Damage caused by rodents in Polish forests*

Abstract

The impact of small rodents on Polish forest trees was examined at both the national and regional levels. Detailed information based on a questionnaire was collected at the national level in 1993. Field studies at the regional level were carried out from 1994 through to 1997. The damage due to rodents constituting a significant economic problem occurred in only 4% of the Forest Districts in Poland. The tree species that small rodents preferred most were larch, ash, beech and maple, whereas birch, Norway spruce, Scots pine and black alder were the least preferred. Regional field studies were conducted in localities with the highest levels of damage situated in the Sudety Mountains (southern Poland). In this region, the most common rodent species was the field vole. Levels of tree-seedling damage were correlated with vole population density in the Autumn. I conclude that: (1) at the national level, the damage caused by small rodents has limited impact on Polish forestry; (2) at the regional level small rodents may exert considerable pressure on the over-wintering survival of tree seedlings.