POPULATION FLUCTUATIONS AND FOOD WEB COMPLEXITY IN MODEL ECOSYSTEMS

摘要

This investigation uses simulation of stochasticallyrnassembled Lotka-Volterra models to investigate thernpattern of transient and steady state fluctuations inrnrelation to complexity of model ecosystems. Thernsimulation shows that complex food webs have in generalrna higher probability of transient and steady staternoscillations than simple webs. Under identical randomrnnoises, the amplitude of fluctuations increases with bothrnspecies richness and connetance in locally asymptoticallyrnstable systems while showing no obvious trend in locallyrnasymptotically unstable systems. The frequency ofrnfluctuations does not exhibit any strong dependence onrnspecies richness while generally increases withrnconnectance in both locally asymptotically stable systemsrnand locally asymptotically unstable systems.