Bark Gnawing by Rodents in Orchards during the Growing Season—Can We Detect Relation with Forest Damages?

Abstract

Rodent bark gnawing is common during winter in times of low or unavailable food supply. During the growing season, it is a rare phenomenon, but can occur due to low food supply and/or poor food quality resulting from climatic influence. We evaluated this unusual damage of apple tree (Malus domestica) orchards by rodents in two localities in the Czech Republic. In 2019, 24% of trees in the orchard in Brno were gnawed by the common vole (Microtus arvalis) population. Damage in the Holovousy orchard by water vole (Arvicola amphibius) was inspected in 2020 and showed that 15% of trees were damaged with massive root gnawing. These findings were compared with gnawing in forest beech plantations in 2019, with up to 13% of trees damaged. Three rodent species (Microtus agrestis, M. arvalis and Clethrionomys glareolus) participated in the damage. Detailed description of the various vole species’ damage in vegetation period, which somehow differs from winter time damage, may help in the future in early recognition and early application of plant protection in times when this phenomenon may reappear.