Abstract
BackgroundSynchrony among populations has been attributed to three major hypotheses: dispersal, the Moran effect, and trophic-level interactions. Unfortunately, simultaneous testing of these hypotheses demands complete and detailed data, which are scarce for ecological systems.Methodology/Principal FindingsHudson's Bay Company data on mink and muskrat fur returns in Canada represent an excellent opportunity to test these hypotheses because of the detailed spatial and temporal data from this predator-prey system. Using structural equation modelling, support for each hypothesis was evaluated at two spatial scales: across Canada and dividing the country into three regions longitudinally. Our results showed that at both scales mink synchrony is a major factor determining muskrat synchrony, supporting the hypothesis of trophic-level interactions, but the influence of winter precipitation synchrony is also important in eastern Canada. Moreover, mink synchrony is influenced principally by winter precipitation synchrony at the level of all Canada (Moran effect), but by distance at regional level, which might suggest some influence of dispersal at this level.Discussion/SignificanceOur result is one of the few reports of synchrony mediated by trophic-level interactions, highlighting the importance of evaluation of scale effects in population synchrony studies.
Highlights
The first law of geography said: ‘‘everything is related to everything else, but near things are more related than distant things’’ [1]
Our results show a change in the relative influence of winter precipitation and distance on the synchrony of mink when the geographic scale of the analysis is reduced from country to regional
At the level of all Canada, mink synchrony appears influenced principally by winter precipitation synchrony which suggests that the Moran effect is the more important factor, but at the regional level of analysis the most important path acting on mink synchrony was distance, which adds some relative support for the dispersal hypothesis, given that the effects of the main environmental variables were removed
Summary
The first law of geography said: ‘‘everything is related to everything else, but near things are more related than distant things’’ [1]. This law is key for ecological and evolutionary studies dealing with spatially structured data. In population ecology this law takes great relevance when examining synchrony in numerical fluctuations among populations. Three mechanisms have been proposed as causal mechanisms underlying population synchrony: dispersal or migration, the Moran effect, and trophic-level interactions [4]. Synchrony among populations has been attributed to three major hypotheses: dispersal, the Moran effect, and trophic-level interactions. Simultaneous testing of these hypotheses demands complete and detailed data, which are scarce for ecological systems
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
