Urban forests provide a range of important ecosystem services including recreation for residents and habitats for plants and animals. However, intensive recreational activities may negatively affect the native vegetation. Degraded forest sites are less attractive and have a reduced recreational value. Empirical data on the effects of both recreation and other human-mediated disturbances on plant diversity in urban forests are so far not available from cities in Central Asia. We assessed the recreational use of urban and suburban forests (visitor frequencies and characteristics of visitors) and its potential impact on plant diversity in the city of Pavlodar, Kasakhstan. The people of this Western Siberian region experienced very rapid changes in the traditional husbandry system with a dramatic impact on the social and economical development as a result of the Virgin Land Campaign in 1954–1963. We show that urban and suburban forests differ in the age structure and group size of visitors as well as in the activities of visitors. In urban forests, total plant species richness was reduced by both recreation pressure and overall disturbance. Urban forests also harboured a large proportion of alien plant species. In suburban forests, recreational pressure did not affect plant species richness, while overall human-mediated disturbance appeared to enhance the invasion of alien species. We conclude that adequate management actions are required to prevent further degradation of urban forests with the corresponding decrease in recreational value in this Western Siberian city.