Showing papers by "François Gillet published in 1998"

Occurrence of the wild vine Vitis vinifera ssp. silvestris in Europe

Abstract: This paper summarizes the occurrence of the European wild vine - Vitis vinifera L. ssp. silvestris (Gmelin) Hegi - from bibliography and observations made in the framework of research on its ecology in the alluvial and colluvial forests of Europe. The state of the wild vine is disquieting within most of the European countries; in some countries we noticed a lack of recent reliable data. The subspecies silvestris can principally be distinguished from cultivated grapevine by its dioicity. Morphological vegetative criteria are very variable; in particular, we demonstrate that sexual dimorphism occurs in Austrian populations, while it is not found in those of the Basque countries.

Réflexions sur les relations sol-végétation : trois exemples du Jura sur matériel allochtone

Abstract: Study of spatial and temporal relations between soil and vegetation requires explicit identification of organization level of phyto-ecological systems. Three phytocoenoses, developed on soils formed by loess deposit over limestone bedrock, illustrate different relations, vertical and horizontal, between the elements of these systems. Finally, the problem of the choice of an adequate temporal scale for the perception of vegetation and soil dynamics is assessed. Vegetation organization is the mirror of the soil organization, on either side of the level zero, represented by the litter, at the interface between soil and vegetation. Thus a symetrical process can be recognized but with a time scale with an order of magnitude 10 for the vegetation evolution.