Small rodent population cycles and plants – after 70 years, where do we go?
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https://hdl.handle.net/10037/31653Date
2023-10-12Type
Journal articleTidsskriftartikkel
Peer reviewed
Abstract
Small rodent population cycles characterise northern ecosystems, and the cause of these cycles has been a long-lasting
central topic in ecology, with trophic interactions currently considered the most plausible cause. While some researchers
have rejected plant–herbivore interactions as a cause of rodent cycles, others have continued to research their potential
roles. Here, we present an overview of whether plants can cause rodent population cycles, dividing this idea into four
different hypotheses with different pathways of plant impacts and related assumptions. Our systematic review of the
existing literature identified 238 studies from 150 publications. This evidence base covered studies from the temperate
biome to the tundra, but the studies were scattered across study systems and only a few specific topics were addressed
in a replicated manner. Quantitative effects of rodents on vegetation was the best studied topic, and our evidence base
suggests such that such effects may be most pronounced in winter. However, the regrowth of vegetation appears to take
place too rapidly to maintain low rodent population densities over several years. The lack of studies prevented assessment
of time lags in the qualitative responses of vegetation to rodent herbivory. We conclude that the literature is currently
insufficient to discard with confidence any of the four potential hypotheses for plant–rodent cycles discussed herein.
While new methods allow analyses of plant quality across more herbivore-relevant spatial scales than previously possible,
we argue that the best way forward to rejecting any of the rodent–plant hypotheses is testing specific predictions of dietary
variation. Indeed, all identified hypotheses make explicit assumptions on how rodent diet taxonomic composition and
quality will change across the cycle. Passing this bottleneck could help pinpoint where, when, and how plant–herbivore
interactions have – or do not have – plausible effects on rodent population dynamics.
Publisher
WileyCitation
Soininen EM, Neby MN. Small rodent population cycles and plants – after 70 years, where do we go?. Biological Reviews. 2023Metadata
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