0000000000649885

AUTHOR

Janica Ylikarjula

showing 3 related works from this author

Effects of patch number and dispersal patterns on population dynamics and synchrony.

2000

In this paper, we examine the effects of patch number and different dispersal patterns on dynamics of local populations and on the level of synchrony between them. Local population renewal is governed by the Ricker model and we also consider asymmetrical dispersal as well as the presence of environmental heterogeneity. Our results show that both population dynamics and the level of synchrony differ markedly between two and a larger number of local populations. For two patches different dispersal rules give very versatile dynamics. However, for a larger number of local populations the dynamics are similar irrespective of the dispersal rule. For example, for the parameter values yielding stab…

0106 biological sciencesStatistics and ProbabilityPopulationPopulation DynamicsBiology010603 evolutionary biology01 natural sciencesPopulation densityModels BiologicalGeneral Biochemistry Genetics and Molecular Biology03 medical and health sciencesQuantitative Biology::Populations and EvolutionAnimalsLocal populationPopulation dynamicseducation030304 developmental biologyPopulation Density0303 health scienceseducation.field_of_studyGeneral Immunology and MicrobiologyEcologyApplied MathematicsHigh intensityDynamics (mechanics)General MedicineRicker modelModeling and SimulationBiological dispersalGeneral Agricultural and Biological SciencesJournal of theoretical biology
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Non-unique population dynamics: basic patterns

2000

We review the basic patterns of complex non-uniqueness in simple discrete-time population dynamics models. We begin by studying a population dynamics model of a single species with a two-stage, two-habitat life cycle. We then explore in greater detail two ecological models describing host‐macroparasite and host‐parasitoid interspecific interactions. In general, several types of attractors, e.g. point equilibria vs. chaotic, periodic vs. quasiperiodic and quasiperiodic vs. chaotic attractors, may coexist in the same mapping. This non-uniqueness also indicates that the bifurcation diagrams, or the routes to chaos, depend on initial conditions and are therefore non-unique. The basins of attrac…

0106 biological scienceseducation.field_of_studyMathematical modelEcologyEcological ModelingPopulationChaoticBiologyBifurcation diagram010603 evolutionary biology01 natural sciences010601 ecologyFractalAnimal ecologyQuasiperiodic functionAttractorStatistical physicseducationEcological Modelling
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Dynamic complexities in host-parasitoid interaction

1999

In the 1970s ecological research detected chaos and other forms of complex dynamics in simple population dynamics models, initiating a new research tradition in ecology. However, the investigations of complex population dynamics have mainly concentrated on single populations and not on higher dimensional ecological systems. Here we report a detailed study of the complicated dynamics occurring in a basic discrete-time model of host-parasitoid interaction. The complexities include (a) non-unique dynamics, meaning that several attractors coexist, (b) basins of attraction (defined as the set of the initial conditions leading to a certain type of an attractor) with fractal properties (pattern of…

0106 biological sciencesStatistics and ProbabilityEcology (disciplines)PopulationChaoticBiologyBifurcation diagram010603 evolutionary biology01 natural sciencesGeneral Biochemistry Genetics and Molecular Biologylaw.invention03 medical and health sciencesFractalControl theorylawIntermittencyAttractorQuantitative Biology::Populations and EvolutionStatistical physicseducation030304 developmental biology0303 health scienceseducation.field_of_studyGeneral Immunology and MicrobiologyApplied MathematicsGeneral MedicineComplex dynamicsModeling and SimulationGeneral Agricultural and Biological SciencesJournal of theoretical biology
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