The plight of the bumblebee

 作者:毋璐蚵     |      日期:2019-03-08 07:15:13
By Rob Edwards CHANGES in farming practices are threatening the survival of the bumblebee in the British countryside, according to a comprehensive study of bumblebees in Britain. “The area of land occupied by several key species has declined by more than 95 per cent over the past three decades,” says Mike Edwards, who coordinated the study. Of Britain’s 16 bumblebee species, one may already be extinct, three are close to extinction and six are threatened. The researchers did not find a single population of Bombus subterraneus, and found only small numbers of three other species. To feed and nest, bumblebees need large areas of flowers throughout the summer. But the meadows that were common earlier this century have been ploughed up for crops or are now grazed by cattle and sheep. The only parts of Britain still ideal for bumblebees are the military training area on Salisbury Plain and grasslands in the Outer Hebrides. The loss of meadows is “the major factor in the modern population crash of these bees”, the researchers argue. Summer grazing deprives them of the pollen they need to survive and “may be the final factor that drives a population to extinction”. The study, by Edwards and 17 other specialists, also found that certain plants, such as red clover (Trifolium pratense) and bird’s-foot trefoil (Lotus corniculatus),