In linear food chains, resource and predator control produce positive and negative correlations, respectively, between biomass at adjacent trophic levels. These simple relationships become more complex in food webs that contain alternative food chains of unequal lengths. We have used a “minimum” model for the microbial part of the pelagic food web that has three such food chains connecting free mineral nutrients to copepods: via diatoms, autotrophic flagellates, and heterotrophic bacteria. Trophic cascades from copepods strongly modulates the balance between the three pathways and, therefore, the functionality of the microbial food web in services such as food production for higher trophic levels, DOM degradation, and ocean carbon sequestration. The result is a theoretical framework able to explain, not only apparent conflicts in Arctic mesocosm experiments, but also biogeochemical features of the Mediterranean. Here, the fundamental difference between Arctic and Mediterranean microbial food webs is the way they are predator driven by seasonal migration of large copepods in the Arctic, but resource driven due to the anti-estuarine circulation in the Mediterranean. In this framework, global change effects on microbial ecosystem functions are more like to come indirectly through changes in these drivers than through direct temperature effects on the microbes.

中文翻译：

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营养级联与光合带养分含量如何相互作用以在微生物食物网中产生盆地尺度的差异

在线性食物链中，资源和捕食者控制分别在相邻营养级的生物量之间产生正相关和负相关。在包含长度不等的替代食物链的食物网中，这些简单的关系变得更加复杂。我们对上层食物网的微生物部分使用了“最小”模型，该模型具有将游离矿物质营养成分与co足动物连接的三个这样的食物链：通过硅藻，自养鞭毛和异养细菌。co足类的营养级联作用强烈地调节了这三种途径之间的平衡，因此，微生物营养网的功能性在诸如营养水平更高的食品生产，DOM降解和海洋碳固存等服务中发挥了作用。结果是一个可以解释的理论框架，不仅在北极中观实验中存在明显的冲突，而且还具有地中海地区的生物地球化学特征。在这里，北极和地中海微生物食物网的根本区别在于，它们是由大型pe足类动物在季节性迁徙驱动的掠食者方式，而资源是由于地中海的逆河口环流驱动的。在这种框架下，全球变化对微生物生态系统功能的影响更像是间接地通过这些驱动力的变化而不是温度对微生物的直接影响。但由于地中海地区的反河道环流，资源驱动。在这种框架下，全球变化对微生物生态系统功能的影响更像是间接地通过这些驱动力的变化而不是温度对微生物的直接影响。但由于地中海地区的反河道环流，资源驱动。在这种框架下，全球变化对微生物生态系统功能的影响更像是间接地通过这些驱动力的变化而不是温度对微生物的直接影响。