Most of Northern Ireland today is covered by grassy fields, and grass has become the most important crop in the Province. Grass (together with the various herbaceous species growing with the grass species) is either grazed by animals or harvested for storage as hay or silage; either way it is a crop of great economic importance to the modern farming industry.
Traditionally we divided farm grasslands into either meadows, which are mown for hay, or pastures, which are grazed by cattle or sheep. This distinction hardly holds true today. Also, until recent times, farmers relied on the natural local grass and other herbage species to provide the makeup of the vegetation for grazing or mowing. Nowadays, there is an increasing tendency to sow artificial grass mixtures composed of selected varieties of a rather limited number of species. These are known as artificial leys, and the most important element of these is the varieties of perennial rye-grass (Lolium perenne). This policy of replacing semi-natural herbage with artificial leys has unfortunately resulted in both the loss of biodiversity and a decline in the attractiveness of most farm landscapes.
A traditionally managed meadow is rich in species, both of grasses and other species. They are visually attractive as well as being important reservoirs of biodiversity, but unfortunately are now remarkably rare in Northern Ireland.
Mowing or grazing is required to maintain grasslands, otherwise they naturally turn into heath, scrub or woodland over a period of a few decades. It appears, in fact, that most grasslands are not a truly natural vegetation type, but are essentially artificially created and maintained by grazing or mowing, or a combination of both. Grazing and mowing prevent the development of any seedlings of woody scrub or woodland shrubs and trees.
The grasses themselves are a wind-pollinated family of flowering plants known as the Poaceae or Gramineae. Some of the most important species are:
The other herbaceous species found in a traditional meadow include: