Effects Of Nitrogen Deposition On Stoichiometry,Nutrient Resorption Of Leaf And Nutrient Return Of Leaf Litter In A Moso Bamboo Forest

Litterfall,as an important component of the nutrient cycling in the forest ecosystem,is an important source of soil nitrogen?N?,phosphorus?P?and other nutrients.Foliar nutrient resorption efficiency reflects the nutrient conservation,utilization and adaptation of plants to nutrient-poor environments before leaf litter.As an important phenomenon of global change,N deposition has been and will continue to affect the resorption of plant nutrients,stoichiometric characteristics,and plant litterfall.In this study,a field experiment was conducted to estimate the effects of simulated nitrogen?N?deposition(low-N:N30,30 kg N ha^-1year^-1;moderate-N:N60,60 kg N ha^-1year^-1;high-N:N90,90 kg N ha^-1year^-1;Control:N-free addition)on stoichiometry and N,P return of leaf litterfall in Moso bamboo?Phyllostachys edulis?forest under conventional management?CM?and intensive management?IM?practices and the stoichiometry and nutrient resorption of leaf in different Moso bamboo ages?1-year-old,3-year-old and 5-year-old?under IM.This study providing an important reference for a comprehensive understanding of the ecological effects under atmospheric N deposition.The main results were as follows:?1?Nitrogen deposition increased the foliar N,P concentrations and reduced the N:P ratio of 1-year-old Moso bamboo,significantly,and increased the N:P ratio in 3-year-old bamboo;?2?Nitrogen deposition significantly reduced the resorption of foliar N and P of 1-and 3-year-old Moso bamboo,but increased the resorption of foliar P in 5-year-old Moso bamboo;?3?The leaf litterfall and N,P return occurred mainly from March to June.IM significantly increased the leaf litterfall and N,P return under the low-and moderate-N deposition in Moso bamboo forest;?4?The C,N,and P concentrations of leaf litterfall increased by 9.3%,32.4%,and 22.7%of bamboo under IM compared with CM,respectively,while the C:N,C:P,and N:P ratios decreased by 17.4%,54.3%and 44.6%,respectively.Under both CM and IM,low-and moderate-N deposition significantly increased P concentration of leaf litterfall but decreased C:P and N:P,which were opposite under high-N deposition.