Vanilla plants could have a future that’s not so sweet.
Wild relatives of the vanilla plant — which could be essential if the original cash crop disappears — may someday live in different places than their usual pollinators, according to two climate change predictions. The result could be a major mismatch, with habitat overlap between one vanilla species and its pollinator decreasing by up to 90 percent, researchers report July 3 in Frontiers in Plant Science.
Climate change–produced alterations in rainfall and temperature can shift plant habitats. But more than 87 percent of flowering plants also need a pollinator to thrive. Those pollinators may also have to move. And in some cases, the plant and its erstwhile pollinator could fail to move together.
That has Charlotte Watteyn, an ecologist at KU Leuven in Belgium and the University of Costa Rica, worried about vanilla (Vanilla planifolia), a cultivated orchid, and its wild relatives in Central America.
“Vanilla, and orchids in general, are known for their specialized relationships with pollinators,” Watteyn says. Wild species are pollinated by bees, but cultivated vanilla is a delicate princess, hand-pollinated and at constant risk from disease and climate change. Wild relatives could provide genes to help it survive and thrive.
Watteyn and her colleagues used computer simulations to examine how habitats for 11 vanilla species and their bees might change by 2050 under two environmental scenarios. One was middle-of-the-road, assuming that countries work together to reduce climate change impacts. Another was more pessimistic, presuming more global conflict and less action.
In both scenarios, four of the species’ habitats were expected to shrink, while seven of the species saw expanded habitat possibilities. But no matter the direction of the change, the pollinators did not follow behind. All ended up with less habitat, and in every case, the overlap in area between a vanilla species and its bees shrank.
For one wild vanilla, V. trigonocarpa, the predictions showed a 90 percent decrease in the expected overlap between the flower and its bees. Some species might be able to recruit a new pollinator, but others could be out of luck. The results suggest that habitat conservation and fighting climate change will be important to protect a flavorful future.