The world is facing a pollinator crisis, and the situation is dire. As global CO₂ levels continue to rise, the very survival of pollinators, including bees, flies, wasps, moths, butterflies, and some nectar-loving birds, is at stake. This is particularly concerning for larger bees, which are among our most effective pollinators. These big bees, such as Bombus asiaticus and Xylocopa pubescens, are facing a dire situation as their populations are smaller and less genetically diverse in areas with high CO₂ levels.
The study, conducted in Pakistan, examined how bees and hoverflies coped with different levels of CO₂ across 25 sites. It found that smaller pollinators may actually do better in higher-CO₂ environments, while larger-bodied pollinators were less abundant in areas with more CO₂. This is a cause for concern, as existing evidence shows that larger-bodied bees are already more vulnerable to climate change.
The implications of this research are far-reaching. Larger bees are among our most effective pollinators, carrying and depositing more pollen than smaller-bodied species. They also fly longer distances, helping plants reproduce and spread their genes to new places. This is particularly evident in Australia, where Melastoma plants are most effectively pollinated by large pollinators such as Xylocopa bees.
So, what can we do to protect our larger pollinators? Here are four practical ways:
- Protect their habitat by preventing further land clearing, such as making room for more livestock farms.
- Ensure pollinators have access to wildlife corridors to help them move to areas that are naturally lower in CO₂, such as dense forests.
- Plant more bee-friendly trees, such as Eucalyptus, Corymbia, Angophora, Melaleuca, Banksia, and Brachychiton.
- Maintain populations of larger-bodied bees by reducing other threats such as competition from introduced honey bees, to ensure they have the genetic diversity to adapt to rising CO₂ levels.
In conclusion, the pollinator crisis is a complex issue, and climate change is a key factor. As Australia contributes to higher CO₂ levels as the second-largest fossil fuel exporter in the world, it is crucial to take action to protect our pollinators. By protecting their habitat, ensuring access to wildlife corridors, planting bee-friendly trees, and maintaining populations of larger-bodied bees, we can help our pollinators thrive in a warming world.
