The global decline of bees, hoverflies and other pollinators poses a serious threat to food security and biodiversity a team of scientists from Wageningen University and Doñana Biological Station have reported in the Ecology Letters.
They say that a further deterioration of conditions for pollinators may lead to the sudden extinction of numerous species as networks of interactions between plants and pollinators break down.
These networks have a characteristic structure that is similar in very different natural landscapes, such as rainforests and river deltas, as well as in human-dominated landscapes with orchards, fields and meadows.
The scientists of Wageningen University show, with the help of mathematical models, that the implications of a further deterioration of conditions for pollinators, is strongly influenced by the way in which interaction networks are put together. Due to the structure of these networks, pollinator species support each other under difficult circumstances. Pollinator species that live in the same area may therefore maintain themselves under more difficult conditions.
Pollinator species are, however, also highly dependent on each other when circumstances are harsh. The pollinator community, consisting of bees, butterflies, hoverflies and many other species, may therefore collapse entirely when increasingly harsh conditions pass a critical point and recovery after conditions have passed such a tipping point might not be easy.
J. Jelle Lever, Egbert H. van Nes, Marten Scheffer, and Jordi Bascompte, 2014. The sudden collapse of pollinator communities. Ecology Letters, online 3 January 2014.