AA #2: The Green Green Grass
The cache, a camo-taped 35mm film canister, is hidden near a corner of the field a short distance off the main trail, which in this part of the amble descends through extensive grassland towards the River Wharfe.
Flower-rich grasslands, once a part of every farm, are part of our culture. Most have developed alongside humans because of livestock grazing and cutting for hay. Many have archaeological and historical features.
Grassland is either upland (>300m) and lowland because the cooler, wetter climate of upland areas favours different species to the warmer, drier and less exposed lowlands. Both may are also classified as: Calcareous - found on shallow lime-rich soils, Acidic - found on sands, gravels and siliceous rocks or Neutral - found on clay and loam soils.
In this location on the gentle northern slopes of the Wharfe valley, the glacial deposits of the valley floor have formed high quality Grade 2 and 3a soils which produce better quality grazing pastures than further up the valley sides (such as that above the upper parts of the Amble) where thinner more acidic soils produce poorer quality, often marginal, pasture.
Meadows are enclosed grasslands where a hay or silage crop is taken in the summer, while pasture is generally grazed - as in these grasslands.
UK grasslands store 2B tonnes of carbon in their soils, but this is vulnerable to disturbance. Between 1990-2006, conversion from grassland to arable production (such as ploughing to grow crops) released 14M tonnes of CO2. Species-rich grasslands are huge carbon stores and when managed carefully they lock in carbon and boost biodiversity.
Their huge potential for locking up carbon, is due not only to the surface plants, but also the relationships between the plants, fungi, bacteria and many other species which help enrich the soil with carbon.
Grassland is an ancient habitat. After the last Ice Age c.12,000 years ago, mossy vegetation and weedy plants colonised bare ground which was left after the glaciers covering 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 by woodland to exposed sites on the coast or high in the mountains.
Grasslands also existed in areas where trees were lost over time such as on floodplains or woodland clearings grazed by wild animals. However, it wasn’t until human activities intensified around 6,000 years ago that grassland began to expand. Today around 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 4.5M of grassland, of which only 100,000ha are unimproved.
Degradation began as fertilisers started to be used. During the 1940s and 1950s chemical fertilisers, herbicides and new grass varieties were used to increase yields. At the same time government incentives encouraged farmers to plough up grasslands. During the C20, 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 moorland and blanket bog being converted to less wildlife-rich upland acid grassland and rush pasture.
In some areas, including some parts of this Amble, horse grazing also reduces the quality of pasture grasslands as ragwort and thistle become prominent, and field boundaries change from dry stone walls to smaller post and wire enclosures.
Unimproved, species-rich grassland is still being lost and grassland on protected sites is deteriorating. As a result, the numbers of butterflies and breeding birds, such as curlew and lapwing, continue to decline. Unimproved grassland supports many rare and beautiful species. This includes orchids, snake’s-head fritillary (see image below), waxcap fungi and blue butterflies.
Historically, grasslands have been used in many different ways. The traditions and skills associated with water meadows, shepherding and haymaking are part of our cultural heritage.
Environmental agencies 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 ways fragile grassland habitats can be kept in good condition. They also work closely with farmers and landowners to promote wildlife-friendly practices for managing grassland habitats.
