After 3 beautiful years in Spain, I am getting quite excited starting up a new postdoc position in Switzerland at ETH in Zurich. I will be part of a multidisciplinary program bringing together geneticists, ecologists, and biologists studying empirically and theoretically adaptation to a changing environment.
Only a handful of studies demonstrate the existence of hysteresis in bistable systems. In a follow-up from our earlier work, we study the recovery trajectory of a light-stressed plankton population in a chemostat experiment (early view in Oikos). We find that reverse trajectories can be explained by hysteresis, time-delays and adaptive process, all of which pose interesting questions for the behavior of bistable systems under changing conditions.
Recently, we summarized a set of measures that can be used as spatial indicators for detecting loss of resilience. We now add another measure that can be used as early warning of critical transitions in spatially explicit systems: spatial heteroskedasticity. In short, this indicator is the analog of conditional heteroskedasticity in timeseries (the non constant variance along a timeseries). We now expand its use from indicator of critical transitions in timeseries to spatial data (early view in Ecology & Evolution).
In this just published paper we develop a framework of detecting tipping points in the context of mutualistic networks. Under a scenario of global environmental change that might affect species interactions we show how indicators of resilience could provide early warning in complex communities such as those represented by the network of interactions between plants and their animal mutualists. This work is a first step towards quantifying the risk of network collapse and the possibility to monitor community resilience based on best-indicator species.
Regime shifts have been a long sought theme of research in marine ecosystems. Controversies, new methods and alternative hypotheses on how to study and understand such marine regime shifts are summarized in the special issue of the Philosophical Transactions of the Royal Society on Marine regime shifts around the globe: theory, drivers and impacts that just appeared online. Thus, we couldn’t think of a better place to publish a review-research paper on the use and misuse of resilience indicators as early warnings for regime shifts in marine but not only systems.
Together with David Seekel and Jessica Gephart, we are organizing a session on regime shifts in the upcoming American Society for Limnology & Oceanography conference in Granada, Spain in February 2015. The abstract submission is open with a deadline on the 10th of October 2014.
A new experience attending a conference of another community for the first time. European Conference on Complex Systems in Lucca Italy. A mix of physicists, mathematicians and engineers. Probably few ecologists and biologists, although one of the complex systems track on the conference is about living systems. I hope I can get inspired and make some new connections with my talk.
Just a week before the resilience conference 2014 in Montpellier a short brochure of our forthcoming book on “Principles for Building Resilience: Sustaining Ecosystem Services in Social-Ecological Systems” (Cambridge University Press, 2014) has become available by the Stockholm Resilience Center. The brochure summarizes the expanded treatment of resilience principles as we have discussed in an earlier paper “Towards principles for enhancing the resilience of ecosystem services“.
Recently our paper on spatial indicators for critical transitions was published in PloS One. In this paper we summarize methods and create a flowchart for looking for indicators of upcoming transitions in spatial data. It is a natural follow-up paper from our previous work on methods for timeseries. The methods of the paper are now summarized in the spatial indicators section of the EWS toolbox website together with the actual R code.
Our submission of an interactive visualization version of the earlywarnings R package for critical transitions in the Data Challenge competition organised by the Waterloo Institute for Complexity and Innovation got into the 4 finalists. Although we didn’t get the first place, the judges were very flattering and Leo Lahti and myself are really proud to have made it that far in a short time. We hope that this will be a kick into developing more the package and making it more interactive and available. You can read more on it here.
A first joint work in my new lab of Jordie Bascompte got published in Nature Communications few weeks ago. By simulating mutualistic communities of 57 empirical plant pollinator and plant seed-disperser networks we identify scenarios where species’ tolerance is extremely sensitive to the direction of change in the strength of mutualistic interaction, as well as to the observed mutualistic trade-offs between the number of partners and the strength of the interactions.