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.
Acknowledgements
The study was financed by grant BLP-702 from the General Directorate of Polish Forestry. I am grateful to Dr James Richards and to Dr Mark A. Jervis for linguistic correction of the text, and to two anonymous reviewers for their valuable comments and suggestions.
Notes
*The work described in this paper was conducted in accordance with both Polish and European Union regulations. The Catch-Mark-Release method was used in field studies.