New bamboo usually grows to a height of 10–20 m and a diameter of 8–16 cm at breast height within 35–40 days after germination from the soil in the spring. Due to the enormous ecological and socioeconomic benefits, Moso bamboo forests have expanded rapidly in subtropical China, with an annual increase of 3% in recent decades 18.īeing greatly different from the arbor species, the woody rhizomatous plant Moso bamboo is well known for its startlingly high growth rate. The forest covers an area of 3.87 million ha, representing 70% of the Chinese bamboo forest area and 80% of the global distribution of Moso bamboo 18, 19. As a highly representative plantation forest in the subtropical region of China, the Moso bamboo forest is currently the most important source of non-wood forest products in China 18. de Lehaie) is a monopodial giant bamboo widely distributed in southern China and neighboring countries, such as Japan and Korea 17. Moso bamboo ( Phyllostachys pubescens Mazel ex H. Previous studies have reported that N addition increased the foliar N concentration and N:P ratio and both increases and decreases have been found in the subsequent P uptake capacity of plants 4, 9, 14, including in fast-growing arbor species such as Eucalyptus grandis 15 and hybrid poplar 16. The increasing consumption of fossil fuels and application of agricultural fertilizers have largely enhanced the amount of anthropogenic available N being input into ecosystems worldwide in the last few decades 12, 13 and the ecological effects are attracting attention. 10 reported that the foliar N and P concentrations of three wetland plants were highest in the early stages of growth and the smallest in the middle growth stage. Foliar N:P stoichiometry can be strongly affected by environmental nutrient availability 7, 8, 9 and plant growth stage 10, 11. Stoichiometric homeostasis varies with plant species, some are able to maintain their nutrient balance other not 5, 6. N and P are essential for plant growth and the foliar N:P ratio is thought to be useful for assessing N versus P limitation in primary production in terrestrial ecosystems 3, 4. The quantitative relationships between foliar nitrogen (N) and phosphorus (P) concentrations, as well as the effects of N and P limitation on plant growth under global climate change, are increasingly concerning in ecological stoichiometry theory 1, 2. The effects of N deposition on foliar stoichiometry combined with anthropogenic management practices can influence ecosystem production, decomposition and subsequent N and P cycles in Moso bamboo plantations. The positive effects of N deposition on foliar stoichiometry were influenced by management practices and bamboo growth stage. Nitrogen increased foliar N concentrations but aggravated P deficiency in CM bamboo plantations. Nitrogen increased foliar N and P concentrations in IM bamboo plantations, but the positive effects were diminished when the addition rate exceeded 60 kg N ha −1yr −1. IM significantly increased the foliar N concentrations of young bamboo and P concentrations of mature bamboo but decreased mature bamboo foliar N:P ratios ( P < 0.05). Young bamboo had significantly greater foliar N and P concentrations and N:P ratios than mature plants ( P < 0.05). We observed the effects of two years of simulated N deposition (30, 60 and 90 kg N ha −1yr −1) on the foliar stoichiometry of Moso bamboo plantations under conventional management (CM) and intensive management (IM). However, how anthropogenic management practices regulate the effects of N deposition on Moso bamboo stoichiometry remains poorly understood. Moso bamboo, well known for its high growth rate, is being subjected to increasing amounts of nitrogen deposition.
0 Comments
Leave a Reply. |