中文摘要：

植物组织中非结构性碳水化合物（non-structural carbohydrate,NSC）的浓度反映了植物整体的碳供应状况,但其对氮沉降的响应人们仍知之甚少。毛竹是我国分布最广、产值最大的禾本科竹类植物,在亚热带地区生态环境建设和山区经济发展中发挥着重要作用。本文以粗放经营的毛竹林为研究对象,设计4个模拟氮沉降处理水平：低氮（L,30kg·hm^-2·a^-1）、中氮（M,60 kg·hm^-2·a^-1）、高氮（H,90 kg·hm^-2·a^-1）和对照（CK,0kg·hm^-2·a^-1）,处理时间32个月。结果表明：（1）毛竹中可溶性糖是NSC的主要组分;（2）毛竹中NSC浓度表现为秆（4.1%）〉叶（3.6%）〉枝（3.3%）;（3）4龄竹竹叶的NSC浓度显著低于2龄竹（P〈0.05）,竹龄对竹秆NSC浓度的影响显著（P〈0.05）,对竹枝NSC浓度的影响不显著（P〉0.05）;（4）氮沉降对毛竹竹枝和竹秆的NSC浓度影响显著（P〈0.05）,竹枝的NSC浓度随着氮沉降量的增加呈现先上升后下降的趋势,竹秆的NSC浓度随着氮沉降量的增加呈现先下降后上升的趋势,对竹叶的NSC浓度影响不显著（P〉0.05）;（5）氮沉降和竹龄的交互作用对毛竹竹叶、竹枝和竹秆的NSC浓度均有显著影响（P〈0.05）。适当的氮沉降会促进该区域粗放经营毛竹林的生长,利于积累更多的生物量碳。

英文摘要：

The non-structural carbohydrate（ NSC） concentration in plant tissues reflects carbon supply of the whole plant; however,the response of NSC to increasing nitrogen（ N） deposition is poorly understood. Phyllostachys edulis is widely distributed in southern China and plays an important role in the construction of ecological environment in subtropical regions and the economic development in mountainous areas. An experiment was conducted in conventionally managed P.edulis plantations with three N addition treatments of 30,60,90 kg·hm^-2·a^-1,and the control（ no fertilization） over a 32-month period. The results showed that：（ 1） The soluble sugar was a major component of the NSC in P. edulis.（ 2） The NSC concentration in three organs of P. edulis was ranked by trunk（ 4.1%）〉 leaf（ 3.6%） 〉branch（ 3.3%）.（ 3） The NSC concentration of leaf of 4-year-old P. edulis was significantly lower than that of 2-year-old one（ P〈0.05）,the P.edulis age significantly influenced the NSC concentration in trunk（ P〈0. 05） but not in branch（ P〉0.05）.（ 4） N deposition significantly influenced the NSC concentrations of branch and trunk（ P〈0.05）,and the NSC concentrations of trunk under the low N addition treatment（ 30 kg·hm^-2·a^-1） was the lowest.（ 5） The interaction of N deposition and P. edulis age significantly influenced the NSC concentrations of the three organs（ P〈0. 05）. The moderate N deposition would promote the growth of P. edulis and contribute to more biomass carbon accumulation.