Grassland is an ancient habitat. Following the last Ice Age around 12,000 years ago, mossy vegetation and weedy plants colonised bare ground. This was left after the glaciers that covered the UK had melted. Gradually they developed into communities of grasses, sedges and herbs as more plants found a home. As birches and other tree species arrived and spread, these grassland habitats were pushed back to exposed sites on the coast or high in the mountains.
Grasslands also existed in areas where trees were periodically lost, such as on floodplains or within woodland clearings opened up by storms and grazed by wild animals. They also developed in areas that changed too frequently for trees to grow, such as sand dunes. However, it wasn’t until human activities intensified around 6,000 years ago that grassland began to expand. Now, some 40% of the UK’s land surface is grassland.
Most of today’s grassland is farmland or rough upland grazing, with only a tiny proportion of ‘unimproved’ grassland remaining. This is grassland that hasn’t been reseeded, fertilised or drained and tends to be full of flowers and wildlife. In England there are around 4.5 million hectares of grassland, of which just 100,000ha are unimproved.
Degradation began in the 19th Century, when guano (droppings from seabird colonies) was used as fertiliser. This was later replaced by artificial alternatives. During the 1940s and 1950s chemical fertilisers, herbicides and new grass varieties were used to increase yields. At the same time government incentives (to help national self-sufficiency) encouraged farmers to plough up grasslands. During the 20th Century, 90% of lowland grasslands were lost.
In the uplands, the story was different, but the decline in grassland was just as dramatic. Here, overgrazing led to the conversion of moorland and blanket bog to less wildlife-rich upland acid grassland and rush pasture.
Unimproved, species-rich grassland is still being lost (although the rate of loss has slowed) and grassland on protected sites is deteriorating. The numbers of butterflies and breeding birds, such as curlew and lapwing, continuing to decline.
How grassland is classified.
Grassland is generally divided into upland (above about 300m) and lowland types. This is because the cooler, wetter climate of upland areas favours different species to the warmer, drier and less exposed lowlands. Both types may also be classified as:
· Calcareous -found on shallow lime-rich soils
· Acidic -found on sands, gravels and siliceous rocks
Meadows are enclosed grasslands where a hay or silage crop is taken in the summer, while pasture is generally grazed.
Unimproved grassland supports many rare and beautiful species. This includes orchids, snake’s-head fritillary, waxcap fungi and blue butterflies. As grassland habitats have changed in response to human management they are an expression of our cultural heritage. Historically, grasslands were used in many different ways. The traditions and skills associated with water meadows, lammas lands (land on which people other than the owner have the right of pasturage during winter), shepherding and haymaking are part of our cultural heritage.
How you can help
You can help to protect and restore precious grassland habitats. Volunteer for your local Wildlife Trust and you could be involved in everything from stockwatching to surveying meadow flowers. You could look after grassland habitats in your garden or local community by creating a mini meadow.
Wildlife Trusts are working to ensure that precious grassland habitats and traditional management techniques are not lost. Careful grazing with traditional breeds and hay-cutting at the right time are some of the ways our fragile grassland habitats are kept in good condition. We are also working closely with farmers and landowners to promote wildlife-friendly practices for managing grassland habitats. Supporting your Wildlife Trust helps to keep these special places safe for future generations.