Skip to Main content Skip to Navigation
Theses

AGRICULTURE ET BIODIVERSITÉ : APPROCHE PLURI-ÉCHELLE DE L'ÉVOLUTION D'UNE COMMUNAUTÉ DE PETITS MAMMIFÈRES ET DE DEUX RAPACES PRÉDATEURS LE LONG D'UN GRADIENT DE PAYSAGES AGRICOLES CONTRASTÉS

Abstract : During the last decades, drastic changes in farming landscape structure and composition have been
induced by changes in agricultural production methods and policies (increase of machinery use, expansion of cultivated areas to the detriment of semi-natural habitats, growing use of chemical products....). A question increasingly associated with all these changes in modern agriculture is to known if there have been impacts of agricultural intensification on biodiversity.
In that way, we study a community of small mammals (rodents & insectivores < 40g) living in hedgerows, in three contrasted farming landscapes differing by their level of land-use intensity and hedgerow network density, giving an agricultural intensification gradient. The framework of the study is : (1) to characterize the composition and the structure of the community in the agricultural landscapes, (2) to identify (in a multi-scale approach) which environmental variables could be
predominant for explaining differences in species assemblages between hedgerows, (3) to characterize seasonal variations of the community and component populations in response to landscape dynamics. (4) We also compare abundances of two small mammal predators, Buteo buteo and Falco tinnunculus, in response to the composition of the three sites, and to small mammal availability.
The results show the importance to develop an approach utilizing several organization levels and observation scales. Diversity, abundance, composition and biomass of the community, as well as abundance of the two raptor species, clearly differ between the study sites, showing an influence of agricultural intensification on the small mammal community and an higher trophic level. Both
landscape and habitat scale are implied in structuring species assemblages. Seasonal patterns in the small mammal populations are the same whatever the site, but amplitude fluctuations are different, particularly for the dominant species.
These results could permit to propose action plans for the conservation of biodiversity in agricultural landscapes.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00097063
Contributor : Valerie Briand <>
Submitted on : Wednesday, September 20, 2006 - 6:05:49 PM
Last modification on : Thursday, January 14, 2021 - 11:51:29 AM
Long-term archiving on: : Tuesday, April 6, 2010 - 1:05:13 AM

Identifiers

  • HAL Id : tel-00097063, version 1

Citation

Nadia Michel. AGRICULTURE ET BIODIVERSITÉ : APPROCHE PLURI-ÉCHELLE DE L'ÉVOLUTION D'UNE COMMUNAUTÉ DE PETITS MAMMIFÈRES ET DE DEUX RAPACES PRÉDATEURS LE LONG D'UN GRADIENT DE PAYSAGES AGRICOLES CONTRASTÉS. Ecologie, Environnement. Université Rennes 1, 2006. Français. ⟨tel-00097063⟩

Share

Metrics

Record views

854

Files downloads

1706