Sand burial plays an irreplaceable and unique role in the growth and distribution of vegetation on the Shell Dike Island in the Yellow River Delta. There are still some unknown on the effects of sand burial on the morphology, biomass, and especially the stoichiometry of Periploca sepium, as well as the relationship between these factors. Shell sand burial depth had a significant influence on seedling emergence, growth, and biomass of P. sepium. Shallow sand burial shortened the emergence time and improved the emergence rate, morphological and biomass of P. sepium compared to deep burial and the control. Burial depth significantly affected the nitrogen (N) and phosphorus (P) contents of the leaves. With deep burial, the carbon/nitrogen (C/N) and carbon/phosphorus (C/P) ratios decreased firstly and then increased with depth, while the nitrogen/phosphorus ratio (N/P) presented the contrary trend. Correlation analysis showed that the stoichiometry of N/P was positively correlated to morphology and biomass of P. sepium at different burial depths. Structural equation model analysis revealed that N was the largest contributor to P. sepium biomass. Optimal burial depth is beneficial to the seedling emergence, growth and nutritional accumulation of P. sepium. Stoichiometry has an important influence on the morphological formation and biomass accumulation.

中文翻译：

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贝壳砂埋葬对Periploca sepium Bunge幼苗出苗，生长和化学计量的影响

埋葬在黄河三角洲壳牌迪克岛的植被生长和分布中起着不可替代的独特作用。关于沙埋对Periploca sepium的形态，生物量，尤其是化学计量的影响以及这些因素之间的关系，仍然存在一些未知的问题。贝壳砂的埋藏深度对P. sepium的出苗，生长和生物量具有重要影响。与深埋和对照相比，浅沙埋缩短了P. sepium的出苗时间，提高了出苗率，形态和生物量。埋葬深度显着影响叶片的氮（N）和磷（P）含量。随着深度的埋藏，碳/氮（C / N）和碳/磷（C / P）的比例随着深度的增加先降低然后增加，氮磷比（N / P）却呈现相反的趋势。相关分析表明，不同埋深下N / P的化学计量与棕褐色形态和生物量呈正相关。结构方程模型分析表明，N是棕褐色体育生物量的最大贡献者。最佳埋葬深度有利于棕褐色幼苗的出苗，生长和营养积累。化学计量学对形态形成和生物量积累具有重要影响。最佳埋葬深度有利于棕褐色幼苗的出苗，生长和营养积累。化学计量学对形态形成和生物量积累具有重要影响。最佳埋葬深度有利于棕褐色幼苗的出苗，生长和营养积累。化学计量学对形态形成和生物量积累具有重要影响。