Tag: plants

Maybe it makes sense to talk to plants after all

Although I’ve alluded to talking to plants in the title for this post, the interesting thing here is that research shows they can sense vibrations made by insects like caterpillars. This allows the plants to prepare for an attack by producing defensive chemicals.

Some research suggests that plants can even detect the sound of water, which could have implications for sewer systems. The findings open up possibilities for using sound-based interventions in agriculture, such as drones equipped with speakers to warn crops of impending pest attacks.

Plants have been evolving alongside the insects that pollinate them and eat them for hundreds of millions of years. With that in mind, Heidi Appel, a botanist now at the University of Houston, and Reginald Cocroft, an entomologist at the University of Missouri, wondered if plants might be sensitive to the sounds made by the animals with which they most often interact. The researchers recorded the vibrations made by certain species of caterpillar as they chewed on leaves. These vibrations are not powerful enough to produce sound waves in the air. But they are able to travel across leaves and branches, and even to neighbouring plants if their foliage touches.

The researchers then exposed Thale cress—the plant biologist’s version of the laboratory mouse—to the recorded vibrations while no caterpillars were actually present. Later, they put real caterpillars on the plants to see if exposure had led them to prepare for an insect attack. The results were striking. Leaves that had been exposed had significantly higher levels of defensive chemicals like glucosinolates and anthocyanins, making them much harder for the caterpillars to eat. Leaves on control plants that had not been exposed to vibrations showed no such response. Other sorts of vibration—caused by the wind, for instance, or other insects that do not eat leaves—had no effect.


The research may have practical consequences, too. “Drones armed with speakers and the right audio files could warn crops to act when pests are detected but not yet widespread,” says Dr Cocroft. Unlike chemical pesticides, sound waves leave no toxic residue. With the help of weather forecasts, the system could even be used to prepare crops for cold snaps.


Farmers monitor the health of their crops by eye. (Mosaic virus, for instance, is so named because of the mottled pattern produced on the leaves of suffering plants.) That can be hard to do properly over an entire field. But if plants are broadcasting auditory indicators of distress, then wiring a field with microphones might help farmers keep an ear out for trouble.

Source: Plants don’t have ears. But they can still detect sound | The Economist

When it’s getting too hot for plants to photosynthesize, you know we’ve got a problem

I used to run a site called extinction.fyi which documented the climate emergency. This definitely would have been an article I would have featured on there.

As would the news that French nuclear power stations had to stop running when the water in the rivers next to where they’re situated became too hot. The additional heat of water coming out of the cooling circuits would raise the temperature further, killing aquatic life.

Leaves in the world’s tropical forests are approaching critical temperatures at which photosynthesis breaks down—and a fraction have likely already passed that threshold—raising alarms about the fate of these essential ecosystems under the most pessimistic projections of human-driven climate change, reports a new study.


The ECOSTRESS data, along with follow-up measurements from the ground, showed that tropical canopy temperatures tend to peak at around 34°C, though some regions experienced temperatures that exceeded 40°C. Because there is a surprising amount of temperature variation between the individual leaves on a single tree, the researchers estimated that about a tenth of a percent of all leaves in tropical forests are annually pushed beyond the critical threshold of 46.7°C that marks the breaking point of photosynthesis.


As global temperatures continue to rise, more tropical leaves will be pushed beyond their photosynthetic capabilities, causing plants to perish. While the researchers emphasized that there is a lot of uncertainty in their models, they warned that an increase in global air temperatures of about 3.9°C could trigger a major photosynthetic meltdown for tropical forests. This estimated increase is within the range of climate models that project a future where human greenhouse gas emissions don’t begin to fall until after 2080.

Source: It’s Getting Too Hot for Tropical Trees to Photosynthesize, Scientists Warn | VICE