Using a long-term laboratory experiment, the study demonstrates that, even under constant conditions, all species in a food web continued to fluctuate in a chaotic fashion. Chaos makes long-term prediction of species abundances impossible.
Theoretical ecologists already argued in the 1970s that populations of plants and animals might fluctuate in an unpredictable manner, even without external influences. These predictions, derived from chaos theory, attracted a lot of debate. However, only few scientists believed that species in real ecosystems would truly fluctuate in a chaotic fashion. The common perception was that species fluctuations result from changes in external conditions, driven by climate change or other disturbances of the balance of nature.
This classic perspective has been radically changed by new findings of graduate student Elisa Benincà and Professor Jef Huisman of the Institute for Biodiversity and Ecosystem Dynamics of the University of Amsterdam, The Netherlands, in collaboration with colleagues from Wageningen University (The Netherlands), the University of Rostock (Germany), and Cornell University (USA).
The core of their work consists of a laboratory experiment in which a plankton community isolated from the Baltic Sea was studied for more than eight years. The experiment was maintained under constant light and temperature conditions by the German biologist Reinhard Heerkloss, who reported the development of the different plankton species twice a week. To his major surprise, the food web never settled at equilibrium and the species abundances continued to vary wildly. He sent his data to Amsterdam for statistical analysis. This revealed that the fluctuations were caused by the species themselves; competition and predation generated a dynamic food web in which none of the species succeeded in getting the upper hand. Advanced mathematical techniques proved the indisputable presence of chaos in this food web.
According to the authors, these findings have far-reaching implications: “Our results demonstrate that species abundances are essentially unpredictable in the long term. For many years, we thought that a better understanding of all relevant processes would enable sound prediction of changes in species abundances in response to external factors (e.g., climate change). Now we know that things are not as simple as that.” Professors Jef Huisman and Marten Scheffer, both from The Netherlands, had already foreseen the possibility of chaos in plankton communities by means of mathematical models. However, the experimental demonstration of chaos in this study provides the real breakthrough. The limited predictability of species in food webs is comparable to the weather forecast. Benincà: “Short-term prediction is possible, but long-term prediction is not. We can at best indicate within which boundaries species will fluctuate”.
The research was financed by the Earth and Life Sciences Foundation, which is subsidized by the Netherlands Organization for Scientific Research (NWO).
Josje Spinhoven | alfa
Machine learning helps predict worldwide plant-conservation priorities
04.12.2018 | Ohio State University
From the Arctic to the tropics: researchers present a unique database on Earth’s vegetation
20.11.2018 | Martin-Luther-Universität Halle-Wittenberg
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals
Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.
Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.
Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...
Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.
The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.
10.12.2018 | Event News
06.12.2018 | Event News
03.12.2018 | Event News
10.12.2018 | Life Sciences
10.12.2018 | Physics and Astronomy
10.12.2018 | Life Sciences