Nutrient loading into coastal sediments is increasing due to anthropogenic activity and climate change. We examined the effects of sediment nutrient enrichment on the growth and reproduction of Zostera marina by adding nitrogen (N) and phosphorus (P) fertilizers into sediments. Areal productivity and shoot density increased by ca. 60% in N and N + P enrichment plots and by ca. 20% in the P enrichment plots. Biomass and shoot height were also higher in the N and N + P enrichment plots than in the P enrichment and control plots. These results suggest that sediment N availability was more important than P availability in stimulating the vegetative growth of Z. marina . The density and morphology of reproductive shoots and seed production increased in only the N enrichment plots. The sediment N enrichment stimulated both the vegetative growth and sexual reproduction, improving the meadow resilience through both sexual and asexual mechanisms. The P enrichment slightly increased only the vegetative growth and might have limited influence on seagrass reproduction. According to these results, the alteration of the sediment nutrient regimes might shift the balance between the vegetative growth and sexual reproduction of Z. marina. These findings may have important implications for the management of seagrass meadows under fluctuations in sediment nutrients caused by anthropogenic activity and climate change.

中文翻译：

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海草 Zostera marina 对沉积物养分富集的生长和繁殖反应

由于人为活动和气候变化，沿海沉积物中的养分负荷正在增加。我们通过在沉积物中添加氮 (N) 和磷 (P) 肥料来检查沉积物养分富集对海带状藻生长和繁殖的影响。面积生产力和枝条密度增加了约。60% 在 N 和 N + P 富集地块和约。在 P 富集地块中占 20%。N 和 N + P 富集区的生物量和枝高也高于 P 富集区和对照区。这些结果表明，沉积物中氮的有效性比磷的有效性在刺激滨海藻的营养生长方面更为重要。仅在 N 富集地块中，生殖芽的密度和形态以及种子产量增加。沉积物N富集刺激了营养生长和有性繁殖，通过有性和无性机制提高了草甸的恢复力。P 富集仅略微增加了营养生长，可能对海草繁殖的影响有限。根据这些结果，沉积物营养状况的改变可能会改变 Z. marina 的营养生长和有性繁殖之间的平衡。这些发现可能对人为活动和气候变化引起的沉积物养分波动下的海草草甸管理具有重要意义。根据这些结果，沉积物营养状况的改变可能会改变 Z. marina 的营养生长和有性繁殖之间的平衡。这些发现可能对人为活动和气候变化引起的沉积物养分波动下的海草草甸管理具有重要意义。根据这些结果，沉积物营养状况的改变可能会改变 Z. marina 的营养生长和有性繁殖之间的平衡。这些发现可能对人为活动和气候变化引起的沉积物养分波动下的海草草甸管理具有重要意义。