Grazing systems, landscape patterns and biodiversity

In grazed areas, grazing activities are Often the main factor that controls and influences plant and animal community dynamics. One of the new functions the society asks to the domestic herbivores is to maintain or improve the biodiversity of both plant and animal communities and the integrity of pastoral landscape as well. However, a shortage of basic knowledge characterizes the relationships between grazing activities and vegetation especially at landscape level. Grazing of vegetation by domestic herbivores is a complex hierarchical ecological process. It involves different levels of organization either in the case of free ranging animals or when feeding and spatial behaviour of grazing animals is under human control. In this paper we propose theoretical and methodological elements to help answering two important questions to improve the understanding of the relationships between grazing activity, landscape patterns and biodiversity. 1)How changes in land use management with grazing animals influence landscape patterns? 2) To which extent changes in grazing practices affect ecological characteristics of vegetation (disturbance, stability, and reversibility) ? Our skills are in the field of system analysis applied to ecology with special reference to hierarchy theory. organization of biological system theory and landscape ecology. (C) Elsevier/Inra.