Dr. Berg Publishes Article in Ecology Letters

March 1, 2018 / By: UST CISC Department

CISC Assistant Professor Sergey Berg recently published a research article in the journal Ecology Letters on the use of Bayesian statistics in the demographic modeling of ecological systems. The paper detailed joint research conducted by Sergey Berg, Drs. Emily Schultz and Tom Miller from Rice University, and Drs. James Eckberg and Svata Louda from the University of Nebraska.

Since its inception, Ecology Letters has been a forum for the very rapid publication of the most novel research in ecology, prioritizing the exploration and testing of clearly stated hypotheses relating to the ecology of all taxa, in any biome or geographic area.



Native Insect Herbivory Overwhelms Context Dependence to Limit Complex Invasion Dynamics of Exotic Weeds


Understanding the role of consumers in density-dependent plant population dynamics is a longstanding goal in ecology. However, the generality of herbivory effects across heterogeneous landscapes is poorly understood due to the pervasive influence of context-dependence.

We tested effects of native insect herbivory on the population dynamics of an exotic thistle, Cirsium vulgare, in a field experiment replicated across eight sites in eastern Nebraska. Using hierarchical Bayesian analysis and density-dependent population models, we found potential for explosive low-density population growth (λ > 5) and complex density fluctuations under herbivore exclusion. However, herbivore access drove population decline (λ < 1), suppressing complex fluctuations.

While plant–herbivore interaction outcomes are famously context-dependent, we demonstrated that herbivores suppress potentially invasive populations throughout our study region, and this qualitative outcome is insensitive to environmental context. Our novel use of Bayesian demographic modelling shows that native insect herbivores consistently prevent hard-to-predict fluctuations of weeds in environments otherwise susceptible to invasion.