0.05). The NSC content of leaf and branch of 3-year-old bamboo, and trunk of 1-year-old bamboo (P< 0.05) was significantly decreased by N deposition. The interaction between N deposition and moso bamboo ages significantly influenced the NSC content of branch and trunk (P< 0.01) but not leaf were.[Conclusion] The content and distribution of NSC in moso bamboo were significantly impacted by N deposition, and these effects varied significantly with the bamboo ages. Our result indicated that the excessive atmospheric N deposition (≥ 90 kg·hm^-2a^-1) in the future would restrain the NSC accumulation in moso bamboo and thus its carbon sequestration capacity.

Key words: nitrogen deposition, moso bamboo, non-structural carbohydrates, soluble sugar, starch