The Effects Of Nitrogen Deposition On Ecological Stoichiometry Of Moso Bamboo

Studying ecological stoichiometry is an approach to understand the response of plant to environmental change.As one of the important phenomenon of global change,increasing nitrogen(N)deposition would have an impact on the ecological stoichiometry of plants.Moso bamboo forest is the highly representative type of plantation forests in subtropical China and the most important source of non-wood forest products in China.Now,more than 50% of Moso bamboo plantations had been intensively managed.Up to now,N deposition effects on ecological stoichiometry,singly or combinedly,are still poorly understood.We conducted a field experiment to study the effects of simulated N deposition on ecological stoichiometry of leaves,branches and stems of Moso bamboo with different age under intensive management.The results showed that:(1)Simulated N deposition significantly increased contents of C,N and P of leaves of Moso bamboo(P<0.05),and these effects on C and P contents became stronger generally with N deposition level.The contents of C,N and P of leaves did not show regular changes between Moso bamboo of different age under the same N deposition level.Moso bamboo age alone significantly impacted C,N and P contents and C?N,N?P ratio(P<0.01).The N deposition level alone and combined with Moso bamboo age had significant effects on the contents of C,N and P and ratios of C?N,C?P and N?P(P<0.01).Our findings indicate that the productivity of Moso bamboo forest is still limited by N element.(2)C,N contents of stems from 3-year-old Moso bamboo generally showed increasing trend with N deposition and P content of stems showed decreasing trend,while the contents of C,N and P of 1-year-old Moso bamboo generally showed increasing trend with N deposition.Nitrogen deposition level had a high significant influence on N,P contents of stems and ratios of C?N,C?P,N?P(P<0.01)and had no significant influence on C.The contents of C,N and P of stems did not show regular changes between Moso bamboo of different age under the same N deposition level.Bamboo age had a significant influence on the C content of stems(P<0.05)and had a high significant impact on the N,P contents and ratios of C?N,C?P,N?P of stems(P<0.01).Interaction of N deposition level and age have a significant impact on C content of stem(P<0.05)and N,P contents of stems and ratios of C?N,C?P,N?P(P<0.01).(3)N,P contents of branches from 3-year-old and 1-year-old Moso bamboo generally showed increasing trend with N deposition.C content of branches of 3-year-old bamboo showed increasing trend with N deposition,while the C contents of 1-year-old Moso bamboo generally kept stable trend.The contents of C,N and P of branches did not show regular changes between Moso bamboos of different age under the same N deposition level.Bamboo age had a significant influence on the C content of branches(P<0.05)and had a high significant impact on the N,P contents and ratios of C?N,C?P,N?P of branches(P<0.01).Nitrogen deposition and its interaction with age have a high significant influence on C,N,P contents of branches and ratios of C?N,C?P,N?P(P<0.01).