Friday seminar: "Behavioural responses to increasingly frequent extreme climatic events" & "Population responses to environmental variation"
By Martijn van de Pol & Callum Lawson
Behavioural responses to increasingly frequent extreme climatic events
Abstract: Climate change has many faces, and one aspect that is receiving increasing attention are extreme climatic events. Although there are many studies on extreme climatic events, most are anecdotal and focus on immediate short-term consequences. Consequently, we still know very little about how individuals and population respond to extreme climatic events in the longer term. Particularly in long-lived species phenotypical plasticity is thought to be a key mechanism for responses to changes in climate means, but does this also hold for extreme climatic events that are by nature more unpredictable and rare? I will show long-term behavioural data on long-lived shorebirds facing increasing flooding risk of their nesting sites. I will address the question whether birds move to higher places during their lifetime and whether this is sufficient for the population to keep up with climate change.
Martijn van de Pol
Netherlands Institute of Ecology (NIOO-KNAW) & Australian National University
Population responses to environmental variation
Abstract: Under global warming, populations face both long-term environmental changes such as increases in average temperature, and short-term environmental variation such as stochastic fluctuations in weather. Environmental variation exposes individuals to more extreme and erratic changes in conditions, and may be amplified by global warming, but we lack a general basis to predict how it will affect population responses to environmental change. In this talk, I use published population dynamical models to explore (1) how changes in environmental variance affect long-term population growth rates, and (2) how environmental variance alters population growth responses to changes in mean environmental conditions. I also present empirical analyses investigating how changes in the mean and variance of rainfall combine to determine the population sizes of desert annual plants under climate change. The results of these studies help to shed light on whether the effects of environmental variance on population dynamics could be predicted using species traits such as phylogenetic history, or body mass, or dormancy.
Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW)