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I present here a conceptual model that combines several factors known individually to be important in microtine population dynamics, but are insufficient separately as causal agents. Specifically, I bring together insights from trophic web theory, particularly the role of generalist and specialist predators, with landscape theory, particularly the influence of habitat patchiness on demographic processes. The resulting trophic/ROMPA interaction model (TRIM) is sufficiently complex and realistic to be used as a substrate for building even more complex and/or locally specific models. Yet, it remains simple enough to be general and widely applicable. The model suggests that predators are an important but not sufficient factor in causing multi-annual cycles greater than two years in length. In a patchy system, generalist predators have a slightly more severe impact than do specialists, and spillover predation plays a significant role. The ratio of optimal to marginal patch areas (ROMPA) influences the tendency for multi-annual cycles to occur such that medium ratios generate the strongest tendency toward cycling. However, cycles can occur with high ROMPA and specialist predators. Communities with more than three trophic levels and greater species diversity will be less likely to show cycles. Finally, it should be noted that the model combines factors intrinsic to microtines, extrinsic food-web interactions, and contextual landscape processes into an integrated framework. A plethora of null hypotheses are thereby generated against which population data can be compared.