Sexual reproduction is critical to the resilience of seagrass beds impacted by habitat degradation or environmental changes, as robust seed banks allow new shoots to establish each year. Reproductive strategies of seagrass beds range on a continuum from strictly annual to perennial, driven by local environmental conditions. We examined the reproductive dynamics of Zostera marina beds at six sites on the Atlantic coast of Canada to characterize how life history strategies are shaped by the surrounding environment. Sites were categorized as wave protected and wave exposed, where protected sites were warm, shallow, with little water movement and muddy sediments, and exposed sites were either shallow or deep, with cooler water and sandy sediments. While mixed life history strategies were evident at all sites, protected eelgrass beds exhibited both the highest and lowest sexual reproductive effort relative to exposed beds. These beds regularly experienced thermal stress, with higher temperature range and extended warm water events relative to exposed beds. The development of reproductive shoots were similar across sites with comparable Growing Degree-days at the beginning and end of anthesis, but the First Flowering Date was earlier at the protected warmer sites relative to exposed sites. With different reproductive shoot density among sites, seed production, seed retention, and seedling recruitment also varied strongly. Only one site, located in a warm, shallow and protected lagoon, contained a mixed life history population with a high reproductive effort (33.7%), strong seed bank, and high seedling establishment. However, a primarily perennial population with the lowest reproductive effort (0.5%) was identified at the warmest site, suggesting that conditions here could not support high sexual reproduction. Robustness of seed banks was strongly linked to reproductive shoot density, although the role of seed retention, germination and seedling survival require further investigation. Our study provides insights into one key aspect of seagrass resilience, and suggests that resilience assessments should include reproductive shoot density to inform their management and conservation.

有性繁殖对于受栖息地退化或环境变化影响的海草床的恢复能力至关重要，因为强大的种子库每年都允许新芽生长。在当地环境条件的驱动下，海草床的繁殖策略范围从严格的一年生到多年生。我们检查了Zostera marina的繁殖动态加拿大大西洋沿岸六个地点的床，以描述周围环境如何塑造生活史策略。场地分为波浪防护和波浪暴露，其中防护场地温暖，浅，水运动少，泥质沉积物，暴露场地或浅或深，水较冷和沙质沉积物。虽然所有地点的混合生活史策略都很明显，但相对于暴露的床，受保护的鳗草床表现出最高和最低的有性生殖努力。这些床经常经历热应力，相对于暴露床具有更高的温度范围和更长的温水事件。不同地点的生殖芽发育相似，在开花开始和结束时具有可比的生长期，但相对于暴露的地点，受保护的温暖地点的初花日期更早。不同地点之间的生殖枝密度不同，种子产量、种子保留和幼苗补充也有很大差异。只有一个地点位于温暖、浅水和受保护的泻湖中，包含具有高繁殖力 (33.7%)、强大的种子库和高幼苗建立率的混合生活史种群。然而，在最温暖的地点发现了繁殖努力最低（0.5%）的主要多年生种群，这表明这里的条件不能支持高性繁殖。种子库的稳健性与生殖枝密度密切相关，尽管种子保留、发芽和幼苗存活的作用需要进一步研究。