Invasion Lags: The Stories We Tell Ourselves and Our Inability to Infer Process from Pattern

Often in ecology we cannot do the experiments we want due to logistical constraints and ethical concerns. This is especially true when studying species invasions. Ethically, we cannot release an invasive species in multiple locations to see what happens, and even if we could, the scale of species invasions (which typically happen over tens of … Read more

Extrapolating Demography: Approach With Caution

We often want to measure how populations will respond to an environmental change (such as global warming), the introduction of an invasive species, or a management intervention (such as the release of a bio-control agent). However, demographic data is time consuming and expensive to collect. Many individuals have to be tagged and their fates recorded … Read more

BES Beyond Demography Symposium: The Challenges of Prediction

Model performance and extrapolation between populations.

Last week I was at the BES Beyond Demography symposium. Looking at the speaker list it’s a who’s who of not just demography, but population and ecological modelling in general. One persistent topic across many of the talks and general hallway talk was how our population models often have very poor predictive power. This is a … Read more

Weed Control in Multi-Manager Systems

Serrated tussock

Most populations of weeds and pests already cover a large area by the time they are considered problematic. As a result, most invasive populations end up being managed by multiple people, each only having the legal right and/or economic incentive to manage the population on their land. Despite this, the vast majority of research on … Read more

Global Sensitivity Analysis using Meta-Models

Models are used for both prediction and attribution in ecological and conservation research. In both cases we need to rigorously test the behavior of our models over a wide range of parameter combinations. This process is called global sensitivity analysis. There a several tools to carry out global sensitivity analysis. In our paper Coutts and … Read more