The quintessential ice cream flavour is under threat, and many other dessert staples along with it, according to climate change researchers at the University of Costa Rica and Belgium's KU Leuven university.
Increasing climate extremes are changing the habitats of wild vanilla species — primarily found in the tropical regions of Central America — and their mainly animal pollinators, the researchers say. This, in turn, is putting global production of vanilla at risk.
In some regions, the plants may find more favourable conditions, but the insects that pollinate them may no longer find suitable habitats, according to the study published in the journal Frontiers in Plant Science in July.
These changes could lead to a reduced overlap between the habitats of pollinators and plants, resulting in less pollination.
"Conserving the natural populations of wild vanilla species, and the huge genetic diversity they hold, is crucial to ensure the future of vanilla, a key tropical crop for the global food industry," says KU Leuven's Professor Bart Muys, a senior author of the study.
The researchers used modelling to analyse the distribution areas of 11 neotropical vanilla species and seven observed bee species under two climate scenarios up to 2050: one moderate scenario with climate protection measures, and another with more conflicts and less global climate protection.
While some species could expand their potential habitats due to global warming, others face a decline of more than half. For all bee genera, the models predict a reduction in suitable habitats, with particularly severe consequences under the less climate-protective scenario.
Vanilla inodora, for example, grows only in cloud forests and low-lying regions with heavy rainfall, while other species thrive only in hot regions with long dry periods and could therefore benefit.
A decoupling of plants from their pollinators could threaten the survival of wild vanilla species, lead author Charlotte Watteyn warns.
A particularly problematic factor is that the species are often dependent on only a few or even individual pollinators, leaving little scope for alternative relationships. For species reliant on a single bee genus, the overlap of habitats could shrink by as much as 60 to 90%.
Wild vanilla plants are also important for agriculture. Commercially used vanilla (Vanilla planifolia) has low genetic diversity, making it particularly vulnerable to diseases, drought and heat — factors that already make it a victim of global warming.
For vanilla ice cream, pudding and other desserts, global warming could have a similar impact as it already does on many other foods. Poor harvests of coffee, chocolate and olive oil, for example, have repeatedly caused shortages and higher prices.
The authors noted a limitation of their study: comprehensive information on pollination mechanisms was not available for all the species examined.
The team called for increased international collaboration and further research, aiming to enhance the resilience of vanilla cultivation and thus secure the livelihoods of many small-scale farmers in tropical regions.
Vanilla pompona and a bee of the genus Eulaema cingulata: A team from the Belgian University of Leuven and the University of Costa Rica reports in the journal Frontiers in Plant Science that increasing climate extremes are changing the habitats of wild vanilla species. Charlotte Watteyn/Eurekalert/dpa
