Strandberg, B., Axelsen, J. A., Kryger, P., Enkegaard, A. 2011: Bestøvning og biodiversitet. Danmarks Miljøundersøgelser, Aarhus Universitet. 86 sider – Faglig rapport fra DMU nr. 831, http://www.dmu.dk/Pub/FR831.pdf.
The interplay between pollinators and plants is a classic example of a mutualistic relationship where both parties benefit from interaction. Plant produced pollen and nectar is the main source of food for pollinating insects, and when the insect visits the plant its pollen is spread to other plants, and thereby pollination is secured.
Among the approximately 1500 plant species occurring in Denmark, almost 80% are animal-pollinated and insect pollination is by far the most common. This means that the plants are fully or partially dependent on the presence of pollinating insects. Several insect groups are involved in pollination and bees are considered by far the most important, however, butterflies, flies - especially hoverflies – wasps, and moths also participate. Besides honey bee, the Danish bee fauna consists of about 275 species of wild bees which encompass 29 species of bumblebees and about 275 species of solitary bees. In the present report, emphasis is on bees, bumblebees in particular, since it is by far the most well-studied group.
Pollination is a very important ecosystem service and maintenance of pollination is essential for the diversity of both plants and insects. However, in recent decades a sharp decline of pollinating insects, both regionally, nationally and globally have been reported. Few studies have documented a similar decline in insect-pollinated plants. Therefore, concerted efforts are needed to halt this trend and secure diversity of insects as well as pollination of wild plants and crops.
This report documents the research on wild pollinators, their food plants and pollination. Despite many years’ research we do not know the pollination requirements for the vast majority of wild plants, and it is currently not possible to predict which species are most threatened by the decline of pollinators.
