For the February issue of Oikos, we decided to highlight Sorte’s forum paper on the importance of flow direction and limitation to redistribution for the persistence of species in the light of climate change, and the contribution of Stier et al., demonstrating the use of model-based approaches to study functional predator-prey responses within a community context. These contributions were chosen according to our motto of synthesising ecology.
Sorte (2013) emphases the role of directional flows of wind or water currents as an important factor limiting species’ distributions, especially when equilibrium conditions become disrupted by human interference. There is a consensus that adaptation or tolerance may not be sufficient for many species to persist under conditions of climate change, and that dispersal is essential to keep track with the shifting climate window. In cases of actively moving organisms, such movements can be expected to be informed and at least partly in the direction of the shifting window. Passively dispersing organisms, being either wind dispersed plants, rafting arthropods or planktonic stages of many marine vertebrates and invertebrates are expected to face constrained movements due to their dependency on flow directions. Such asymmetric air and water flows need to be considered when assessing the vulnerability of populations and species to climate change. Cascade Sorte provides a synthesis on how the interplay between directional flows and life histories may limit species’ distributions and their persistence under climate change. The review comes up with clear predictions that may help ecologists to detect the set of passively dispersing species at risk, but equally provides clear considerations for future research.
Adrian Stier and colleagues provide a novel analytical tool for analysing predator foraging behaviour and offer insight into the processes driving the dynamics of coral reef fish. While group benefits are well documented from a single-species point of view, we lack insights on how such group benefits change according to the community context. In their study, the authors use a shoaling coral reef fish as a model species to test how prey group benefits change according to group size, the presence of competing predators and alternative prey. They use an original approach by quantifying mortality rates as perceived from the predator’s perspective, so by quantifying changes in the predator’s functional response. Their sets of experiments confirm group size advantages by reduced predation risks, but these benefits decrease in the presence of alternative prey species. While there is already quite some literature demonstrating such a community context of predator-prey interactions, the applied model-based approach allowed for testing several alternative hypotheses of mechanisms leading to variation in functional responses.