Wednesday, July 02, 2025

Climate crisis could force wild vanilla plants and pollinating insects apart, threatening global supply

Researchers find that a reduced overlap of suitable habitats for vanilla plants and the insects that pollinate them could threaten the survival of wild vanilla

Frontiers

Vanilla pompona flower — image:
*Vanilla pompona* flower with one of its pollinators *Eulaema cingulata*. Credit: Charlotte Watteyn.
view more
Credit: Charlotte Watteyn

Vanilla flavoring is widely used in food, pharmaceutics, and cosmetics. The primary source, Vanilla planifolia, however, is vulnerable to diseases, drought, and heat – stressors expected to become more frequent under climate change. Wild Vanilla species offer a genetic reservoir of crop wild relatives ensuring the future of the vanilla crop. Scientists have now examined how climate change could cause mismatches in habitat overlap of wild vanilla and their pollinating insects.

“Climate change may lead to a reduced habitat overlap between Vanilla orchid species and their pollinators, resulting in plant-pollinator decoupling that negatively affects the survival of wild vanilla populations,” said Dr Charlotte Watteyn, a researcher at KU Leuven and Lankester Botanical Garden Research Center at University of Costa Rica (UVR) and first author of the Frontiers in Plant Science study.

“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,” added senior author Prof Bart Muys of KU Leuven.

Mismatched habitats

The team modeled the habitat distribution and overlap of 11 neotropical Vanilla species and seven previously observed pollinators under two climate change scenarios. The ‘middle of the road’ scenario (SSP2.4-5) represents moderate challenges to both climate change mitigation and adaptation, and follows a pathway of balanced energy development, while the ‘rocky road’ scenario (SSP3-7.0) is characterized by many challenges, relies heavily on fossil fuels, and there is less global cooperation to mitigate climate change.

They found that for seven Vanilla species, climate conditions could become more favorable by 2050 in both scenarios. These species could expand their habitats by up to 140%, while the area with suitable habitat for the other four species was predicted to shrink by up to 53%.

For pollinators, the future on a warming planet could be more dire. Habitat suitability of all pollinators was found likely to decline, with a slightly higher negative change under the SSP3-7.0 scenario. “Despite the possible increase in suitable habitat for some Vanilla species, their pollinator-dependency may imperil the survival of natural populations,” Watteyn explained.

It is unclear if other pollinators can take the place of those that might disappear from wild vanilla habitats. “Vanilla species are known for their specialized relationships with pollinators, hence, they may experience difficulties in replacing pollinators” Watteyn said. “The future may look brighter for species that are not reliant on a single vector for pollination.” Most species, however, usually depend on just one or a few certain pollinators.

Robust crops needed

Maintaining wild vanilla plants is not only important for biodiversity but also for agriculture. The commercially used crop species is characterized by low genetic diversity which can affect product yield, quality, and stability negatively, but agricultural resilience could be enhanced by diversifying crops. “Wild Vanilla species have potential to mitigate these problems as they continue to co-evolve in the wild, developing traits of interest for crop improvement, for example drought and heat tolerance and pathogen resistance,” explained Muys.

Many Vanilla species are already threatened, and natural pollination rarely occurs. Forest fragmentation, habitat loss, and extreme temperatures exacerbate an already dire scenario for the survival of the ‘queen of all flavors’. “Collaborative research on the ecology and genetic diversity of wild vanilla across its natural distribution is paramount if we want to take vanilla breeding into the future, by ethically and sustainably using the local variation to answer global needs,” said co-author Prof Adam Karremans, the director of Lankester Botanical Garden Research Center at UCR.

The results, the authors cautioned, should be interpreted carefully as occurrence records for wild Vanilla species and pollinators are sparse. Habitat overlaps could shift when ecological interactions like seed dispersion and interactions with microorganisms, or disturbances like habitat conversion and illegal extraction are also included in the models.

“Like cacao and coffee, vanilla is a global export crop with high international market value. It’s grown to make profit, and is a key driver for rural development, agricultural innovation, and overall welfare,” Watteyn concluded. “Cultivation benefits smallholder farming communities across the tropics, so there is an urgent need to enhance the resilience of vanilla farming systems.”

Vanilla hartii flower. Credit: Charlotte Watteyn.

Vanilla trigonocarpa flower. Credit: Charlotte Watteyn

All vanilla species pictured were included in the study. Credit: Charlotte Watteyn.

Journal

Frontiers in Plant Science

DOI

10.3389/fpls.2025.1585540

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Wild Vanilla and pollinators at risk of spatial mismatch in a changing climate

Article Publication Date

3-Jul-2025

Diver-operated microscope brings hidden coral biology into focus

Scripps Oceanography scientists develop cutting-edge microscope to study coral photosynthesis and health

University of California - San Diego

Microscope image of the coral Stylophora pistillata — image:
An image of the coral *Stylophora pistillata* taken with the new micrsope, BUMP. Each polyp has a mouth and a set of tentacles, and the red dots are individual microalgae residing inside the coral tissue.
view more
Credit: Or Ben-Zvi

The intricate, hidden processes that sustain coral life are being revealed through a new microscope developed by scientists at UC San Diego’s Scripps Institution of Oceanography.

The diver-operated microscope — called the Benthic Underwater Microscope imaging PAM, or BUMP — incorporates pulse amplitude modulated (PAM) light techniques to offer an unprecedented look at coral photosynthesis on micro-scales.

In a new study, researchers describe how the BUMP imaging system makes it possible to study the health and physiology of coral reefs in their natural habitat, advancing longstanding efforts to uncover precisely why corals bleach.

Engineers and marine researchers in the Jaffe Lab for Underwater Imaging at Scripps Oceanography designed and built the cutting-edge microscope with funding from the U.S. National Science Foundation. The microscope is already yielding new insights into the relationship between corals and the symbiotic microalgae that support their health, revealing for the first time how well individual algae photosynthesize within coral tissue.

Their findings were published July 3 in the journal Methods in Ecology and Evolution.

“This microscope is a huge technological leap in the field of coral health assessment,” said Or Ben-Zvi, a postdoctoral researcher at Scripps Oceanography and lead author of the study. “Coral reefs are rapidly declining, losing their photosynthetic symbiotic algae in the process known as coral bleaching. We now have a tool that allows us to examine these microalgae within the coral tissue, non-invasively and in their natural environment.”

Corals are reef-building animals that can’t photosynthesize on their own. Instead, they rely on microalgae living inside their tissues to do it for them. These symbiotic algae use sunlight, carbon dioxide and water to produce oxygen and energy-rich sugars that support coral growth and reef formation.

At just 10 micrometers across, or about one-tenth the width of a human hair, these algae are far too small to be seen with the naked eye. When corals are stressed by warming waters or poor environmental conditions, they lose these microalgae, leading to a pale appearance (“coral bleaching”) and eventual starvation of the coral. Although this process is known, scientists don’t fully understand why, and it hasn’t been possible to study at appropriate scales in the field — until now.

“The microscope facilitates previously unavailable, underwater observations of coral health, a breakthrough made possible thanks to the National Science Foundation and its critical investment in technology development,” said Jules Jaffe, a research oceanographer at Scripps and co-author of the study. “Without continued federal funding, scientific research is jeopardized. In this case, NSF funding allowed us to fabricate a device so we can solve the physiological mystery of why corals bleach, and ultimately, use these insights to inform remediation efforts.”

The new imaging system builds upon previous technology developed by the Jaffe Lab, notably the Benthic Underwater Microscope, or BUM, from 2016. The main component of the BUMP is a microscope unit that is controlled via a touch screen and powered by a battery pack. Through an array of high-magnification lenses and focused LED lights, the microscope captures vivid color and fluorescence images and videos, and it now has the ability to measure photosynthesis and map it in higher resolution via focal scans.

With this tool, scientists are literally shining a light on biological processes underwater, using PAM light measurement techniques to visualize fluorescence and measure photosynthesis, and using imaging to create high-resolution 3D scans of corals.

When viewing the corals under the microscope, the red fluorescence of corals is attributed to the presence of chlorophyll, a photosynthetic pigment in the microalgae. With the PAM technique, the red fluorescence is measured, providing an index of how efficiently the microalgae are using light to produce sugars. The cyan/green fluorescence, concentrated around specific areas such as the mouth and tentacles of the coral, is attributed to special fluorescent proteins produced by the corals themselves and play multiple roles in the coral's life functions.

The tool is small enough to fit in a carry-on suitcase and light enough for a diver to transport to the seafloor without requiring ship-based assistance. In collaboration with the Smith Lab at Scripps Oceanography, Ben-Zvi, a marine biologist, tested and calibrated the instrument at several coral reef hot spots around the globe: Hawaii, the Red Sea and Palmyra Atoll.

Peering through the microscope, she was surprised by how active the corals were, noting that they changed their volume and shape constantly. Coral behavior that looks like kissing or fighting has been previously documented by the Jaffe Lab, and Ben-Zvi was able to add some new observations to the mix, such as seeing a coral polyp seemingly trying to capture or remove a particle that was passing by, by rapidly contracting its tentacles.

“The more time we spend with this microscope, the more we hope to learn about corals and why they do what they do under certain conditions,” said Ben-Zvi. “We are visualizing photosynthesis, something that was previously unseen at the scales we are examining, and that feels like magic.”

Because scientists can bring the instrument directly into underwater study sites, their work is non-invasive — they don’t need to collect samples or even touch the corals.

“We get a lot of information about their health without the need to interrupt nature,” said Ben-Zvi. “It's similar to a nurse who takes your pulse and tells you how well you're doing. We're checking the coral's pulse without giving them a shot or doing an intrusive procedure on them.”

The researchers said that data collected with the new microscope can reveal early warning signs that appear before corals experience irreversible damage from global climate change events, such as marine heat waves. These insights could help guide mitigation strategies to better protect corals.

Beyond corals, the tool has widespread potential for studying other small-scale marine organisms that photosynthesize, such as baby kelp. Several researchers at Scripps Oceanography are already using the BUMP imaging system to study the early life stages of the elusive giant kelp off California.

“Since photosynthesis in the ocean is important for life on earth, a host of other applications are imaginable with this tool, including right here off the coast of San Diego,” said Jaffe.

In addition to Ben-Zvi and Jaffe, this study was co-authored by Paul Roberts — formerly with Scripps Oceanography and now at the Monterey Bay Aquarium Research Institute — along with Dimitri Deheyn, Pichaya Lertvilai, Devin Ratelle, Jennifer Smith, Joseph Snyder and Daniel Wangpraseurt of Scripps Oceanography.

A field deployment of the BUMP in the Red Sea, where local corals were imaged and measured.

Credit

Or Ben-Zvi