Influence of “soil-vegetation-farming practices” system on the population dynamics of the fossorial form of the water vole (Arvicola terrestris sherman) in Franche-Comté, France.
Small mammals are the most important vertebrate pests in Central European agriculture. In French mid-altitude mountains, cyclic outbreaks of Arvicola terrestris populations have caused dramatic grassland damage since the 1970s. One possible explanation is that intensive agriculture has created homog...
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| Other Authors: | , , , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | French |
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HAL CCSD
2005
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| Subjects: | |
| Online Access: | https://tel.archives-ouvertes.fr/tel-00341535 https://tel.archives-ouvertes.fr/tel-00341535/document https://tel.archives-ouvertes.fr/tel-00341535/file/Morilhat-These.pdf |
| Summary: | Small mammals are the most important vertebrate pests in Central European agriculture. In French mid-altitude mountains, cyclic outbreaks of Arvicola terrestris populations have caused dramatic grassland damage since the 1970s. One possible explanation is that intensive agriculture has created homogeneous grassland ecosystems with a high risk of outbreaks. While the role of the landscape structure on A. terrestris outbreaks has been identified on a large scale, little is known about the quantitative effects of grassland management on a local scale. We aimed to investigate the impact, on a parcel scale, of soil, vegetation and farming practices on the A. terrestris population dynamics. We examined different phases of an A. terrestris population cycle in agricultural parcels : low density, increase and high density. For each parcel, relative densities of A. terrestris were estimated by an index method. Talpa europaea and Microtus arvalis populations were also taken into account, because of their possible interactions with A. terrestris. Farmers were interviewed about their land-use practices related to fertilisation, mowing, soil work and grazing. We studied structural and functional characteristics of the vegetation (heightcompactness, plant traits) and morphological and physico-chemical characteristics of the soil (depth, texture, structure, organic matter, pH, hydromorphy). The principal results showed that intensive farming practices, such as organic fertilisation and mowing, stimulated an early and more rapid growth of the A. terrestris populations. This agricultural mode generated a vegetation characterized by a low specific diversity, a strong pastoral value and a homogeneous and dense cover. In contrast, disturbances such as grazing and soil work were unfavourable to the abundance level of the A. terrestris population at the high density phase. However, no effect of the soil could be shown. Grassland management practices could influence A. terrestris populations while acting on food supply and plant ... |
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