Author Archives: vasilisdakos

earlywarnings package in R libraries

logoEWS Together with Leo Lahti, we fixed bugs and moved the earlywarnings toolbox in R. It is now a library ready to be installed from your preferable CRAN repository. In the process, we also migrated the earlywarnings toolbox to github for shifitng towards open-source, community-based project development. We hope this will facilitate the use of the toolbox both for research and education. More details on the Early Warning Signals Toolbox webpage.

Passing slowly tipping points: opportunities and challenges

In a short conceptual paper that appeared this month in TREE, we play around with the idea that depending on the scale and the rate of change of ecological systems, responses to crossing tipping points may differ widely. Ecosystems without tipping points may appear hysteretic, whereas hysteretic systems may offer a window of opportunity for averting a regime shift even after having passed their tipping point. Such insights may change the way ecosystem managers and policy makers view common practices in a changing world.

Flickering before a shift to eutrophication

Together with colleagues from China and the UK we just published work on a paleo limnological record in a big chinese lake that shows a transition to eutrophication during the last 30 years. Interestingly, the data offer the possibility to show that the system exhibits bimodality and that approaching to the permanent shift ‘flickering’ between the oligotrophic and eutrophic state may be observed. We compared these results to model simulations and we conclude that flickering may be more possible to detect in the most common ecological records at hand.

Review on anticipating critical transitions in last week´s issue in Science

Our review paper on Anticipating Critical Transitions summarizes the advancement and popularity in estimating early-warning signals for approaching transitions in a variety of disciplines together with some ground-breaking experimental demonstrations that followed the earlier review on early-warnings. In addition, new ideas are mapped out and the challenge of merging network perspectives on stability and collapse with early-warnign research is pioneered.

Does predator interference cause alternative stable states in multispecies communities?

Our paper with Jiangfeng Feng and Egbert van Nes in Theoretical Population Biology just appeared online http://dx.doi.org/10.1016/j.tpb.2012.06.003 . We show that predator interference has a dual effect on the dynamics of multispecies predator prey communities: on one hand it increases their dynamical stability (in the sense of leading to stable equilibrium dynamics), while on the other hand it decreases their resilience (in the sense of increasing the number of alternative stable states that these communities may end to).

ASLO meeting Japan: Session on Ecosystem change and predictability

Together with Elisa Benincà from the University of Amsterdam and Chih-hao Hsieh from the National Taiwan University, we are putting together a special session on

ECOSYSTEM CHANGE AND PREDICTABILITY OF AQUATIC ECOSYSTEMS,

in coming July during the ASLO Aquatic Sciences meeting in Japan. George Sugihara of Scripps Institution of Oceanography is going to kick start our session on a tutorial on nonlinear dynamics and the broad spectrum of the rest of the speakers will ensure an interesting and lively session!

Session Topic: Under global environmental pressure, the risk of unwanted changes in aquatic systems is high. Such changes occur across different scales and take a variety of forms depending on the properties of the ecosystem itself. For example, regime shifts may occur among multiple states, communities may change in composition and structure, ecosystem dynamics can shift from stable states to oscillatory regimes. As we still lack proper understanding of the mechanisms behind these phenomena, predicting system changes, anticipating their risk, and above all identifying their main drivers have a crucial role for the conservation and the management of aquatic ecosystems. This session will draw upon the expertise of empirical and theoretical aquatic ecologists to present methods, theories and evidence of understanding and anticipating changes in aquatic systems.

KNAW colloquium on Early Warnings in October 2012

Our colloquium and masterclass on ‘Early-warning signals for critical transitions: bridging the gap between theory and practice’ will be hosted by the Dutch Royal Science and Arts Society (KNAW) from 10 to 12 of October 2012 in Amsterdam.

We have now opened the registration for the masterclass till the end of August!