Rodent-caused damage to forest trees from the viewpoint of forestry practice

Abstract

Small mammals cause serious damage to forests but there is only little knowledge of their ecology and possibilities of plantation protection. The objective of our study was to collect information on the damage caused by rodents to plantations of forest tree species. Data were obtained from a survey conducted in 2008 that was aimed at damage caused by small mammals. Questionnaires were sent mostly to foresters engaged in the Lesy CR state enterprise. We obtained usable data from 316 foresters. The response rate was 81%. It was confirmed that rodents cause significant damage all over the Czech Republic and that the occurrence of damage cannot be easily predicted with certainty as significant damage may appear perhaps in a small part of the threatened plantations where the key conditions for small mammals have been fulfilled. The main factors which affected probability of damage include: presence of a woody species attractive to rodents; suitable structure of ground vegetation enabling the pest species to breed sufficiently during the vegetation period; and also long-lasting snow cover. The current approach of forestry practice to damage by small mammals is considerably passive and we are missing an alert system of threat to stands and a methodology of dealing with problematic situations. Most of the foresters are uninterested in small mammals and many have only very smattering knowledge of the dangerousness of individual species and their ecological requirements. The use of rodenticides is expensive and the most effective and economic measure to lower damage by small mammals is to support forest management favouring natural regeneration of forest stands.

Relationship between rodent density, environmental factors and tree damage caused by rodent species

“…of forest stand damage is apparent (Kamler et al 2010). An analogous situation may also be found in other European countries, where generally only a small percentage of forest sites is aff ected, yet with signifi cant economic damage in the given areas (Borowski 2007;Huitu et al 2009 etc.).…”

“…Diff erences in the species spectrum of damaged trees and the extent of damage in various areas of Europe give evidence of a number of diff erent complex factors at play and as such require an assessment of the issue at a regional level and deem any generalization of results unsuitable. While mainly coniferous species are damaged in the boreal zone (Sullivan, Sullivan 2008;Huitu et al 2009), which is related mainly to the given environmental conditions, the area of Central Europe encompasses regionally diff ering spectrums of tree species with various ratios of broadleaved and coniferous species, which is aff ected both by the specifi c natural conditions and silviculture as well (Borowski 2007;Kamler et al 2010Kamler et al , 2011. While for example mainly rowan and beech are damaged in the Czech Republic (Kamler et al 2010), larch and ash are damaged in Poland (Borowski 2007).…”

“…Other mountain ranges are subject to sporadic monitoring of damage (e.g. Kamler et al 2010), yet assessments of the impact of various factors are not available. Th e Jeseníky Mts.…”

Diversity of small mammals synusias of the open forest sites of the Beskydy and Jeseníky Mts.

“…Apart from a single environmental study of sites affected by air pollution (Nesvadbová, Gaisler 2000), only faunisic data on the occurrence of individual small mammal species are available from the Jeseníky Mts Beneš 2001, 2002;Anděra 2000Anděra , 2011 as well as a one-off monitoring of browsing damage to trees summarized by Kamler et al (2010Kamler et al ( , 2011. Preliminary evaluations of habitat preferences of selected small mammal species in a nonforest environment (Suchomel et al 2009) and the impact of voles (Arvicolinae) on beech (Fagus sylvatica) plantations were conducted in the area only recently.…”

Influence of forest fragmentation on the distribution of small terrestrial mammals in fir-beech commercial forest

“…The knowledge of microhabitat preferences of forest rodents can help to prevent their impact by the herb layer management (Suchomel et al 2009). Kamler et al (2010) pointed out the role of the herb layer for the intensity of tree damage caused by rodents, when significant differences in the intensity of damage to trees at clearings were found in dependence on the structure of the herbaceous cover.…”