Conservation experts have compiled the first ever global map of bi-diversity to help track the distribution of populations of the vital pollinators.
There are about 20,000 individual species of bees living on Earth – but accurate, aggregate data on their distribution had been lacking.
Researchers from China, Singapore and the United States analyzed and validated nearly 6 million different data sources to map the range of different bee species.
Their findings reveal that there are more species of insects in the northern hemisphere than in the south – and more in arid and temperate environments.
The creation of the map is an important first step in assessing the distribution and potential decline of bipopulations, the team said.
Conservation experts have compiled the first ever global map of bi-diversity to help track the distribution of populations of the vital pollinators. The picture is part of the bee map
‘People think of bees as just honey bees, bumble bees and maybe a few others,’ said paper 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 the vast majority of species of bees, but there are also large areas on the African continent and the Middle East that have high levels of undiscovered diversity more than in tropical areas,’ ‘he added.
Professor Ascher and colleagues cross-referenced a checklist of more than 20,000 bee species with nearly 6 million records of the occurrence of individual species, enabling them to get a clearer picture of population distributions.
‘We are very interested in the abundance of bees, but it is something that needs to be done in relation to a baseline,’ explained Professor Ascher.
“We are trying to establish that baseline. We really cannot interpret abundance until we understand species richness and geographical patterns. ‘
Such a pattern revealed on the map reveals how several bi-species are concentrated both away from the poles as well as the equator – in what experts refer to as a bimodal latitude gradient.
This is something unusual, where most plants and animals follow a so-called latitude gradient, where species diversity increases towards the tropics and falls 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 flowers that can literally carpet the entire area,’ said paper 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. ‘
There are approximately 20,000 individual species of bees (including Amegilla andrewsi, pictured) currently living on Earth – but accurate, aggregate data on their distribution were lacking
Some of the patterns the team identified had previously been assumed by researchers – but it had previously been impossible to prove given the frequent unevenness, unavailability or unreliability of relevant data sources.
‘I was amazed at how awful most of the previous global data really was about bi-diversity,’ said paper author and conservation biologist Alice Hughes of Xishuangbanna Tropical Botanical Garden.
‘Many of the data were just too uneven – or too concentrated on a small number of countries that have prioritized data sharing – to be able to use these resources for any large-scale analysis,’ she explained.
Experts from China, Singapore and the United States analyzed and validated nearly 6 million different data sources to map the range of different bee species. The picture map of America
The team said they hoped their work would help conserve bees around the world – an important goal given their key role as plant pollinators.
‘Many crops, especially in developing countries, rely on native bees, not honey bees,’ added Professor Hughes.
‘There is not nearly enough data out there about them – and it is important to provide a sensible baseline and analyze it in a sensible way if we are to preserve both biodiversity and also the services these species provide in the future.’
The full findings of the study were published in the journal Current Biology.
The creation of the map is an important first step in assessing the distribution and potential decline of bipopulations, the team said. The picture is a bee from Amegilla insularis
Decreases in recent months to the number of honey bees and health have caused global concern due to the critical role of insects as a major pollinator.
Bee health has been closely monitored in recent years as nutritional sources available for honeybees have declined and pollution from pesticides has increased.
In animal model studies, the researchers found that combined exposure to pesticides and poor nutrition reduced the bees’ health.
Bees use sugar to burn airplanes and work inside the nest, but pesticides reduce their hemolymph (‘bee-blood’) sugar content and therefore reduce their energy stores.
When pesticides are combined with limited food supply, the bees lack energy to function, causing the survival rate to plummet.