Demography in a Continuous World: New Advances in Integral Projection Models (IPMs)
Sunday, August 4, 2013: 12:00 PM-5:00 PM
101A, Minneapolis Convention Center
In recent decades, population projection models (PPM) have become an important link between theoretical pursuits and applied analyses of experimental demographic data. With advances in computing power and newly developed theories, these matrix models have evolved and new approaches, such as integral projection models (IPMs), have developed. Although the same set of ecologically and evolutionarily meaningful outcome can be obtained from IPMs as those obtained from PPMs, the approach is radically different. In PPMs individuals are assigned to discrete classes assuming similar demographic performance within each class, while IPMs are formed from a series of regressions on vital rates of interests (e.g. survival, reproduction) as a function of continuous state variables such as size. With so many ecologists working on diverse questions but a similar toolbox, the time has come to discuss model selection and formally test which approaches are more appropriate for which questions and organisms/growth forms. Participants of this workshop will learn how to organize and analyze their own data (or subsets provided by the organizers) in order to construct IPMs with a variety of recent advancements. We will draw from the R package IPMpack to perform basic (population growth rate, stable stage distribution, lifespan, passage time…) and more advance model construction and demographic projections and perturbations (discrete x continuous state models [e.g. seedbank, dormancy, multiple continuous size classes], age x size models, stochastic models with environmental covariates).