Publications by authors named "R A Ims"

Ecosystems are subjected to increasing exposure to multiple anthropogenic drivers. This has led to the development of national and international accounting systems describing the condition of ecosystems, often based on few, highly aggregated indicators. Such accounting systems would benefit from a stronger theoretical and empirical underpinning of ecosystem dynamics.

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Herbivorous rodents in boreal, alpine and arctic ecosystems are renowned for their multi-annual population cycles. Researchers have hypothesised that these cycles may result from herbivore-plant interactions in various ways. For instance, if the biomass of preferred food plants is reduced after a peak phase of a cycle, rodent diets can be expected to become dominated by less preferred food plants, leading the population to a crash.

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In the Arctic tundra, predators face recurrent periods of food scarcity and often turn to ungulate carcasses as an alternative food source. As important and localized resource patches, carrion promotes co-occurrence of different individuals, and its use by predators is likely to be affected by interspecific competition. We studied how interspecific competition and resource availability impact winter use of carrion by Arctic and red foxes in low Arctic Fennoscandia.

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Large carnivores influence ecosystem dynamics in multiple ways, for example, by suppressing meso-carnivores and providing carrions for smaller scavengers. Loss of large carnivores is suggested to cause meso-carnivore increase and expansion. Moreover, competition between meso-carnivores may be modified by the presence of larger carnivores.

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Studies of spatial population synchrony constitute a central approach for understanding the drivers of ecological dynamics. Recently, identifying the ecological impacts of climate change has emerged as a new important focus in population synchrony studies. However, while it is well known that climatic seasonality and sequential density dependence influences local population dynamics, the role of season-specific density dependence in shaping large-scale population synchrony has not received attention.

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