Ian Carroll, 2012 Postdoctoral Scholar



Ecologists are deeply invested in understanding the maintenance of biodiversity, or answering the question: Why are there so many, yet not more, species inhabiting an ecosystem? Ian Carroll is interested in providing answers to this question for reasons including its application to the conservation of endangered species but also to add clarity to the emerging picture of how biodiversity mediates ecosystem processes, including “free” services on which we all rely.

Phytoplankton communities are a great study system for understanding what regulates biodiversity. Working with Heidi Sosik and Mike Neubert, Ian is applying mathematical models of population dynamics to analyze long-term monitoring data obtained at the Martha’s Vineyard Coastal Observatory (http://www.whoi.edu/mvco), where over 400 million images of diatoms and other plankton have been recorded since 2006 (http://ifcb-data.whoi.edu/mvco). The hypothesis being evaluated is whether the daily to seasonal fluctuations in sunlight, water temperature and other environmental variables create opportunities for diversity that would not exist in a constant environment. Ian hopes to understand how the effects of global climate change on the variability of the physical environment on New England’s coastal shelf might impact the diversity of the phytoplankton community.

A general difficulty with mathematical models that seek to explain levels of biodiversity is how to handle rare but irreversible events, among which population extinction is by far the most salient. Ian is developing approaches to accurately include this kind of stochastic event in models of interacting populations. Doing so will improve the ability to estimate the risk of extinction, or other irreversible events, before they occur.

Ian arrived at WHOI after completing his Ph.D. with Roger Nisbet at the University of California in Santa Barbara and an undergraduate degree in Biology at Brown University. Between his student years, Ian worked at the Heinz Center for Science, Economics and the Environment in Washington, D.C.