During the three-year long study of the rodent community, a total of 139 individuals belonging to three families and eleven species were investigated. The studied rodent families included Muridae, (Mus musculus, Nesokia indica, Rattus norvegicus, Rattus rattus, Apodemus witherbyi, Apodemus hyrcanicus, Apodemus uralensis, and Rhombomys opimus), Gliridae (Glis glis), and Cricetidae, (Microtus levis, Cricetulus migratorius). Specimens were captured with modified Sherman live traps at four altitude levels covering clay plains around Alagol and Almagol wetlands, the sub-mountainous range of Hyrcanian forests, the Alborz Mountain range, and steppes of the northern slopes of the Alborz Mountain range in the easternmost part of the Hyrcanian region, northeast of Iran. Shannon–Wiener’s, Simpson’s diversity and evenness indices were calculated. Our data showed that species diversity varies with vegetation coverage. Moreover, species richness and evenness indices show the tendency to decrease with increasing altitude. The highest Shannon–Wiener’s and Simpson’s diversity indices were recorded at lower altitudes and the lowest at the highest. In accordance with the generalized Rapoport’s elevation rule, our results show an inverse correlation between species diversity and altitude. The results obtained suggest that the mountainous and sub-mountainous ranges of the Hyrcanian region should be strictly controlled because of lower diversity and greater susceptibility of rodents to ecosystem alterations.

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