data analysis

New Publication in Nature: Long-term cyclic persistence in an experimental predator-prey system.

Realization of the longest known predator-prey time series

Long-term cyclic persistence in an experimental predator–prey system

Predator–prey cycles rank among the most fundamental concepts in ecology, are predicted by the simplest ecological models and enable, theoretically, the indefinite persistence of predator and prey. However, it remains an open question for how long cyclic dynamics can be self-sustained in real communities. Field observations have been restricted to a few cycle periods and experimental studies indicate that oscillations may be short-lived without external stabilizing factors. Here we performed microcosm experiments with a planktonic predator–prey system and repeatedly observed oscillatory time series of unprecedented length that persisted for up to around 50 cycles or approximately 300 predator generations.

Length–volume relationship of lake phytoplankton

The shapes of phytoplankton units (unicellular organisms and colonies) are extremely diverse, and no unique relationship exists between their volume, V, and longest linear dimension, L. However, an approximate scaling between these parameters can be …

A periodic Markov model to formalize animal migration on a network

Regular, long-distance migrations of thousands of animal species have consequences for the ecosystems that they visit, modifying trophic interactions and transporting many non-pathogenic and pathogenic organisms. The spatial structure and dynamic …

The marine bacterium Phaeobacter inhibens secures external ammonium by rapid buildup of intracellular nitrogen stocks

Reduced nitrogen species are key nutrients for biological productivity in the oceans. Ammonium is often present in low and growth-limiting concentrations, albeit peaks occur during collapse of algal blooms or via input from deep sea upwelling and …

The intermediate distance hypothesis of biological invasions

Biological invasions are a worldwide phenomenon, but the global flows between native and alien regions have rarely been investigated in a cross‐taxonomic study. We therefore lack a thorough understanding of the global patterns of alien species …

Competition-induced starvation drives large-scale population cycles in Antarctic krill

Antarctic krill (Euphausia superba)—one of the most abundant animal species on Earth—exhibits a five to six year population cycle, with oscillations in biomass exceeding one order of magnitude. Previous studies have postulated that the krill cycle is …

No saturation in the accumulation of alien species worldwide

Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of …

Predicting the spread of marine species introduced by global shipping

Predicting the arrival of alien species remains a big challenge, which is assumed to be a consequence of the complexity of the invasion process. Here, we demonstrate that spreading of alien marine species can be predicted by a simple model using only global shipping intensities, environmental variables, and species occurrence data. We provide species lists of the next potentially invading species in a local habitat or species causing harmful algal blooms with their associated probability of invasion. This will help to improve mitigation strategies to reduce the further introduction of alien species. Although this study focuses on marine algae, the model approach can be easily adopted to other taxonomic groups and their respective drivers of invasion

Global trade will accelerate plant invasions in emerging economies under climate change

Trade plays a key role in the spread of alien species and has arguably contributed to the recent enormous acceleration of biological invasions, thus homogenizing biotas worldwide. Combining data on 60‐year trends of bilateral trade, as well as on …