Baines Celina B, McCauley Shannon J, Rowe Locke
Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S3B2
Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, Ontario, Canada L5L1C6.
Biol Lett. 2014 Jun;10(6). doi: 10.1098/rsbl.2014.0287.
Dispersal dynamics have significant consequences for ecological and evolutionary processes. Previous work has demonstrated that dispersal can be context-dependent. However, factors affecting dispersal are typically considered in isolation, despite the probability that individuals make dispersal decisions in response to multiple, possibly interacting factors. We examined whether two ecological factors, predation risk and intraspecific competition, have interactive effects on dispersal dynamics. We performed a factorial experiment in mesocosms using backswimmers (Notonecta undulata), flight-capable, semi-aquatic insects. Emigration rates increased with density, and increased with predation risk at intermediate densities; however, predation had minimal effects on emigration at high and low densities. Our results indicate that factorial experiments may be required to understand dispersal dynamics under realistic ecological conditions.
扩散动态对生态和进化过程具有重大影响。先前的研究表明，扩散可能取决于环境。然而，尽管个体可能会根据多种可能相互作用的因素做出扩散决策，但影响扩散的因素通常被单独考虑。我们研究了两个生态因素，捕食风险和种内竞争，是否对扩散动态具有交互作用。我们使用仰泳蝽（Notonecta undulata），一种有飞行能力的半水生昆虫，在中型生态箱中进行了析因实验。迁出率随密度增加而增加，在中等密度时随捕食风险增加而增加；然而，捕食在高密度和低密度时对迁出的影响最小。我们的结果表明，可能需要进行析因实验来理解现实生态条件下的扩散动态。
