Department of Biological Sciences and Institute of Environment, Florida International University, North Miami, FL, USA.
School for Environment and Sustainability, University of Michigan, 440 Church St, Ann Arbor, MI, 48109, USA.
Oecologia. 2024 Aug;205(3-4):445-459. doi: 10.1007/s00442-024-05582-3. Epub 2024 Jul 7.
Irruptive or boom-and-bust population dynamics, also known as 'outbreaks', are an important phenomenon that has been noted in biological invasions at least since Charles Elton's classic book was published in 1958. Community-level consequences of irruptive dynamics are poorly documented and invasive species provide excellent systems for their study. African Jewelfish (Rubricatochromis letourneuxi, "jewelfish") are omnivores that demonstrate opportunistic carnivory, first reported in Florida in the 1960s and in Everglades National Park (ENP) in 2000. Twelve years after invasion in ENP, jewelfish underwent a 25-fold increase in density in one year. By 2016, jewelfish represented 25-50% of fish biomass. Using a 43-year fish community dataset at two sites (1978-2021), and a 25-year dataset of fish and invertebrate communities from the same drainage (1996-2021), with additional spatial coverage, we quantified differences in fish and invertebrate communities during different phases of invasion. During jewelfish boom, abundant, native cyprinodontiform fishes decreased in density and drove changes in community structure as measured by similarity of relativized abundance. Density of two species declined by > 70%, while four declined by 50-62%. Following the jewelfish bust, some species recovered to pre-boom densities while others did not. Diversity of recovery times produced altered community structure that lagged for at least four years after the jewelfish population declined. Community structure is an index of ecological functions such as resilience, productivity, and species interaction webs; therefore, these results demonstrate that irruptive population dynamics can alter ecological functions of ecosystems mediated by community structure for years following that population's decline.
爆发性或兴衰动态，也称为“爆发”，是自查尔斯·埃尔顿（Charles Elton）的经典著作于 1958 年出版以来，生物入侵中已经注意到的一个重要现象。爆发动态的群落水平后果记录甚少，而入侵物种为其研究提供了极好的系统。非洲宝石鱼（Rubricatochromis letourneuxi，“宝石鱼”）是杂食动物，表现出机会主义的肉食性，于 20 世纪 60 年代在佛罗里达州首次报道，并于 2000 年在大沼泽地国家公园（Everglades National Park，ENP）出现。入侵 ENP 12 年后，宝石鱼的密度在一年内增加了 25 倍。到 2016 年，宝石鱼的生物量占鱼类生物量的 25-50%。利用两个地点（1978-2021 年）的 43 年鱼类群落数据集和同一流域（1996-2021 年）的 25 年鱼类和无脊椎动物群落数据集，以及更多的空间覆盖范围，我们量化了入侵不同阶段鱼类和无脊椎动物群落的差异。在宝石鱼爆发期间，丰富的本地脂鲤科鱼类的密度降低，并导致群落结构发生变化，这可以通过相对丰度的相似性来衡量。两个物种的密度下降了>70%，而四个物种的密度下降了 50-62%。在宝石鱼衰退之后，一些物种的密度恢复到了爆发前的水平，而另一些则没有。恢复时间的多样性产生了改变的群落结构，这种滞后至少持续了四年，直到宝石鱼数量下降。群落结构是生态功能的指标，如弹性、生产力和物种相互作用网络；因此，这些结果表明，爆发性的种群动态可以在种群数量下降后的多年内改变由群落结构介导的生态系统的生态功能。
