Diversity and germination patterns of diatom resting stages at a coastal Mediterranean site
Diversity and germination patterns of diatom resting stages at a coastal Mediterranean site
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DOI：
10.3354/meps10236
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发表时间：
2013-01-01
影响因子：
2.5
通讯作者：
Zingone, Adriana
中科院分区：
文献类型：
--
作者：
Montresor, Marina;Di Prisco, Carmen;Zingone, Adriana
许多浮游硅藻产生在沉积物中存活的休眠阶段，并允许物种在不发生营养生长的时期持续存在。为了描述硅藻底栖生物产量的年际变化，并了解浮游和底栖生物动力学之间的关系，我们在那不勒斯湾(地中海)的长期生态研究站(LTER-MC)对15mo的表层水中的硅藻及其在表层沉积物中的可生存休眠阶段进行了量化。在水柱中记录的硅藻物种中，有相当一部分也是通过表层沉积物的萌发获得的，这表明休眠阶段的形成是沿海地区普遍存在的一种生命策略。浮游生物中记录到的最丰富的种类是角毛藻属、骨架藻属、海链藻属、环藻属、拟菱形藻属和杆菌属。未从底泥中检出后2属的物种。可存活休眠阶段的高峰期通常与浮游生物中个别物种的水华记录在同一时期。用相同的沉积物重复萌发实验表明，有些物种比其他物种对长时间黑暗的抗性更强，而不同的日长条件对萌发模式没有明显的影响。这项对沿海种子库的首次时间序列分析表明，沉积物中可存活的硅藻组合随年份而变化，反映了水柱中的硅藻动态，但也反映了物种特有的生存能力特征，可能是生物和非生物因素造成的干扰。
Many planktonic diatoms produce resting stages that survive in the sediment and allow species persistence over periods in which vegetative growth does not occur. With the aim of depicting the annual variability of diatom benthic stage production and understanding the relationships between planktonic and benthic dynamics, we quantified diatoms in surface waters and their viable resting stages in surface sediments at the long-term ecological research station MareChiara (LTER-MC) in the Gulf of Naples (Mediterranean Sea) over 15 mo. A considerable fraction of the diatom species recorded in the water column was also obtained from germination in surface sediments, showing that the formation of resting stages is a widespread life strategy in coastal areas. The most abundant taxa recorded in the plankton were several species of the genera Chaetoceros, Skeletonema, Thalassiosira, Cyclotella, Pseudo-nitzschia and Bacteriastrum. Species of the latter 2 genera were never retrieved from the sediment. Peaks of viable resting stages were generally recorded in the same period as blooms of the individual species in the plankton. Repeated germination experiments with the same sediments demonstrated that some species are more resistant than others to prolonged darkness, while different daylength conditions did not produce a clear effect on germination patterns. This first time-series analysis of a coastal seed bank demonstrates that the assemblage of viable diatoms in the sediment varies over the year, reflecting the diatom dynamics in the water column, but also species-specific characteristics in survival capability and likely the disturbance due to biotic and abiotic factors.