Biological Filtering of Noise Colour and Synchrony
(English)Manuscript (preprint) (Other academic)
Environmental variation is a major force driving fluctuations in population densities. Here, we investigated the impact of such variation on population dynamics by studying noise color and synchrony of environmental variation compared to noise color and synchrony of variation of local population densities. We used Ricker models with over- or undercompensatory density-dependent regulation, and local populations were connected by dispersal. For both noise color and synchrony, we measured the shift between environmental variation and fluctuations in population densities. We also analyzed how the shifts were affected by dispersal rate and type of density regulation. Populations with undercompensatory dynamics showed the classical picture of increasing positive shifts in synchrony with increasing dispersal rates. The color of the environmental variation also affected the positive shift in synchrony, which was increased by reddened noise in populations with undercompensatory dynamics. Populations with overcompensatory dynamics showed no shifts in synchrony regardless of dispersal rates. Shifts in noise color exhibited the same pattern: populations with overcompensatory dynamics displayed only minor shifts in noise color, whereas those with undercompensatory dynamics had distinct positive shifts that increased with dispersal rates and also depended on the degree of synchrony. These findings demonstrate that noise color and synchrony are determined by and equal to synchrony and close to the color of environmental variation in populations with overcompensatory dynamics, but differ from the corresponding aspects of environmental variation in populations with undercompensatory dynamics. The shifts in populations with undercompensatory dynamics are determined by several factors: degree of population responsiveness, dispersal rates, and both the color and synchrony of environmental variation.
Noise color; synchrony; correlated fluctuations; biological filtering; spatially subdivided
IdentifiersURN: urn:nbn:se:liu:diva-72944OAI: oai:DiVA.org:liu-72944DiVA: diva2:464021