Europe’s wild bee population is in dramatic decline with nearly one in 10 species facing the threat of extinction, according to the first ever assessment of all the continent’s nearly 2,000 bee species.

Another 5.2% of bee species are likely to be threatened in the near future, while more than a quarter of species such as the European bumblebees are at risk of dying out, said the study by the International Union for the Conservation of Nature (IUCN).

Population trends for 79% of the continent’s pollinators – mostly wild honeybees – are still unknown, but over a third of bee populations for which data was collected were shown to be in decline.

“This report should be a wake up call to the ecological disaster that is unfolding in Europe’s countryside,” Ariel Brunner, the head of EU policy at Birdlife told the Guardian. “It’s very clear that something is going horribly wrong with our agricultural practices which are the main driver of these declines, whether it is increased pesticide use, the destruction and conversion of grasslands, or the loss of natural vegetation and intensified farming methods.”

The IUCN paper said that sources of food and forage for pollinators have been hit hard by intensive silage production at the expense of hay-cropping. The widespread use of insecticides and herbicides has also reduced the availability of flowers and promoted rank grassland, which is low in flowering plants and legume species.

Climate change has been another factor in the dip in bee numbers, the report said, because heavy rainfalls, droughts and increased temperatures can alter and reduce habitats that species have adapted to over many generations.

Of 1,965 bee species in Europe, the EU-funded paper found 9.2% were threatened with extinction, 12.6% of species were stable and 0.7% were increasing. But the peer-reviewed research by more than 40 experts was constrained by a lack of verifiable data, and the true number of bees at risk could be higher.

“This assessment is the best understanding we have had so far on wild bees in Europe,” said Jean-Christophe Vié, the deputy director of IUCN’s Global Species Programme. “However, our knowledge about them is incomplete as we are faced with an alarming lack of expertise and resources.”

Bees play an essential role in sustaining ecosystems and pollinating crops and the IUCN is calling for urgent investment into new research on ways of reversing the decline.

The EU’s environment commissioner Karmen Vella described the study’s findings as “very worrying”.

“Our quality of life – and our future – depends on the many services that nature provides for free,” he said. “If we don’t address the reasons behind this decline in wild bees, and act urgently to stop it, we could pay a very heavy price indeed.”

However, Brussels has been criticised for the application of measures to ‘green’ its Common Agricultural Policy, which were intended to make farmland management across all 28 EU states more sustainable.

“It is shocking that just a couple of weeks ago, the commission accepted a French implementation of this ‘greening’ which recognises maize monoculture as green,” Brunner said. “Monoculture is about the most unfriendly thing you can do to biodiversity in general and pollinators in particular. In the name of greening the CAP, we are actively fomenting this crisis with public policies.”

The annual value of global crop pollination by bees has been estimated at €153bn globally and €22bn in Europe.

More than a third of global agricultural volumes come from crops supported by bees, while 84% of crops grown for human consumption require insect pollination to enhance product quality and yields.

Arthur Neslen in Brussels