In general, people think that the term bees refers to a specific species, the honey bee ( Apis melifera ). Very often, the messages that scientific publications warn about the risks faced by bees, in a broad sense, are confused, and these conclusions tend to be directed, incorrectly, at the honey bee.
What bees are we really talking about?
In the natural environment there are multiple species of bees. According to the Wild Bees Association, in Spain alone there are more than a thousand species of wild bees, each with their own behaviors, very different from those of the honey bee.
The honey bee is, in fact, an exception to these generalizations. After all, the honey bee is a domestic species, used for livestock, like cows or pigs.
As far as environmental impacts are concerned, studies on wild bees usually exclude the honey bee and vice versa, precisely because of the human factor. The effects of a given disturbance on a species wholly managed by humans can and often are very different from those suffered by wild populations. And when we talk about anthropogenic climate change, it is no exception.
The impact of climate change on wild bees
Wild bees are animals closely linked to climate trends. Temperature and rainfall have a direct and indirect impact on their life cycle and behavior. Directly, by affecting their biological rhythm, and indirectly, by affecting the flowering periods of the plants they feed on.
According to a study carried out by Professor Peter Soroye, from the University of Ottawa (Canada) and collaborators, and published in the prestigious journal Science , an increase in the frequency of high temperature events such as the one we are experiencing will cause local extinctions of species of bees and, above all, bumblebees.
Many of these species are likely to move to other places where the climate is more favourable. These colonization events forced by climate change will bring into contact species that were not previously in contact, causing new competition and altering the species composition of ecosystems.
The consequence of climate change will be a widespread loss of bumblebee species, and the monopolization of resources by the few that are suitable for the new conditions.
On the other hand, some plant species have a deep dependence on certain pollinating species, and cannot be pollinated by others. The loss of diversity of bumblebees will therefore have, as a direct consequence, the loss of diversity of the flora. Ultimately, there may be a cascading effect that ends up affecting the entire ecosystem, and contributing to biodiversity loss much more generally.
The impact of climate change on the honey bee
While the impacts on wild bees are of enormous ecological importance, the harms of climate change on honey bees can have serious socio-economic consequences. The honey bee is not only the only domestic animal capable of producing honey, it is also the most economically valuable crop pollinator in the world.
Fortunately, both because of its biology, as a result of centuries of artificial selection and domestication, and because of technological advances, the honey bee species has a great capacity for adaptation. There are bee farms in almost all the world and in very diverse climates.
In a context of climate change, the honey bee shows high resilience, great plasticity, and sufficient genetic variability to develop new varieties suitable for the new environmental conditions. In addition, it is easy to import populations of bees already adapted to a new climate, from places with those climatic conditions.
However, a possible effect of climate change, especially if it happens very quickly – as it seems to be happening – is that there is a loss of that valuable genetic variability. If climatic conditions change and imports take place, varieties that were adapted to the old climate will be replaced by others more suitable to the new conditions. In this way, those most disadvantaged varieties can be lost, while the most suitable ones are favored.
The reduction of genetic variability makes the species more sensitive to other disturbances, such as diseases, which could cause epidemic events.
References:
Bartomeus, I. et al. 2022. Wild Bee Association . https://www.abejassilvestres.es/.
Conte, Y. L. et al. s. f. Climate change: impact on honey bee populations anddiseases. 13.
Kammerer, M. et al. 2021. Wild bees as winners and losers: Relative impacts of landscape composition, quality, and climate. Global Change Biology, 27(6), 1250-1265. DOI: 10.1111/gcb.15485
Soroye, P. et al. 2020. Climate change contributes to widespread declines among bumble bees across continents. Science, 367(6478), 685-688. DOI: 10.1126/science.aax8591
