This map shows the great heterogeneity in the proportion of grasslands in Europe with the areas of high abundance: all the mountain areas, west of the Iberian Peninsula, the British Isles, Romania and Bulgaria as well as the coastal areas of the English Channel and the North Sea.
In most European countries, the permanent grassland surface has declined over the last fifty years, especially in France and Great Britain (Huyghe et al, 2010). The only notable exception is Ireland, having a high stability of this type of grassland.
Surfaces of temporary grasslands and annual forage in various European countries show relatively contrasting developments with countries like Italy and the United Kingdom that are starting to decline or to the contrary starting to increase in surface like the Netherlands.
France manifests a stability that can be linked to the phenomena of compensation between perennial and annual crops.
Accurate analysis of the French situation: We notice a relatively contrasted development of the various grasslands before and after 1990 (Huyghe et al, 2005). It is the case for example with annual fodder, whose surface was increasing up until 1990, then stabilised, with a trend to decrease for the past twenty years. Conversely, temporary grasslands follow an opposite pattern: after a reduction in area until 1990, this kind of grassland has tended to increase since then.
As for artificial grasslands, they show regular decline since the end of 1970s Their situation must be considered over a longer period of time. In France, artificial grasslands occupied a very important place (more than three million hectares) from the 1930s to early 1960s, followed by a steep decline in area over the next fifteen years, then a more moderate decline until today.
To understand the reason for this particular development, it is necessary to focus on the roles of artificial grasslands in agriculture. In fact, these grasslands, primarily composed of lucerne, red clover and sainfoin, ensured, on the one hand, feed for animals, as well as their needed proteins, and on the other hand, the fertility of the land (thanks to the symbiotic fixation of nitrogen).
Before 1960, all artificial grassland was used in the form of hay, a particularly expensive method labour-wise.
The sharp decline recorded after this date is attributed to three factors. 1- The role of legumes as a source of nitrogen fertiliser is less great because mineral nitrogen fertilisers are readily available. 2- The social restructuring that occurs in France (and particularly in the labour world) in the late 1960s rapidly depletes the countryside of its labour force, which is vital to hay production 3- Finally, during this period, new harvesting / conservation methods appear (including silage) to which some plant species such as legumes in pure crops are poorly adapted.
The early 1980s introduced another, much slower period of decline. It is generally related to a phenomenon of substitution of proteins resulting from artificial grasslands with proteins from crops such as soybeans.
[Ajouter les références complètes de (Huyghe et al, 2010) et (Huyghe et al, 2005)]