The majority of flowering plants are pollinated by insects and other animals. It has been estimated that the proportion of animal-pollinated wild plant species rises from an average of 78 percent in temperate-zone communities to 94 percent in tropical communities. Taxonomically speaking, pollinators are a diverse group, including more than 20,000 species of bees, many other types of insects such as flies, butterflies, moths, wasps and beetles, and even vertebrates such as some birds and bats. Most pollinators are wild but a few species of bees can be managed, such as honeybees, some bumblebees and a few solitary bees.
Our food production depends heavily upon these pollinators - more than 75 percent of the leading global food crops benefit from pollination. Some of these crops - especially fruits and vegetables - are key sources of human nutrition. High yields in large-scale intensive production of crops such as apples, almonds and oilseeds depend on insect pollination but so do the crops of smallholder farmers in the developing world, where healthy populations of wild pollinators increase yields significantly. Economically, pollination increases the global value of crop production by 235 to 577 billion dollars per year to growers alone and keeps prices down for consumers by ensuring stable supplies.
Changing land use due to agricultural intensification and urban expansion is one of a number of key drivers of pollinator loss, especially when natural areas, that provide foraging and nesting resources, are degraded or disappear. Improving habitat diversity within the landscape, and the inclusion of nonagricultural habitats within land management plans, have been shown to ameliorate pollinator loss, boost pollinator numbers and improve ecosystem services. Landscape-scale initiatives to improve habitat heterogeneity and connectivity have been incorporated in several national and international initiatives which focus on protecting pollinators. The abundance, diversity and health of pollinators is also threatened by a number of other drivers including a changing climate, invasive species and emerging diseases and pathogens; appropriate local, national and global actions are needed to mitigate these threats as well.
