Quelles pratiques agricoles pour préserver les peuplements riches en espèces messicoles ?

A consequence of the agricultureal intensification of the second part of the XXth century is the depletion of some species linked to arable fields. These species called “segetal” are considered since 2012 under a National Action Plant (PNA). A survey has been conducted to explore the relationships between these segetal weeds and agricultural practices. It involved 159 farm plots for two years in three regions having contrasted climates, soils and farming systems. Data of species richness are presented in relation to agricultural practices. They cannot allow hierarchical ranking of the most favourable practices, whatever the region, but rather the presence of segetal weeds is associated with…