Changing climate cues differentially alter zooplankton dormancy dynamics across latitudes
Changing climate cues differentially alter zooplankton dormancy dynamics across latitudes
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DOI：
10.1111/1365-2656.12474
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发表时间：
2016-03-01
影响因子：
4.8
通讯作者：
Gilbert, Benjamin
中科院分区：
文献类型：
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作者：
Jones, Natalie T.;Gilbert, Benjamin
在季节性气候中，休眠是构成生物多样性的一种常见策略，对许多物种的持续生存是必要的。气候变化可能会通过改变两个重要的孵化线索来改变浮游动物的休眠动态，浮游动物是水生食物网的基础：无冰季节的平均温度，以及湖泊无冰时的平均日长。理论表明，这些变化可以改变湖泊中的多样性、孵化丰度和物候，并且由于最佳孵化线索和策略的不同，这些响应可能会在不同纬度之间发生差异。为了研究温度和日长对孵化动态的影响，我们从横跨1800公里纬度梯度的25个湖泊采集了沉积物，并将沉积物样本暴露在代表历史上南部(短光周期，温暖)和北部(长光周期，凉爽)的两个光周期(12和16小时)和两个温度(8和12摄氏度)的因子组合中。我们测试了对这些孵化线索的敏感性是否因纬度来源而不同，也因分类群而不同。较高的温度促进了所有分类群的物候，其中枝角类的进步最大，其次是桡足类和轮虫。尽管不同类群的物候学不同，但温度的影响不随纬度而变化。卵库的纬度来源影响卵的丰富度和孵化的丰度和多样性，后者的影响因分类群、温度和光周期的不同而不同，中纬度和长光周期处理的桡足类孵化丰度最高，而其他浮游动物的孵化丰度在低纬度和高温处理时最大。甲壳类浮游动物(桡足类和枝角类)的总体多样性也反映了每个类群对我们的处理的不同反应，其中最大的多样性出现在中纬度(类似于北纬56度)的较短光周期处理中。我们的结果表明，对于不同的发育和生活史策略，广泛的分类类群的孵化线索不同。据预测，这些差异将推动浮游动物随着气候变化而出现的纬度变化，并可能改变水生食物网的基础。
In seasonal climates, dormancy is a common strategy that structures biodiversity and is necessary for the persistence of many species. Climate change will likely alter dormancy dynamics in zooplankton, the basis of aquatic food webs, by altering two important hatching cues: mean temperatures during the ice-free season, and mean day length when lakes become ice free. Theory suggests that these changes could alter diversity, hatchling abundances and phenology within lakes, and that these responses may diverge across latitudes due to differences in optimal hatching cues and strategies.To examine the role of temperature and day length on hatching dynamics, we collected sediment from 25 lakes across a 1800km latitudinal gradient and exposed sediment samples to a factorial combination of two photoperiods (12 and 16h) and two temperatures (8 and 12 degrees C) representative of historical southern (short photoperiod, warm) and northern (long photoperiod, cool) lake conditions. We tested whether sensitivity to these hatching cues varies by latitudinal origin and differs among taxa.Higher temperatures advanced phenology for all taxa, and these advances were greatest for cladocerans followed by copepods and rotifers. Although phenology differed among taxa, the effect of temperature did not vary with latitude. The latitudinal origin of the egg bank influenced egg abundance and hatchling abundance and diversity, with these latter effects varying with taxa, temperature and photoperiod.Copepod hatchling abundances peaked at mid-latitudes in the high temperature and long photoperiod treatments, whereas hatchling abundances of other zooplankton were greatest at low latitudes and high temperature. The overall diversity of crustacean zooplankton (copepods and cladocerans) also reflected distinct responses of each taxa to our treatments, with the greatest diversity occurring at mid-latitudes (similar to 56 degrees N) in the shorter photoperiod treatment.Our results demonstrate that hatching cues differ for broad taxonomic groups that vary in developmental and life-history strategies. These differences are predicted to drive latitude-specific shifts in zooplankton emergence with climate change and could alter the base of aquatic food webs.