Vole densities and consumption of bark in relation to soil type and bark mineral content
1992
Hansson, L. (Sveriges Lantbruksuniv., Uppsala (Sweden). Inst. foer Viltekologi)
A recent hypothesis predicts that folivorous rodents should better overcome plant defence if the vegetation is rich in minerals. Vole densities, damage to bark by voles and calcium, phosphorus and sodium contents of bark were compared for forest plantations on various soil types in north-central Sweden. The folivorous field vole had a minor but prolonged cyclic population peak in a limestone area and showed a more rapid decline on granitic bedrock. Damage to seedlings was slight during this cycle but most extensive on abandoned fields and on hill slopes of newly cut forest, where seedlings contained higher levels of sodium and calcium in the bark, respectively. Factors other than food or minerals may drive the vole cycles but peak populations may still be limited by lack of certain minerals in vole food so that animals then turn to mineral-rich seedling bark. There was thus certain evidence of mineral effects and tentative recommendations are given on avoidance of vole damage on soils with high mineral content.
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