The bee map shows the global distribution and can help conservation efforts

Conservationists have drawn up the world’s first bee diversity map to help trace the distribution of viable pollinator populations.

There are about 20,000 individual bee species currently living on Earth, but accurate and compiled data on their distribution was lacking.

Researchers from China, Singapore and the United States analyzed and validated nearly 6 million different data sources to map the ranges of different bee species.

Their findings reveal that there are more insect species in the Northern Hemisphere than in the South, and more in arid and temperate environments.

Creating the map is an important first step in assessing the distribution and potential decline of bee populations, the team said.

“People think of bees only as honey bees, bumblebees and perhaps a few others,” said article author and biologist John Ascher of the National University of Singapore.

“But there are more species of bees than birds and mammals combined.”

“The United States has by far the most bee species, but there are also large areas of the African continent and the Middle East that exhibit high levels of unknown diversity, more so than in tropical areas,” he added.

Professor Ascher and colleagues crossed a checklist of over 20,000 bee species with nearly 6 million records on the presence of individual species, which allowed them to get a clearer picture of the population distribution.

‘We are extremely interested in the abundance of bees, but it is something that has to be done in relation to a baseline,’ explained Professor Ascher.

‘We are trying to establish that baseline. We can’t really interpret abundance until we understand species richness and geographic patterns. ‘

One such pattern revealed in the map reveals that multiple bee species are concentrated both far from the poles and from the equator, in what experts call a bimodal latitudinal gradient.

This is somewhat unusual, with most plants and animals following a so-called latitudinal gradient in which species diversity increases towards the tropics and decreases towards the poles.

There are far fewer bee species in forests and jungles than in arid environments, for example, as trees tend to offer fewer compatible food sources than low-lying plants and flowers.

“When it rains in the desert, there are these unpredictable mass blooms that can literally carpet the entire area,” said article author and zoologist Michael Orr of the Chinese Academy of Sciences.

“There is a much higher turnover in the desert due to how uneven the resources are year after year. So there is a lot of potential for new species there. ‘

Some of the models identified by the team had been hypothesized by researchers in the past, but previously it had been impossible to prove them due to the frequent fragmentation, unavailability or unreliability of relevant data sources.

“I was surprised at how terrible most of the previous global data on bee diversity was,” said article author and conservation biologist Alice Hughes of Xishuangbanna Tropical Botanical Garden.

“A lot of the data was simply too fragmented – or too focused on a limited number of countries that prioritized data sharing – to be able to use these resources for any large-scale analysis,” he explained.

The team said they hope their work will help preserve bees around the world, an important goal given their key role as plant pollinators.

‘Many crops, especially in developing countries, depend on native bee species, not honey bees,’ added Professor Hughes.

“There is hardly enough data out there about them and providing a reasonable basis and analyzing it sensibly is essential if we are to maintain both the biodiversity and the services these species provide in the future.”

The full results of the study were published in the journal Current Biology.