Harmful role of mice - like rodents
in lowland forests of republic Croatia

by Josip Margaletiæ

Lowland forests in Croatia, with pedunculate oak (Quercus robur L.) and common ash (Fraxinus angustifolia Vahl.) as their main tree species, are more or less spread in the area between rivers Sava, Kupa and Drava.

Recently, we are witnessing increased forest weakening, with pedunculate oak being especially sensitive. Noxious impact of numerous biotic factors, among which rodents play a significant role, along with unfavorable site conditions can cause severe disturbances in forest ecosystems. Mice - like rodents attack acorn of pedunculate oak and damage oak and other broadleafed seedlings. Rodents become serious problem when their population explodes and when years with minor acorn yield occur. Areas where natural and artificial regeneration of oak stands is taking place are especially threatened. Among rodents significant in forestry several harmful and most common species can be mentioned: Clethrionomys glareolus Schreib., Arvicola terrestris L., Microtus subterraneus de Sel., Microtus arvalis Pall., Microtus agrestis L., Apodemus agrarius Pall., Apodemus sylvaticus L., Apodemus flavicollis Melch. Because of the increase of their detrimental impact in forest ecosystems, Croatian forestry must regard this problem with full attention and due respect.