Spatial Subsidies and Mortality of an Estuarine Copepod Revealed Using a Box Model
Spatial Subsidies and Mortality of an Estuarine Copepod Revealed Using a Box Model
复制标题
使用盒模型揭示河口桡足类的空间补贴和死亡率
作者：
W. Kimmerer;E. Gross;Anne;J. Durand
浮游种群的死亡率很难确定，因为这些方法的假设很少得到满足，在潮汐交换确保违反封闭或空间均匀种群假设的河口更是如此。河口浮游生物种群因离开生产区域而遭受损失，从而为生产力较低的区域提供相应的补贴。我们使用垂直生命表方法和贝叶斯估计方法，结合使用具有基于盐度边界的空间盒模型来估计空间补贴和损失，估计了旧金山河口桡足类 Pseudodiaptomus forbesi 的死亡率。数据来自长期监测计划以及 1991-2007 年和 2010-2012 年的三个样本集。流体动力学模型与粒子跟踪模型相结合，提供了盒子之间以及每个盒子到多个水槽的交换率。原地死亡率，即根据移动校正的死亡率，变化很大。成虫的原位死亡率很高（按箱和采样程序 0.1-0.9 天−1 表示），并且似乎与盐度或年份无关。无节幼体和桡足类的原地死亡率从淡水（~ 0）到咸水（意味着 0.4–0.8 day−1）增加，可能是因为蛤和掠食性桡足类在咸水中消耗。低盐度箱中的高死亡率被 1993 年之后增加的补贴所抵消，表明死亡率有所增加。我们的结果强调了死亡率和空间补贴在人口结构中的重要性。河口浮游生物的死亡率估计是可行的，只要进行足够的采样以克服高变异性，只要根据移动情况进行调整。
Mortality of planktonic populations is difficult to determine because assumptions of the methods are rarely met, more so in estuaries where tidal exchange ensures violation of the assumption of a closed or spatially uniform population. Estuarine plankton populations undergo losses through movement from productive regions, creating a corresponding subsidy to regions that are less productive. We estimated mortality rates of the copepod Pseudodiaptomus forbesi in the San Francisco Estuary using a vertical-life-table approach with a Bayesian estimation method, combined with estimates of spatial subsidies and losses using a spatial box model with salinity-based boundaries. Data came from a long-term monitoring program and from three sample sets for 1991–2007 and 2010–2012. A hydrodynamic model coupled with a particle-tracking model supplied exchange rates between boxes and from each box to several sinks. In situ mortality, i.e., mortality corrected for movement, was highly variable. In situ mortality of adults was high (means by box and sampling program 0.1–0.9 day−1) and appeared invariant with salinity or year. In situ mortality of nauplii and copepodites increased from fresh (~ 0) to brackish water (means 0.4–0.8 day−1), probably because of consumption by clams and predatory copepods in brackish water. High mortality in the low-salinity box was offset by a subsidy which increased after 1993, indicating an increase in mortality. Our results emphasize the importance of mortality and spatial subsidies in structuring populations. Mortality estimates of estuarine plankton are feasible with sufficient sampling to overcome high variability, provided adjustments are made to account for movement.
影响因子：
4.5
作者：
Hirst, A. G.;Bonnet, D.;Kiorboe, T.
通讯作者：
Kiorboe, T.