Temperature fluctuation facilitates coexistence of competing species in experimental microbial communities
Temperature fluctuation facilitates coexistence of competing species in experimental microbial communities
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DOI：
10.1111/j.1365-2656.2007.01252.x
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发表时间：
2007-07-01
影响因子：
4.8
通讯作者：
Morin, Peter J.
中科院分区：
文献类型：
--
作者：
Jiang, Lin;Morin, Peter J.
1.温度波动是一种普遍现象，影响自然界中的许多物种，如果不是全部的话。虽然少数研究表明，温度波动可以促进物种共存，但对不同温度波动机制对共存的影响知之甚少。我们通过实验研究了温度波动和不同的温度波动模式(温度序列具有正的时间自相关性的红色环境和温度序列几乎没有自相关性的白色环境)如何影响争夺细菌资源的两种纤毛虫原生动物的共存：纹状体草履虫和草履虫。我们之前已经证明，这两个物种对温度变化的生长反应和资源利用模式不同。这两个物种并不总是能够在恒定的温度(22、24、26、28和30摄氏度)下共存，草履虫在26和28摄氏度时被竞争性地排除在外，这表明资源分配不足以维持在这些温度下的共存。在这里，我们发现在红色和白色的环境中，温度在22到32摄氏度之间变化，草履虫和草履虫共存。草履虫种群动态基本不受温度条件的影响，与温度对其固有生长率的差异一致，而草履虫在红色环境中表现出更多的种群动态变化。草履虫对草履虫的温度依赖竞争效应和资源分配似乎是白色环境中共存的原因；资源分配和贮藏效应似乎是红色环境中共存的原因。这些结果表明，温度波动可能在调节生态群落中物种的共存和多样性方面起着重要作用。
1. Temperature fluctuation is a general phenomenon affecting many, if not all, species in nature. While a few studies have shown that temperature fluctuation can promote species coexistence, little is known about the effects of different regimes of temperature fluctuation on coexistence.2. We experimentally investigated how temperature fluctuation and different regimes of temperature fluctuation ('red' environments in which temperature series exhibited positive temporal autocorrelation vs. 'white' environments in which temperature series showed little autocorrelation) affected the coexistence of two ciliated protists, Colpidium striatum Stein and Paramecium tetraurelia Sonneborn, which competed for bacterial resources.3. We have previously shown that the two species differed in their growth responses to changes in temperature and in their resource utilization patterns. The two species were not always able to coexist at constant temperatures (22, 24, 26, 28 and 30 degrees C), with Paramecium being competitively excluded at 26 and 28 degrees C. This indicated that resource partitioning was insufficient to maintain coexistence at these temperatures.4. Here we show that in both red and white environments in which temperature varied between 22 and 32 degrees C, Paramecium coexisted with Colpidium. Consistent with the differential effects of temperature on their intrinsic growth rates, Paramecium population dynamics were largely unaffected by temperature regimes, and Colpidium showed more variable population dynamics in the red environments.5. Temperature-dependent competitive effects of Colpidium on Paramecium, together with resource partitioning, appeared to be responsible for the coexistence in the white environments; resource partitioning and the storage effect appeared to account for the coexistence in the red environments.6. These results suggest that temperature fluctuation may play important roles in regulating species coexistence and diversity in ecological communities.