Community assembly and seasonal succession of marine dinoflagellates in a temperate estuary: The importance of life cycle events
Community assembly and seasonal succession of marine dinoflagellates in a temperate estuary: The importance of life cycle events
复制标题
DOI：
10.4319/lo.2006.51.2.0860
复制
发表时间：
2006-03-01
影响因子：
4.5
通讯作者：
Rengefors, K
中科院分区：
文献类型：
--
作者：
Anderson, DM;Rengefors, K
采用野外调查和室内调查的方法，对北美东海岸温带河口鲈塘甲藻的生长速率、包囊成熟期和萌发温度阈值进行了研究。优势种是根据Smayda和Reynolds装配规则生命形式模型预测的物种。三种连续策略的特点是：(1)全浮游，(2)meroplankton（即从囊中发芽）和(3)平流引入。所研究的浮游甲藻的季节演替反映了它们强制休眠期的不同长度以及它们的温度阈值或发芽“窗口”的差异。鲈鱼池全年低密度的全浮游物种具有较宽的生长耐温性，因此不需要包囊期来度过极端的季节。另一种不形成囊泡的物种完全依靠平流接种盐池；因此，与其他两种策略相比，连续几年的开花在本质上更具有随机性。在某些情况下，浮游生物囊状体形成和数量下降的时间与食草动物数量的增加相对应，这表明放牧可能导致了囊状体形成导致的水华减少。这个时间点也暗示了将它们包裹起来作为一种躲避捕食者的策略的可能性。我们认为形成囊的鞭毛藻的季节更替不是随机的。相反，浮游生物中这些物种的出现是可以预测的，这是基于它们在休眠和静止期间对内源性和外源性因素的可测量的生理反应。
Dinoflagellate successional strategies and community structure were investigated in Perch Pond, a temperate estuary on the North American east coast by field surveys as well as laboratory investigations on growth rates, cyst maturation period, and cyst germination temperature thresholds. The dominant species were those predicted by the Smayda and Reynolds Rules of Assembly life form model. Three successional strategies were characterized: (1) holoplanktonic, (2) meroplanktonic (i.e., germinated from cysts), and (3) introduced by advection. The seasonal succession of the meroplanktonic dinoflagellates that were studied reflects the differential lengths of their mandatory dormancy periods as well as differences in their temperature thresholds or "windows" for germination. The holoplanktonic species present at low densities year-round in Perch Pond had a wide temperature tolerance for growth and thus did not need a cyst stage to survive seasonal extremes. Another non-cyst-forming species relied solely on advection to inoculate the salt pond; thus, blooms in successive years would be expected to be more stochastic in nature than for the other two strategies. The timing of cyst formation and population decline for meroplanktonic species corresponded on several occasions to an increase in grazers, suggesting that grazing might have contributed to bloom decline from cyst formation. This timing also suggests the possibility of encystment as a predator avoidance strategy. We suggest that seasonal succession of cyst-forming dinoflagellates is not stochastic. Instead, the appearance of these species in the plankton is predictable on the basis of measurable physiological responses to both endogenous and exogenous factors that they experience during dormancy and quiescence.