The high nature conservation value of these meadows stems from their species richness. In exceptional circumstances they can support up to 40 species of plant per square metre! The high floral diversity in turn leads to a high diversity of invertebrates and birds that are dependant upon them. The presence of rare plants such as the snake’s head fritillary (now found on only a handful of sites in the UK) adds further to their value. Therefore they form the basis of a rich food web and a complex ecological system that is very hard to replace. Their floodplain location and sensitivity to nutrient and water level changes in the wider catchment now makes them important early indicators of environmental change.
Many sites are ancient grasslands and have not been ploughed for many hundreds of years. Looking at historical records can tell us that the earliest record for hay making on Pixey Mead, near Oxford, dates as far back as 1142! Looking at the plants can tell us similar information. For example, sites in central and northern England with populations of wood anemone (Anemone nemorosa) may be many centuries old as this plant is unlikely to have survived any arable cultivations, due to its poor dispersal powers.
Meadows are a product of the rural agricultural system from which they evolved, so local people were both dependant on the hay they produced, and essential in shaping the wildlife value of meadows. Village folklore, songs and rhymes have arisen out of the importance of meadows in the local community (Littleboy blue, come blow your horn, the cow’s in the meadow, the sheep’s in the corn for example). Those that remain today are small reminders of the rural heritage we all share, and the impact of that heritage on wildlife.
A number of threatened and rare plants also occur in floodplain meadows. Most well known is the snakeshead fritillary (Fritillaria meleagris), a beautiful species found on a handful of meadows in Southern England and the Midlands.Looking at the pre-1950 distribution of fritillary compared to that of 1999 reveals a 38% decrease in the number of 10 km squares in which the species was recorded between those two dates. The Floodplain Meadows Partnership has been recording the change in the population of snake’s head fritillary at North Meadow, Cricklade for over 15 years. This count takes place at the time of peak flowering in mid April every year by a team of volunteers. See here for more information.
As with other lowland semi-natural grasslands of wildlife interest, species-rich floodplain meadow has sustained large but unquantifiable losses over the last 50 years, primarily as a result of agricultural intensification. More recently gravel extraction, urban and industrial development, water abstraction and lack of management have added to the pressures and losses.
Of all lowland grassland types of conservation importance, meadows have historically been most vulnerable to agricultural improvement. This is because they are typically located on flat ground which can be easily drained and ploughed, and they have naturally high levels of soil fertility because of their long history of flooding, with sediment and nutrient deposition.
Built development has caused the loss of meadows directly in the past. It can also bring unexpected indirect impacts. In some cases, it can change the local water table to an extent that it impacts on sensitive meadow communities; in other cases the development of large numbers of houses so close to meadows, can bring damaging activities such as vandalism, burning, tipping and driving.
A lack of management is probably now one of the greatest threats facing meadows, with poorly maintained ditches, failure to take an annual hay cut and a lack of grazing animals often contributing to an overall decline of species richness on a site.
The recent increase in very wet summers has led to a number of management problems including the inability to take a hay cut as the ground is too wet for machinery, and the increase in the number of dominating invasive species such as some of the larger sedges. These problems, if not managed, may well lead to a decline in the quality of meadows across the country.