Key causes of wildlife decline in the South West
Climate change Many species have very specific requirements and a change in temperature or rainfall in either direction can have significant impacts on populations. Some species though are thriving in our changing climate; however many of these are non-native and are threatening the region’s natural fauna and flora.
Fragmentation The loss of habitats and isolation of the remainder into smaller and smaller ghettos, preventing less mobile species such as insects, reptiles and plants from moving through the countryside. This stops different populations from mixing and has two major impacts; firstly without nearby sites to replenish numbers, species are at risk from extinction if there are sudden changes eg a lack of grazing or a natural catastrophe like fire or flood, secondly this lack of mixing can also lead to inbreeding and genetic weaknesses with many species recorded as producing fewer seeds or offspring.
Changes in farming Traditional mixed farming has all but disappeared in the West Country. This small scale sustainable type of farming suited a wide range of species. With the push to increase food production and the squeeze on farm income, more emphasis was placed on productive areas. This had two effects. In these productive areas farming became more intensive, squeezing out hedgerows, flower meadows and the like and all they provided. Conversely, in more marginal areas, particularly where livestock was kept, land has been abandoned or under-grazed, leaving little space for those species that had come to rely on open grazed land.
Development Pressure on our countryside comes from physical development and increased disturbance. There are countless examples of woods, meadows and hedgerows being lost under concrete and tarmac but even our most valuable sites are under continued threat, with roads, housing and other pressures closing the noose around islands of wildlife rich habitats.
Non-native species There are nearly 2000 non-native species that are considered established in the UK, 15% of these are considered to have a negative impact and are estimated to cost the UK economy £1.7 billion each year. These species impact on native species in many ways with species such as Japanese knotweed, winter heliotrope and rhododendron covering large areas of land preventing native plants from growing, whilst aquatic plants such as parrot’s-feather and Australian swampstonecrop clog our waterways and shade out fish and other wildlife. Others such as the harlequin ladybird and American mink prey on native species and another group, including signal crayfish and grey squirrel, not only compete for habitat but carry diseases fatal to their native relatives.
Diseases Several of the species in the report are dependent on the great English elm and the loss of 40 million trees from the countryside because of Dutch elm disease had an irreparable effect, yet we could soon be suffering those losses once again with the region’s ash and oak trees both facing new disease threats. Amphibians also face an uncertain future with two virulent infections increasing in the UK.
Nitrogen This is a natural element that is essential to plant growth, but nature does not provide enough nitrogen to grow our food so chemical fertiliser is added in vast quantities to ensure we don’t go hungry- almost half of the nitrogen found in our bodies started out in a factory. However not all this nitrogen goes into the crops, it leaches through the soil contaminating drinking water and causing algal blooms suffocating wildlife in lakes and estuaries. It also escapes into the atmosphere exacerbating climate change or adding unwanted nutrients to rainfall, fertilising previously untouched meadows leading to an increase in grasses at the expense of flowering plants and damaging our internationally important lichen flora. NB agriculture is not the only source for nitrogen, cars and power stations also play their part.
The loss of traditional skills The Southwest’s farms and woods were managed by hand and horse for centuries. This led to a great tradition of haymaking, hedgelaying, coppicing and charcoal production to name just a few all of which are now dying arts. These rural skills not only maintained family farms they fuelled local economies, all the while creating and managing the very habitats our wildlife required to thrive. Without this management fields and woods have become poorer as species were unable to adapt to the speed of change or the cessation of management.
Afforestation - Tree cover has doubled in the UK since the Second World War. However, much of this consists of conifer plantations of limited benefit to wildlife. In many cases these plantations were planted on valuable wildlife habitats such as heathland, Culm grassland and moorland.
Find out more about the report