A new study reveals how it is possible to protect plants from the hungry maws of herbivorous mammals by fooling them with the smell they naturally avoid.
A significant issue for the ecology and economy is plant loss due to herbivore eating. The majority of approaches to address issue are costly, impractical, or both. Patt Finnerty, a PhD candidate, has created a novel technique that depends on animal preferences.
Researchers from the University of Sydney have shown that plants may be protected from herbivorous animals’ ravenous mouths by tricking them into thinking they are a different kind that they usually avoid.
The study published in The Nature Ecology & Evolution indicates that tree seedlings placed adjacent to a solution that mimics the scent of plants that animals avoid were 20 times less likely to be consumed by animals.
This method essentially creates a scenario where the seedlings are enveloped by real plants that herbivores find unappealing, thereby deceiving the animals and prolonging the time it takes for them to locate and consume the seedlings, according to lead author Patrick Finnerty.
Finnerty emphasized:
“Herbivores cause significant damage to valuable plants in ecological and economically sensitive areas worldwide, but killing the animals to protect the plants can be unethical.
“So, we created artificial odours that mimicked the smell of plant species they naturally avoid, and this gently nudged problematic herbivores away from areas we didn’t want them to be.
As many herbivores heavily rely on plant odors to navigate and forage, this innovative method introduces a fresh approach that could help protect valued plants globally, whether in conservation efforts or the protection of agricultural crops.
The research, conducted within Sydney’s Ku-ring-gai Chase National Park, employed the swamp wallaby as a representative herbivore model. To examine the concept, researchers chose Boronia pinnata, an unappetizing shrub in the citrus family, and Eucalyptus punctata, a palatable canopy species.
The study compared the effectiveness of using the B. pinnata odor mimic with the real plant and found both to be equally efficient in safeguarding eucalypt seedlings from wallaby consumption.
While conducting his doctoral research, Mr. Finnerty also successfully tested the method with African elephants; however, this aspect of fieldwork is not detailed in the current research paper.
According to Mr. Finnerty, prior attempts to utilize repellent substances like chilli oil or motor oil to deter animal consumption of plants have inherent limitations.
“Animals tend to habituate to these unnatural cues and so deterrent effects are only temporary.”
“By contrast, by mimicking the smell of plants herbivore naturally encounter, and avoid in day-to-day foraging, our approach works with the natural motivators of these animals, with herbivores less likely to habituate to these smells.”
Taking inspiration from this concept, researchers developed solutions capable of emitting these undesirable aromas.
This new method “offers many advantages over using real plants as a way to nudge herbivores away from plants we are trying to protect,” accoring to the author.
Real plants fight with one other for nutrients and water, which might exceed the protective benefits of offering a place to browse.
“Our approach should be transferable to any mammalian, or potentially invertebrate, herbivore that relies primarily on plant odour information to forage and could protect valued plants globally, such as threatened species.”
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