Lennon Jay T, Martiny Jennifer B H
Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA.
Ecol Lett. 2008 Nov;11(11):1178-1188. doi: 10.1111/j.1461-0248.2008.01225.x. Epub 2008 Jul 17.
Predation and parasitism often regulate population dynamics, community interactions, and ecosystem functioning. The strength of these top-down pressures is variable, however, and may be influenced by both ecological and evolutionary processes. We conducted a chemostat experiment to assess the direct and indirect effects of viruses on a marine microbial food web comprised of an autotrophic host (Synechococcus) and non-target heterotrophic bacteria. Viruses dramatically altered the host population dynamics, which in turn influenced phosphorus resource availability and the stoichiometric allocation of nutrients into microbial biomass. These virus effects diminished with time, but could not be attributed to changes in the abundance or composition of heterotrophic bacteria. Instead, attenuation of the virus effects coincided with the detection of resistant host phenotypes, suggesting that rapid evolution buffered the effect of viruses on nutrient cycling. Our results demonstrate that evolutionary processes are important for community dynamics and ecosystem processes on ecologically relevant time scales.
捕食和寄生作用常常调节种群动态、群落相互作用以及生态系统功能。然而，这些自上而下的压力强度是可变的，并且可能受到生态和进化过程的影响。我们进行了一项恒化器实验，以评估病毒对由自养宿主（聚球藻属）和非靶标异养细菌组成的海洋微生物食物网的直接和间接影响。病毒极大地改变了宿主种群动态，进而影响了磷资源的可用性以及养分向微生物生物量的化学计量分配。这些病毒效应随时间减弱，但不能归因于异养细菌丰度或组成的变化。相反，病毒效应的减弱与抗性宿主表型的检测同时出现，这表明快速进化缓冲了病毒对养分循环的影响。我们的结果表明，进化过程在生态相关的时间尺度上对群落动态和生态系统过程很重要。
