LOSS OF HABITAT
The main threat to biodiversity, the variety of species alive on earth, is human activity. In the last 50 years with increasing global population and rapid economic growth our demand for natural resources has doubled, and meeting this increasing need for food, fresh water, fuel and other resources places an enormous strain on the natural environment. One of the biggest problems that human activity causes is habitat loss, the physical environment that provides a home to populations of different species. All species have specific food and habitat needs, and the more specific these needs the more vulnerable they are to extinction. The International Union for the Conservation of Nature (IUCN) produce a comprehensive inventory of the global conservation status of plant and animal species and they estimate that the current rate of species extinction is between 1000 and 10,000 times higher than it would naturally be as a result of human activity. This means that we are changing ecosystems faster than at any time in human history.
There are some habitats known as biodiversity hotspots because of the sheer number of different species they host and the vulnerability of these species following significant loss of habitat. Some hotspots, such as Madagascar and its neighbouring islands, are home to plant and animal species that exist nowhere else on Earth such as the critically endangered greater bamboo lemur. Madagascar's biodiversity is threatened by habitat loss to agriculture, logging and mining. Forest habitats globally are home to as much as 90% of plant and land-based animal species, with new species being discovered all the time. These valuable habitats are being lost and fragmented as forest land is cleared for logging, livestock grazing, agriculture and biofuel production. Many other biodiversity-rich habitats are under threat from human activity, including wetlands, coral reefs and mangrove swamps, which are being lost to coastal developments.
IN THE UK
Closer to home, habitat loss has had a big impact on biodiversity in Britain. Nearly 500 known species of animals and plants have become extinct in England as a result of human activity since 1800, with some now globally extinct. Natural England list 943 species at risk of extinction within the next 30 years, including the iconic red squirrel. The intensification of agriculture has been a major cause of biodiversity loss, in particular the ploughing of grasslands and lowland meadows. This has removed vital habitat for rare species of plants and farmland birds as well as insects critical for pollinating crops. Urban and housing developments have also displaced many species. Here in Manchester we need to protect our rare Black Redstart, a small robin-sized bird, which usually lives on the south coast but has ventured ‘up north’. In Manchester it likes rough scrubby ground but its breeding sites have been largely lost to inner city regeneration programmes. MERCi has created a brown roof on Bridge 5 Mill to provide a valuable habitat for the Black Redstart and other city wildlife.
On a global scale, habitat loss is a major threat to biodiversity. We need to protect habitats to preserve biodiversity and the resources of the natural world we depend upon for our survival.