A widespread loss of pollinators in recent decades has been revealed by the first national survey in Britain, which scientists say “highlights a fundamental decline” in nature.
The analysis of 353 species of wild bees and hoverflies found that the insects had been lost from a quarter of the places they found in 1980. A third of the species now live in smaller ranges, with one t in 10 were expanding their size, and the average number decreased by 11 in the species found in square kilometers.
A small group of 22 bee species known to be important in pollinating crops such as oilseed oil violence saw an increase in range, possibly due to farmers increasingly planting wild flowers around fields. However, the scientists found that there was a “serious” decline in other bee species from 2007, coinciding with the introduction of a widely used neonicotinoid insecticide, which has since been banned.
Researchers have become increasingly concerned about dramatic leaks in insect populations, which are the basis of much nature. Some warned in February that these falls threatened “the catastrophic collapse of nature ecosystems”, while studies of Germany and Puerto Rico have shown numbers in the last 25 to 35 years.
The study, published in the journal Nature Communications, is based on more than 700,000 festivals made by volunteers across the UK from 1980 to 2013. These are used to map the range of all species of bees and hoverflies over time. The data did not allow assessment of the number of insects, but some researchers believe that populations have fallen faster than range.
Pollinators are vital to people's food safety, as three quarters of crops rely on them. They are also essential for other wildlife, such as food and as wild plant pollinators. “The decline in Britain can be seen as a warning about the health of our countryside,” said Gary Powney at the Center for Ecology and Hydrology at Wallingford, which led the research.
He called for more volunteers to take part in the UK Pollinator Monitoring Scheme: “Their contribution is vital for us to understand what is happening in our landscape.” Another recent study has found that allotments, weed corners and gardens can be found. Fancy be urban havens for bees.
It's probably the biggest factor in the decline in pollinators is the destruction of wild habitats and the use of pesticides because farming has intensified. But the analysis also revealed a very large reduction of 55% in the range of upland bees and hoverflies, and significant falls in northern Britain, which could lead to climate change making conditions too warm.
Among the bees whose range has shrunk is the red cardi bee, which fell by 42%, and the big bees, and its range fell by 53%. But once rare corrugated bees have expanded its range five times and is now considered an important crop pollinator in England.
Powney said that the growing range of crops pollinating bees is good news and more oilseed rape may be grown, as well as wildflower edges being planted. But he also warned: “They are a relatively small group of species. Therefore, with species generally declining, it would be dangerous to rely on this group to support the long-term food safety of our country. If anything happens to them in the future there will be fewer other species to step up. ”
Professor Dave Goulson, at Sussex University, said and was not part of the latest research: t “Previous studies have described a decline in butterflies, moths, carabid beetles, bees and hoverflies in the UK – this new study confirms that insect declines are continuing. ”
If the loss of upland and northern species is due to climate change, “then we can expect a faster decline of these species in the future, as climate change has hardly begun”, he said. Goulson also said that the start of a faster decline in southern bees after 2007 coincided with the first use of neonicotinoid pesticides which have now been banned.
Roy van Grunsven, in the Butterfly Conservation project in the Netherlands, said that the fall in insect numbers was highly likely to be much higher than the fall of their range: “Going from bee-rich flowering meadows to intensive agriculture with a few individuals in the roadside does not lead to a change in distribution, but of course there is a big change [numbers]. ”
Matt Shardlow, of the conservation charity Buglife, said unless the pesticide approval process had been improved to help bee safety and green subsidies were being targeted to create corridors linking wild places, t we can expect the decline to continue or worsen.