Seedling establishment in eelgrass: seed burial effects on winter losses of developing seedlings
Seedling establishment in eelgrass: seed burial effects on winter losses of developing seedlings
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DOI：
10.3354/meps09612
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发表时间：
2012-01-01
影响因子：
2.5
通讯作者：
Orth, Robert J.
中科院分区：
文献类型：
--
作者：
Marion, Scott R.;Orth, Robert J.
限制种子到幼苗的过渡有可能控制植物的传播和持久性。我们调查的过程中，导致低的初始幼苗建立在大叶藻通过一个操纵性的田间试验评估发芽失败和幼苗损失的相对重要性，在冬季。10月在切萨皮克湾（美国）地区的3个无植被的地点建立了种子地，种子要么在沉积物表面，要么埋在2至3厘米处。新兴的幼苗进行了监测，在12月和4月之间的6周的时间间隔，使用摄像机，种子发芽进行了跟踪，在单独的破坏性取样的地块。沉积物的高度变化进行了测量，沉积物扰动深度估计部署与示踪剂颗粒分层的核心和检查示踪剂的损失后，核心检索。我们发现，播种后6个月（1.2，3.8，和2.8%的表面种子在3个网站），这主要是由于种子和幼苗的损失，而不是发芽失败，与90%的种子12月后检索发芽率低的幼苗建立。种子埋藏显着提高幼苗建立在2个3个网站（40.4%，16.8%，10.3%建立埋藏的种子）。种子损失主要发生在第一个月的实验，是最严重的种子在沉积物表面。指示芯的结果表明，沉积物的深度，可能有逐出早期幼苗从表面种子，并在较小程度上从埋种子幼苗的广泛干扰。我们的发现有助于确定实质性Z的性质和时间。指出了本地区海水育苗的关键环节，并提出了一些解决方法。码头招聘动态和最佳恢复策略涉及物理沉积物幼苗的相互作用，而不是种子发芽。
Constraints on the transition of seeds to seedlings have the potential to control plant dispersal and persistence. We investigated the processes leading to low initial seedling establishment in eelgrass Zostera marina through a manipulative field experiment assessing the relative importance of germination failure and seedling loss during the winter. Seed plots were established in October at 3 unvegetated sites in the Chesapeake Bay (USA) region, with seeds either at the sediment surface or buried at 2 to 3 cm. Emerging seedlings were monitored at 6 wk intervals between December and April using a video camera, and seed germination was tracked in separate destructively-sampled plots. Sediment height change was measured, and sediment disturbance depth was estimated by deploying cores layered with tracer particles and examining tracer loss upon core retrieval. We found a low rate of seedling establishment 6 mo after seeding (1.2, 3.8, and 2.8% for surface seeds at the 3 sites) that was largely due to seed and seedling loss rather than to germination failure, with 90% of seeds retrieved after December having germinated. Seed burial significantly enhanced seedling establishment at 2 of 3 sites (40.4, 16.8, and 10.3% establishment for buried seeds). Seed loss occurred mostly within the first month of the experiment, and was most severe for seeds at the sediment surface. Indicator core results showed widespread disturbance of sediments to depths that could have dislodged early seedlings developing from surface seeds, and to a lesser degree seedlings from buried seeds. Our findings help identify the nature and timing of a substantial Z. marina seedling establishment bottleneck in our region, and show that some of the key processes pivotal to Z. marina recruitment dynamics and optimal restoration strategies involve physical sediment-seedling interactions rather than seed germination.