Park John S, Post David M
Committee on Evolutionary Biology University of Chicago Chicago IL USA.
Ecology & Evolutionary Biology Yale University New Haven CT USA.
Ecol Evol. 2017 Dec 10;8(2):859-865. doi: 10.1002/ece3.3678. eCollection 2018 Jan.
Consumers with different seasonal life histories encounter different communities of producers during specific seasonal phases. If consumers evolve to prefer the producers that they encounter, then consumers may reciprocally influence the temporal composition of producer communities. Here, we study the keystone consumer whose seasonal life history has diverged due to intraspecific predator divergence across lakes of New England. We ask whether grazing preferences of have diverged also and test whether any grazing differences influence temporal composition patterns of producers. We reared clonal populations of from natural populations representing the two diverged life history types for multiple generations. We conducted short-term (24 hr) and long-term (27 days) grazing experiments in equal polycultures consisting of three diatom and two green algae species, treated with no consumer, from lakes with anadromous alewife, or from lakes with landlocked alewife. After 24 hr, life history and grazing preference divergence in drove significant differences in producer composition. However, those differences disappeared at the end of the 27-day experiment. Our results illustrate that, despite potentially more complex long-term dynamics, a multitrophic cascade of evolutionary divergence from a predator can influence temporal community dynamics at the producer level.
具有不同季节性生活史的消费者在特定季节阶段会遇到不同的生产者群落。如果消费者进化到偏好他们所遇到的生产者，那么消费者可能会反过来影响生产者群落的时间组成。在这里，我们研究了关键消费者，其季节性生活史因新英格兰湖泊间的种内捕食者差异而发生了分化。我们询问其放牧偏好是否也发生了分化，并测试任何放牧差异是否会影响生产者的时间组成模式。我们从代表两种分化生活史类型的自然种群中培育了多代的克隆种群。我们在由三种硅藻和两种绿藻物种组成的等量混养中进行了短期（24小时）和长期（27天）放牧实验，分别设置无消费者处理、来自有溯河产卵的锯腹脂鲤的湖泊的消费者，或来自有陆封型锯腹脂鲤的湖泊的消费者。24小时后，消费者的生活史和放牧偏好差异导致了生产者组成的显著差异。然而，这些差异在27天实验结束时消失了。我们的结果表明，尽管可能存在更复杂的长期动态，但捕食者引发的多营养级进化级联可以影响生产者水平的时间群落动态。
