Rising nutrient-pulse frequency and high UVR strengthen microbial interactions.
Rising nutrient-pulse frequency and high UVR strengthen microbial interactions.
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DOI：
10.1038/srep43615
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发表时间：
2017-03-02
影响因子：
4.6
通讯作者：
Carrillo P
中科院分区：
文献类型：
--
作者：
Cabrerizo MJ;Medina-Sánchez JM;Dorado-García I;Villar-Argaiz M;Carrillo P
太阳辐射和营养脉冲调节生态系统的功能。然而，很少有人知道如何在高紫外线辐射（UVR）水平下更高频率的脉冲营养素，预计在不久的将来，可能会改变初级生产者和分解者之间的反应和相互作用。在这份报告中，我们证明了通过一个在拉卡尔德拉湖（西班牙）的围隔研究，一个重复的（新闻）相比，一个一次性的（脉冲）的时间表下紫外线促使更高的增加主要（PP）比细菌生产（BP）加上光合自养的替代兼养nanoflagellates（MNF）。这些放大的植物营养反应的机制是双重控制MNF对细菌通过有机碳的排泄和增加自上而下的控制bacterivory。我们还表明，在整个6年的全湖研究，从光合自养生物的变化，MNF主要与脉冲养分（如沙漠灰尘输入）的频率。我们的研究结果强调了如何更好地了解慢性和随机环境因素之间的相互作用是至关重要的预测生态系统功能的持续变化及其对气候驱动的变化的反应。
Solar radiation and nutrient pulses regulate the ecosystem’s functioning. However, little is known about how a greater frequency of pulsed nutrients under high ultraviolet radiation (UVR) levels, as expected in the near future, could alter the responses and interaction between primary producers and decomposers. In this report, we demonstrate through a mesocosm study in lake La Caldera (Spain) that a repeated (press) compared to a one-time (pulse) schedule under UVR prompted higher increases in primary (PP) than in bacterial production (BP) coupled with a replacement of photoautotrophs by mixotrophic nanoflagellates (MNFs). The mechanism underlying these amplified phytoplanktonic responses was a dual control by MNFs on bacteria through the excretion of organic carbon and an increased top-down control by bacterivory. We also show across a 6-year whole-lake study that the changes from photoautotrophs to MNFs were related mainly to the frequency of pulsed nutrients (e.g. desert dust inputs). Our results underscore how an improved understanding of the interaction between chronic and stochastic environmental factors is critical for predicting ongoing changes in ecosystem functioning and its responses to climatically driven changes.