Exploring the factors that affect water vole (Arvicola terrestris) outbreaks in grasslands
Genèse de la problématique du campagnol terrestre (Arvicola terrestris) en prairies
Abstract
The water vole naturally occurs at low densities throughout most of eastern France. However, densities can reach 500voles/ha during the species’
periodic outbreaks (which occur about every 6years); these high densities lead to considerable damage, particularly to grasslands. Also, because
chemical pesticides are used to control vole populations, outbreaks can have a negative, indirect impact on local fauna, and thus ultimately harm
the net income of farms and disrupt the natural balance of agroecosystems. Water vole outbreaks were studied in Franche-Comté and Auvergne.
They were found to be caused by multiple factors, including the proportion of the landscape dedicated to agriculture, the proportion of land under
permament grass, and landscape heterogeneity. The increasing degree of specialisation taking place in livestock-producing regions over the last
few years has promoted water vole outbreaks, whose breadth and intensity vary across regions.
Le campagnol terrestre (Arvicola terrestris) est omniprésent dans une grande partie de l’est de la France mais, lors de pullulations cycliques
(tous les 6ans environ), ses effectifs peuvent atteindre 500individus/ha, perturbant l’équilibre naturel des agroécosystèmes et les résultats
économiques des exploitations. Ce phénomène a été étudié en Franche-Comté et en Auvergne: son origine est multifactorielle (part de
surfaces agricoles dans le paysage et de surfaces toujours en herbe, hétérogénéité du paysage...). La spécialisation croissante des régions
d’élevage ces dernières années a favorisé le développement de ces pullulations dont l’ampleur et l’intensité varient selon les régions.