Issues affecting British honey bee biodiversity and the need for conservation of this important ecological component

Abstract

INTRODUCTION Bees are the dominant and most specialised pollinators of the world’s quarter million angiosperms (Buchmann and Ascher, 2005). Both generalist and specialist bees harvest vast amounts of pollen for their brood, moving grains from flower to flower, thus, greatly effecting pollination (Buchmann and Nabhan, 1997). Although, it is the wind-pollinated grain and cereal crops that keep the worlds six billion humans from starvation, healthy human diets would lack the tasty and nutritious fruits, seeds, vegetables and some nuts if it were not for bee pollination (Buchmann and Nabhan, 1997). Fruits and seeds also provide many by products (fibres, oils, beverages, botanicals and medicines) that humans need, while also feeding many of the world’s mammals, birds and some reptiles. Pollination by bees is obvious (Free, 1964), but ecologists, economists and others often forget the important ecological role played by bees. Within the United Kingdom (UK) recent estimates suggest that for both horticultural and agricultural crops grown commercially that benefit from bee pollination are in the region of £200 million per annum (Carreck and Williams, 1998; Temple et al., 2001; Wilkins et al., 2007). Many important UK horticultural crops, such as apples, may cease to be economically viable if it were not for honey bee pollination (Cuthbertson and Brown, 2006a). The overall value of bees, in general, to wild plant pollination is without doubt substantial, but impossible to evaluate in economic terms because the pollination requirements of most of the nearly 1800 species of wild plant in the British Isles are unknown. The millennium ecosystem assessment project estimates the global annual monetary value of pollination to be in the order of many hundreds of billions of dollars (M. E. A. 2005). Natural and anthropogenic threats to bees are not unique, as these include familiar causes of biodiversity losses in other animals and plants. Fragmentation of landscapes into habitat islands, conversion of wildlands for human uses (agriculture, housing, roadways, mining, etc.) impact bee populations by eliminating nesting sites and decreasing floral resources and nesting materials. Since most of the worlds bees are ground nesting, urbanization covers over prime bee habitat. Some species can survive, even prosper in human-altered landscapes, but housing developments eliminate many bee species due to loss of their nest sites and floral hosts. The production of roadways pose hidden threats as killing lanes, probably killing many bees and other pollinators annually. However, run-off from roadsides, often rich in nitrates, can result in profuse bloom of many flowers visited by bees.