The human activities such as combustion of fossil fuels and intensive agriculture, have changed the nitrogen(N) cycle considerably, and have significantly increased the formation and deposition of the reactive N. The increasing deposition of N has exerted much effect on activities of forest ecosystems, such as the alteration of litter production and nutrient concentration of litterfall. In the forest ecosystem, litterfall as the source of soil nutrient and energy plays an important role not only in conserving soil and water and improving the structure and physical-chemical properties of soil, but also in maintaining soil fertility, which links the nutrient pool of vegetation and the soil nutrient pool. The annual nutrient input from litterfall is the product of annual litter production and the nutrient concentration of litterfall, which is the major source of soil fertility. Therefore, exploring the influence of nitrogen deposition on totally annual nutrient input from litterfall has the vital significance, while the related report is rare.
From November 2007 to December 2010, a simulated nitrogen (N) deposition experiment was conducted in a Pleioblastus amarus plantation in Rainy Area of West China, which was aimed to explore the effect of nitrogen deposition on the litterfall and related total nutrient input in P. amarus plantation in order to provide some basic data about the material circulation and energy flow of the bamboo ecosystem. Four treatments was installed, i.e., control (0 g N·m^-2·a^-1), low nitrogen (5 g N·m^-2·a^-1), medium nitrogen (15 g N·m^-2·a^-1) and high nitrogen (30 g N·m^-2·a^-1). At the end of each month NO₃NH₄ was added to each N-treated plots and each square plot was 3 m×3 m, and randomly distribute in the plantation, which interval was more than 3 m. Litterfall production was measured every half a month through the whole year of 2010. The annual nutrient input from litterfall was measured and calculated. The results showed that simulated N deposition significantly increased the litter production in P. amarus plantation. The concentrations of N, P, K, Ca, and Mg in litter fractions (leaf litter and twig litter) were also significantly increased. This research results suggested that simulated N deposition increased the annual nutrient input from litterfall significantly, which is beneficial for the maintenance of woodland fertility and the continuous growth of P. amarus plantation.