Egbert H. van Nes

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MARTIN SØNDERGAARD,* ERIK JEPPESEN,*† TORBEN L. LAURIDSEN,* CHRISTIAN SKOV,‡ EGBERT H. VAN NES,§ RUDI ROIJACKERS,§ EDDY LAMMENS¶ and ROB PORTIELJE¶ * National Environmental Research Institute, Department of Freshwater Ecology, University of Aarhus,Vejlsøvej 25, DK-8600 Silkeborg, Denmark; † Department of Plant Biology, University of Aarhus, Ole Worms Allé,(More)
The submerged vegetation in Veluwemeer (The Netherlands) has shown large changes over the past 30 years. Potamogeton pectinatusL. remained present in the lake even during the hypertrophic period with total phospohorus (P) levels of about 0.6 mg P l-1. Furthermore, the data suggest that there may be one critical level of Secchi depth for the presence of(More)
Generic early-warning signals such as increased autocorrelation and variance have been demonstrated in time-series of systems with alternative stable states approaching a critical transition. However, lag times for the detection of such leading indicators are typically long. Here, we show that increased spatial correlation may serve as a more powerful(More)
Most work on generic early warning signals for critical transitions focuses on indicators of the phenomenon of critical slowing down that precedes a range of catastrophic bifurcation points. However, in highly stochastic environments, systems will tend to shift to alternative basins of attraction already far from such bifurcation points. In fact, strong(More)
Shallow lakes have become the archetypical example of ecosystems with alternative stable states. However, since the early conception of that theory, the image of ecosystem stability has been elaborated for shallow lakes far beyond the simple original model. After discussing how spatial heterogeneity and fluctuation of environmental conditions may affect the(More)
Seagrasses are threatened by human activity in many locations around the world. Their decline is often characterized by sudden ecosystem collapse from a vegetated to a bare state. In the 1930s, such a dramatic event happened in the Dutch Wadden Sea. Before the shift, large seagrass beds (Zostera marina) were present in this area. After the construction of a(More)
Alternative stable states in shallow lakes have received much attention over the past decades, but less is known about transient dynamics of such lakes in the face of stochastic perturbations such as incidental extremes in water levels driven by climatic variability. Here, we report on the ecosystem dynamics of 70 lakes in the floodplains of the Lower Rhine(More)
A large number and wide variety of lake ecosystem models have been developed and published during the past four decades. We identify two challenges for making further progress in this field. One such challenge is to avoid developing more models largely following the concept of others (‘reinventing the wheel’). The other challenge is to avoid focusing on(More)
The effects of fish stock reduction have been studies in 3 Dutch lakes (Lake Zwemlust, Lake Bleiswijkse Zoom and Lake Noorddiep) and 1 Danish lake (Lake Væng) during 4–5 years. A general response id described. The fish stock reduction led in general to a low fish stock, low chlorophyii-a, high transparency and high abunuance of macrophytes. Large Daphnia(More)
A positive feedback between submerged vegetation and water clarity forms the backbone of the alternative state theory in shallow lakes. The water clearing effect of aquatic vegetation may be caused by different physical, chemical, and biological mechanisms and has been studied mainly in temperate lakes. Recent work suggests differences in biotic(More)