Influence de l’hétérogénéité des paysages sur la biodiversité des agroécosystèmes et sur le contrôle biologique des ravageurs

Agricultural landscape heterogeneity divided in two components which are the cultural diversity and the proportion of natural elements may be a factor which can improve conservation biological control within this landscape by promoting global diversity at the origin of this control. In this study, we want to confirm on the one hand if landscape heterogeneity allows to improve predation of aphids and lepidopteran (some significant pests) and on the other hand if it sustains the biodiversity which is measured with a bioindicator (the family of ground beetles) and may content natural enemies of these preys. We could determinate if these hypothesis were confirmed by experimental way within a mixt unity of research (Dynafor-INRA) in the context of one national project (SEBIOPAG) and one international project (Farmland) . These researches confirms that biodiversity is improved with landscape heterogeneity by providing multiple shelters and resources, but not the biological control. Habitat generalist predators are at the origin of the predation processes observed. These predators are not represented by the biodiversity measured in this study and supported by natural elements of the landscape.