 Last winter the extremely dense vole population caused record damage in sapling stands in Southern Finland. Preliminary estimates indicate that there are tens of thousands of hectares of damaged sapling stands.
The survey catches of moles made by the Finnish Forest Research Institute in the autumn 2008 indicated extremely dense vole populations. This, as foreseen, resulted in extensive destruction of sapling stands last winter. The estimate is that there are 18,000 hectares of totally destroyed sapling stands, which entitle to subsidies. The amount of sapling stands, which have suffered less extensive damage and are therefore not entitled to subsidies, is estimated to be many times larger.
The amount of eaten sapling tops of coniferous trees was extremely large last winter. In many places the area of destroyed saplings was equivalent to the planted area of one whole year. The vole damage in Middle Finland and in the province of Savo gives the impression that there is almost no untouched sapling stands at all.
The regular population changes facilitate the prediction of years with great vole populations. The Southern Finnish population that collapsed this year is predicted to stay small until the spring of 2010, if the pattern of past periods is repeated The population will then be at maximum level again in the autumn of 2011. Thereafter the most extensive damage is predicted for the winter of 2011 - 2012.
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