Award: OCE-2048894

Temporal variation in environmental conditions such as temperature can have strong impacts on the health and performance of all organisms. However, fully accounting for the biological effects of temporal environmental variation can be extremely difficult because an organisms performance is a complex function of both current and past environmental conditions. We addressed this critical issue by developing a new mathematical framework to understand how to integrate the historical effects of temporal environmental variation into dynamical models of population growth and validated these predictions using laboratory experiments. Our new mathematical framework revealed that all existing models that purport to measure the effects of temporal environmental variation on population growth suffer from a form of ecological memory loss because they implicitly assume that either (i) organisms respond instantaneously to the environment (i.e., there are no historical effects, which corresponds to full ecological memory loss) or (ii) all organisms within a population respond identically to past conditions even though they were born at different times and thus experienced different sequences of environmental variation (i.e., all organisms have the same historical effects despite their different exposure histories, which corresponds to partial ecological memory loss). By parameterizing our mathematical models with experimental data, we showed that full or partial ecological memory loss typically leads to large errors when estimating population growth and size of organisms experiencing temporal environmental variation. Overall,this project yielded a critical new mathematical tool to accurately model the effects of temporal environmental variation on population dynamics. This new tool has the potential to promote our fundamental understanding population biology, improve our ability to predict the ecological effects of environmental change, and inform conservation policies or management decisions. In terms of broader impacts, this project provided research training and professional development for multiple undergraduate and graduate students as well as a research scientist. The research results are currently being integrated into our teaching material and outreach activities in order to benefit the broader community. Last Modified: 10/18/2024 Submitted by: TarikGouhier