What Is the Allee Effect?

Stephens, Philip A.; Sutherland, William J.; Freckleton, Robert P.

doi:10.2307/3547011

Cited by 1,169 publications

(932 citation statements)

References 28 publications

Supporting

Mentioning

905

Contrasting

Unclassified

Order By: Relevance

“…To leading order, ϕ(u) ≃ u 2 and As an example, for a = 2 we find 46) which coincides with the result in [36]. We have verified the result (3.45) by numerical simulations.…”

Section: A and N0 Are Evensupporting

confidence: 74%

“…In the second reaction (death by competition), c individuals interact with each other to remove d individuals at a constant rate µ. The fact that b, in general, can be larger than 1 includes scenarios where a single individual cannot generate by itself new individuals, which represents a type of Allee effect [46]. Equation (2.12) reduces to the logistic equation if b = 1 and c = 2.…”

Section: Birth and Death/competition Processesmentioning

confidence: 99%

See 1 more Smart Citation

Stochastic dynamics and logistic population growth

et al. 2015

View full text Add to dashboard Cite

The Verhulst model is probably the best known macroscopic rate equation in population ecology. It depends on two parameters, the intrinsic growth rate and the carrying capacity. These parameters can be estimated for different populations and are related to the reproductive fitness and the competition for limited resources, respectively. We investigate analytically and numerically the simplest possible microscopic scenarios that give rise to the logistic equation in the deterministic mean-field limit. We provide a definition of the two parameters of the Verhulst equation in terms of microscopic parameters. In addition, we derive the conditions for extinction or persistence of the population by employing either the "momentum-space" spectral theory or the "real-space" Wentzel-KramersBrillouin (WKB) approximation to determine the probability distribution function and the mean time to extinction of the population. Our analytical results agree well with numerical simulations.

show abstract

“…To leading order, ϕ(u) ≃ u 2 and As an example, for a = 2 we find 46) which coincides with the result in [36]. We have verified the result (3.45) by numerical simulations.…”

Section: A and N0 Are Evensupporting

confidence: 74%

Section: Birth and Death/competition Processesmentioning

confidence: 99%

Stochastic dynamics and logistic population growth

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Third, demographic pressure and climatic change might be factors accelerating the extinction of a language, in the same way that they are affecting the biosphere [33]: natural habitats are modified, reduced and fragmented, populations are displaced and, eventually, increasing competition and further weakening of small populations supervenes. There is evidence to support that these small populations may suffer from an accelerated decline, in resemblance to the Allee effect in biology [10,34].…”

Section: Discussionmentioning

confidence: 99%

River density and landscape roughness are universal determinants of linguistic diversity

Axelsen

Manrubia²

2014

Proc. R. Soc. B.

View full text Add to dashboard Cite

Global linguistic diversity (LD) displays highly heterogeneous distribution patterns. Though the origin of the latter is not yet fully understood, remarkable parallelisms with biodiversity distribution suggest that environmental variables should play an essential role in their emergence. In an effort to construct a broad framework to explain world LD and to systematize the available data, we have investigated the significance of 14 variables: landscape roughness, altitude, river density, distance to lakes, seasonal maximum, average and minimum temperature, precipitation and vegetation, and population density. Landscape roughness and river density are the only two variables that universally affect LD. Overall, the considered set accounts for up to 80% of African LD, a figure that decreases for the joint Asia, Australia and the Pacific (69%), Europe (56%) and the Americas (53%). Differences among those regions can be traced down to a few variables that permit an interpretation of their current states of LD. Our processed datasets can be applied to the analysis of correlations in other similar heterogeneous patterns with a broad spatial distribution, the clearest example being biological diversity. The statistical method we have used can be understood as a tool for cross-comparison among geographical regions, including the prediction of spatial diversity in alternative scenarios or in changing environments.

show abstract

“…Theory suggests that rare species are prone to extinction due to stochastic events or biological processes that create positive density dependence (38). Alternatively, rare taxa may represent a reservoir of genetic diversity that actively responds to environmental change (22,39).…”

Section: Resultsmentioning

confidence: 99%

Dormancy contributes to the maintenance of microbial diversity

Jones

Lennon

2010

Proc. Natl. Acad. Sci. U.S.A.

750

638

View full text Add to dashboard Cite

Dormancy is a bet-hedging strategy used by a variety of organisms to overcome unfavorable environmental conditions. By entering a reversible state of low metabolic activity, dormant individuals become members of a seed bank, which can determine community dynamics in future generations. Although microbiologists have documented dormancy in both clinical and natural settings, the importance of seed banks for the diversity and functioning of microbial communities remains untested. Here, we develop a theoretical model demonstrating that microbial communities are structured by environmental cues that trigger dormancy. A molecular survey of lake ecosystems revealed that dormancy plays a more important role in shaping bacterial communities than eukaryotic microbial communities. The proportion of dormant bacteria was relatively low in productive ecosystems but accounted for up to 40% of taxon richness in nutrient-poor systems. Our simulations and empirical data suggest that regional environmental cues and dormancy synchronize the composition of active communities across the landscape while decoupling active microbes from the total community at local scales. Furthermore, we observed that rare bacterial taxa were disproportionately active relative to common bacterial taxa, suggesting that microbial rank-abundance curves are more dynamic than previously considered. We propose that repeated transitions to and from the seed bank may help maintain the high levels of microbial biodiversity that are observed in nearly all ecosystems.biodiversity | ecosystem function | microbial ecology | modeling | seed bank

show abstract

What Is the Allee Effect?

Cited by 1,169 publications

References 28 publications

Stochastic dynamics and logistic population growth

Stochastic dynamics and logistic population growth

River density and landscape roughness are universal determinants of linguistic diversity

Dormancy contributes to the maintenance of microbial diversity

Contact Info

Product

Resources

About