population dynamics

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.

Long-term stability of marine dissolved organic carbon emerges from a neutral network of compounds and microbes

Dissolved organic carbon (DOC) is the main energy source for marine heterotrophic microorganisms, but a small fraction of DOC resists microbial degradation and accumulates in the ocean. The reason behind this recalcitrance is unknown. We test whether the long-term stability of DOC requires the existence of structurally refractory molecules, using a mechanistic model comprising a diverse network of microbe-substrate interactions...

Modeling community assembly on growing habitat islands: a case study on trees and their vascular epiphyte communities

The number of available sites for establishment is a key determinant of species richness on habitat islands. While most theoretical studies assume habitat size or capacity to be constant, many natural habitats are characterized by dynamic growth in …

Resource competition and species coexistence in a two-patch metaecosystem model

The metaecosystem framework has been proposed to conceptualize the interactive effects of dispersal and resource flows on the structure and functioning of communities in a heterogeneous environment. Here, we model a two-patch metaecosystem where two …

Diel light cycle as a key factor for modelling phytoplankton biogeography and diversity

Understanding the mechanisms driving species biogeography and biodiversity remains a major challenge in phytoplankton ecology. Using a model of two phytoplankton species with a gleaner-opportunist trade-off and competing for light and a limiting …

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 …

Enhanced Moran effect by spatial variation in environmental autocorrelation

Spatial correlations in environmental stochasticity can synchronize populations over wide areas, a phenomenon known as the Moran effect. The Moran effect has been confirmed in field, laboratory and theoretical investigations. Little is known, …

Cycles, phase synchronization, and entrainment in single-species phytoplankton populations

Complex dynamics, such as population cycles, can arise when the individual members of a population become synchronized. However, it is an open question how readily and through which mechanisms synchronization-driven cycles can occur in unstructured …

Community response to enrichment is highly sensitive to model structure

Biologists use mathematical functions to model, understand and predict nature. For most biological processes, however, the exact analytical form is not known. This is also true for one of the most basic life processes: the uptake of food or …